ABSTRACT
Purpose: This study reports the presentation of two families with gyrate atrophy (GA). The aim of this study was to characterize the potential effect of therapeutic regimens on macular edema.
Methods: Two unrelated patients with GA were studied for the potential effect of low protein diet (≤ 0.8 g/kg/d), and oral administration of pyridoxine (500 mg/day), on serum ornithine levels, best corrected visual acuity (BCVA), slit-lamp, OCT, and auto-fluorescence findings. Blood samples for DNA, mRNA, and exons of the OAT gene were screened for mutations and splicing effect when relevant.
Results: At presentation, both patients manifested typical ophthalmic features of GA including cystoid macular edema (CME). One patient also exhibited optic nerve head hamartoma. Following treatment ornithine levels have lessened, BCVA improved, and central macular thickness (CMT) markedly decreased in all four studied eyes. The molecular pathologic features included a novel splice site mutation (c.900+1G>A).
Conclusions: We have identified a novel mutation and two formerly described mutations in patients with GA. Of them, one patient comprised an unusual phenotype including bilateral astrocytic hamartomas. We have recognized for the first time improvement in CME following treatment with low protein intake and pyridoxine supplement. This finding may have significance in the understanding of treatment options for macular edema regardless of underlying etiology.
Acknowledgments
The authors are grateful to all family members for their participation in this study. This work was performed in partial fulfillment of the requirements for a MSc degree by Chen Weiner at the Sackler Faculty of Medicine, Tel Aviv University, Israel.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.
Funding
This study was supported by the Clair and Amedee Maratier Institute for the Study of Blindness and Visual Disorders, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. This work was also supported in part by the Consortium for Mapping Retinal Degeneration Disorders in Israel; funded by the Foundation for Fighting Blindness (FFB) Grant no. BR-GE-0214-0639-TECH, and the “Lirot” Association – The Israeli research association for eye health and blindness prevention (http://lirot.org).