The rod photoreceptors in retinopathy of prematurity - An electroretinographic study

Objective: To test the hypothesis that the more severe the acute phase reti nopathy of prematurity (ROP) was in the preterm weeks, the more severely co mpromised is rod photoreceptor function after the ROP has resolved. Methods: Electroretinographic (ERG) responses were recorded from 25 dark-ad apted children (ages 2.5 months' postterm to 14 years) categorized by maxim um, acute phase ROP (None to Very Severe). From the ERG a-wave "S," a sensi tivity parameter for the rod photoreceptor response, and R-mp3, the saturat ed amplitude of the rod photoreceptor response were calculated using a mode l of the activation of rod phototransduction. The patients' results were co mpared with those of healthy controls (n=71). Results: Among those in the None, Mild, Moderate, and Severe categories, bo th S and R-mp3 varied significantly with severity of acute phase ROP. In th e Very Severe category, ERG responses were too attenuated to calculate S an d R-mp3. Conclusions: The rod photoreceptors must be involved in ROP. The more sever e the acute phase ROP, the more severe is the compromise of the processes i nvolved in the activation of phototransduction in the rods.