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When capsulorrhexis becomes complicated by a radial tear, pulling the flap backward, first circumferentially and then centrally, can rescue the tear-out. Here, an ophthalmologist shares a technique to successfully address this complication.
Atlanta-A maneuver based on applying sequential backward then central traction on the capsule flap in the capsular plane is a simple and highly effective technique for rescuing the capsulorhexis from a radial tear, said Brian Little, MD, at the annual meeting of the American Academy of Ophthalmology.
"Part of the art of managing capsulorhexis tear-out is early detection, catching it at the earliest sign of peripheral migration," said Dr. Little, consultant ophthalmic surgeon, Royal Free Hospital NHS Trust, London. "At this point, stopping and refilling the chamber with the ophthalmic viscosurgical device [OVD] to flatten the anterior lens surface may limit the tear.
"However, a retrieval maneuver that involves unfolding the flap and using backward then central traction to redirect the forces centrally may even salvage more advanced tears that might appear impossible to recover," he added.
Tools, moves important
"Only a forceps should be used to pull the flap," Dr. Little said. "A needle cystotome does not provide adequate directional or force control and can also tear the flap.
"The tear must be pulled back circumferentially first and then in centrally. If you just attempt to pull centrally, the tear will continue out," he added.
Achieving the maneuvers within the eye can be difficult if the tear develops sub-incisionally. In that situation, Dr. Little said he recommends creating a new stab incision at a position that will enable an appropriate angle of approach for applying traction on the flap.
"Always take your time, and if you are having difficulty seeing the edge of the capsulorhexis, put in some trypan blue to improve visualization," he said.
Reason for tear explained
Recognizing the reason that a radial tear develops and progresses is helpful for understanding the efficacy of the salvage maneuver. Dr. Little explained that any applied force can be resolved into horizontal, radial, and vertical vectors. The radial tear results from application of an excessive amount of force in the wrong direction.
"The rescue technique resolves the tangential and central vector forces and redirects the tear predictably toward the center of the pupil," he said.
Dr. Little also said that although capsulorhexis tear-out is a disheartening beginning to a cataract surgery procedure, if one considers zonular anatomy, the infrequency with which a radial tear occurs is testament to surgeon skill.
"There really exists only a very small safety margin because the zonular insertions on the anterior lens capsule are more central than one thinks," he said. "Consider that the diameter of an average lens is about 10.5 mm and that the most central zonular insertions can extend for 2.5 mm inside of that. This leaves a 5.5-mm central safety zone, and if you are creating a 5-mm continuous curvilinear capsulorhexis, you are left with only a 0.25-mm zonule-free surrounding margin."