Association of Deep Retinal Capillary Plexus ischemia with Inner Segment/Outer Segment Disruption in Diabetic Macular Ischemia

Abstract

ABSTRACT Background: Diabetic macular ischemia (DMI) is an important cause of visual impairment in patients with diabetic retinopathy. In some patients, it may lead to irreversible visual loss. Purpose: The aim of the work was to assess the presence of outer retinal structural changes at the level of inner segment /outer segment (IS/OS) in relation to macular capillary non-perfusion at the level of deep capillary plexus (DCP) in diabetic retinopathy (DR). Patients and Methods: A prospective observational study was carried on 250 eyes of 125 patients. They underwent scanning using Optical coherence tomography/ Optical coherence tomography angiography (OCT/OCTA) simultaneously. Results: 250 of 125 diabetic patients were classified according to presence of capillary non perfusion (NP), into two groups (ischemic- non ischemic). The incidence of DCP NP was 100% in eyes with DMI while the incidence of superficial capillary plexus (SCP) NP was 71% . The incidence of foveal avascular zone (FAZ) irregularity, inner segment /outer segment (IS/OS) disruption was 100% and 95% respectively among eyes with DMI. DCP NP was more than SCP NP in eyes with FAZ irregularity, which make it the possible main cause of the structural changes in the retina during ischemia. There was a strong association between the presence of IS/OS disruption with duration, severity of DR and BCVA. Conclusion: It could be concluded thatIS/OS disruption is associated with ischemia at DCP. It could be considered a reliable OCT findings that indicate an underling DMI and their presence can affect visual prognosis.