Benji Wright1, Naz Raoof1,2, Andrea L. Vincent1,2
Purpose: To investigate the characteristics of cystic maculopathy(CM) in patients with inherited retinal disease (IRD) from the New Zealand IRD Database to ascertain prevalence, correlation with genotype, effect on retinal sensitivity, and response to the topical carbonic anhydrase inhibitors, Brinzolamide.
Methods: 151 patients with rod cone dystrophies (RCD) were identified from the New Zealand IRD Database. Clinical and family history, examination findings, Optical coherence tomography (OCT) imaging, and genotype were ascertained. The prevalence of CM was determined, and clinical features of individuals who received topical Brinzolamide were investigated to determine treatment response, assessed by subjective and objective change in visual acuity (VA), and OCT parameters.
Results: 34 of the 151 patients developed cystic maculopathy (CM) (22.5%). The prevalence of CM varied between autosomal dominant (AD), (32.6%), autosomal recessive (AR) (22.5%), and X-linked (XL) (0%) inheritance. The prevalence of CM in Usher syndrome was 16.6%, and 20% with a confirmed genetic diagnosis. Of the 23 patients on Brinzolamide, 17 (73.9%) had reduction of CM on OCT, 13 (56.5%) reported a subjective VA improvement, and 10 (43.5%) an objective improvement in VA which on average, improved from 6/19 to 6/15.
Conclusion: The prevalence of CM in patients with RCD was 22.5%, with a variation in CM prevalence dependent on the inheritance, – specifically no CM was observed in XLRP.Brinzolamide drops provide an effective treatment for the majority of patients, with improved VA in those who respond well to the treatment.