Surgical technique for macular holes
Inverted ILM peeling effective at closing larger macular holes.
An inverted internal limiting membrane flap technique for the treatment of large macular holes offered a higher incidence of anatomical closure compared with the standard internal limiting membrane peel, according to a study presented at the 9th EURETINA Winter Meeting in Prague.
“While we found similar closure rates and visual acuity outcomes with smaller holes, larger macular holes over 400 microns achieved a better closure rate with the inverted flap technique. The visual acuity outcomes depend on the diameter of the macular hole and on the preoperative visual acuity,” said Eva Klofacova MD, Charles University and General University Hospital in Prague, Czech Republic.
Her retrospective study included 50 eyes with idiopathic macular holes that were randomly assigned into two groups. Group 1 patients underwent standard internal limiting membrane (ILM) peel, and group 2 patients underwent inverted ILM flap technique. The researchers evaluated visual acuity and postoperative macular hole closure as the primary outcome measures.
In smaller holes of less than 400 microns, a closure rate of 100% was achieved in both groups with very similar visual acuity outcomes, said Dr Klofacova. In macular holes larger than 400 microns, a closure rate of 100% was achieved with the inverted flap approach compared to 95% for standard ILM peeling.
Macular hole surgery has evolved greatly from the initial studies of Wendel in 1991 when closure rates were in the region of 73%, noted Dr Klofacova.
“Since 1996, ILM peeling has greatly improved the anatomical success rate of the surgery up to around 90%. In some instances, however, this standard procedure does not work so well, including cases of macular holes of large diameter, long-standing macular holes and macular holes secondary to ocular trauma, high myopia and uveitis. Until recently, there was no efficient surgical procedure for these cases,” she said.
Further advances in idiopathic macular hole surgery came with the inverted ILM flap technique by Zofia Michalewska and colleagues in 2010, which involved covering the macular hole with an inverted remnant of ILM that is left attached to the margins of the macular hole after ILM peeling.
“The ILM functions as a scaffold for proliferation and migration of Müller cells, which can induce gliosis and contribute to closure of the hole. The ILM flap may also provide an environment in which photoreceptors can assume new positions in direct proximity to the fovea and improves postoperative visual acuity,” she concluded.