Pupil dilatation with intracameral 1% lidocaine during glaucoma filtering surgery

Abstract

In the article titled by Lee and associates (Am J Ophthalmol 2003;136:201–203), the authors used a combination of topical tetracaine along with nonpreserved intracameral lidocaine (1%) in the anterior chamber to produce ocular anesthesia in their glaucoma patients. The topical tetracaine anesthetizes the ocular surface while the intracameral injection of lidocaine anesthetizes the pain sensitive iris tissue. The authors performed trabeculectomy in 25 phakic patients under this anesthesia. We infer that this form of combination anesthesia was used by the authors to circumvent the disadvantages of procedures like peribulbar or retrobulbar injection which are more painful, lengthy, need a larger dose of anesthetic agent, and have an added risk of perforating the globe. Our main consideration is the surgery, that is, trabeculectomy in phakic patients for which this form of anesthesia was used by the authors. We feel that any form of manipulation in the anterior chamber including a needle perforation should be avoided in phakic patients. This has an inherent risk of damaging the anterior lens capsule and accelerating the formation of lens opacity. Our second concern is that after pupillary dilation (as with intracameral lidocaine), the iris tends to crowd in the periphery. Hence, the surgeon tends to snip a larger piece of iris while doing peripheral iridectomy following trabecular excision. That is why constriction of pupils is usually advised in patients who have to undergo trabeculectomy. For this, pilocarpine is used both topically (in chronic angle closure patients) and in the form of an intracameral injection. We feel that such combination anesthesia would have been more appropriate if the surgeons had to do cataract extraction along with glaucoma surgery. First, in this combined procedure there is no danger from any sort of manipulation in the anterior chamber. Second, at the conclusion of surgery, an appropriate size periphery iridectomy can be done after constricting pupil with inracameral pilocarpine following intraocular lens insertion. Author replyAmerican Journal of OphthalmologyVol. 137Issue 4Preview Full-Text PDF