The contrast sensitivity acuity tester (CAT-CP, Neits Instrument, Nagoya, Japan) was developed to overcome these disadvantages. This instrument determines the logarithm of the minimal angle of resolution (logMAR) visualacuity using different contrast Landolt rings instead of letter optotypes, and the tests can be performed under photopic and mesopic conditions. To date, the contrastvisualacuity has been used mainly to assess preoperative and postoperative visual acuities in patients with cataracts, intraocular lens implantation, 11 and refractive surgery. Contrastvisualacuity
The subjective test of this part is divided into two sections. Firstly, the performance of our seam assisted shrinkability method was subjectively compared to the seam carving and shrinkability only methods on healthy subjects. We then separately per- formed a comparison of our seam assisted shrinkability algorithm with ordinary (lin- ear) resizing. This second study is to explore the tradeoffs ’ between improved object sizes with inevitable levels of jitter. 6 video files were used in this evaluation, which were each retargeted with the three algorithms plus retargeting them with the ordinary resizing technique. The first video sequence consisted of four subjects passing a tennis ball to each other while they are standing and not moving. In the second video sequence, 5 subjects pass a basket ball while they are moving in a circular form. The third video consists of a subject moving (in the middle of the scene) towards the screen from a distance while three other subjects enter and exit from the frame. In the fourth video, a subject is playing with golf balls, so the motion in this video was con- siderably slow. The fifth video consists of a subject skating on the water. The final video consisted of eight subjects dancing in a small room. This was the busiest of the 6 videos.
peripheral blood circulation most likely penetrates into the intraocular cavity, intraocular ET-1 levels must correlate with plasma ET-1 levels. This suggests that ET-1 is indeed involved in the pathogenesis of several ocular diseases, including RP, and the plasma ET-1 level is a useful marker for evaluation of intraocular hemodynamics. Cellini et al have reported that plasma ET-1 levels were significantly higher in RP patients than those in control subjects, 6 suggesting that an increase
ganglion cell death in a mouse model of normal tension glaucoma. In this report, they indicated that VPA exerts neu- roprotective effects through suppression of oxidative stress and stimulation of cell survival signaling. Therefore, patients may have felt that it was easier to see with reduced visual “noise” from spontaneous firing of ganglion cells or with neuroprotective effects. This phenomenon may also explain why BCVA and VF were improved in our study with vari- ous types of genetic patterns. However, this hypothesis was based on subjective symptoms of VPA-treated RP patients, and we need further objective evaluation of cone-related functions, including color vision or contrast sensitivity, in VPA-treated patients.
Optical coherence tomography (OCT) is a noninvasive technique that provides information about the morphology of the retina, and especially of the macular area in vivo. Some studies support the idea that OCT determines structural changes in the macula that are correlated with subjective visual function, including visualacuity (VA) and visual threshold in patients with RP. Additionally, multifocal electroretinogram (mfERG) evaluation can be useful in moni- toring macular function in RP, and mfERG responses have been shown to be associated with the subjective visual field size. 14,15 However, to date, there are relatively few reports
Case 1 was a 31-year-old woman with best-corrected visualacuity of 0.9 in the right eye and 1.0 in the left eye. A color fundus photograph of the right eye showed fundus changes typical of retinitispigmentosa, ie, black bone spicule pig- mentation and depigmentation, narrowing of the retinal vessels, and retinal degeneration (Figure 1A). Scotopic and photopic full-field electroretinograms were undetectable in both eyes (data not shown). An abnormal parafoveal ring of high-density fundus autofluorescence was observed in the fundus autofluorescence image (arrows in Figure 1B), which indicated abnormal phagocytosis and concomitant lipofuscin accumulation in the retinal pigment epithelium. The fovea showed a normal dark area on fundus autofluorescence.
The pro forma for the study was developed by the authors based on the definition and clinical diagnostic criteria for RP, which are combinations of arteriolar narrowing/attenuation, retina pigments, optic atrophy, and night blindness. History obtained from the files of all the patients included present- ing complaints, family history of RP and use of refractive spectacles. Eye examinations included visualacuity assess- ment, refraction, tonometry (applanation), slit lamp examina- tion, and dilated funduscopy. One center had a fundus camera, so fundus photographs were available for a few patients. The age, sex, symptoms, visualacuity, intraocular pressure, retinal findings, and diagnosis on the first presentation to the eye outpatient departments were extracted from the patients’ records. The visualacuity was classified based on the World Health Organization’s category of vision 14 as follows: visual
In this study, we enrolled 212 patients with RP who visited the Department of Ophthalmology at Kyoto University Hospital between July 2007 and June 2009. As of July 2012, 126 of these patients had been followed-up for 3 or more years. Of these 126 patients, we included baseline and 3-year interval data of those patients who underwent comprehensive ophthalmic examinations, including best-corrected visualacuity (VA) measurement, fundus photography, static visual field test (Humphrey field analyzer, standard 10-2 program), kinetic visual field test (Goldmann perimeter), and spectral domain optical coherence tomography (SD-OCT). Conven- tional electroretinography (ERG), recorded according to the 2008 recommendations of the International Society for Clini- cal Electrophysiology of Vision, 27 was performed at least
Limitations of this study include the inadequate technical expertise in our unit which prevented some relevant tests being performed, in particular ERGs, which are of paramount importance in patients with retinitispigmentosa. In the very early stages of the disease, the ERG response is either off or limited to a small photopic b-wave which disappears sud- denly. There is no relationship between ERG and visual acu- ity, in that an ERG may be off in the presence of good central visualacuity. It is possible to conduct this examination even in children aged younger than six years, in whom the visual field is hard to obtain. 21 On the other hand, owing to the lack
weighted distance logMAR visualacuity (WVA) were sig- nificantly associated with the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) composite score and that WVA alone was the strongest predictor of self- reported assessment of total visual function in BD patients. The purpose of this study was to associate the vari- ous objective measurements of visual function with the patients’ self-assessment of vision measured by the VRQL- questionnaire subscales. The aim was also to provide insight into the perceived visual function of this defined type of RP patients, and to describe the impact of vision loss caused by BD on everyday life, which previously has not been described. The patients in this study represent all ages and stages of the BD phenotype.
Patients and Methods: This was a non-interventional two-arm comparative study of visual outcomes after uncomplicated bilateral cataract or refractive lens exchange surgery with IOL implantation between 6 months and 5 years before a single diagnostic examination visit. There was no masking and no control group. Subjects had to have uncorrected distance visualacuity (UDVA) of 20/40 (0.3 logMAR) or better measured at the time of their study visit. Clinical evaluations included the manifest refraction, visualacuity (VA) at distance, intermediate (60 cm) and near (40 cm), low contrast (10%) VA and contrast sensitivity. Results: A total of 50 bilaterally implanted patients (25 trifocal, 25 EDOF) were examined; the two groups had similar characteristics, including corneal astigmatism. Postoperative refractive outcomes were also similar. There were no statistically signi ﬁ cant differences in distance or intermediate VA between groups, but the trifocal group had signi ﬁ cantly better near VA both uncorrected (p = 0.009) and distance-corrected (p = 0.014). There were no statistically signi ﬁ cant differences in the low contrastacuity measures between IOLs at either distance or 40 cm, with or without glare. Contrast sensitivity in mesopic and photopic conditions was similar.
Three months after the last laser session participants were administered a structured questionnaire in the vernacular language regarding their visual disabilities before and after laser treatment. The questionnaire was administered by a single trained interviewer who was blind folded regarding the BCVA and CS of the participants. Questions mentioned in the questionnaire were adapted from NEI VFQ-25 (National Eye Institute, Visual Function Questionnaire (25 Item)) and VDQ (visual disability questionnaire). VFQ-25 was selected because of the scale being able to compare the relative burden of visual disorders on the same scale which is designed to capture the impact of visual problems on physical functioning, emotional wellbeing and social functioning. The rigorous multi-condition evaluation of the scale proved it to be reliable and valid. 13 VDQ has been designed in India by Marella et al. 14 keeping in mind the Indian population and the difficulties they face in their daily activities. Activities like self grooming which was given maximum importance by the participants with visual disabilities have been incorporated in our questionnaire. The response from participants was recorded as worsening, improvement or no change as compared to the discomfort in these activities prior to laser treatment.
Retinitispigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visualacuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms). Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema), and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis).
Abstract: Objective: To describe and analyze the clinical features and results of exome sequencing of a distinct form of retinitispigmentosa (RP) associated with retinal vascular occlusion (RVO). Design: This case series was a retrospective study. Participants: 23 patients with RP/RVO during 1992-2015. Methods: Information obtained from medical records includes age, gender, clinical history, visualacuity, and results of investigations using the slit-lamp, indirect ophthalmoscope, fundus photography, optical coherence tomography, angiography, electroretinography (ERG) and visual evoked potentials (VEP). Exome sequencing was performed in 8 blood samples. Results: Both eyes were affected. The optic disc was pale in 25 eyes, pale-white in 20 and normal in 1. Retinal vessels were attenu- ated in all eyes. There were widespread retinal pigment epithelium (RPE) abnormalities, including pigment discolor- ation and pigmented spots; no ‘bone spicules’ were observed. There was no inflammation, exudation, hemorrhage, neovascularization or proliferative vitreoretinopathy. Dye filling of vessels (angiography) was minimal/absent in 22 eyes, extended 1-3 diameters from the disc in 12, reached the posterior pole in 8, and reached the periphery in 4. ERG revealed severe a- and b-wave attenuation in 13 cases. VEP recordings showed implicit time prolongation and reduced amplitude. In 2 cases, progression from an intermediate to an advanced stage took 3.5-4 years. Prognosis was poor. In the results of exome sequencing, we found the SNP related RP, which had been reported previously. Conclusion: RP with RVO may be a distinct form of RP.
Improvement in visualacuity and contrast sensitivity are the main aims for successful YAG laser posterior capsulotomy. Previous reports have focused primarily on visualacuity improvement after Nd:YAG laser as the main outcome measure. But this is inadequate to assess visual function which necessitates evaluation of contrast sensitivity 57 . In our study,
Retinitispigmentosa (RP) is a clinical diagnosis and includes a genetically heterogenous group of patients with rod-dominant retinal degeneration and a classic triad of bony spicule pigmentation, vessel attenuation, and a waxy pallid optic disc. These patients initially suffer from night blindness, which is followed by con- striction of the visual field, and finally impaired visualacuity. Most syndromic variants of IRD, such as Usher syndrome and Bardet-Biedl syndrome, have the reti- nal phenotype of RP. Thus far, at least 120 genes are reported to cause syndromic or non-syndromic RP (RetNet, https ://sph.uth.edu/retne t/). The prevalence
Treatment of CMV retinitis should be individualized, taking into account the size and location of the retinitis, the patient’s experience with HAART, and the risk of treatment- related complications. The location of infected retina deter- mines the risk for vision loss; posterior retinitis threatens the macula and optic nerve; and anterior retinitis increases the risk of retinal detachment. The ocular fundus is divided into three zones; zone 1 encloses the area within 1500 µ m of the nerve or 3000 µ m of the fovea, zone 2 includes the area outside of zone 1 but posterior to the equator (as defined by the vortex veins), and zone 3 includes the peripheral retina between the equator and the ora serrata (Figure 5). 8
The visual system must detect contrast over a huge range of light intensities at least 12 log units. The area of the pupil can vary only 16-fold (1.3 log units) and therefore its role in visual adaptation is limited. Light adaptation is a form of "automatic gain control". Over a range of at least 3 log units of cone function, the intensity increment required for detection, DI, where DI/I is a constant, is known as the Weber-Fechner relation, and the constant is called the Weber fraction. The relationship breaks down at higher light levels, when saturation occurs. Light adaptation works very quickly, gets faster as background intensity increases and is dependent on calcium Ion flux; it is abolished when calcium is buffered inside photoreceptors. The light adapted eye is maximally sensitive at about 555 nm.
Our study showed that only one eye in the STM group, which had severe NPDR at baseline, progressed to vitreous hemorrhage at month 6. Moreover, it reported no significant difference between various parameters, such as visualacuity, LCVA, or visual field, between the CWL and STM groups. There was a slight advantage noted in the STM group in terms of LCVA as well as visual field. The CWL group showed a drop in the LCVA, visual field index, and scotopic b/a ratio in comparison to the STM group, although the change was statistically insignificant.