Abstract
Purpose :
Rod photoreceptors are known to be involved in the ROP disease process, but dark adaptation that depends upon cooperative activity in the photoreceptors and pigment epithelium has not been evaluated in ROP. We studied dark adaptation, that is, recovery of retinal sensitivity at two eccentricities, 30 deg and 10 deg, a site previously shown to have elevated dark adapted threshold in children with a history of ROP and in control subjects.
Methods :
Subjects (n=15) with a history of ROP, controls with a history of preterm birth but no ROP, and term born controls were studied. After 30 minutes of dark adaptation from room light, the dark adapted threshold was measured at both sites (10 deg, 30 deg) in temporal retina of each participant. Then following a 5 minute exposure to a light estimated to bleach 50% of rhodopsin, the recovery of sensitivity was followed. The recovery of rod mediated sensitivity was expressed as the slope, S2 [Lamb & Pugh, 2006].
Results :
In term born controls (n=8), S2 values ranged from 0.22 to 0.34 log unit/minute and within subject differences between the sites (10 deg and 30 deg) were small (0.00 to 0.06). For these controls, there was no significant difference between S2 at the two sites. To date, among the former preterms, there is a slightly larger range of S2 values, 0.13 to 0.28 log unit/minute. The lowest S2 value and the largest discrepancy (0.11) between the 10 deg and 30 deg S2 values were found in a participant with a history of mild ROP.
Conclusions :
The results demonstrate the feasibility of investigating the kinetics of dark adaptation in former preterms. The kinetics will further characterize the persistent effect of ROP on rod mediated retinal function.
This is a 2020 ARVO Annual Meeting abstract.