Abstract
Purpose :
Among the autosomal recessive retinitis pigmentosa (RP), the PDE6β gene, encoding the β subunit of rod phosphodiesterase accounts for about 4-5% of these conditonsa. Actually, there is an ongoing phase I/II clinical study for PDE6β gene replacement therapy. So, the aims of this study was to investigate the ophtalmological caracteristics of patients with PDE6β gene mutation.
Methods :
Patients, with PDE6β mutation, underwent an opthalmological examination with additional multimodal investigation included color fundus photography (TOPCON TRC-NW6S, OPTOS), fundus autofluorescence (FAF)(Spectralis HRA-OCT, Heidelberg Engineering), static and kinetic visual field (Octopus 900, Haag-streit Inc), microperimetry (Spectral OCT SLO™, OPKO Health) and OCT scans (Spectralis HRA-OCT,Heidelberg Engineering).
Results :
A cohort of 8 patients with PDE6β mutation, ages from 10 to 54 years, has been analysed. All patients presented a rod cone dystrophy with an early onset night blindness. Visual acuity ranged from light perception to 20/20. Six eyes presented lens opacities and four eyes are pseudophakic. The fundus showed an attenuation of the retinal blood vessels, a pallor of the optic disc, a multitude of osteoblasts in the retinal periphery and mid periphery, with or without macular involvement. Heterogeneous pattern of hypo/hyper autofluorescence was observed on FAF exams. Visual field constriction is rapidly severe. Microperimetry responses are extremely reduced. In the OCT scan, half of the patients have a macular edema.
Conclusions :
Retinal dystrophy related to the mutation of the PDE6β gene is a rod cone dystrophy with a rapid alteration of rod function. The current challenge is to try to recognize patients who can participate in trials to provide genetic screenings and to inform them of ongoing clinical trials.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.