OPTICAL COHERENCE TOMOGRAPHY IN RETINITIS PIGMENTOSA Reproducibility and Capacity to Detect Macular and Retinal Nerve Fiber Layer Thickness Alterations ELENA GARCIA-MARTIN, PHD,*† ISABEL PINILLA, PROF,†‡ EVA SANCHO, BA,* CARMEN ALMARCEGUI, MD,§ ISABEL DOLZ, MD,§ DIEGO RODRIGUEZ-MENA, MD,§ ISABEL FUERTES, PHD,* NICOLAS CUENCA, PROF¶ Purpose: To evaluate the ability of time-domain and Fourier-domain optical coherence tomographies (OCTs) to detect macular and retinal nerve fiber layer atrophies in retinitis pigmentosa (RP). To test the intrasession reproducibility using three OCT instruments (Stratus, Cirrus, and Spectralis). Methods: Eighty eyes of 80 subjects (40 RP patients and 40 healthy subjects) underwent a visual field examination, together with 3 macular scans and 3 optic disk evaluations by the same experienced examiner using 3 OCT instruments. Differences between healthy and RP eyes were compared. The relationship between measurements with each OCT instrument was evaluated. Repeatability was studied by intraclass correlation coefficients and coefficients of variation. Results: Macular and retinal nerve fiber layer atrophies were detected in RP patients for all OCT parameters. Macular and retinal nerve fiber layer thicknesses, as determined by the different OCTs, were correlated but significantly different (P , 0.05). Reproducibility was moderately high using Stratus, good using Cirrus and Spectralis, and excellent using the Tru-track technology of Spectralis. In RP eyes, measurements showed higher variability compared with healthy eyes. Conclusion: Differences in thickness measurements existed between OCT instruments, despite there being a high degree of correlation. Fourier-domain OCT can be considered a valid and repeatability technique to detect retinal nerve fiber layer atrophy in RP patients. RETINA 32:1581–1591, 2012 R etinitis pigmentosa (RP) refers to a heterogeneous group of genetic retinal disorders that primarily affect the rod and cone photoreceptors and the retinal pigment epithelial cells. Retinitis pigmentosa is a major cause of blindness and the most commonly inherited form of severe retinal degeneration, with a prevalence of approximately 1 in every 3,500 births. Several genes have been found to be associated with RP, which can be inherited as an X-linked, autosomal dominant, or autosomal recessive condition. Cases with no known family history, referred to as RP simplex, can also occur. 1,2 Optical coherence tomography (OCT) is a well- recognized method of analyzing the in vivo retinal architecture. Optical coherence tomography has been used in diagnosing and following-up retinal diseases, and it has been proven particularly useful and accurate From the *Department of Ophthalmology, Miguel Servet Univer- sity Hospital, Zaragoza, Spain; †Aragones Institute of Health Scien- ces, Zaragoza, Spain; ‡Department of Ophthalmology, Lozano Blesa University Hospital, Zaragoza, Spain; §Department of Neurophysi- ology, Miguel Servet University Hospital, Zaragoza, Spain; and ¶Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain. Supported in part by the Instituto de Salud Carlos III grant PI080976, FIS PS09/01854 (E.G-.M., I.P.) and RETICS RD07/ 0062/0012 (I.P., N.C.). The authors report no financial or proprietary conflict of interest. Reprint requests: Elena Garcia-Martin, PhD, Hospital Uni- versitario Miguel Servet, C/Padre Arrupe, Consultas externas de Oftalmología, 50009-Zaragoza, Spain; e-mail: egmvivax@ yahoo.com 1581