Rates of Decline in Regions of the Visual Field Defined by Frequency-Domain Optical Coherence Tomography in Patients with RPGR-Mediated X-Linked Retinitis Pigmentosa

Purpose: To determine whether annual decline in visual field sensitivity is greater in the transition zone at the edge of the frequency-domain optical coherence tomography (fdOCT) inner segment ellipsoid zone (EZ) than at other locations in the visual field. Design: Prospective, longitudinal, observational study. Participants: Forty-four patients with X-linked retinitis pigmentosa (XLRP) resulting from a mutation in the RPGR gene. Methods: Static perimetric fields (Humphrey 30-2; Carl Zeiss Meditec, Dublin, CA) were obtained annually for 4 years. Beginning with year 2, fdOCT scans were obtained annually with a Heidelberg Spectralis HRA + OCT (Heidelberg Engineering, Heidelberg, Germany). Main Outcome Measures: The rate of visual field decline at locations near the edge of the EZ compared with the rates for the macula and in the mid periphery. Results: Sensitivity just inside and outside the edge of the EZ declined at rates of 0.84 and 0.92 dB/year, respectively. By comparison, average sensitivity in the macula and mid periphery declined by 0.38 and 0.61 dB/year, respectively. Conclusions: The edge of the EZ in each patient with XLRP indicates a transition zone between relatively healthy and relatively degenerate retina. The annual loss of sensitivity in the transition zone is more rapid than it is elsewhere in the retina. (C) 2015 by the American Academy of Ophthalmology.