Epiretinal Membrane With DRIL Worsens Intraoperative Risk

Epiretinal membrane with disorganization of retinal inner layers (DRIL) can worsen outcomes for patients undergoing pars plana vitrectomy with membrane peel, according to research published in BMC Ophthalmology. Patients with idiopathic epiretinal membrane (IERM) with DRIL, as compared with those without DRIL, have more intraoperative adverse events and limited benefit from epiretinal membrane peeling surgery, the study shows.

Researchers retrospectively analyzed data from 74 eyes of 74 patients with idiopathic epiretinal membrane with DRIL and without (mean age, 65.88±5.66 years; 53% women and 47% men) treated by pars plana vitrectomy with peeling of the internal limiting membrane and combined cataract surgery between January 2017 and January 2020. 

The participants were divided into 3 groups based on whether they experienced superficial hemorrhaging during membrane peeling. Patients without bleeding were placed in group A (n=35; mean age, 64.80±5.50 years), patients with bleeding in the area outside the center of the macula with a diameter of 3 mm were placed in group B (n=22; mean age, 67.53±5.02 years), and patients with bleeding in the area within the center of the macula with a diameter of 3 mm were placed in group C (n=17; mean age, 65.81±6.27 years). Preoperative optical coherence tomography (OCT) revealed epiretinal membrane with DRIL in 36 patients. 

At baseline, all patients underwent OCT and preoperative examinations. The main outcome measures were correlation between DRIL and superficial hemorrhage in membrane peeling, and postoperative best-corrected visual acuity (BCVA) and OCT angiography (OCT-A) outcomes. Patients had follow-up examinations including OCT at 1, 3, 6 and 12 months postoperatively, and OCT-A was performed at 12 months postoperatively.

The groups showed no significant difference in preoperative BCVA, with measures ranging from 0.59 to 0.65 logMAR (P =.267).

Rates of epiretinal membrane with DRIL and mean postoperative BCVA were significantly different between the groups at all postoperative time points (P <.001). It also revealed that superficial hemorrhage was significantly correlated with poor postoperative BCVA (r=0.698; P =.000).

From OCT-A, the FD-300 value (P =.001) and deep capillary plexus measures were lower in all parafoveal regions in eyes epiretinal membrane with DRIL

 than those without DRIL (superior: P =.001; inferior: P =.002; nasal: P =.014; temporal: P =.004). A multiple linear regression analysis showed a significant relationship between FD-300 and postoperative BCVA (t=-2.807; P =.011).

“The possible pathological mechanism is that the mechanical traction force of IERM not only destroys the normal macular capillary distribution and also is accompanied by various nerve cell damage, macular capillary ischemia and microcirculation destruction, resulting in abnormal distribution and exudation of blood vessels, extracellular fluid accumulation in the inner retinal space, and finally the inner retinal layer structure disorder,” according to the researchers. “Macular vascular abnormalities cause bleeding during IERM surgery, and hemorrhagic injury further aggravate the destruction of macular microcirculation, which is responsible for the persistence of DRIL and poor postoperative visual recovery.”

Limitations of the study included the retrospective design and loss of some patients to follow up.