The hyporeflectability of the ellipsoid zone (EZ) on en face optical coherence tomography (OCT) may represent a novel biomarker for visualizing and quantifying recovery after rhegmatogenous retinal detachment (RRD) repair, according to an investigation published in the American Journal of Ophthalmology. The research team demonstrated that these changes are associated with improvements in visual acuity. The report also shows that EZ recovery persists for years following RRD repair.

Researchers noted that, in the following retinal detachment surgery, the area of EZ hyporeflectivity steadily declines, and that this decline can take many years for those with delayed recoveries and who underwent procedures with longer durations of macula-off.

At the outset, the research team hypothesized that suboptimal functional outcomes after RRD repair may be associated with photoreceptor abnormalities, such as alterations of the EZ, not evident on cross-sectional OCT. 


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This investigation was a post-hoc analysis of the PIVOT trial (ClinicalTrials.gov identifier: NCT01639209). The participants, culled from the PIVOT trials, all underwent macula-off RRD and were followed at 3, 6, 12 and 24 months postoperatively and then annually using en face OCT imaging. The primary outcome was change in the area of EZ hyporeflectivity from 3 to 24 months. The association of change in the area of EZ hyporeflectivity from 3 to 24 months and its association with ETDRS visual acuity over the same time period was also examined.     

The study reviewed 271 images of 61 patients. A total of 46 eyes completed the first 24 months of follow-up and 7 eyes completed the 6 years of extended follow-up. Of the 61 patients, 28 were randomly assigned to pneumatic retinopexy and 33 were randomly assigned to pars plana vitrectomy.

Investigators found that the mean area of hyporeflectivity significantly reduced from 3 to 24 months [-2.98 (95% CI, 1.82-4.13) mm2, P <.0001], with further reductions observed up to 4 years. Linear regression demonstrated an association between change in hyporeflective area and change in ETDRS letter score from 3 to 24 months (β=-0.31, P =.009, R2=14.8%). Linear regression also revealed an association between duration of macula-off and change in hyporeflective area from 3 to 24 months (β=-0.37, P =.018, R2=13.7%).

Limitations of the study include a substantial loss of follow-up after the 24-month visit (57%, n=33), segmentation errors, and low-quality scans. Additionally, researchers say these findings should be considered “hypothesis generating” since this is a post-hoc analysis. 

“This study demonstrates that en face OCT may be a valuable clinical tool for both patients and physicians to visualize the extent of photoreceptor disruption in the early postoperative period and provide a method to assess photoreceptor recovery longitudinally following RRD repair,” according to the researchers. “This study also suggests that duration of macula-off detachment to intervention impacts the speed of photoreceptor recovery, which can continue over a period of at least 4 years and likely longer.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of author’s disclosures. 

Reference

Figueiredo N, Sarraf D, Gunnemann F, et al. Longitudinal assessment of ellipsoid zone recovery using en face optical coherence tomography after retinal detachment repair. Am J Ophthalmol. Published online October 22, 2021. doi:10.1016/j.ajo.2021.10.012