Eyeworld

EW CATARACT/IOL 62 March 2011 by Matt Young EyeWorld Contributing Editor Study examines post-surgery DMD D escemet's membrane de- tachment (DMD) follow- ing cataract surgery is a known complication that is sometimes mild but other times requires surgical inter- vention, according to a new report. "DMD should be suspected in patients showing unexpected corneal edema postop eratively who have undergone uneventful phacoemul sification and be treated in a timely manner," reported study co-author Jagat Ram, M.D., depart- ment of ophthalmology, Postgradu- ate Institute of Medical Education & Research, Chandigarh, India. "Surgi- cal intervention is recommended in cases with significant separation of the membrane from stroma and curling or folding of the Descemet's membrane." Dr. Ram and colleagues based their conclusions on a clinical series of 11 consecutive eyes with DMD. "The incidence of DMD in our series was 0.1%," Dr. Ram reported in the study, published online in July 2010 in Ophthalmic Surgery, Lasers & Imag- ing. Still, it's an important 0.1% to take note of. "Corneal clarity can be maintained in the majority of cases of DMD provided the condition is recognized early and managed ade- quately," Dr. Ram noted. Solving the DMD problem The DMD diagnosis in the 11 eyes was made either intra-op or post-op upon slit lamp examination. "In 3 eyes (3 cases), diagnosis of DMD was made on the operating table under the microscope," Dr. Ram reported. "Eight eyes (8 cases) were diagnosed with DMD in the postoperative period by slit-lamp biomicroscopic ex amination. In all cases, detachment originated from the surgical wound." These patients all underwent clear corneal incisions originally. "In most cases diagnosed in the postop- erative period, topi cal anhydrous glycerin was used to dehydrate the cornea to delineate the extent of de- tachment," Dr. Ram reported. DMD resulted for various rea- sons. "Three cases where DMD was recognized intra operatively were at- tributed to inadvertent injection of sodium hyaluronate anterior to De- scemet's membrane prior to intraoc- ular lens insertion in one eye, while fashioning the incision in one eye, and during hydra tion of the incision at the end of surgery in one eye," Dr. Ram noted. "In these three cases, 14% C3F8 gas was injected intracam erally to fill up to two- thirds of the anterior chamber at the end of surgery. None of these three cases required any additional surgi- cal intervention." In the remaining eight eyes, seven were discovered to have DMD on the first day post-op. One eye was found to have DMD 2 weeks post-op. "All received isoexpansile C3F8 gas intracameral injection," Dr. Ram reported. "Two cases required more than one injection; one eye received two injections of C3F8 and the other had two injections of C3F8 gas fol- lowed by an injection of intracam- eral Healon to reattach the Descemet's membrane." In these eight eyes, DMD af- fected more than 50% of the cornea. "One eye had residual DMD not af- fecting the visual axis after two in- jections of C3F8 gas," Dr. Ram reported. They also had significant separa- tion of the membrane from the stroma and experienced curling of the membrane. "Curling or folding of the Descemet's membrane was not noted in any of the other pa- tients," Dr. Ram reported. The 11 eyes had a BCVA of better than 6/12 (or 20/40). Understanding, preventing, and treating DMD Dr. Ram suggested that blunt knives, reusable knives, anterior and shelved incisions, anterior chamber entry in a soft eye with a shallow chamber during IOL implantation, and inad- vertent injection of Healon (sodium hyaluronate, Abbott Medical Optics, Santa Ana, Calif.) between the mem- brane and stroma could be risk fac- tors for DMD development. "Another factor that we believe is important as far as DMD is con- cerned is the technique of corneal lip hydration to aid incision sealing in clear corneal phacoemulsifi - cation," Dr. Ram noted. "Injecting fluid into the deeper stroma may at times strip the membrane. The cor- rect technique with a more superfi- cial injection would avoid such an occur rence." Slit lamp examination of an eye with corneal edema should allow for the identification of most DMD cases, Dr. Ram believes. "We recommend early C3F8 gas isoexpansile injection as soon as a diagnosis of DMD is made in pa- tients with limited separation of the Descemet's membrane from the stroma without any folding or curl- ing of the mem brane," Dr. Ram noted. "All cases in which there is folding or curling of the membrane need more aggressive treatment with repeated injections of C3F8 gas or Healon. Corneal clarity can be main- tained in the majority of cases of DMD provided the condition is rec- ognized early and managed ade- quately." Mark Packer, M.D., clinical as- sociate professor of ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, said he has seen DMD and considers "lit- tle Descemet's detachments" to be "incredibly common" after cataract surgery. "It's not at all unusual to see that during surgery," Dr. Packer said. He described it as a half millimeter flap just anterior to the incision. Tears at the anterior lip of the incision are not problematic, Dr. Packer said. "However, I have seen complete Descemet's detachment where the patient was referred from another surgeon for persistent unex- plained corneal edema after cataract surgery," Dr. Packer said. "The cornea was white. There was no view. It actually required an anterior segment OCT to demonstrate De- scemet's membrane separated from the cornea." To solve the problem, air was in- jected under Descemet's membrane in the anterior chamber, floating the membrane back up against the corneal stroma. The cornea cleared in a matter of weeks, Dr. Packer said. EW Editors' note: Dr. Packer has no finan- cial interests related to his comments. Dr. Ram has no financial interests related to this study. Contact information Packer: 541-687-2110, mpacker@finemd.com Ram: drjagatram@yahoo.com Descemet's membrane detachment Source: Mark Packer, M.D.

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