Fluorescein dye improves visualization during capsulorhexis in mature cataracts

Continuous curvilinear capsulorhexis (CCC), developed by Gimbel and Neuhann in 1986,1 is regarded as the safest means of opening the anterior capsule during cataract surgery. A red reflex is essential for visualizing the transparent capsular flap using coaxial illumination. In very dense and mature white cataracts, the red reflex is absent. Continuous curvilinear capsulorhexis is therefore hazardous because it is difficult to identify the tearing edge of the anterior capsule against a white background. Fritz2 injected fluorescein under the capsule and under a blue filter in coaxial light to assist visualization. We have found that fluorescein on the anterior capsule is sufficient and prevents the need for additional blue filters in the microscope. We performed a study to evaluate the performance and safety of this technique in eyes with mature cataracts and explain why the fluorescein dye improves visualization during the capsulorhexis. Between September 1997 and April 1998, phacoemulsification was performed in 12 consecutive cases (10 patients) with white cataract using topical and subconjunctival anesthesia. A scleral incision was performed and the anterior chamber (AC) filled with methylcellulose (Ocucoat™). A Rycroft cannula mounted on a 1.0 mL syringe was used to introduce a drop of fluorescein 2% (Minims™) onto the anterior capsule under the Ocucoat cushion. Capsulorhexis was initiated with a 30 gauge needle and completed with a capsulorhexis forceps. As the flap was folded over, the underlying lens epithelium was stained green, contrasting against the nonstaining cortex. The anterior chamber depth was maintained by an additional Ocucoat injection if required. A 5.0 to 5.5 mm capsulorhexis was performed in all cases. Excess fluorescein in the anterior chamber was replaced with fresh Ocucoat. The visual acuity was checked before surgery and on the 1st and 15th postoperative day. Dilation was performed preoperatively to identify the extent of the white cataract and on the second postoperative visit to check the intraocular lens (IOL) position and the fundus. At the end of surgery, all the corneas were clear with no sign of endothelial dysfunction or damage. At the second postoperative appointment, all patients had an acuity of at least 6/9 and were discharged or listed for the second eye. The major difficulty during capsulorhexis of white cataracts is the lack of the red reflex. Many surgeons therefore perform an extracapsular cataract extraction (ECCE) or convert to ECCE because of capsulorhexis problems. Over the past few years, fluorescein use during CCC has been discussed among surgeons in the United Kingdom, and many have used it. At the same time, little has been published to establish this technique. Hoffer and McFarland3 described the use of fluorescein underneath the capsule. Fritz2 improved the technique by using blue light during the CCC. Fluoroscein stains the capsular epithelium located on the inner surface of the capsule. As the capsulorhexis is begun, fluorescein stains the epithelium on the everted flap, leaving the cortical lens to stand out white in bold contrast. This enables the surgeon to identify the tearing edge accurately, ensuring a continuous circular opening. Cells remain on the capsular bag throughout the procedure, which was confirmed histologically. The technique we describe does not require a blue light and can be readily used in any operating theater with standard equipment available. With increasing experience, we feel confident in recommending this technique to surgeons wishing to perform safe phacoemulsification in these difficult eyes with mature white cataracts.