Screening for Retinopathy of Prematurity—A Problem Solved?

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Fig 1. Normal premature infant fundus appearance of blood vessels leaving the optic disc.

PEDIATRICS Vol. 95 No. 5 May 1995 755

EDITORIALS

Screening

for Retinopathy

of Prematurity-A

Problem

Solved?

John T. Flynn, MD*; Augusto Sola, MDII; William V. Good, MD; and Roderic H. Phibbs, MDII

ABBREVIATION. ROP, retinopathy of prematurity.

In the United States there are about 4 million births

annually,1 of which about 10% are premature. The

percentage of premature births has increased over the last decade2 and every year there are >20 000

From the *Bascom Palmer Eye Institute, Miami; Neonatal Clinical Services,

and the Departments of §Ophthalmology and IPediatrics, University of California (San Francisco) School of Medicine, San Francisco.

Received for publication Aug 31, 1994; accepted Aug 31, 1994.

Reprint requests to (J.T.F.) Bascom Palmer Eye Institute, 900 N W 17th

Street, Miami, FL 33136.

Acad-emy of Pediatrics.

infants whose birth weight is 1250 g or under who

survive beyond 28 days of life.3 An additional 32 000

surviving infants weigh between 1251 and 1500 g at

birth. Both birth weight strata contain, by all that we

know about the disease, infants at the highest risk for the development of retinopathy of prematurity (ROP). If infants of these birth weights are to be examined by ophthalmologists competent to

per-form indirect ophthalmoscopy on these tiny

prema-tures, an average of 6 times during the period of

highest susceptibility for the development of

thresh-old ROP’ disease-32 to 40 weeks postconceptional

age5’6-then we are talking about ±300 000 such

ex-aminations per year in the neonatal intensive care

units across this country. Although we have no exact

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Fig 2. Dilated, tortuous vessels typical of “plus disease” exiting the disc.

756 SCREENING FOR RETINOPATHY OF PREMATURITY

figures, we estimate” that there are about 1000

oph-thalmologists in the subspecialty areas of pediatric, retina-vitreous as well as general ophthalmology

in-terested and trained to perform these examinations accurately, expeditiously, and safely on these cohorts

of infants. This task, which is, in essence, a diagnostic

examination and not a screening, seems, with the available manpower, to be one that is being well done. For this group of infants, this has proven to be

very useful and necessary. It is an example of the close cooperation that has developed between the

two specialties dealing with this dreadful disease. However, there are some 350 000 premature

in-fants whose birth weight is >1500 g who are at re-duced, but not zero risk of the disease. To establish an early diagnosis and provide proven therapy, a subset of those with the disease may need to be seen

by an ophthalmologist. Although current guidelines call for all these infants to be examined by an

oph-thalmologist as well,7’8 the number of examinations, manpower, and time become quite unmanageable for the available resources.

This estimate was arrived at as follows: 500 members of the American

Association of Pediatric Ophthalmology and Strabismus with 100%

involve-ment in ROP screening + 1500 members of 3 retina-vitreous societies with

20% involvement +9000 general ophthalmologists with 2% involvement =

±1000 ophthalmologists currently involved in neonatal ophthalmology. A generous estimate, we feel.

What should we do? We would like to suggest that this cohort of infants are candidates for screening: ideal in every sense in which the word is currently understood.9’#{176} ROP is a disease for which a

success-ful treatment exists that will modify its outcome

substantially. It is frequent enough that its detection

seems to justify assuming the risks and costs associ-ated with the development of a screening technique for nonophthalmologists when weighed against the failure to provide this service to today’s premature infant. Neonatal medicine has a long tradition of diverse, successful screening programs to detect the possibility of serious diseases akin to ROP in their devastating effect on the infant. And in today’s cost-conscious environment, failure to prevent its most serious outcomes-blindness or severe visual dis-ability in this case-are costly to all.2

Where do we go from here? Although no proven

screening technique currently exists, we would like

to suggest one that employs low cost technology-the hand-held direct ophthalmoscope. A poorly

di-lated pupil with or without engorged blood vessels

on the iris is a sign of serious ROP and can be easily

identified with the direct ophthalmoscope. Through

a well dilated pupil, screening for the caliber, tortu-osity and arterio-venous color difference of the reti-nal vessels around the optic disc is the easiest exam-ination to teach and perform on the premature eye.

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EDITORIALS 757

As early observers suggested’12 and later studies

confirmed, this latter finding, called “plus disease,”

when positive is a reliable sign of the possibility of

serious ROP elsewhere in the eye.’3 The screening

would call for the ability to detect the difference

between normal blood vessels exiting from the optic

disc (Fig 1), and engorged, tortuous blood vessels

exiting the disc (Fig 2), suggesting the possibility of

serious disease elsewhere prompting a referral to the

ophthalmologist. A veritable library of high-quality

fundus photographs illustrating this difference is

currently

available among the collections of ophthal-mologists with an interest in this disease. Examina-tion of the posterior pole of the eye with a lid specu-lum in place would be performed at times known to be critical for the development of threshold ROP (34 to 40 weeks) by neonatologists, fellows, neonatal

nurse practitioners, and residents trained by the

oph-thalmologist(s) responsible for that nursery. This

would seem to meet the criteria of a valid,

cost-effective’4 screening program. The screening should not replace indirect ophthalmoscopic examination in

infants whose birth weight is <1500 g who are at

higher risk for ROP.

It is clear that we are a long way from

implement-ing such a program. To raise the issue is but a first

step, necessary but not sufficient to move the

corn-bined communities concerned. It may be that there are other, better methods of screening these infants who now might leave the unit with nobody looking at their eyes than the one we have suggested. The

program we have sketched here is not unique to us.

Others are exploring its reliability as a teaching tool

among otherwise untrained ophthalmologists and

residents (R.A.S., personal communication to J.T.F.,

1994). All of us who have experience with this

dis-ease have come to recognize its vagaries and to see

infants whose birth weights are in excess of 1500 g,

sometimes surprisingly in excess of that figure, with

very

serious or blinding ROP. Some of these infants will have risk factors that might have led to an

oph-thalmologic examination but others will not. The

planning, development, and implementation of a

re-alistic screening program for all infants >1500 g

would seem to be a logical next step for our

com-bined communities to take on their behalf.

REFERENCES

1. Wegman ME. Annual summary of vital statistics-1992. Pediatrics. 1993; 92:743-754

2. MMCD. Increasing incidence of low birthweight-United States, 1981-1991. JAMA. 1994271:1821-1822

3. Javitt J, Dei Cas R, Chaing YP. Cost effectiveness of screening and

cryotherapy for threshold retinopathy of prematurity. Pediatrics. 1993;

91:859-866

4. Cryotherapy for Retinopathy Cooperative Group. Multicenter trial of cryotherapy for retinopathy of prematurity-.3 month outcome. Arch Ophthalmol. 1990;108:1195-1204

5. Palmer EA, Flynn JT, Hardy RJ, et al. Incidence and early course of retinopathy of prematurity. Ophthalmology. 199298:1628-1640

6. Schaffer DB, Palmer EA, Plotsky DF, et al. Prognostic factors in the

natural course of retinopathy of prematurity. Ophthalmology. 1993;100:

230-237

7. Guidelines for Perinatal Care. Third Edition. American Academy of

Pediatrics, American College of Obstetrics and Gynecology. 1992:

202-203

8. American Academy ofOphthalmology. Policy Statement: Infant and

Chil-dren’s Vision Screening. San Francisco, CA: American Academy of

Ophthalmology; 1991

9. Hennekins CH, Burring JE. Screening. In: Mayrent SL, ed. Epidemiology

in Medicine. Boston, MA: Liftie Brown and Co; Chapter 13. 1987:327-347 10. Hall DMB. Health for All Children. A Programme for Child Health

Surveil-lance. 2nd Ed. New York, NY: Oxford Medical Publications; 1991:1-23

11. Flynn TF, O’Grady GE, Herrera J, Kushner BJ, Cantolino S, Milam W.

Retrolental fibroplasia. I. Clinical observations. Arch Ophthalmol. 1977; 95:217-223

12. Quinn GE, Schaffer DB, Johnson L. A revised classification of retinop-athy ofprematurity. Am IOphthalmol. 198494:744-749

13. Cryotherapy for Retinopathy of Prematurity Cooperative Group. The natural ocular outcome of premature birth and retinopathy: status at one year. Arch Ophthalmol. 1994;112:903-912

14. Eddy DM. Screeningfor Cancer: Theory, Analysis and Design. New Jersey:

Prentice Hall; 1980

GO WHERE THE FOOD IS

Science is not exactly the same as the feeding frenzy of sharks, but a major,

lavishly funded research program does make scientists take notice. Nobody wants

to be left behind.

REFERENCE

1. Desowitz RS. The Malaria Capers. Tales of Parasites and People. NY: WW Norton; 1991.

Submitted by Student

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1995;95;755

Pediatrics

John T. Flynn, Augusto Sola, William V. Good and Roderic H. Phibbs

A Problem Solved?

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