Retinopathy ofPrematurity (ROP):

History and Introduction

2 Retinopathy of Prematurity: A Text and Atlas

HISTORY AND INTRODUCTION

Retinopathy of prematurity (ROP) is a diseaseaffecting the retina of premature infants (Figs1.1A to C). Its key pathologic change, retinalneovascularization, has several features incommon with the other proliferative retino-pathies such as diabetic and sickle cell retino-pathy. Each of these proliferative retinalvascular disorders appears to be associatedwith local ischemia and the subsequentdevelopment of neovascularization.

Historical Perspective

• First identified by Terry1 in 1942, Terry’soriginal reports designated the conditionretrolental fibroplasia based on his impres-sion that the primary change involved aproliferation of the embryonic hyaloidsystem which incorporated the retina. Hestudied the unilateral pathologicalspecimens (most likely to be PHPV) andprovided details which he thought maybe identical with bilateral cases of retro-lental fibroplasia.

• The term ROP was coined by Heath in1951. He was much more precise in hisdescriptions and his histopathologicalstudies offered rare insight into the diseaseprocesses as it was then understood.

• In 1951, Campbell suggested that toxiceffects of uncontrolled oxygen to new-borns were responsible for the epidemic.2

She suggested avoiding use of oxygen anduse only if the child is cyanosed.

• The incrimination of oxygen as theprincipal cause of ROP was made in the1950s.3,4 Subsequent studies showed highlevels of oxygen obliterated blood vessels

of the neonatal retina. Controlled use ofoxygen although lowered the proportionof blindness (In USA alone from 50% in1950 to 4% in 1965) but it increased theneonatal deaths due to atelectasis andrespiratory distress secondary to hyalinemembrane disease.5,6

Figs 1.1A to C: Prematurechildren before examination

ROP: History and Introduction 3

• During the late 1970s and 1980s, resur-gence of ROP was noted and called thesecond epidemic due to increased survi-val of very low birth premature infants(750-999 gm).7-9

• In 1981, Phelps8 estimated the incidenceof ROP associated with an increase insurvival rates of infants with birthweights less than 1,000 gm.

• In 1983, International Classification ofRetinopathy of Prematurity was devisedunder the leadership of John Flynn.10

• In 1970s the Japanese physicians treatedthe ridge and the adjacent avascularretina.11 Hindle and Leyton, in Canada,treated the ridge, and the retina anteriorand posterior to it. McPherson, Hittner,

and Kretzner advocated cryotherapy ofthe ridge and adjacent posterior avas-cular zone to destroy the spindle cells,the presumed source of angiogenicfactor.12

• In Asian countries like India, due tolopsided health care, i.e. due to extremesof health care, state of the art tertiaryhealth care neonatal center and almostdefunct neonatal primary health carecenters, both first and second epidemicexist, and may be called as the third ormixed epidemic.

• However, more recent reports indicatea decline in the incidence, severity andprogression to threshold disease indeveloped countries.13-17