Greater ellipsoid zone (EZ) area loss is associated with poorer fixation stability in MacTel, and an EZ area loss threshold of ~1 mm² may serve as an exploratory marker of fixation instability risk, though this threshold requires independent validation.
EZ area loss was significantly associated with reduced fixation stability (P1 index) at both baseline and month 24 in MacTel.
Each 1-mm² increase in EZ area loss doubled the odds of poor fixation stability.
Change in P1 over the study did not differ significantly between the implant and sham groups.
In exploratory analyses stratified by median baseline EZ area loss, sham-treated eyes declined more in fixation stability than implant-treated eyes, although the treatment-by-baseline interaction was not significant.
ROC analysis identified an EZ area loss threshold of 1.075 mm² for unstable fixation.
This study looked at people with macular telangiectasia type 2 (MacTel), a rare eye disease in which light-sensing cells in the center of the retina gradually degenerate. Researchers analyzed data from 212 adults who took part in two large clinical trials. They asked whether the amount of damage seen on retinal scans (loss of a layer called the ellipsoid zone) was related to how steadily a person can hold their gaze on a target, a measure called fixation stability. They found that more ellipsoid zone loss was linked to less stable fixation, both at the start of the trials and two years later. Each additional square millimeter of loss roughly doubled the odds of having poor fixation stability. A threshold of about 1 mm² of loss was identified as a possible marker of unstable fixation, though the authors say this needs to be confirmed in independent groups. Fixation stability did not change significantly differently between eyes receiving the implant and those receiving sham treatment overall. In an exploratory split by baseline damage, sham eyes declined slightly more than implant eyes, but this difference was not statistically confirmed. This research suggests that scan-based measures of retinal damage reflect functional aspects of vision, such as the ability to fixate steadily, in MacTel. This may help clinicians and researchers track disease and design future trials. The findings are from a retrospective analysis, and the threshold is exploratory.
Hatcher K, Aaberg T, Yankey J, Lad E, Coussa R, Kissling R, et al.. (2026). Association Between Ellipsoid Zone Area and Fixation Stability in Macular Telangiectasia Type 2.. Investigative ophthalmology & visual science. https://doi.org/10.1167/iovs.67.12.57