Macular retinal vessel density assessment of the superficial, deep plexus and choriocapillaris in patients with retinitis pigmentosa and in healthy individuals using SS-OCT Angiography

Abstract

Purpose : To describe the vascular differences between patients affected by retinitis pigmentosa (RP) and healthy controls using optical coherence tomography angiography (OCTA)

Methods : Twelve eyes of 12 patients with retinitis pigmentosa and 12 eyes of 12 healthy subjects presenting at the Department of Ophthalmology, Manises University Hospital in Valencia, were prospectively included in this study. Inclusion criteria were: diagnosis of Retinosis pigmentosa (RP), clear ocular media, adequate pupillary dilation, and stable fixation. The main outcome was identification of OCTA diferences between RP and healthy patients in superficial capillary plexus (SCP), deep capillary plexus (DCP), and the choriocapillaris (CC). OCT-A was performed using Swept Source DRI OCT Triton. The macula was imaged with a 6x6mm² scan. The OCTARA (OCT-angiography ratio analysis), image processing algorithm was applied at 100.000 A scans per second coupled with the SMARTtrack eye tracking system. We use the vascular density analysis system provided by the device, which includes two concentric circles, of 1mm and 3 mm in diameter, centering it in the foveal avascular zone (FAZ)

Results : 24 patients (24 eyes) were recruited. Mean age was 47.1±13.4 years in patients with retinosis and 55±16.4 in healthy patients (HP). Vessel density analysis disclosed a statistical significant difference in the SCP (183.41±11.45 vs 194.63±10.54; p=0.02), in the DCP (187.17±12.02 vs 204.57±9.34; p=0.0006) and at the level of the CC (246.42±7.68 vs 259.69±6.37; p=0.0001) between the patients and the controls.
The whole retinal vascular density from the superficial capilar plexus to choriocapillaris, was significantly lower in the retinitis pigmentosa group when compared with the control group (191.89±12.75 vs 206.56±12.85; p=0.01)

Conclusions : Patients with retinitis pigmentosa show a decreased macular perfusion compared with healthy subjects. Most of the vascular impairment in patients affected by RP are localised in the DCP. In the parafoveal zone we found vascular impairment in SCP, DCP and CC, being more prononced at the DCP. OCTA microvascular imaging análisis may be useful in the diagnosis and monitoring of disease progression in RP patients

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.