Drusen of the Optic Disk Head in Retinitis Pigmentosa: HRT, OCT Findings Related to Visual Field Damage

Abstract

Abstract: : Purpose:To determine in patients with retinitis pigmentosa the incidence , clinical findings and impact on vision of optic nerve head drusen and to perform an objective analysys of them with HRT, OCT related to visual field data.Methods: we detected on a large population of 1200 rp patients clinically followed in the department of inherited retinal diseases of the University "La Sapienza" of Rome. were diagnosed 46 patients (92 eyes) with associated RP and Optic disk drusen. The overall incidence on the our whole sample was documented with FA. HRT and Optical Coherence Tomography were performed to evaluate single case and clinical aspects of the drusen. Visual field was performed with humphrey perimeter. Results: Even if a wide number of data were presented in the literature ranging from 1.4% to 80% our sample was of 3.6%. HRT was useful to follow the surface of optic nerve head drusen and follow them through the time while OCT data were able to demonstrate the content of drusen sometimes optically empty, while specially in deep ones, with inhomogeneous material deriving from the optic nerve fibers. Visual defects correlated to presence of Optic nerve head drusen were detected in 56% of the patients. Moreover OCT measurements showed that Nerve Fiber Layer was significantly thinner than other RP data previously reported. Conclusions: Observed incidence in our group of RP patients was within the range reported in literature when a substantial number of RP patients was examined. Mainly HRT and OCT seems to contribute to a better differential diagnosis with other forms of optic disk swelling also recognizable in natural history of the disease but due to optic disk edema or papillitis.

Keywords: clinical (human) or epidemiologic studies: pre • optic disc • retinal degenerations: hereditary