Lamellar holes usually don’t require treatment, but it is important to recognize the eyes that may benefit from vitrectomy.
By Vanessa Caceres; Reviewed by John T. Thompson, MD.
Continuity of the external limiting membrane (ELM)/ellipsoid layers can help to identify eyes with lamellar macular holes that are likely to benefit from surgery, according to John T. Thompson, MD.
Dr. Thompson of Retina Specialists, Baltimore, MD, addressed two types of partial thickness macular holes-lamellar macular holes and pseudomacular holes (also called pseudoholes). It can be hard to tell them apart, he pointed out.
The patient at the top fits the definition of a lamellar macular hole; while the patient at the bottom has biomicroscopic evidence of a pseudomacular hole. The central macular thicknesses are virtually identical (213 microns versus 208 microns). So, are they fundamentally different disease entities?
“You can have two patients with similar central macular thickness,” Dr. Thompson said. “One may fit the definition of a lamellar macular hole and the other a pseudomacular hole.”
Dr. Thompson defined pseudomacular holes as a clinical diagnosis as seen via slit lamp biomicroscopy versus optical coherence tomography (OCT). “Use pseudomacular holes only to describe the biomicroscopic appearance,” he added.
In contrast, a lamellar macular hole is defined by the appearance of the fovea via OCT.
“I’d propose that there is often a steep irregular contour,” Dr. Thompson outlined. “It may have interretinal splitting. Epiretinal membranes are virtually always present, and some eyes have lamellar hole-associated epiretinal proliferation. The natural history of lamellar macular holes is reasonably good, and they don’t tend to progress.”
Dr. Thompson also described a subgroup of patients who have secondary lamellar macular holes. These same patients often have chronic diabetic macular edema or cystoid macular edema and they don’t tend to benefit from vitrectomy.
Although studies of surgical results for the treatment of lamellar macular holes have been positive, the studies tend to be small and are not randomized, Dr. Thompson said.
Dr. Thompson has a study pending publication that includes 64 eyes with lamellar macular holes in patients with decreasing visual acuity. The study will share the results from patients at both 3 months and 1 year.
Dr. Thompson detailed additional differences between lamellar macular holes and macular pseudoholes.
“Spectral-domain OCT is required to diagnose lamellar macular holes,” Dr. Thompson said. “They are characterized as having an abnormally steep foveal contour.
“Almost all are associated with epiretinal membrane (ERM),” he added. “The central fovea may be thick, normal, or thin. Macular pseudoholes are a biomicroscopy diagnosis, and there may or may not be a lamellar hole.”
Most lamellar holes do not require treatment. “Visual acuity, especially if it’s decreasing, should be the primary determinant of whether or not to offer surgery,” Dr. Thompson said.
Eyes with prominent ERM may require surgery because they tend to have less favorable results if they are not treated.
“The most helpful thing in predicting surgical outcome is the continuity of the ELM/ellipsoid layer,” Dr. Thompson concluded. “If they have poor continuity, they are less likely to benefit from surgery.”