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Pupil enlargement for safe phacoemulsification surgery
from the editor.
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Pupil enlargement for safe phacoemulsification surgery Early in the course of learning phacoemulsification, we are taught that proper patient selection is an important factor for performing a successful procedure. We are told to choose patients whose pupils dilate well and whose nuclei are not too dense or brunescent. If we follow this advice most cases, even in the early phacoemulsification experience, will be uneventful and the patient will benefit from a satisfying visual and functional outcome. When problems arise intraoperatively, they are often associated with iris trauma and irritation that result in miosis with loss of the previous operative control. In this situation the significant advantages of the wide pupil are emphasized. As ophthalmologists become more conversant and skilled with phacoemulsification techniques, the benefits of small incision surgery are extended to a greater range of patients. This frequently includes patients whose pupils do not adequately dilate preoperatively. While some highly skilled surgeons are capable of performing phacoemulsification through a relatively small pupil, most ophthalmologists require a greater comfort level. During the past several years, techniques that permit widening of the pupil before phacoemulsificationhave evolved. Fine described a method of making small, multiple sphincterotomies and then stretching the iris muscle fibers to mechanically dilate the pupil. The result is a slightly distorted pupil but one that remains centric and somewhat functional. In this issue, Drs. Masket and Mackool present methods to produce a pupil of adequate size to perform a safe phacoemulsification procedure. Masket recommends iris surgery and then reconstituting the pupil to restore its anatomic integrity and function. He combines an inferior sphincte-
rotomy, familiar to most surgeons, with a modification of McCannel's retrievable suture. Masket feels that since most endolenticular maneuvers are performed in the lower portion of the anterior chamber, visualization in this area is best served by an inferior sphincterotomy. Other surgeons, including Neuhann and Grabow, have advocated making a superior sphincterotomy. In Mackool's technique, small, self-retaining iris retractors are inserted through ab externo incisions. These remain in place during the procedure to retain a widened pupil. With this technique the widening is temporary and the pupil returns to its usual shape once the retractors are removed. There is no need for iris suturing with this method. It would be inappropriate to simply accept these techniques without recognizing that a degree of surgical sophistication is required for them to be performed successfully. Each of these methods, including Fine's, is meant to influence the pupil's size during phacoemulsification to make the procedure safer. According to Learning's 1991 survey, also published in this issue, there is a continued steady increase in phacoemulsification. As a greater number of ophthalmologists adopt phacoemulsification, both in the United States and abroad, refinements in surgical technique must evolve to create an assurance in this method that at least equals that previously felt with planned extracapsular cataract extraction. In this regard, methods that enlarge the inadequately dilating pupil are valuable adjuncts to performing safe and effective phacoemulsification in a broader patient population.
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
Stephen A. Obstbaum, M.D.
427
• •
Pupil enlargement for safe phacoemulsification surgery Early in the course of learning phacoemulsification, we are taught that proper patient selection is an important factor for performing a successful procedure. We are told to choose patients whose pupils dilate well and whose nuclei are not too dense or brunescent. If we follow this advice most cases, even in the early phacoemulsification experience, will be uneventful and the patient will benefit from a satisfying visual and functional outcome. When problems arise intraoperatively, they are often associated with iris trauma and irritation that result in miosis with loss of the previous operative control. In this situation the significant advantages of the wide pupil are emphasized. As ophthalmologists become more conversant and skilled with phacoemulsification techniques, the benefits of small incision surgery are extended to a greater range of patients. This frequently includes patients whose pupils do not adequately dilate preoperatively. While some highly skilled surgeons are capable of performing phacoemulsification through a relatively small pupil, most ophthalmologists require a greater comfort level. During the past several years, techniques that permit widening of the pupil before phacoemulsificationhave evolved. Fine described a method of making small, multiple sphincterotomies and then stretching the iris muscle fibers to mechanically dilate the pupil. The result is a slightly distorted pupil but one that remains centric and somewhat functional. In this issue, Drs. Masket and Mackool present methods to produce a pupil of adequate size to perform a safe phacoemulsification procedure. Masket recommends iris surgery and then reconstituting the pupil to restore its anatomic integrity and function. He combines an inferior sphincte-
rotomy, familiar to most surgeons, with a modification of McCannel's retrievable suture. Masket feels that since most endolenticular maneuvers are performed in the lower portion of the anterior chamber, visualization in this area is best served by an inferior sphincterotomy. Other surgeons, including Neuhann and Grabow, have advocated making a superior sphincterotomy. In Mackool's technique, small, self-retaining iris retractors are inserted through ab externo incisions. These remain in place during the procedure to retain a widened pupil. With this technique the widening is temporary and the pupil returns to its usual shape once the retractors are removed. There is no need for iris suturing with this method. It would be inappropriate to simply accept these techniques without recognizing that a degree of surgical sophistication is required for them to be performed successfully. Each of these methods, including Fine's, is meant to influence the pupil's size during phacoemulsification to make the procedure safer. According to Learning's 1991 survey, also published in this issue, there is a continued steady increase in phacoemulsification. As a greater number of ophthalmologists adopt phacoemulsification, both in the United States and abroad, refinements in surgical technique must evolve to create an assurance in this method that at least equals that previously felt with planned extracapsular cataract extraction. In this regard, methods that enlarge the inadequately dilating pupil are valuable adjuncts to performing safe and effective phacoemulsification in a broader patient population.
J CATARACT REFRACT SURG-VOL 18, SEPTEMBER 1992
Stephen A. Obstbaum, M.D.
427