Specialist explains approaches for a variety of cases encountered during procedure
This article was reviewed by Steven T. Charles, MD.
Differences in surgeon preferences and perceptions may make some issues in vitreomacular surgery seem controversial, according to Steven T. Charles, MD, who addressed topics in macular surgery and shared his evidence- and expert-based insights for achieving best outcomes.
Outlining his indications for internal limiting membrane (ILM) peeling, Charles said he does it in all cases involving lamellar or full-thickness macular holes, epimacular membranes, vitreomacular schisis, and vitreomacular traction, including diabetic macular edema. He also performs ILM peeling in vitreomacular traction syndrome, eyes with macular folds inadvertently created after a suboptimal fluid-air exchange, and in hypotony maculopathy cases, for which he credited Jeroni Nadal, MD. In addition, Charles said he often peels the ILM when operating for diabetic traction retinal detachments (TRDs), after finding it enables better smoothing of macular folds.
“ILM peeling has many advantages,” said Charles, founder of the Charles Retina Institute in Germantown, Tennessee. “On the table, it instantly eliminates striae and guarantees complete removal of residual vitreous cortex and epimacular membranes.”
The peeling is done via a pinch peeling technique performed using an end-grasping forceps and mandates an excellent view and depth control. The pinch peeling technique, which Charles developed 40 years ago, has benefits for greater efficiency and safety compared with other approaches, he said.
“Inside-out, end-grasping ILM pinch peeling eliminates the need for using any other instruments to start the peel,” he explained. “Finding or creating an edge with a bent MVR blade or a forceps with 1 blade under the epiretinal membrane can damage the nerve fiber layer.”
Brilliant Blue G 0.025% ophthalmic solution (Dutch Ophthalmic Research Center) is his dye of choice for staining the ILM. Approved by the FDA at the end of 2019, Brilliant Blue G has many advantages compared with indocyanine green (ICG), Charles said.
“I believe that Brilliant Blue G is the only safe and effective ILM staining agent,” he said. “Unlike ICG, Brilliant Blue G dissolves in balanced salt solution (BSS), not water. It does not fluoresce, and so it poses less risk of phototoxicity, it has a stable pH, osmolarity is not an issue, infusion under air or mixing with dextrose are not necessary.”
Charles said achieving an optimal view for macular surgery requires use of a high quality plano corneal contact lens that will eliminate all corneal asphericity and provide the best resolution. Although a noncontact wide-angle viewing system (eg, BIOM, EIBOS) can be acceptable in eyes with a perfect cornea, noncontact visualization does not reduce lateral and axial resolution.
“Surgeons working without an assistant should choose a self-adhering plano contact lens rather than one with a handle,” Charles recommended.
He cautioned that increased foveal thickness after successful epimacular membrane and ILM peeling is often misdiagnosed as edema and subsequently treated inappropriately with intravitreal steroid injections that cause harm, inducing cataract and glaucoma.
Vitrectomy and the crystalline lens
Charles refuted the idea that vitrectomy causes cataract. He said vitrectomy uniformly causes progression of nuclear sclerosis, acting through a mechanism involving increased oxygen tension in the vitreous cavity. He argued against routine phacoemulsification in eyes needing vitrectomy. “Numerous clear lenses that still have 10 to 20 years of accommodation left are removed, and I am opposed to that because it clearly results in worse refractive outcomes,” he said.
Charles said that 1 month prior cataract surgery is indicated in eyes with a 2+ or greater nuclear sclerotic cataract (NSC) or any posterior subcapsular cataract. He advocated for 2 procedures with the sequence depending on cataract type. Vitrectomy is done first in the case of a 2+ NSC and followed 1 month later by phacoemulsification and IOL implantation. If the cataract is greater than 2+ nuclear sclerotic or posterior subcapsular, then the lens removal/ IOL implantation is done first.
Charles said he believes surgery for lamellar macular holes is indicated if the patient is symptomatic or there is structural damage. The goal is to restore normal foveal anatomy and not to prevent progression to a full-thickness defect, which is an unpredictable phenomenon.
The procedure must include ILM peeling and staining and use 25% sulfur hexafluoride, not air.
Finally, Charles reported his positive experience in more than 50 cases using an autologous full-thickness retinal patch grafts for repair of large macular holes.
Charles identified Tamer Mahmoud, MD, PhD, as a pioneer of the technique. He said the graft is harvested with scissors just inferior to the inferotemporal arcade and moved to the macular hole under medium-term perfluoro-n-octane (PFO).
The PFO, which is removed after 1 week, is favored over silicone oil because PFO supports graft oxygenation that will promote closure, Charles concluded.