Multimodal Imaging Including Optical Coherence Tomography in Pediatric RP2 Patients
Robert B. Hufnagel, MD, PhD; Wadih M. Zein, MD; Laryssa A. Huryn, MD; Amy Turriff, MS; Delphine Blain, MS; Brian P. Brooks, MD, PhD
National Eye Institute – National Institutes of Health
Bethesda, MD, USA
Introduction: The RP2 gene is thought to be the underlying cause of disease in 10-20% of patients with X-linked retinitis pigmentosa. Jayasundera et al. (1) reported the most recent cohort study with clinical phenotype description in 2010. To date, an RP2 cohort study employing Optical Coherence Tomography (OCT) and multimodal imaging has not been performed.
Methods: Five pediatric patients with childhood retinal degeneration enrolled in a National Eye Institute (NEI) protocol to characterize and understand genes involved in eye disease (06-EI-0236). They were confirmed to have mutations of the RP2 gene as the underlying disease cause. Demographic information, visual function (including acuity, fields, and color vision), and multimodal imaging including OCT are summarized herein.
Results: The five RP2 patients (age range 5-15, mean 11.0, SD 3.8 yrs) had a mean visual acuity was 0.18 OD and 0.25 OS (SD 0.09 OD and 0.11 OS). Mean central macular thickness on spectral-domain OCT was 156.5um OD and 148.3um OS (SD 28.1um OD and 18.5um OS). Fundus autofluorescence images are presented.
Discussion: Early macular involvement and high myopia, as noted in the literature, are confirmed in our cohort. Significant macular thinning noted by OCT might present a challenge for therapies necessitating subretinal injection.
Conclusion: Studies characterizing the natural history of RP2 disease in pediatric patients are required for potential therapeutic clinical trials involving gene replacement therapy.
References: Jayasundera T, Branham KE, Othman M, Rhoades WR, Karoukis AJ, Khanna H, Swaroop A, Heckenlively JR. RP2 phenotype and pathogenetic correlations in X-linked retinitis pigmentosa. Arch Ophthalmol. 2010 Jul;128(7):915-23.