Purpose: To determine the progression rate and the variability of rod and cone sensitivities in patients with X-linked retinitis pigmentosa (XLRP) caused by mutations in ORF15-RPGR. Methods: ORF15-RPGR-XLRP patients (n = 15) were studied prospectively over 2 years with static perimetry sampling the visual field under dark-adapted and light-adapted conditions on a 12° square grid covering 168° width and 84° height. Natural history of rod and cone sensitivity loss and test-retest variability were estimated. Data were analyzed pointwise as well as averaged across small regions of neighboring loci of approximately 80 mm2 (900 deg2) in size representing the likely extent of localized gene therapy injections. Results: Retinal loci with mild to moderate loss of sensitivity tended to be in the mid- to far-peripheral retina in most patients. When averaged across small regions, dark-adapted rod vision progressed at an average of 2 dB per year with a coefficient of repeatability (CR) of 6.3 dB, and light-adapted cone vision with white stimulus progressed at an average of 0.9 dB per year with a CR of 3.8 dB. For an average patient enrolled in an early-phase clinical trial, significant (α = 0.05) progression would be predicted to occur with 80% power in 4.5 years for rod vision and 6.1 years for cone vision. Localization of regions in the temporal hemifield and grouping of results from multiple patients would permit trial designs of shorter duration. Conclusions: Measurement of rod sensitivity under dark-adapted conditions averaged across a small region showed the greatest potential for detectability of progression in the shortest period.
Purpose: To determine the progression rate and the variability of rod and cone sensitivities in patients with X-linked retinitis pigmentosa (XLRP) caused by mutations in ORF15-RPGR. Methods:ORF15-RPGR-XLRP patients (n = 15) were studied prospectively over 2 years with static perimetry sampling the visual field under dark-adapted and light-adapted conditions on a 12° square grid covering 168° width and 84° height. Natural history of rod and cone sensitivity loss and test-retest variability were estimated. Data were analyzed pointwise as well as averaged across small regions of neighboring loci of approximately 80 mm2 (900 deg2) in size representing the likely extent of localized gene therapy injections. Results: Retinal loci with mild to moderate loss of sensitivity tended to be in the mid- to far-peripheral retina in most patients. When averaged across small regions, dark-adapted rod vision progressed at an average of 2 dB per year with a coefficient of repeatability (CR) of 6.3 dB, and light-adapted cone vision with white stimulus progressed at an average of 0.9 dB per year with a CR of 3.8 dB. For an average patient enrolled in an early-phase clinical trial, significant (α = 0.05) progression would be predicted to occur with 80% power in 4.5 years for rod vision and 6.1 years for cone vision. Localization of regions in the temporal hemifield and grouping of results from multiple patients would permit trial designs of shorter duration. Conclusions: Measurement of rod sensitivity under dark-adapted conditions averaged across a small region showed the greatest potential for detectability of progression in the shortest period.
Authors: Artur V Cideciyan; Samuel G Jacobson; Alejandro J Roman; Alexander Sumaroka; Vivian Wu; Jason Charng; Brianna Lisi; Malgorzata Swider; Gustavo D Aguirre; William A Beltran Journal: Sci Rep Date: 2020-07-28 Impact factor: 4.379
Authors: Lea D Bennett; Georgiana Metz; Martin Klein; Kirsten G Locke; Areeba Khwaja; David G Birch Journal: Invest Ophthalmol Vis Sci Date: 2019-03-01 Impact factor: 4.799
Authors: Alexander Sumaroka; Alexandra V Garafalo; Evelyn P Semenov; Rebecca Sheplock; Arun K Krishnan; Alejandro J Roman; Samuel G Jacobson; Artur V Cideciyan Journal: Invest Ophthalmol Vis Sci Date: 2019-06-03 Impact factor: 4.799
Authors: Alexandra V Garafalo; Artur V Cideciyan; Elise Héon; Rebecca Sheplock; Alexander Pearson; Caberry WeiYang Yu; Alexander Sumaroka; Gustavo D Aguirre; Samuel G Jacobson Journal: Prog Retin Eye Res Date: 2019-12-30 Impact factor: 21.198