Relation of interdigitation zone changes and right-angle vessels in Macular Telangiectasia Type-2 (MacTel)

BackgroundTo study the relation between interdigitation zone (IDZ) and right-angle vessel (RAV) in Macular Telangiectasia Type-2 (MacTel).MethodsA total of 43 eyes of 38 patients with presence of definite RAV on colour fundus photograph (Gass and Blodi-only stage-3) were confirmed on multimodal imaging. The relation of IDZ changes and associated ellipsoid zone (EZ) alterations on spectral-domain optical coherence tomography (OCT) with RAV were studied at baseline and these OCT changes were followed up in 15 eyes over a mean of 3.86 years.ResultsA total of 58 RAVs were found in the 43 eyes and 53/58 (91.3%) RAVs were associated with IDZ alterations in 39 eyes. On follow-up, IDZ attenuation progressed to IDZ loss and subsequent EZ attenuation and loss. A pre-existing IDZ loss was associated with subsequent EZ defect (P = 0.002). In 36 eyes that had OCT angiography, eyes with RAV showed deep capillary plexus telangiectasia in all 36 (100%) eyes and 32/36 (89%) eyes showed IDZ changes with or without EZ loss.ConclusionsIDZ attenuation and/or loss are associated with RAV and may serve as predictor of EZ loss in MacTel.

Automated summary

This study found that changes in the interdigitation zone (IDZ) are associated with right-angle vessel (RAV) and can predict the loss of ellipsoid zone (EZ) in Macular Telangiectasia Type-2 (MacTel).