Progression to surgery for ERMs with good vision

August 29, 2018
Xuejing (Jing) Chen, MD
Xuejing (Jing) Chen, MD

Editor's note: Ophthalmology Times is pleased to recognize Xuejing (Jing) Chen, MD, vitreoretinal fellow, Tufts Medical Center, Ophthalmic Consultants of Boston, as the fifth-place honoree of the inaugural Ophthalmology Times Research Scholar Honoree Program. Dr. Chen’s abstract is featured here. The Ophthalmology Times Research Scholar Honoree Program is dedicated to the education of retina fellows and residents by providing a unique opportunity for fellows/ residents to share notable research and challenging cases with their peers and mentors. The program is supported by unrestricted grants from Regeneron Pharmaceuticals and Carl Zeiss Meditec Inc. To learn more about the program, go to OphthalmologyTimes.com/2017RSH

Purpose

In the United States, epiretinal membranes (ERMs) affect 30 million adults ages 43 to 86 years.1

The management for ERMs is observation for eyes with tolerable symptoms and surgical membrane peel for eyes with intolerable symptoms. Traditionally, surgery was reserved for eyes with vision 20/50 and worse or with absolutely intolerable symptoms, and patients with better vision were suggested to monitor. More recently, reports on surgery for symptomatic eyes with vision better than 20/50 or 20/60 have indicated favorable outcomes.2–5

These reports suggest that although eyes with good baseline vision have a smaller vision gain from preoperative to postoperative than eyes with worse baseline vision, the eyes with good vision tend to have a better absolute postoperative result, suggesting that advanced ERMs may contain a certain level irreversible vision loss.

For patients with good vision who can currently tolerable their symptoms, a common and important question is the risk of ERM progression. If progression to poor vision is certain within a short time period, then it behooves them to get surgery early and achieve a better absolute postoperative vision. However, if progression to poor vision or intolerable symptoms is prolonged, then the patient may choose to monitor as many are already of advanced age.

Few studies on the natural histories of ERMs exist. The Blue Mountain Study done in Australia showed that in ERM 1/3 progressed, 1/3 regressed, and 1/3 remained stable at 5 years.6

A study by Byon et al.,7 looked at 62 eyes with good vision 20/40 or better and showed that less than 10% had a decrease in vision while 6.5% had an improvement in vision at 2 years. Our study elaborates on these works to look at the progression to surgery for eyes with good vision.

Methods

This is a retrospective, consecutive case series of all patients with newly diagnosed idiopathic ERMs referred to the Retina Service at the Ophthalmic Consultants of Boston between January 2009 and May 2012. Included eyes had 20/40 or better visual acuity without intolerable symptoms.

Eyes with baseline lamellar holes, baseline vitreomacular traction, secondary ERMs (e.g., from retinal detachment, vascular occlusions, uveitis), and the absence of baseline or final optical coherence tomography (OCT) were excluded.

Surgical membrane peeling was typically offered when vision worsened to 20/50 or beyond and/or when patients were unable to tolerate symptoms attributable to the ERM. Primary outcome measure was progression to surgery.

All eligible eyes were categorized by baseline OCT morphology into normal, mild or incomplete, and complete loss of foveal contour.

For the normal foveal contour category, signs of ERM presence must be noted on OCT including hyper-reflectivity overlying the macula or retinal corrugations, otherwise, the eye was excluded. Visual acuities were averaged through conversion to LogMar. Kaplan Meier survival curves for progression to surgical membrane peel were calculated.

Results and discussion

In all, 201 eyes from 170 patients were included in the study. Age averaged 67 years; 28.9% of eyes had normal, 17.4% had mild loss, and 44.3% had complete loss of foveal contour. Average baseline visual acuity ranged from 20/28. Eyes with complete loss of foveal contour had statistically worse baseline visual acuity compared with eyes with normal and mild loss of foveal contour (p = 0.0001).

Kaplan Meier survival curves show that 13% of ERMs with good vision progressed to surgery at 7 years.

Additionally, there appears to be a point in the curve at 4 years where eyes that had not progressed by this point, remain stable without surgery to 7 years.

When categorized by baseline OCT morphology, only 5% of eyes with normal foveal contour progressed to surgery by 5.5 years, whereas 17% of eyes with incomplete and 16% of eyes with complete loss of foveal contour progressed to surgery at 6 and 7 years, respectively.

Additionally, while the final rate of progression is similar between the latter two groups, eyes with complete loss of foveal contour appears to have a more rapid initial rate of progression that eventually converged with the incomplete loss of the foveal contour group.

Next, we looked at the survival curves categorized by the presence or absence of symptoms typically correlated with ERMs, such as blurry vision, metamorphopsia, and diplopia. A greater number of initially symptomatic eyes (15%) progressed to surgery compared with asymptomatic eyes (9%) at 7 years.

However, this visual trend was not statistically significant (p = 0.38).

Our study is limited by its retrospective nature. The best available visual acuity was used as opposed to the best-corrected visual acuity.

Additionally, these are all eyes referred to a retina practice which may be a more selective population of eyes, presumably more advanced ERMs, than general ophthalmology practices, which would lead to an over-estimate of the progression rate.

Furthermore, most patients in this cohort deferred surgery until 20/50 or worse vision with a few opting for surgery with better vision but significant metamorphopsia. This preference trend may vary by patient population. In the absence of a more rigorous prospective study, our report offers data to this common clinical question posed by patients.

Conclusions

In summary, 13% of ERMs referred to a retina practice with good vision became sufficiently symptomatic to consider surgery at 7 years. The progression of ERMs with good vision is associated with baseline OCT morphology, where no eyes with normal foveal contours progressed to surgery at 7 years and eyes with complete loss of foveal contour progressed faster than those with incomplete loss of foveal contour but the curves converge at 4 years. Eyes with symptoms did not have a statistically different progression to surgery as eyes without symptoms.

The purpose of this study is not to advocate for early or late surgery for ERMs with good vision, but rather to produce statistics to help counsel patients and allow them to make an informed decision with their retina specialists.