Reformation of ellipsoid zone in en face OCT imaging in patients with solar maculopathy and laser injuries

Abstract

Purpose : To analyze multimodal imaging findings including spectral domain en face (transverse) optical coherence tomography scanning (SD OCT) in patients with solar maculopathy and laser injuries, focusing on the possible regeneration of photoreceptors. We performed a retrospective observational study to analyze the changes of the ellipsoid zone and visual acuity during follow-up.

Methods : Analysis of 4 patients (5 eyes) with solar maculopathy and 2 patients (3 eyes) with laser injuries who underwent a comprehensive ocular examination including en face (transverse) SD OCT imaging at the initial visit and during follow-up (3 males, 3 females, age 19 – 67 years). SD OCT data were exported and the ellipsoid zone was segmented. The total area including greatest linear diameter of the size of ellipsoid zone loss were measured manually with the built-in caliper tool. Data were analyzed with SPSS. To guarantee linearity, the number of days, the ellipsoid zone defect and visual acuity outcomes were transformed logarithmically. Linear Mixed Models approach was taken for investigations.

Results : En face OCT scans at the level of the ellipsoid zone revealed a well demarcated hyporeflective lesion surrounded by a hyperreflective border. No abnormalities were noted at the level of the choroid. All patients showed signs of regeneration. Mean ellipsoid zone defect reduced from 0.12mm² (range: 0.05-0.32) at baseline to 0.07 mm² (range: 0.01-0.22) at last follow-up (p=0.00, average follow-up time: 240 days). Change of BCVA (logMAR) from 0.25 ± 0.27 at initial presentation to 0.14 ± 0.26 at last follow-up was not significant (p=0.84). One patient was lost to follow-up after initial visit and was not included in the analysis.

Conclusions : En face OCT imaging clearly delineated the area of loss of the ellipsoid zone in patients with solar maculopathy and laser injuries. There is a significant reformation of the ellipsoid zone, suggesting photoreceptor recovery. However, there was a lack of significant improvement of BVCA, which might be due to the good BCVA at baseline.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

En face SD OCT imaging of a patient with foveal laser burn. Note the gradual ellipsoid zone recovery from baseline (left) to the follow-up at month 8 (right).

 

Defect area of ellipsoid zone versus days after incident of all patients using logarithmic transformation for linear regression.