Ellipsoid Zone recovery in Macular Telangiectasia Type 2 (MacTel)

Purpose: To describe imaging features of Macular Telangiectasia Type 2 (MacTel) eyes experiencing ellipsoid zone (EZ) recovery. Methods: MacTel patients with EZ-recovery were identified from the Natural History and Observational Registry Study and underwent retinal imaging including optical coherence tomography (OCT) and fundus photography. Eyes were graded according to the classification system by Gass and Blodi, the EZ-loss area was measured and OCT parameters were assessed by two independent readers. Parameters were analysed for their presence prior to EZ-recovery. Results: Twenty-four eyes of 21 patients (12 female, 57.12%; mean age 68 ± 8.54 years) were included in this study and followed for 21.25 ± 12.79 months. At baseline, mean EZ-loss area was 0.036 ± 0.028 mm 2 and 0.01 ± 0.013 mm 2 at follow-up (p<0.001). A persisting external limiting membrane overlaying the EZ-loss was detected in 16 cases (66%) and hyperreflective changes in the outer retina were present in 18 cases (75%). Best corrected visual acuity was 0.23 (20/32) ± 0.33 logMar at baseline and 0.34 (20/40) ± 0.34 logMar at follow up (p=0.3). Conclusion: Distinct OCT features precede ellipsoid zone recovery in MacTel and warrant further studies investigating implications for patient care and clinical trial interpretation.