Abstract
Purpose :
To further characterize the ADRP phenotype associated with the P23H rhodopsin mutation and improve our understanding of its long-term prognosis.
Methods :
We investigated in detail in 18 affected patients (age: 49±18, 8M/10F) the manifestations, phenotype class, and variability in ADRP severity characterizing symptoms of onset, best corrected visual acuity (BCVA), full-field electroretinogram (ffERG), kinetic perimetry (KP), spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) and photography. Furthermore, we analyzed longitudinal data available for 4 of our patients and compared our findings with previously published data from the literature (n=42).
Results :
P23H patients initially exhibited a Class B1 phenotype, with regional/altitudinal retinal changes and KP loss, and good ffERG preservation, only later evolving to a more severe and diffuse (Class B2) presentation – yet with partial ffERG response preservation. Peripheral metallic tapetal-like reflexes characterized pre- or minimally symptomatic cases. Hyper-AF bands on FAF imaging had a close correlation with visual field I4e detection limits. Furthermore, the limits of the external limiting membrane (ELM) and ellipsoid zone (EZ) on SD-OCT corresponded closely with the outer and inner boundaries respectively of the hyper-AF band. Desensitized but persistent vision on KP was also present outside the boundaries of the hyper-AF bands. SD-OCT also showed a consistent asymmetry in the ONL thickness between the inferior and the superior hemiretinas, present also at the pre-symptomatic stage. Cystoid macular edema (CME) was seen in 6 cases and was visually significant (and responsive to treatment) in 3. An unusual amount of macular geographic-like damage was observed in 2 patients with choroidal thinning. Trend lines and curves for BCVA and ERG b-wave decline for our patients were parallel, although shifted upward, to the literature data.
Conclusions :
In our case series we confirm the general Class-B characteristics and evolution associated with P23H rhodopsin-linked ADRP. The long-term prognosis for central vision is overall favorable, except in cases with macular atrophy. CME is common but a treatable and rarely significant complication. Due to its close correlation with best visual function (KP) and microanatomy (SD-OCT), FAF may represent a useful outcome measure in treatment trials.
This is a 2020 ARVO Annual Meeting abstract.