Expanded Retinal Disease Spectrum Associated With Autosomal Recessive Mutations in GUCY2D.

PURPOSE: GUCY2D has been associated with autosomal recessive Leber congenital amaurosis and autosomal dominant cone-rod dystrophy. This report expands the phenotype of autosomal recessive mutations to congenital night blindness, which may slowly progress to mild retinitis pigmentosa. DESIGN: Retrospective case series. METHODS: Multicenter study of 5 patients (3 male, 2 female). RESULTS: All patients presented with night blindness since childhood. Age at referral was 9-45 years. Length of follow-up was 1-7 years. Best-corrected visual acuity at presentation ranged from 20/15 to 20/30 and at most recent visit averaged 20/25. No patient had nystagmus or high refractive error. ISCEV standard electroretinography revealed nondetectable dark-adapted dim flash responses and reduced amplitude but not electronegative dark-adapted bright flash responses with similar waveforms to the reduced-amplitude light-adapted single flash responses. The 30 Hz flicker responses were relatively preserved. Macular optical coherence tomography revealed normal lamination in 3 patients, with abnormalities in 2. Goldmann visual fields were normal at presentation in children but constricted in 1 adult. One child showed loss of midperipheral fields over time. Fundus appearance was normal in childhood; the adult had sparse bone spicule-like pigmentation. Full-field stimulus testing (FST) revealed markedly decreased retinal sensitivity to light. Dark adaptation demonstrated lack of rod-cone break. Two patients had tritanopia. All 5 had compound heterozygous mutations in GUCY2D. Three of the 5 patients harbor the Arg768Trp mutation reported in GUCY2D-associated Leber congenital amaurosis. CONCLUSIONS: Autosomal recessive GUCY2D mutations may cause congenital night blindness with normal acuity and refraction, and unique electroretinography. Progression to mild retinitis pigmentosa may occur.

Vitritis in pediatric genetic retinal disorders.

PURPOSE: To determine which types of pediatric retinal degeneration are associated with inflammatory cells in the anterior vitreous. DESIGN: Retrospective, observational study in humans. METHODS: Retrospective chart review was performed for pediatric patients with suspected retinal degeneration presenting to a single examiner from 2008 to 2013. Age, visual acuity (VA), slit-lamp examination of anterior vitreous (SLAV), and clinical and molecular genetic diagnoses were documented. Anterior vitreous cells were graded clinically with SLAV from rare cells (1-4) to 1+ (5-9), 2+ (10-30), or 3+ (>30). Cells were also counted in magnified slit beam photographs masked to molecular diagnosis when obtainable. MAIN OUTCOME MEASURES: Cell counts in SLAV, best-corrected VA, and molecular and clinical diagnoses. RESULTS: We evaluated 105 charts, 68 of which (64.8%) included SLAV data. Numerous (1+ or greater) cells were present in 22 of 68 patients (32.4%), whereas 4 of 68 (5.9%) had rare cells and 42 of 68 (61.8%) had no cells. The average age between patients with cells, no cells, and rare cells did not differ significantly (P = 0.25). The VA averaged 20/124 in patients with cells, 20/143 in patients with no cells, and 20/68 in patients with rare cells (P = 0.70). The most frequent diagnoses with cells included Bardet Biedl syndrome (BBS), Leber congenital amaurosis (LCA), and retinitis pigmentosa. The most frequent diagnoses without cells included congenital stationary night blindness (CSNB), LCA, Stargardt disease, and blue cone monochromacy. DISCUSSION: A nonrandom subset of pediatric retinal degenerations exhibit vitritis. Cells were present in 5 of 5 BBS patients (a progressive degeneration), whereas cells were not detected in any of the 12 patients with CSNB (a stable dysfunction). CONCLUSIONS: Studying vitritis in pediatric retinal degenerations may reveal whether inflammation accompanies progressive vision loss in certain subtypes. Potentially, inflammation could be treated. In addition, SLAV may aid in clinical diagnosis.