Anterior Capsulorhexis in Hypermature Cataracts

different from that seen with the large can-opener. A much more common filmy, patchy, early translucency (Figure 8) has taken the place of crystal clear capsules, only some of which became opacified with a three-dimensional pearly plaque formation (Figure 9). In my hands, early opacification also seems more common with planar design IOLs with no step vaulting and little curve on the posterior optic. I am performing YAG posterior capsulotomies earlier and the rate is directly related to the amount of overlap and the size of the capsulorhexis. The smaller the tear and the more overlap, the earlier the capsulotomy. The main drawback of reduced optic diameters may be that they require smaller capsulorhexes. Perhaps the edge of the capsulorhexis should be outside the optic edge with no overlap as is done more commonly in Europe. We are beginning to understand the long-term ramifications of capsulorhexis; specifically, that this surgical technique has a greater effect on optic position and posterior capsular transparency than the choice of the IOL. Short- and long-term symmetry between the forces of zonular traction, capsular fibrosis, and haptic compression resistance, as well as the prohibition of asymmetric optic fibrosis squeezing effect, should help ensure optic centration and good vision for more patients. James A. Davison, M.D. Marshalltown, Iowa

CATARACT SURGERY WITHOUT RETROBULBAR OR PERIBULBAR ANESTHESIA To the Editor: Several months ago, I started performing most of my phacoemulsification cataract surgeries without any retrobulbar or peribulbar anesthesia. This came after experiencing two cases of diplopia after peribulbar anesthesia during the past year. The success of this technique is highly dependent on the proper choice oflocal anesthetic. I have obtained the best results with lidocaine (Xylocaine® 4 %); a few drops are applied in the superior and inferior fornices, and on the corneal surface at five minute intervals (X2), allowing the anesthetic to bathe it for a few seconds. Lidocaine in its 4% concentration provides superb corneal anesthesia and markedly decreases the palpebral reflexes, which in turn facilitates the insertion of the lid speculum and prevents lid squeezing during surgery. The topical anesthetic is supplemented by a subconjunctival injection of about 0.2 to 0.3 cc of an equal mixture of Xylocaine 4% and bupivacaine (Marcaine® 0.5%). The subconjunctival injection of this anesthetic mixture abolishes any painful sensation during conjunctival dissection and during the passing of the superior rectus bridle suture (needed to stabilize the eye). No 116

ocular massage or Honan balloon application is necessary. During the surgery, the patient is always monitored by an anesthesiologist. The patient is awake at all times and rarely complains of any pain. Intravenous medications are administered for the relief of anxiety, for sedation, and/or for anterograde amnesia. Our anesthesiologist favors the use of Midazolam hydrochloride (Versed®) 0.5 mg fentanyl citrate (Sublimaze®) 25 ~g or both depending on the patient. Surgery "without" peribulbar or retrobulbar anesthesia has major advantages. No needle is injected blindly behind the eye, thus abolishing any risk of retrobulbar hemorrhage, optic nerve injury, extraocular muscle infiltration, or even a lid hematoma. On the other hand, the block provided temporary paralysis of the extraocular muscles, a decreased sensitivity to the microscope lights, and a sustained postoperative analgesia. I did not find any of these issues to be a drawback. The free eye movements have made it easier to place the superior rectus bridle suture and easier to center the eye under the microscope. During the surgery, the eye is stabilized by the phaco tip and the cyclodialysis spatula. I have had only one uncooperative patient that necessitated more I. V. sedation. In restrospect, this younger patient should have had peribulbar anesthesia. Each patient is given two acetaminophen (Tylenol®) tablets at discharge and there has been no major complaint of postoperative discomfort. There is also no postoperative paresthesia sensation, usually associated with the retrobulbar/peribulbar anesthesia. At present, I am using this technique on most of my anterior segment surgeries. Of course, each patient has to be judged individually and I would not recommend this technique for young, uncooperative, or apprehensive patients. H. John Shammas, M.D. Lynwood, California

ANTERIOR CAPSULORHEXIS IN HYPERMATURE CATARACTS To the Editor: Continuous curvilinear anterior capsulorhexis has gained widespread use in phacoemulsification techniques because it is associated with anterior capsular tears less than other capsulectomy techniques (such as the can-opener capsulotomy, the linear capsulotomy, or the capsulopuncture).1-3 A red reflex is essential for visualizing the transparent capsular flap using coaxial illumination. In very dense cataracts, the red reflex is absent and anterior circular capsulorhexis becomes difficult to perform. Hausmann and Richard4 have used a straight bipolar high-frequency diathermy probe to perform circular capsulorhexis in intumescent or hyper-

J CATARAcr REFRAcr SURG-VOL 19, JANUARY 1993

mature cataractous lenses. I present a simple technique to enhance visualization of the anterior capsular flap during capsulorhexis in hypermature cataracts. An endoilluminator is placed at the limbus parallel to the plane of the iris and 90 degrees from the intended capsular flap. The intensity of the fiberoptic illumination of the microscope is decreased to a medium level. Using a bent cystotome, a linear pericentral capsulotomy is performed and a flap is created by turning the capsulotomy incision 90 degrees. Side illumination provides a beam of light that is perpendicular to the flap, allowing the edges of the anterior capsular flap to be relatively refractile and well delineated. Using this technique, a hypermature cataract was emulsified without complication (5 mm circular capsulorhexis) and an intraocular lens was implanted in the bag in a 65-year-old diabetic man from Mexico (preoperative visual acuity of light perception and postoperative uncorrected visual acuity of 20/50 at two weeks of follow-up). Endoilluminators are routinely used in posterior vi-

trectomies. Operating room nurses can be requested to save these disposable endoilluminators at the end of the procedure; these used illuminators (and therefore inexpensive) can be gas sterilized and used during capsulorhexis in dense cataracts. An alternative to endoilluminators is the use of sterile hand-held, batteryoperated transilluminators. A.M. Mansour, M.D. Galveston, Texas REFERENCES I. Gimbel HV, Neuhann T. Development, advantages, and methods of the continuous circular capsulorhexis technique. J Cataract Refract Surg 1990; 16:31-37 2. Gimbel HV. Two-stage capsulorhexis for endocapsular phacoemulsification. J Cataract Refract Surg 1990; 16: 246-249 3. Assia EI, Apple DJ, Barden A, et al. An experimental study comparing various anterior capsulectomy techniques. Arch Ophthalmol 1991; 109:642-647 4. Hausmann N, Richard G. Investigations on diathermy for anterior capsulotomy. Invest Ophthalmol Vis Sci 1991; 32:2155-2159

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