Macular Edema Common After Epiretinal Membrane, Macular Hole Procedures

Postsurgical macular edema is both clinically relevant and common in patients with idiopathic epiretinal membrane and full thickness macular hole, according to research results published in Eye and Vision. 

Researchers conducted a retrospective, longitudinal analysis in order to estimate the rate postsurgical macular edema following vitrectomy for idiopathic epiretinal membrane and full thickness macular hole. Participants were recruited from a single institution and diagnosed via biomicroscopy and spectral-domain optical coherence tomography (SD-OCT). 

Investigators reviewed electronic medical records from patients with idiopathic epiretinal membrane and full thickness macular hole between June and December 2018. All participants underwent a preoperative ophthalmological evaluation as well as standard postoperative evaluations at 1 week and month 1, 3, and 6. 

A total of 101 eyes from 101 consecutive patients were initially enrolled; after exclusion, 71 eyes from 71 patients remained (54.9% women; mean age, 71±7 years). In total, 69% of eyes had idiopathic epiretinal membrane and 31% had full thickness macular hole; average macular hole diameter was 328±75 µm. 

Overall, 20 eyes with full thickness macular holes (FTMH) received endotamponade with 10% SF6. Two eyes with small FTMHs were closed under air. In 7 eyes with idiopathic epiretinal membrane, fluid air exchange took place at the end of surgery due to an intraoperative finding of peripheral holes or iatrogenic retinal tear (6 eyes and 1 eye) without detachment. 

A combined phacovitrectomy was performed in 69% of cases. The remaining eyes (31%) required an isolated vitreoretinal procedure. Of these 22 eyes, 59% previously underwent an uncomplicated cataract extraction in the 32.4±10 months prior. 

Distance best corrected visual acuity (BCVA) significantly improved over the follow-up period in both groups. Those with idiopathic epiretinal membrane at baseline had a higher BCVA vs those with full thickness macular hole, although no statistically significant between-group differences were noted. In this same group, BCVA of eyes affected by postsurgical macular edema was, at the 6-month follow-up, “averagely deteriorated” and statistically similar to presurgical values. 

Trends were similar in the full thickness macular hole group; BCVA of eyes that developed postsurgical macular edema did not improve after surgery. 

After surgery, central foveal thickness was significantly decreased in those with idiopathic epiretinal membrane. These patients also had thicker fovea at baseline compared with the full thickness macular hole group. 

Global frequency of postsurgical macular edema was 26.7% and was similar between both groups (27.3% vs 26.5%). In the idiopathic epiretinal membrane group, postsurgical macular edema rates were significantly higher among those in stage 4 (57.1%) vs those in lower stages (14.3%). No participants in stage 1 developed edema after surgery. 

The overall postsurgical macular edema rate in the FTMH group was not influenced by adjunct phacoemulsification to pars plana vitrectomy. Edema proportion in combined surgery was 26.7% and 28.6% with the isolated vitreoretinal procedure. Despite the “slightly superior” rate of PSME in the idiopathic epiretinal membrane edema group vs isolated vitreoretinal procedures, statistical significance was not reached. 

All 19 eyes that developed postsurgical macular edema received initial topical therapy; 12 eyes were treated for 4 weeks and 4 eyes required drops tapered over a longer period of up to 10 weeks. Two eyes received intravitreal triamcinolone, and 1 eye was scheduled for a dexamethasone implant. 

Study limitations include the underpowered nature to detect relative differences compared with higher stage holes, the retrospective study design, and a lack of electrophysiology. 

“Postsurgical macular edema remains a clinically relevant and frequent event after surgery for [idiopathic epiretinal membrane] and FTMH,” according to the researchers. “Patients with stage 4 [idiopathic epiretinal membrane] have an 8-fold higher likelihood of developing [postsurgical macular edema] in a 6-month postsurgical period compared with [stages 1 through 3], especially when combined with cataract extraction.” 

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures. 

Reference

Iuliano L, de Gresy GC, Fogliato G, Corbelli E, Bandello F, Codenotti M. Increased risk of postsurgical macula edema in high stage idiopathic epiretinal membranes. Eye Vis. 2021;8(1):29. doi:10.1186/s40662-021-00252-4