1) i i. LAMKIN LAMKIN
A. . NEURO-OPHTHALMOLOGY NEURO-OPHTHALMOLOGY
L1 . Photostress recovery test Photostress recovery test
a. This simple clinical test may help to differentiate central visual loss cause d by a macular lesion from that
derived from optic neuropathy. Each eye is tested separately.
b. Best corrected visual acuity is measured (the test is accurate only with acui ty of 20/80 or better), after which
the patient is instructed to gaze directly into a strong light (eg, direct ophth almoscope or slit-lamp beam)
held 2-3 cm from the affected eye.
c. The patient is then directed to read the previously measured best acuity line as soon as possible.
d. Normal recovery time is typically 45-60 seconds, and this is maintained with optic nerve disease.
e. In patients with maculopathy, however, recovery times are frequently 90-180 s econds or more.
L2 A pattern visual evoked response (VER)
a. The two crucial parameters used for functional evaluation include the height of the first positive or upward
wave (amplitude) and the time between stimulus presentation and the appearance o f this wave (latency).
Implicit time, which is the time it takes to reach peak amplitude after a stimulu s is applied.
b. (As opposed to a flash VER) is required for visual acuity assessment in preve rbal children.
c. Although the VER is useful in establishing factitious visual loss, its reliab ility is limited by the fact that
patients can produce false readings by using accommodation to fog their vision. d. Abnormalities in VER latency and amplitude have been reported in various macu lopathies and
retinopathies, and, therefore, these features cannot distinguish optic neuropath y from retinal disorders with
complete reliability.
L3 Although OKN, the rocking mirror test and base up prism can help discover fac titious monocular visual loss, these
tests are not sensitive enough to diagnose factitious visual deficit at 20/100 l evel. For mild visual deficit, a fogging
refraction, stereo acuity, and red-green glasses may be useful in diagnosing fac titious visual loss.
L4 An optic tract lesion may cause unilateral decrease VA if the lesion is not c omplete or if the optic nerve or chiasm is
also involved. If the optic nerve or chiasm is involved, the APD is typically ip silateral. Pure optic tract lesion can
produce a contralateral APD as well as a complete homonymous hemianopia.
L5 In the setting of upgaze paresis, upturning of the eyes on forceful opening o f closed eyelid (intact Bell's
phenomenon) implies supranuclear lesion. Upturning of the eyes upon forceful ope ning of closed eyelids is known
as the Bell phenomenon. If forcefully opening closed eyelids stimulates upgaze, the final common pathway
(infranuclear) for upgaze must be intact.
L6 Some tissue such as cortical bone, rapidly flowing fluid (blood) and air give s no signal at all on MRI {dark
(hypointense)}. T1-weighted images tend to show the anatomy well, whereas T2-wei ghted images tend to show the
pathology well.
L7 The macular fibers constitute a large portion of the chiasm and decussate in the posterior chiasm. The chiasm lies
approximately 1 cm (not 1 mm) above the anterior pituitary gland.
L8 Optokinetic nystagmus (OKN) abnormalities indicate lesions of the parietoocci pital (slow-phase pursuit
abnormalities) or the frontal lobe (fast-phase recovery abnormalities). High con gruity of visual field deficits indicates
a lesion in the occipital lobe. Both partial complex seizures and formed visual hallucinations may be seen with
temporal lobe lesions. Inferior nerve fibers from the superior retina course ant eriorly in Meyer's loop; therefore,
lesions affecting Meyer's loop will result in pie-in-the-sky defects contralater al to the lesion.
L9 Although OKN abnormalities asymmetry may occur rarely with occipital lobe les ion, this finding is generally
indicative of parietal lobe lesion.
L10 Causative events in the pathophysiology of optic disc oedema include: swolle n axons, intracellular fluid
accumulation, and interruption of axonal transport.
L11 The most typical visual field finding in acute (not chronic) papilloedema is an enlarged blind spot. Although rare
unilateral papilloedema may occur, for example, if contralateral optic atrophy e xists, papilloedema may be
detectable only in a viable disc.
L12 Pseudotumor cerebri is characterized by (i) increased intracranial pressure on lumbar puncture, (ii) normal
neuroimaging studies (although the ventricles may be small), and (iii) normal ce rebrospinal fluid (CSF).
Papilledema need not be present for the diagnosis. Although the neurologic exami nation is usually normal, sixth
nerve palsy may occur with increased intracranial pressure of any etiology. L13 Indications of treatment of pseudotumour cerebri are severe headache and vis ual field loss. Obesity is not an
indication for treatment, although weight loss (even as little as 6% of total bo dy weight) often improve the condition.
L14 The most common cause of permanent visual loss in patients with cavernous si nus-dural fistulae is open-angle
glaucoma. Studies have documented that up to 80% of patients with cavernous sinu s-dural fistulae will develop
ocular hypertension. Twenty-five percent of patients will develop optic disc cup ping and 20% visual field defects.
Any entity that raises episcleral venous pressure can cause secondary open-angle glaucoma.
L15 GCA:
b. 65% of untreated patients will have contralateral involvement after permanent visual loss in one eye.
c. The second eye may still become involved in 25% of cases despite early and ad equate steroid
administration, usually within 6 days of starting treatment. Visual loss is usua lly profound and is unlikely to
improve even with immediate treatment.
d. 20% of patients do not have systemic symptoms (i.e. occult GCA).
L16 Nonarteritic anterior ischemic optic neuropathy (NAION) is far more common t han arteritic anterior ischemic optic
neuropathy (AAION) (approximately 95% vs. 5%) and patients have a lower mean age at diagnosis than patients
with AAION (60 years vs. 70 years). It usually occurs in a younger age group and may resemble optic neuritis.
L17 The various ways to differentiate the NAION from optic neuritis include (i) the absence of pain with eye movement,
(ii) the age group affected, and (iii) delayed optic disc filling present in 75% of NAION cases (whereas filling should
be normal in optic neuritis).
L18 Although aspirin effective in reducing systemic vascular events and is frequ ently prescribed in patients with NAION,
it doesn t appear to reduce the risk of involvement of the fellow eye.
L19 Nearly 100% of patients dying of multiple sclerosis had some degree optic ne rve demyelination.
L20 Ninety percent of optic gliomas occur in the first two decades of life. The percentage of patients with optic nerve
glioma that have associated neurofibromatosis (NF-1) ranges from 14% to 60%. Mal ignant gliomas of the visual
pathways, although rare, occur more frequently in middle-aged adults than in chi ldren. Survival averages 6 to 12
months after diagnosis.
L21 Yanoff and Kanski. Gliomas of the optic nerve develop in 10 15% of affected pa tients. They can occur unilaterally
or bilaterally and frequently involve the optic chiasm.
L22 Optociliary vessels occur in optic nerve meningioma, CRVO, sphenoid wing men ingioma, long standing
POAG, optic glioma and chronic papilloedema.
L23 In contrast to optic nerve gliomas, meningiomas occur primarily in adults an d are three times more common in
women. Although persons with neurofibromatosis (NF-1) have a higher incidence of meningiomas than the general
population, only a few patients with meningiomas have NF-1. With contrast comput ed tomography (CT) scanning,
the peripheral part of the involved optic nerve may show enhancement, resulting in the railroad track sign
( kinking is specific for optic nerve glioma).
L24 Dominant (Kjer) optic neuropathy (DOA) manifests between 5 and 10 years of a ge. Visual loss may progress
until the mid-teens, at which point it usually stabilizes. Color defects are alm ost universally present, and tritanopia
(which can be detected with the Farnsworth-100 hue testing) is suggestive of DOA . Inheritance is naturally
autosomal dominant.
L25 Leber's hereditary optic neuropathy (LHON).
a. All offspring of a female carrier are either affected or carriers. b. Ten percent of female carriers will be affected.
c. There is generally sequential asymmetric bilateral involvement.
d. A small percentage of patients will enjoy partial or complete recovery late i n their course. The incidence of
spontaneous recovery has been reported to be as high as 10%.
L26 Patients with papillophlebitis have normal or near normal visual acuity. It ma y be a form of incomplete central
retinal vein occlusion (CRVO) and usually resolves spontaneously within 12 month s.
L27 Optic disc drusen occurs almost exclusively in white individuals. They are g enerally bilateral.
L28 Morning glory anomaly F: M is 2:1.
L29 Non-secreting tumors often present with visual field loss, whereas secreting tumors present with endocrine
dysfunction. An exception is prolactin-secreting tumor in male patients because the decreased libido and
impotence are often not reported early in their course.
L30 When the causative lesion is not located at the site responsible for a clini cal sign, it is described as false
localizing. Bitemporal macular hemianopia can only arise from compression of the posterior chiasm. Although
most lesions responsible for this compression are parasellar, a lesion distant f rom this site (e.g., a tumor at the
base of the brainstem) also may lead to chiasmal compression. This occurs if the lesion causes obstructive
hydrocephalus, which enlarges the third ventricle, compressing the chiasm. L31 Precipitous aneurysmal distention caused by hemorrhage of the posterior comm unicating artery at its junction
with the internal carotid artery may occur, creating a third nerve palsy. Ninety -five percent include pupillary
involvement, and pain is nearly always present, although not universally. Furthe rmore, many third nerve palsies
resulting from diabetic vasculopathy also can be intensely painful.
L32 Third nerve aberrant regeneration never occurs with diabetic oculomotor neur opathy. Aberrant regeneration of the
third nerve implies another etiology, such as aneurysm, tumor, inflammation, or trauma.
L33 The most common cause of acquired fourth nerve palsy in adult is trauma. L34 The three-step test is useful for diagnosis but does not differentiate betwe en congenital and acquired trochlear
nerve palsy. Large vertical fusional amplitudes (>5 prism diopters) (greater tha n 3.. AAO) and facial
asymmetry from childhood head tilting suggest a decompensated congenital lesion. L35 Congenital fourth nerve palsies may be revealed by old photographs that show head tilting or a large vertical
L36 35-year-old Chinese man presents with right ptosis and an abduction deficit, facial hypesthesia, and
keratoconjunctivitis sicca in the right eye. This picture is highly suggestive o f nasopharyngeal carcinoma.
L37 Nasopharyngeal carcinoma can involve numerous cranial nerves because of its proximity to the prepontine basal
cistern. Most frequently, the trigeminal nerve is involved, causing facial hypes thesia or facial pain. The abducens
nerve is the second most common. The hallmark of nasopharyngeal carcinoma is its propensity to involve
multiple cranial nerves non-contiguously. Nasopharyngeal carcinoma is common in Chinese men. The least
differentiated forms are also known as Schmincke's and Regaud's tumors.
L38 Horizontal saccades originate in the contralateral frontal lobe, but either hemisphere can produce ipsilateral
saccades if the other hemisphere is damaged. Appropriate stimulation of the pari etal or occipital cortex can also
produce contralateral saccades. L39 Oculomotor apraxia.
a. Both congenital and acquired forms of oculomotor apraxia may be observed. b. Saccades are generally affected more than Pursuits.
c. Horizontal movements are generally affected much more than vertical movements .
d. In the acquired form, blinks are frequently used to break fixation.
e. In the congenital form, children frequently use compensatory, exaggerated hea d turns to refixate.
L40 Opsoclonus and ocular flutter, ocular motor disorders most commonly associat ed with malignancy
(neuroblastoma in children and small cell lung carcinoma in adults), these movem ents may be the first presenting
sign of malignancy.
L41 MS may cause ocular flutter.
L42 Ocular bobbing is most commonly seen in comatose or quadriplegic patient wit h large infarcts or brain stem
haemorrhage.
L43 In progressive supranuclear palsy downward are the first affected (saccades are affected than pursuit); in contrast
to Parinaud dorsal midbrain lesion upward is firstly affected.
L44 Latency for smooth pursuit is shorter (125-135 ms), than saccades which requ ire (150-200 ms).
L45 Parinaud syndrome.
a. Collier syndrome may worsen with attempted upgaze.
b. Skew deviation and papilloedema may be seen depending on the etiology.
c. Convergence-retraction nystagmus is also a response to an effort at upgaze th at triggers medial rectus
contraction. Hence this form of nystagmus is worsened by upward OKN testing. L46 Monocular nystagmus in toddlers has been associated with chiasmal glioma and hypothalamic glioma. It is also
seen in blind eyes, MS, and spasmus nutans.
L47 According to Alexander's law, the nystagmus is more pronounced when gaze is directed toward the side of the
fast-beating component.
L48 Of various forms of nystagmus, downbeat nystagmus most frequently violates A lexander's law.
L49 Downbeat nystagmus is almost always present in primary position, but in acco rdance with Alexander's law, the
down beating movements are accentuated in downgaze (especially down gaze to eith er side). Patients usually
g. (AAO)
L50 The nystagmus most likely to be localized is see-saw nystagmus. It results f rom third ventricle tumours or
diencephalic lesion involving the connections to the interstitial nucleus of Caj al and is therefore most localized.
L51 See-saw nystagmus is most frequently associated with bitemporal hemianopia, because posterior chiasm is most
vulnerable to diencephalic tumour.
L52 Vergence eye movements are felt to have a pathway of their own for stimulati ng the brain stem motor nuclei.
L53 Upper motor neuron facial nerve paralysis usually leaves voluntary eyelid cl osure intact. Voluntary eyelid closure is
preserved in upper motor facial nerve paralysis, because of bilateral supranucle ar input to the upper fascial
muscles (orbicularis).
L54 Spontaneous or reflexive blinking requires normal function of the basal gang lia, as do other nonvolitional facial
expressions. Therefore, these are commonly affected in Parkinson's disease. Voli tional movements, in distinction,
are generally not adversely influenced.
L55 Marcus jaw winking reflex is an example of synkinesis (abnormal innervation connecting two groups of normally
unrelated muscles, such that contract together).
L56 Compression of the facial nerve at the cerebellopontine angle has been demon strated in 90% of cases of
hemifacial spasm.
L57 Approximately 85% of patients with Bell's palsy spontaneously recover, altho ugh some will have some degree of
aberrant regeneration. Recovery usually begins within 3 weeks of diagnosis and u sually becomes complete by 2 to
3 months.
L58 The facial nerve is the most frequently involved cranial nerve in neurosarco idosis. The parotid gland can become
infiltrated with granulomas, and the facial nerve is involved at this site. Faci al nerve involvement in sarcoidosis
is frequently bilateral but asymmetric. The second most commonly involved crania l nerve is the optic nerve.
L59 Of the three most common causes of facial nerve overactivity, only essential blepharospasm is believed to be
related to basal ganglia dysfunction. Compression of the facial nerve in the cer ebellopontine angle by anomalous
vessels has been demonstrated in 90% of cases of hemifacial spasm. Tumors in the cerebellopontine angle also
can cause hemifacial spasm. Facial myokymia is caused by disease in the pons inv olving the facial nucleus or
fascicle. The most common causes include multiple sclerosis (MS) in adults and p ontine glioma in children.
L60 The following conditions may be confused with essential blepharospasm. a. Severe dry eye.
b. Retained conjunctival foreign body. c. Tardive dyskinesia.
L61 Hemifacial spasm is distinct from essential blepharospasm in that it is unil ateral, and multiple facial muscles are
involved.
L62 Pupillary dilatation may be the only sign of third nerve palsy in uncal hern iation and basilar meningitis. Total
oculomotor nerve palsy sparing the pupil in elderly patients usually suggests mi crovascular aetiology.
L63 DDX of tonic pupil includes herpes zoster, syphilis, and giant cell arteriti s.
L64 Localization of the lesion in Horner's syndrome is part of the clinical work up and sometimes guided by the extent of
anhidrosis. First-order lesions (central nervous system) cause ipsilateral anhid rosis of the entire body.
Second-order lesions (Pancoast's tumor, neck trauma) cause ipsilateral facial anhidrosi s. Third-order lesions cause
anhidrosis only around the affected eye or none at all.
L65 Painful Horner syndrome may be caused by many disorders (neck trauma, migrai ne, cluster headache), but
spontaneous dissection of the common carotid artery must be ruled out with angio graphy or MRI/MRA.
L66 After determination of which pupil is abnormal, the next step in evaluating a patient with anisocoria is slit-lamp
examination. Most patients with nonphysiologic anisocoria have sphincter muscle dysfunction visible at the slit
lamp. Trauma is most common, followed by Adie's pupil.
L67 The risk of developing multiple sclerosis (MS) for a relative of a patient w ith MS is nearly 20 folds higher than the
general population. MS is a multifactorial disease with both genetic and environ mental risk factors.
L68 The most common cranial mononeuropathy in MS is optic neuritis. The most fre quently affected motor nerve is the
sixth nerve.
L69 5-10% of patients with MS will have findings of posterior uveitis, including pars planitis or retinal periphlebitis.
L70 Pheochromocytomas produce, secrete, and store catecholamines. They are most often derived from the adrenal
medulla but may arise in any of the sympathetic ganglia. Two phakomatoses, neuro fibromatosis, and von
Hippel-Lindau disease, are associated with the tumor.
L71 Astrocytic hamartomas can be seen in tuberous sclerosis or neurofibromatosis , or they can be sporadic. They are
located in the nerve fiber layer of the retina and sometimes can be associated w ith the optic disc.
L72 The triad of adenoma sebaceum, mental retardation, and seizures is considere d pathognomonic for tuberous
sclerosis. This is known as Vogt's triad and is present in 30% of patients with tuberous sclerosis. Facial
angiofibromas (adenoma sebaceum) are present in at least 75% of adults with tube rous sclerosis.
L73 Seizures are part of the classic triad in tuberous sclerosis (80% of patient s have seizures). Patients with
Sturge-Weber syndrome and meningeal hemangioma may have seizure disorders. Patients wit h neurofibromatosis also
have an increased risk of seizures.
L74 Unilateral congenital glaucoma is seen in 25% of cases of Sturge Weber syndr ome. NF1 associated juvenile
glaucoma. Glaucoma may be associated with V. H. L. disease.
L75 Heart block in patient with Kerns Sayre syndrome is lethal and among the las t signs to develop. Some studies
indicate that elevated cerebrospinal fluid (CSF) protein levels correlates with the presence of heart block.
L76 A diagnostic feature of myotonic dystrophy is the presence of polychromatic ( Christmas tree ) cataracts, which
may present even in the amyotonic forms. Wilson's disease is associated with the s unflower cataract.
L77 Lid retraction and lag is the most common sign of Graves's disease.
L78 The most frequently involved muscle in dysthyroid orbitopathy is the inferio r rectus. The medial rectus is the second
most frequently affected muscle and may simulate a sixth nerve palsy. The least frequently involved muscle in
Graves' ophthalmopathy is the lateral rectus. L79 Myasthenia gravis.
a. 75% of MG patients will have eye findings at presentation. b. Only 33-50% will have ocular myasthenia only.
c. 90% will have ocular symptoms during the course of the disease. d. Ptosis is the most common.
e. 5% will develop Graves' disease.
f. 10% will have thymus enlargement on CT scan.
g. Ocular myasthenia should remain localized for 2 years to be reassured that sy stemic disease is unlikely to
develop.
L80 A tiny fraction of patients with Graves' disease will develop MG.
L81 IOP after high grade carotid stenosis are low (caused by ciliary hypoperfusi on), normal, or elevated (caused by
neovascularization of the iris and angle). Unilateral arcus is highly suggestive of contralateral carotid disease.
Carotid stenosis protects the ipsilateral cornea from serum lipid deposition. L82 The etiology of Coats' disease is unknown, and there does not appear to be a ny genetic, familial, racial, or ethnic
predisposition. However, Coats'-type retinal vascular changes have been noted in patients with
facioscapulohumeral muscular dystrophy, Turner's syndrome, Senior-Loken syndrome , and one variant of the
epidermal nevus syndrome. In addition, Coats'-like retinopathy has been noted in up to 3.6% of patients with
retinitis pigmentosa.
L83 Downbeat nystagmus in primary position is localized to the craniocervical ju nction (or certain intoxications). This
patient's clinical symptoms of intermittent occipital headaches with sudden head movements or anger suggest the
diagnosis of Arnold-Chiari malformation. Arnold-Chiari malformation is one of th e most common causes of
downbeat nystagmus.
L84 Clonazepam and suboccipital craniotomy have been used in the treatment of do wnbeat nystagmus in patients with
Arnold-Chiari malformation. By contrast, carbamazepine toxicity has been associa ted with downbeat nystagmus.
L85 A 9-year-old boy presents to the ophthalmologist with the complaint that he has lost his position on the school
basketball team because he cannot see the basket. He notes occasional morning he adaches but denies any
nausea or vomiting. Examination reveals visual acuity of 20/40 in the right eye and 20/25 in the left eye. The patient
has marked symmetric weakness of upgaze bilaterally. His pupils are 7 mm and are poorly reactive to light, with
better reaction to a near target. There is approximately 2 mm of superior sclera l show bilaterally. Fundus
examination suggests optic atrophy in both eyes. A review of the systems reports increased consumption of water,
with frequent urination at night. The most likely diagnosis is: pinealoma. a. This patient appears to have Parinaud's dorsal midbrain syndrome, which may i nclude the following
findings: pupillary light-near dissociation, lid retraction (the Collier sign), upgaze paresis,
convergence-retraction nystagmus, fixation instability, small-amplitude skew deviation, and papilledema (if ventricular
outflow has been compromised). The most common cause in this age group would be a pinealoma. Other
causes include stroke, hydrocephalus, and multiple sclerosis (MS).
b. After neuroimaging has been obtained, a lumbar puncture would be an important step in the diagnostic
evaluation of this patient because pinealoma classically sheds cells into the ce rebrospinal fluid (CSF).
L86 Optic neuritis in childhood is more commonly bilateral. Visual loss can be s evere, although intravenous
corticosteroids can improve visual function. Diffuse enlargement of the optic ne rve on computed tomography
(CT) scan may be seen in this condition, mimicking a neoplasm of the optic nerve sheath. The
demyelination typically follows a viral illness or vaccination by 10 to 14 days. L87 The differential diagnosis for posterior ischemic optic neuropathy (PION) sh ould include radiation optic neuropathy,
status post-coronary artery bypass graft, anemia, acute systemic hypotension, gi ant cell arteritis (GCA), and
syphilis. Well-controlled essential hypertension is associated with anterior isc hemic optic neuropathy (AION) but not
PION.
L88 Bilateral disc oedema and headache may be caused by several reasons, but hyp ertension should be the first to be
excluded because it is quite easy to do so. After checking blood pressure, a neu roimaging should be obtained
immediately.
L89 Meningothelial (syncytial) meningioma is the most common histopathologic typ e of meningioma seen within the
orbit. Pilocytic describes the cell type of gliomas of the visual pathways. L90 A meningioma arising in optic nerve sheath is most likely to lead to optic d isc edema.
L91 In general, optic nerve compression >1 cm posterior to the globe does not ca use disc edema.
L92 Tobacco-alcohol amblyopia seems to be seen only in heavy smokers/drinkers wi th poor nutrition. This has led
many to believe that a combination of toxic plus nutritional insults must be nec essary for the development of the
disorder.
L93 The most common etiologies of bilateral central or cecocentral scotomas incl ude hereditary optic neuropathy and
nutritional optic neuropathy (vitamin B12 and folate deficiency), drug toxicity, tobacco-alcohol amblyopia, and
infiltrative disorders such as syphilis and tuberculosis. Cyanide levels are not helpful in suspected tobacco-alcohol
amblyopia.
L94 Although disc edema, disc hemorrhages, and choroidal rupture may be seen in acute traumatic optic neuropathy,
the most common finding is a normal fundus. Disc pallor would be unusual in the acute setting but present in all
cases after several weeks.
L95 The development of diabetic papillopathy appears to be independent of serum glucose levels. Diabetic papillopathy
is classically seen in young adults with type 1 diabetes with moderate to severe retinopathy (although it can be
seen in patients with type 2 diabetes as well). It is painless, and associated v isual loss is generally mild. The
disorder generally resolves spontaneously.
L96 Thyroid optic neuropathy is considered to be a compressive optic neuropathy because of enlargement of
extraocular muscles at the orbital apex. Treatment of thyroid optic neuropathy m ay include orbital radiation (usually
1,500 to 2,500 rad over a 10-day period) and orbital decompression, which provid es the most potential for
decompression of the optic nerve. Systemic corticosteroids are thought to be eff ective only in the acute congestive
phase and not in the fibrotic period. Therefore, if no response is noted within 3 weeks, systemic steroids should be
tapered and another modality should be considered. Although a subtotal thyroidec tomy may provide primary
treatment of dysthyroid state, it will have no effect on the eye findings (excep t, perhaps, lid retraction).
L97 Bromocriptine has been shown to be effective primarily in the management of prolactin-secreting pituitary tumors
and is less effective or ineffective with other types of pituitary tumors. L98 Acute visual loss associated with severe headache is a typically a sign of p ituitary apoplexy.
L99 Fortification spectra that precede visual loss suggest a diagnosis of migrai ne headaches. A fixed visual defect
suggests a cerebral arteriovenous malformation (AVM). A family history of headac hes and nausea associated with
visual disturbances are more suggestive of a migraine. Field defects may be foun d during acute migraine
headaches, but those present interictally suggest another diagnosis.
L100 A skew deviation is a motility disturbance with a vertical component that d oes not have a pattern consistent with a
discrete muscle underaction or nerve palsy. They are generally due to supranucle ar or vestibulo-ocular dysfunction
and generally reflect brainstem disease. They are typically comitant but not alw ays.
L101 Small vessel disease is the most common cause of unilateral sixth nerve pal sy. More common causes of bilateral
sixth nerve palsy include increased intracranial pressure, head trauma, and tumo rs of the ventral brainstem.
Congenital bilateral sixth and seventh nerve palsies are characteristic of M.biu s' syndrome.
L102 Isolated sixth nerve palsy in children is most commonly attributable to pos tviral inflammation occurring 1 to 3 weeks
following a nonspecific viral illness of the upper respiratory tract. Recovery i s generally complete and occurs within
10 to 12 weeks.
L103 Medial rectus contracture is distinctly uncommon in Duane's syndrome. In co ngenital sixth nerve palsy, it is quite
common and results in esotropia in primary position. To differentiate between Du ane syndrome and congenital sixth
nerve palsy is orthotropia in primary position because medial rectus contracture is uncommon in Duane syndrome,
while sixth nerve palsy result in esotropia in primary position.
L104 Disruption of the medial longitudinal fasciculus (MLF), which carries proje ctions of interneurons from the
contralateral sixth nerve nucleus to the ipsilateral medial rectus subnucleus, r esults in ipsilateral absence or slowing
of adduction and contralateral abduction nystagmus. This combination of findings is termed internuclear
ophthalmoplegia (INO). Vertical nystagmus and skew deviations are frequently fou nd in association with INO but
are not universal.
L105 Bilateral internuclear ophthalmoplegia (INO) is more frequent in demyelinat ing disease than in cerebrovascular
disease. This is because the brainstem blood supply is lateralized right and left circulations are usually discrete
and end at the midline. Demyelinization does not respect the midline.
L106 Exotropia in primary position can occasionally occur in association with a bilateral internuclear ophthalmoplegia
(INO), resulting in a syndrome called wall-eyed bilateral INO.
L107 Miller-Fisher syndrome is generally considered a variant of Guillain-Barré sy ndrome that results in
ophthalmoplegia, ataxia, and areflexia. Serum immunoglobulin G (IgG) autoantibod ies and elevated cerebrospinal
fluid (CSF) protein may be present. Complete recovery is common.
L108 The presence of optic nerve dysfunction, manifested by decreased vision, an afferent pupillary defect, and/or
dyschromatopsia, distinguishes an orbital apex syndrome from a cavernous sinus s yndrome because the optic
nerve passes through the optic canal and does not enter the cavernous sinus. L109 Tolosa-Hunt syndrome.
a. Idiopathic, sterile inflammation that primarily affects the cavernous sinus. b. Pain is almost always present.
c. Painful ophthalmoplegia.
d. Sensory deficit of the trigeminal nerve (most commonly ophthalmic branch). e. Neuroimaging may show a mass, which often is enhanced with contrast.
f. Patients with Tolosa-Hunt syndrome respond dramatically to corticosteroids. g. Normal MRI is unlikely but not impossible.
h. It is DX of exclusion.
L110 Iris and posterior segment neovascularization, as well as rapidly progressi ve cataract, may all be seen as
complications of the ischemic oculopathy that these fistulae generate. Corneal e xposure caused by proptosis is
another potential complication of carotid-cavernous fistula.
L111 Both high-flow and low-flow carotid-cavernous fistulae may be associated wi th a history of head trauma. Low flow
carotid cavernous fistula may also be associated with minor head trauma.
L112 59-year-old man presents to the emergency room with a complaint of sudden-o nset oscillopsia and diplopia.
Examination reveals an alcohol odor to his breath, normal acuity, bilateral abdu ction deficits, and coarse binocular
nystagmus. Appropriate intervention should include intravenous thiamine. Acute t hiamine deficiency (Wernicke's
encephalopathy) can result in central scotomas as well as ophthalmoplegia, prima rily affecting cranial nerves III and
VI. It can be precipitated in nutritionally depleted alcoholics given intravenou s glucose alone because of sudden
consumption of systemic thiamine stores.
L113 Giant cell arteritis (GCA) is common in northern European climates. On the basis of autopsy studies, the
prevalence has been estimated to be 1.1% of the Scandinavian population. L114 Clinical characteristic of chiasmal compression includes:
a. Field abnormalities most notably centrally with fainter test object. b. Postfixation blindness.
c. Temporal color desaturation.
d. Hemifield slip result in diplopia.
L115 The examiner attempts to confirm diagnostic suspicions by eliciting the Pul frich phenomenon. To do this, the
examiner: asks the patient to watch the pendulum on the grandfather clock across the room and report any
three-dimensional movement. The Pulfrich phenomenon probably reflects delayed conducti on in the demyelinated nerve.
Oscillating objects perceived by the affected eye appear to be behind the image seen with the healthy eye,
simulating three-dimensional movement where there is only movement within one pl ane. The delayed implicit time
is the electrophysiologic correlate of the bizarre perception known as the Pulfr ich phenomenon.
L116 LHON, telangiectatic peripapillary vessels not leak on FA.
L117 Sumatriptan is a serotonin antagonist available orally, by injection, or as a nasal spray. The -triptan antimigraine
drugs are used for symptomatic relief of migraines but are contraindicated in pa tients with basilar artery migraine.
They can produce myocardial infarction (MI) and should be used with caution in p atients with severe hypertension
or coronary artery disease.
L118 The best initial choice for prophylaxis of acute, severe migraine headache is propranolol. Methysergide is an ergot
alkaloid with numerous potential side effects. The beta-blockers are effective a nd safer.
L119 The Ischemic Optic Neuropathy Decompression Trial of IONDT for NAION reveal ed no significant benefit for
treatment (improvement in visual acuity by at least three Snellen lines: 32.6% f or treated patients vs. 42.7% for
controls}. Moreover, the treatment group showed a statistically significantly gr eater risks of acuity that worsened by
three Snellen lines or more (23.9% treated vs. 12.4% control). IONDT is not curr ently recommended for the
treatment of NAION. It has been suggested that levodopa has a beneficial effect, but this remains unconfirmed.
L120 Pseudotumor cerebri typically (not universally) presents with visual loss a nd headaches. Neurologic abnormalities
are usually absent except for occasional abducens paralysis. Although the openin g pressure is elevated,
cerebrospinal fluid (CSF) protein levels are either normal or low. Many cases ar e probably based on
decreased reabsorption of CSF.
L121 Binding antibodies to acetylcholine receptors are found in 90% of patients with generalized myasthenia gravis
(MG).
L122 Relative to generalized myasthenia, ocular myasthenia is completely localiz ed to ocular or bulbar involvement.
L123 Drug induced MG is D-penicillamine, with onset average 6 months after initi ation of therapy. Approximately 80% of
patients will remit completely within 6-8 month of cessation.
L124 The Purkinje effect is a benign condition. It is a real, subjective test an d can rarely be used to determine whether a
patient's retina is attached.
L125 Binocular diplopia is relieved by covering one eye. Monocular diplopia is r elieved by covering the affected eye. It
can be caused by keratoconus, lenticonus, high astigmatism, retinal pathologies. L126 The following results in anisocoria in dim light.
a. Horner's syndrome. b. Posterior synechiae. c. Physiologic anisocoria. d. Pharmacologic anisocoria.
L127 There are a host of systemic conditions that can become exacerbated during pregnancy. Pseudotumor cerebri is
not one of them.
L128 AAO. PTC is associated with endocrine or metabolic dysfunction, pregnancy, or the use of exogenous substances
such as vitamin A (> 100,000 U/day), tetracycline, nalidixic acid, cyclosporine, and oral contraceptives, as well as
the use of or withdrawal from corticosteroids.
L129 Duane. Idiopathic intracranial hypertension (IIH) is a syndrome of increase d intracranial pressure characterized by
normal brain imaging, normal cerebrospinal fluid (CSF) composition, and elevated CSF pressure. IIH occurs at the
same rate in pregnant and nonpregnant women, but one study showed worsening of s ymptoms among nine of 11
patients with pre-existing IIH who became pregnant. L130 Sj.gren syndrome associated with CRAO.
L131 Craniopharyngioma is the most common cause of see-saw nystagmus. Other para sellar tumour can cause the
condition as well.
L132 Wyburn-Mason syndrome is a sporadic condition, characterized by a retinal r acemose angioma with an intracranial
arteriovenous malformation (AVM). Patients with Wyburn-Mason syndrome can have o rbital AVMs as well (and
consequent ocular bruits). As of 2004, there have been no reports of photodynami c therapy (PDT) to treat
Wyburn-Mason syndrome (and it is unlikely that PDT would be effective in patients with this condition).
L133 Binasal hemianopia is almost never due to chiasmal compression and is usual ly due to glaucoma.
B. . OCULOPLASTY OCULOPLASTY
L1 Prominent pain in orbital disorder is present in orbital pseudotumour and mal ignant mixed tumour of the lacrimal gland.
If pain is present, Graves' disease is usually not the cause of orbitopathy. L2 Exorbitism refers to an angle between the lateral orbital walls that is great er than 90°, which is usually associated with
shallow orbital depth. This condition contrasts with telorbitism (hypertelorism) , which refers to a wider-than normal
separation of the medial orbital walls.
L3 The weakest orbital wall is the anterior portion of the medial wall is also k nown as the lamina papyracea, or paper-thin
layer.
L4 Sinus system aerates first is ethmoid.
L5 The upper limit of normal exophthalmometry in white man is 22 mm, while in bl ack is 25 mm.
L6 Children's orbits are more plastic, so disorders with a short duration can ca use orbital enlargement. This is not the case
in adults which needs chronic process.
L7 In pediatric autoimmune hyperthyroidism, the systemic findings are more promi nent and the orbital findings less
common and less severe. Furthermore, for similar degrees of exophthalmos, childr en seem to develop exposure
problems less often.
L8 Ocular ultrasound is usually performed in the range of 8 to 15 MHz. Higher fr equencies give better resolution. Lower
frequencies give better penetration.
L9 Computed tomography CT uses less radiation than conventional tomography. L10 Orbital mass.
a. Sinus mucocele will have round, extraconal, smooth regular border, and very l ow internal
reflectivity.
b. Lymphangioma will have irregular border.
c. Neurofibroma will have high internal reflectivity.
d. Metastatic cancer and pseudotumour will have irregular border and high reflec tivity.
e. Cavernous haemangioma has densely packed vascular channel leads to high inter nal reflectivity.
L11 The magnetic field strength used to generate MRI is 2000-15000 times that of the earth's magnetic field.
L12 If fat brighter it is T1 MRI, if vitreous is brighter it is T2.
L13 A bluish bulge above the medial canthus is typically meningocele, whereas on e below is typically a dacryocele.
L14 In infant, increases risk of spread of preseptal cellulitis to orbital cellu litis, so that; infant with preseptal cellulitis
should be treated immediately with IV antibiotic. Inappropriate or delayed treat ment increases the risk.
L15 The agent most likely to cause a severe preseptal cellulitis leading to seco ndary orbital cellulitis and central nervous
system (CNS) infection in infants and toddlers is Haemophilus influenzae. Intrav enous antibiotics are indicated for
Haemophilus influenzae cellulitis in children. The Hib vaccine has significantly reduced the incidence of preseptal and
orbital cellulitis secondary to H. influenzae.
L16 Staphylococcus aureus is the most common cause of preseptal cellulitis secon dary to trauma. Streptococcus
organisms are a close second.
L17 90% of orbital cellulitis is secondary to paranasal sinus extension.
L18 Complication of orbital cellulitis is cavernous sinus thrombosis characteris ed by sudden worsening of orbital cellulitis
with virtually frozen orbit, despite inapparent increase in proptosis, corneal s ensation is likewise diminished, but VA
remain grossly intact.
L19 Tests that are important for distinguishing infectious orbital cellulitis fr om inflammatory orbital pseudotumor include
a. Oral temperature.
b. Orbital computed tomography (CT) scan.
c. Complete blood count (CBC) with differential.
L20 Patients with orbital cellulitis are typically febrile. For pseudotumor, thi s is uncommon except in children. A
leukocytosis with left-shift is also more common in cellulitis. The sedimentation rate may be elevated in either
condition, and in both, computed tomography (CT) scan may show a nonspecific ret robulbar infiltrate but may have
eal abscess).
L21 Orbital cellulitis: failure to dramatically improve after 48-72 hour of anti biotic can indicate subperiosteal abscess.
Relapse after switching to oral antibiotic also may be a sign. Inappropriate cho ice of antibiotic should not be associated
with modest improvement.
L22 Dermoid cyst may induce bony erosion on radiography. The variety that is sil ent until adulthood is generally
intraorbital (retroseptal). L23 Teratomas.
a. Teratomas are rare tumors that arise from two or more germinal layers (but al l three need not to be),
including ectoderm and endoderm or mesoderm (or both).
b. These tumors are usually cystic and can cause dramatic proptosis at birth. c. Exenteration is sometimes performed because of the fear of malignancy. Howeve r, in some cases, cystic
teratomas can be removed without an exenteration, and ocular function may be pre served.
d. Orbital teratomas may simulate malignancy but rarely, if ever, metastasize. L24 Potentially important complications of capillary hemangiomas in childhood ar e occlusion amblyopia, significant
astigmatism. The third is significant cosmetic deformity.
L25 More than 90% of periocular capillary haemangioma manifest by 6-8 months of age. Greater than 50% by 1-2 month
of age. Reach their peak at approximately 6-12 month of age.
L26 . Nevus flammeus is part of Sturge-Weber syndrome and Klippel-Trenaunay synd rome
Nevus flammeus is part of Sturge-Weber syndrome and Klippel-Trenaunay syndrome L27 Capillary haemangioma will blanch with pressure whereas the naevus flammeus does not.
L28 Neither capillary nor cavernous hemangiomas have high blood flow, and neithe r metastasize. Cavernous
hemangiomas are rarely seen in youth, whereas, as the name of each implies, the blood-filled spaces are tiny in a
capillary hemangioma and large in a cavernous hemangioma.
L29 Thrombocytopenia in association with visceral capillary haemangioma is known as Kasabach-Merritt syndrome.
L30 lack fibrous capsule so that its growth is infiltrative. Lymphoid tissue, ev en follicles may be found Lymphangioma
Lymphangiomawithin the substance of the tumour. Unlike capillary haemangioma the cystic spaces are large.
L31 The origin of orbital lymphangioma remains unclear, although vascular malfor mations with lymphatic and venous
components may play a role. Furthermore, noncontiguous vascular malformations ha ve been reported in one study to
occur in up to 25% of patients. Surgical strategies are frequently limited to deb ulking by any safe means possible,
because complete excision is usually not possible.
L32 Tram-tracking of the optic nerve is considered classic for optic nerve sheat h meningioma.
L33 A radiographic feature is considered pathognomonic for optic nerve glioma is kinking of the optic nerve.
L34 Optic nerve glioma may induce a secondary meningothelial hyperplastic respon se misinterpreted as
meningioma.
L35 The management of optic nerve glioma in children is a subject of much discus sion and honest disagreement among
the experts. Any of the options may be correct in a given situation, and the ult imate choice must be individualized to the
patient's circumstances (e.g., vision, size of tumor, extent of centripetal spre ad, age).
L36 arise from undifferentiated pluripotential mesenchymal elements in the orbit al soft tissues Rhabdomyosarcomas
Rhabdomyosarcomasand not from the extraocular muscles. They may be grouped into four categories:
a. . This is by far the most common type found in the orbits of infants and chil dren, accounting for Embryonal
Embryonalover 80% of cases. The embryonal form has a predilection for the supero nasal quadrant of the orbit.
Embryonal rhabdomyosarcomas are associated with a good (94%) survival rate. b. . This form has a predilection for the inferior orbit and accounts for 9% of orbital Alveolar
Alveolarrhabdomyosarcomas. This is the most malignant form of rhabdomyosarcoma. c. . Pleomorphic rhabdomyosarcoma is the least common and the most differentiate d form. The Pleomorphic
Pleomorphicpleomorphic variety tends to occur in older persons and has the best prognosis (97% survival rate).
d. . This rare variant of embryonal rhabdomyosarcoma appears grapelike. It is no t found in the orbit Botryoid
Botryoidas a primary tumor; rather, the botryoid variant occurs as a secondary i nvader from the paranasal sinuses
or from the conjunctiva.
e. Metastatic workup includes lumbar puncture and bone marrow biopsy, best done under anesthesia.
L37 Duane. Although no single regimen is appropriate for every child with orbita l rhabdomyosarcoma, a sample protocol
might include multiple 3-week cycles of chemotherapy, each beginning with intrav enous vincristine, actinomycin-D, and
cyclophosphamide, with vincristine repeated on the 8th and 15th days of each cyc le. The regimen might include
external radiation to a total dosage of 5,040 cGy. For poor prognosis cases (e.g ., metastatic alveolar
rhabdomyosarcoma), newer agents under investigation include ifosfamide, etoposid e, irinotecan, topotecan, and
tirapazamine. Having made the diagnosis and contributed to local staging at the time of presentation, the orbital
surgeon continues to follow the patient along with the pediatric oncology team. In cases of treatment failure, salvage
surgery may take the form of orbital exenteration or excision of residual tumor combined with brachytherapy.
Rhabdomyosarcoma underscores the importance of clinical suspicion when dealing w ith acute proptosis in childhood.
Prompt referral to a tertiary center after appropriate imaging is the responsibi lity of the primary ophthalmologist, family
practitioner, or pediatrician who first encounters the patient.
L38 Most periocular metastases in children are orbital, unlike in adults. The mo st common is neuroblastoma.
L39 Fungal species likely leads to a necrotizing orbital cellulitis are Mucor, R hizopus, and Aspergillus.
L40 is generally seen only in the immunocompromised (chemotherapy, posttransplan t, diabetes Mucormycosis
Mucormycosismellitus). Aspergillosis is probably more common in this population also, but it may be seen in otherwise healthy
individuals, and it also may be seen as a result of allergic aspergillosis sinus itis.
L41 Orbital phycomycosis generally results from invasion by necrotizing fungal s inusitis. Black eschar in the nasal cavity
is virtually diagnostic but is a late finding. (Its absence does not exclude the diagnosis.)
L42 Sebaceous cell carcinoma is more common in women, while fibrous histiocytoma are more common in men.
L43 Thyroid-related orbitopathy can occur despite a persistently euthyroid state (as indicated by clinical and laboratory
findings).
L44 The indications of immediate surgical intervention in patients with Graves's orbitopathy are acute corneal
decompensation and evidence of optic nerve compression.
L45 Sensitive immunometric assay. This is the most sensitive way to thyroid-stimu lating hormone (TSH) levels
thyroid-stimulating hormone (TSH) levelsdetect hyperthyroidism; feedback regulat ion can lead to a reliably detectable decrease in thyroid-stimulating hormone (TSH), even when fluctuating levels of thyroxine (T4) and 3, 5, 3'-triiodothyron ine (T3) may not be indicative.
L46 Surgical procedures that may be indicated during the active, inflammatory ph ase of Graves' ophthalmopathy include:
a. Lateral tarsorrhaphy. b. Orbital decompression.
L47 The histopathologic changes evident in extraocular muscle (EOM) specimen fro m patients with Graves'
ophthalmopathy also may be seen in the lacrimal glands. Fibrosis tends to be les s severe, leading to partial loss of the
L48 Typical manifestations of idiopathic orbital inflammation (pseudotumor) incl ude all of the following:
a. Dacryoadenitis.
b. Extraocular myositis. c. Periscleritis.
d. Optic perineuritis.
e. Changes in corneal sensation may occur, but frank ulceration especially periphe rally is unusual
L49 Clinical findings that are more likely in pediatric orbital pseudotumor than in the adult variety of the disease
include all of the following: a. Bilateral involvement.
b. Systemic symptoms and signs (malaise, fever, vomiting). c. Peripheral eosinophilia.
d. Uveitis.
L50 Orbital pseudotumor is generally quite painful for both children and adults. L51 Some patients do not experience the typical pain. Some may have minimal infl ammatory signs and may present with
a totally fibrotic scarred lesion (idiopathic sclerosing inflammation of the orb it). Such lesions may require biopsy for
diagnosis because it is misdiagnosis for malignancy. There is little response to steroid because it is fibrotic.
L52 Orbital pseudotumor. Although a dosage of 60 mg of prednisone is at the lowe r end of the usual beginning ranges
for steroid therapy, one should consider an orbital biopsy because of the possib ility of other inflammatory diseases and
other orbital pathology. After the diagnosis is confirmed, additional attempts s hould be made to bring about a response
with stronger steroid therapy, orbital radiation, methotrexate, or cyclophospham ide.
L53 Unlike Graves' ophthalmopathy, pseudotumor can and commonly does involve the muscle tendons as well as their
insertions, along with posterior Tenon fascia.
L54 Sarcoidosis generally not associated with pain and spares orbital soft tissu e.
L55 The following disorders may be associated with a clinical presentation indis tinguishable from typical inflammatory
orbital pseudotumor.
a. Systemic lupus erythematosus (SLE). b. Polyarteritis nodosa.
c. Wegener's granulomatosis. d. Churg-Strauss syndrome.
L56 Bilateral painless enlargement of the lacrimal glands is typical presentatio n of sarcoidosis and benign
lymphoepithelial lesion.
L57 Hemangiopericytomas are more likely to limit ocular motility than cavernous hemangiomas.
L58 Hemangiopericytomas (rapidly expansile and aggressive tumour) may restrict o cular motility and cause
conjunctival prolapse and engorgement of vessels in the conjunctival cul-de-sac. Hemangiopericytomas resemble
cavernous hemangiomas on contrast-enhanced CT and may look blue in surgery. Thes e lesions must be completely
excised because they may recur, undergo malignant degeneration, and metastasize. Histopathologically, these
lesions are unique in that microscopically "benign" lesions may recur and metast asize, whereas
L59 Most orbital meningiomas arise outside the orbit and invade secondarily. L60 In NF, the growth pattern of meningioma tends to be paraxial (diffusely alon g the nerve sheath) rather than focal.
L61 Meningioma may be associated with bony changes either osteolytic or osteobla stic, so that CT is a modality of
choice in the initial evaluation. Angiography generally reveals a highly vascula rized tumour (tumour blush). MRI is
particularly useful for the suspected intracranial extension.
L62 Optic nerve sheath meningioma. Excisional biopsy of optic nerve biopsy gener ally result in visual loss, because
fragile pial blood vessel surrounding tumour. Surgeries are usually indicated if there is intracranial extension, severe
proptosis and sever visual loss. Also surgery is usually indicated if tumour gro wth is becoming a potentially a life
threatening. Paediatric meningioma is more aggressive tumour than adult variety and is removed earlier.
L63 Ophthalmologist specialist practice 10% of lacrimal gland lesion will be inf lammatory or lymphoid. In contrast, to orbit
specialist practice probably see 50% epithelial neoplasm and 50% inflammatory/ly mphoid lesions.
L64 The critical features of lacrimal disease:
a. Pain is more typical of acute inflammatory, infectious, or malignant lesions. b. Duration of symptoms is helpful in separating slowly progressive benign lesio n, such as benign mixed
tumour from more acute conditions such as malignant neoplasm or inflammation. c. Radiological findings osteolysis is strongly favor malignant lesion.
L65 Pain in adenoid cystic carcinoma is more commonly due to perineural extensio n and bone destruction.
L66 Soft-tissue contour analysis can help differentiate between lymphoid tumors (elongated smooth masses
pancakes ) from parenchymal tumors (globular masses). Adenoid cystic carcinomas usu ally produce bony destruction.
Benign mixed cell tumors often cause concave pressure changes in the adjacent bo ne. Lymphoid and inflammatory
lesions generally do not cause bony changes.
L67 Benign mixed cell tumor, the male-female ratio is 3:2. The tumor should be a pproached through a lateral orbitotomy
with careful excision to avoid rupture of the tumor's pseudocapsule. Incisional or incomplete biopsy techniques can lead
to infiltrative tumor recurrence (in 32% of cases) and, occasionally, malignant transformation.
L68 Histiocytic disorders is most likely to involve orbital bone is eosinophilic granuloma.
L69 Fibrous histiocytoma is one of the most common mesenchymal tumours of the or bit. 10% have metastatic
potential. Another 16% are termed locally aggressive but not frankly malignant. Most are benign (>90%), and have a
storiform, or matlike, pattern on histopathology. It is usually very firm and ca n displace other orbital structures.
L70 Fibrous dysplasia may be monostotic (affect only one bone) or polyostotic. T he polyostotic variety may present with
precocious puberty and dermal hyperpigmented macules. This disorder, Albright's syndrome, rarely involves the orbit.
Orbital disease is nearly always monostotic and rarely associated with precociou s puberty, regardless of age. Surgical
curettage or excision is usually undertaken. Only woven bone, not cancellous, is found microscopically.
L71 It is impossible to differentiate clinically or radiographically between ben ign reactive lymphoid hyperplasia
It is impossible to differentiate clinically or radiographically between benign reactive lymphoid hyperplasia
and orbital lymphoma. Biopsy with light microscopy, immunochemical staining, and electron microscopy is
and orbital lymphoma. Biopsy with light microscopy, immunochemical staining, and electron microscopy is
. necessary to distinguish between them necessary to distinguish between them
L72 The central nervous system (CNS) is not routinely surveyed in patients with orbital lymphoma. This is in
The central nervous system (CNS) is not routinely surveyed in patients with orbi tal lymphoma. This is in
contrast to patients with intraocular lymphoma. When CNS involvement is suspecte d, computed tomography
contrast to patients with intraocular lymphoma. When CNS involvement is suspecte d, computed tomography
. (CT) scan or magnetic resonance imaging (MRI) is the starting point (CT) scan or magnetic resonance imaging (MRI) is the starting point
L73 The key features separating pseudotumour from lymphoproliferative lesion are :
a. Prominent fibrovascular stroma. b. Hypocellularity.
L74 The three orbital deposits that are hyperintense on T1 weighted MRI are bloo d, melanin, and mucus.
L75 Exceptions to the rule of thumb that all orbital tumors are dark on T1-weigh ted magnetic resonance images (MRI)
include:
a. Retrobulbar hemorrhage of at least 24 hours duration. b. Melanoma.
c. Mucocele.
L76 The nose and paranasal sinuses are more frequently the focus of tumors that secondarily invade the orbit.
L77 The most common sinus lesion that invades the orbit is the mucocele. The mos t common sinus neoplasm to invade
the orbit is squamous cell carcinoma.
L78 Classic features of a tripod fracture include all of the following: a. Downward displacement of the lateral canthus.
b. Infraorbital hypesthesia. c. Trismus.
d. Temporal subconjunctival hemorrhage.
s zygomaticofrontal,
zygomaticomaxillary, and the zygomatic arch. Ocular motility may or may not be n ormal in pure tripod fractures, but
upgaze should be spared. Repair is indicated when there is marked cosmetic defor mity or potential mandibular
instability.
L80 Telecanthus and rounding of the medial canthus is a characteristic finding i n direct naso-orbital-ethmoidal fractures.
L81 The qualifier indirect implies that forces other than direct contact with a bl unt object led to orbital wall fracture (for
instance, suddenly increasing intraorbital pressure). This type is rarely associ ated with orbital rim fracture, which is seen
more.
L82 The following findings in orbital floor fractures is/are exacerbated by the presence of a coincident medial orbital wall
fracture are enophthalmos, subcutaneous emphysema.
L83 With severe muscle contusion, oedema, or haemorrhage, forced duction test ma y be falsely positive or impossible to
interpret. They are more fruitful if performed 5-10 days after injury.
L84 Most diplopia associated with orbital contusion disappears 7-14 days followi ng injury. Most diplopia result as
reversible muscle contusion.
L85 The following are considered indications for surgical repair of orbital floo r fractures:
a. Disabling diplopia present 7 to 10 days after the original injury. b. Large fracture on acute computed tomography (CT) scans.
c. Enophthalmos >2 mm.
d. Inferior rectus entrapment in a pediatric patient present 1 day after injury. L86 Computed tomography (CT) scan of the orbit with direct coronal, axial, and s agittal views gives better definition of
the soft tissue and bony structures than plain films. Magnetic resonance imaging (MRI) has a very limited role, because
bone is dark.
L87 Large, complex anterior fractures lead to marked inferior orbital herniation without entrapment. This causes
Large, complex anterior fractures lead to marked inferior orbital herniation wit hout entrapment. This causes
hypoglobus and enophthalmos. Small posterior fracture can cause significant entr apment as a crowded
hypoglobus and enophthalmos. Small posterior fracture can cause significant entr apment as a crowded
. muscle belly is forced or pinched into the defect. In these cases, enophthalmo s is minimal
muscle belly is forced or pinched into the defect. In these cases, enophthalmos is minimal
L88 : Indication of removal of intraorbital FB Indication of removal of intraorbital FB
b. Anterior, easily approachable FB.
c. When there is evidence of optic nerve compromise as decreased VA, APD, and dy schromatopsia.
L89 The most common postoperative complication of enucleation is superior sulcus deformity.
L90 When ocular or optic disc perfusion is severely compromised by an orbital co mpartment syndrome, immediate
canthotomy with cantholysis should be performed to decompress the orbit.
L91 In direct optic nerve trauma, something physically impinges on the optic ner ve, but it need not be a foreign body
(e.g., bone fragments). In indirect trauma, nothing can be found to have directl y struck the nerve.
L92 Treatment of indirect optic nerve injury is most likely with emergent high-d ose intravenous methylprednisolone to
reduce swelling associated with the injury. Optic canal decompression may also b e considered.
L93 Risk factors that increases the chance of extrusion of orbital implants: a. Implant too large for the orbit.
b. Conformer too large for the fornix. c. Exposed synthetic integrated implant. d. Orbital tissue infection.
L94 The procedure of choice for severe socket contracture following enucleation involves the use buccal mucosa grafts.
L95 Whitnall's ligament should not be confused with the horns of the levator apo neurosis, which are structure to be cut
during ptosis surgery.
L96 The levator palpebrae superioris, the deeper or posterior portion inserts on to the anterior surface of the lower half of
the tarsus, not to its superior border. Müller's muscle inserts into the superior border of the tarsus.
L97 Following trauma to the medial canthus, special attention must be directed t o reattaching the tendon to its more
posterior attachment, the posterior lacrimal crest.
L98 The normal mongoloid slant of the palpebral fissure occurs because of the high er insertion of the lateral canthal
tendon (3 mm higher than the medial canthal tendon [MCT]). Antimongoloid slant occ urs when the lateral tendon
inserts lower than the medial and can occur with trauma (e.g., tripod fracture) or congenital abnormalities (e.g.,
Treacher Collins' syndrome).
L99 Lower eyelid ectropion is a variable feature not a defining feature of bleph arophimosis syndrome.
L100 Blepharophimosis is also known as Kohn-Ramono syndrome.
L101 Primary amenorrhea is the most common condition associated with blepharophi mosis syndrome.
L102 Congenital coloboma of the upper eyelid is generally isolated whereas that of the lower eyelid is more commonly
associated with other facial abnormalities.
L103 The most likely outcome following inadvertent suturing of the orbital septu m into subcutaneous tissue when repairing
a partial thickness eyelid laceration is lid retraction in downgaze.
L104 Hairless skin of similar pigmentation must be chosen for free skin graft in the setting of lid laceration.
L105 Factors important to evaluate before planning therapy for involutional ectr opion are:
a. Position of the inferior punctum.
b. Stability of the lower limb of the MCT. c. Stability of the lateral canthal tendon.
L106 Entropion of any aetiology is more common in the lower lid.
L107 Digital pressure along the inferior border of the inferior tarsus will temp orarily correct involutional entropion
Digital pressure along the inferior border of the inferior tarsus will temporari ly correct involutional entropion
but not cicatricial entropion. but not cicatricial entropion.
In cicatricial entropion, vertical foreshortening is present, rather than the In cicatricial entropion, vertical foreshortening is present, rather than the . redundancy of involutional entropion
redundancy of involutional entropion
L108 To allow maximal spontaneous return of function before surgical repair, it is generally wise to observe traumatic
ptosis in an adult for 6 months. Ptosis repair before the possible spontaneous r eturn of function may lead to
lagophthalmos.
L109 Lid notching, scarring, hypopigmentation, and edema may be seen after lash cryoepilation.
L110 Critical components in the evaluation of corneal protection in patient with ptosis surgery:
a. Assessment of lagophthalmos. b. Assessment of Bell phenomenon. c. Schirmer testing.
d. Assessment of corneal sensation.
L111 The primary abnormality seen in ptosis after cataract surgery is in the lev ator aponeurosis. Aponeurotic dehiscence
has been blamed on anesthetic injection, lid specula, and bridle sutures.
L112 Ptosis of MG is often resistant to anticholinesterase or steroid. Surgery i s usually performed after medical therapy
has been optimized.
L113 In Graves ' disease lateral lid retraction is greater than medial, in conve rse to the collier sign.
L114 Recession of the superior rectus muscle will induce lid retraction, while r esection will induce ptosis.
L115 Lower lid retraction is more challenging than the upper lid repair in patie nt with Graves ' disease, because it needs
L116 Acanthosis nigricans: suddenly appearing multiple seborrheic keratoses know n as Leser-Trelat sign is
Acanthosis nigricans: suddenly appearing multiple seborrheic keratoses known as Leser-Trelat sign is
. usually associated with GIT malignancy usually associated with GIT malignancy
L117 Eyelid lesions are typically slightly elevated with a central ulcerated are a or crater are:
a. Molluscum lesion. b. Basal cell carcinoma. c. Keratoacanthoma.
L118 Cryotherapy selectively destroys melanocytes but is insufficient for cutane ous melanoma and should be considered
a palliative treatment.
L119 Blepharochalasis is a rare idiopathic disorder leading to inflammatory edem a of the eyelids. It is familial, and younger
patients, especially women are affected. The repeated episodes of edema may caus e ptosis and herniation of the
orbital lobe of the lacrimal gland. Dermatochalasis is redundant preseptal skin caused by aging. True ptosis
(involutional) may be present in either disorder.
L120 Hemifacial spasm is rarely bilateral and is usually caused by vascular comp ression of the seventh cranial nerve at
the brainstem and can result in synchronous contractions of the entire side of t he face. Along with partial complex
seizures and myoclonic epilepsy, essential blepharospasm is effaced by sleep. L121 Any treatment for blepharospasm is designed to decrease eyelid closure. Thu s, dry eye will be aggravated. Facial
nerve ablation suffers from recurrence rates as high as 30% and is associated wi th complications such as hemifacial
paralysis. Consequently, its use has significantly decreased. Orbicularis myecto my is usually preferred to facial nerve
avulsion. Botulinum injection is the initial treatment of choice.
L122 Retrospective studies show that the mortality rate from ocular adnexal basa l cell carcinoma is 3%. The vast majority
of patients who died from basal cell carcinoma had disease that started in the c anthal areas, had undergone prior
radiation therapy, or had clinically neglected tumors.
L123 Removal of the orbital lacrimal gland removes the efferent input and interf eres with reflex tearing, whereas removal
of the palpebral lobe damages the ducts from the orbital portion, which run thro ugh the palpebral lobe. This impairs
reflex tearing as well.
L124 Ganglia serves as the home for cell bodies providing postganglionic efferen t innervation to the lacrimal gland is the
sphenopalatine ganglion which receives parasympathetic fibers from the greater s uperficial petrosal nerve (a division of
CN VII).
L125 In congenital NLD obstruction, the blockage is at the valve of Hasner. In a cquired cases, the blockage is within
Intraosseous NLD. Involutional stenosis is one of the most common causes of acqu ired NLD obstruction.
L126 Jones 1 test, one third of normal patient will have false positive result w ith this test.
L127 Single functioning punctum and canaliculus is usually sufficient. L128 Probing of acquired obstructions rarely yields permanent patency. L129 Congenital canalicular obstruction is rare in infants.
L130 Acquired causes of canalicular obstruction. a. Trauma.
b. Phospholine iodide. c. Actinomyces infection. d. Idoxuridine use.
e. Contraceptive pill. f. Steven-Johnson syndrome.
L131 Congenital obstruction of the nasolacrimal system, general anesthesia is ge nerally necessary after the age of 6
months.
L132 Mortality rate of sebaceous gland carcinoma is approximately 20%, although variable studies have published
mortality rate from 3% to 41%.
L133 Acute, lancinating pain in the medial canthal region with minimal noninflam ed enlargement of the lacrimal sac is most
subjective of impacted dacryolith.
L134 The most common malignant tumor of the lacrimal sac is squamous cell carcin oma. Treatment may consist of a
dacryocystectomy and a rhinotomy.
L135 The following constitute indications for dacryocystorhinostomy (DCR). a. Recurrent acute dacryocystitis.
b. Chronic discharge or symptomatic epiphora with a positive secondary dye test (organic obstruction).
c. Persistent epiphora in a child after probing and Silastic intubation of a con genitally impatent system.
L136 In probing the nasolacrimal system of an infant with congenital stenosis, i t is better to start with the superior
canaliculus. The superior canaliculus possesses more maneuverable angles and hen ce is easier to probe. Furthermore,
there is less functional significance if a false passage is created.
L137 The average onset of action of botulinum toxin is 48 to 72 hours. Peak botu linum effect usually occurs 2 to 3 weeks
after injection.
L138 Any patient with sclerokeratitis and coexisting sinus disease should be sus pected for Wegener's granulomatosis.
Ocular disease occurs in 60% of patients with the disease. Eighty percent of pat ients are positive for antineutrophilic
