Ballooning of the conjunctiva during phacoemulsification

Abstract

Attention to incision location during phacoemulsification is usually for the purpose of astigmatic control of cataract surgery.1,2 However, incorrect positioning of clear corneal incisions can cause potential problems. We present 2 cases in which the irrigating solution accumulated subconjunctivally during phacoemulsification with anterior chamber incisions located too peripherally. Potential problems resulting from such an accumulation are highlighted, and preventive measures are discussed. An 85-year-old woman had right cataract extraction by phacoemulsification under peribulbar anesthesia. A 5.5 mm superior scleral tunnel incision was fashioned, and an anterior chamber paracentesis was made with a 15 degree metal blade at the 2 o'clock position to allow the introduction of a second instrument into the eye. During phacoemulsification, irrigating solution was seen to be collecting subconjunctivally around the 2 o'clock position (Figure 1). There was no such accumulation around the scleral tunnel entry seen initially. This was because the paracentesis had breached the conjunctiva instead of entering the anterior chamber through clear cornea.Figure 1.: (Ismail) Perioperative conjunctival ballooning arising from fluid tracking from the side-port entry site (taken at the end of the procedure).Irrigating solution flowing into the anterior chamber was allowed to escape via the paracentesis and track under the conjunctiva, eventually causing ballooning of the entire conjunctiva above the corneal level. This changed the normal convex contour of the globe to a surface, which prevented run-off of the irrigating solution and allowed fluid to pool over the entire cornea. This pooling made visualization of the intraocular structures difficult, although lens matter was removed and an intraocular lens was implanted without complication. The second case occurred during phacoemulsification under peribulbar anesthesia. Conjunctival ballooning resulted from a superior 3.2 mm 2-step corneal section, which, instead of being placed at the posterior limbus, breached the conjunctiva posteriorly. Once again, irrigating solution pooled over the entire cornea and made visualization during the procedure more difficult. The postoperative course was uneventful in both cases; the conjunctival ballooning disappeared on the first postoperative day. However, these events bring to light some important discussion points. Apart from the visualization difficulty caused by the pooling of irrigating fluid in the operative field, there is also an infection risk. In most cases of postoperative endophthalmitis, infection is caused by the patient's own bacterial flora of the eyelids and conjunctival sac.3,4 Collection of irrigating solution under the conjunctiva and pooling of fluid in the conjunctival sac allow free communication with the anterior chamber; any residual bacterial flora within the conjunctival sac can gain access to the intraocular compartment. Thus, poor drainage of irrigating solution from the operating field and pooling can theoretically increase the risk of intraocular infection. Similarly, pooling of irrigating solution during ocular surgery may also result from incorrect placement of peribulbar and sub-Tenon's anesthesia injections, especially when large volumes of local anesthetic agents are used. Patients with very deep-set eyes, in which the fluids can drain from the temporal side but usually pool in the nasal side, can have the same problem, despite small amounts of local anesthetic agent being used. In a case of subconjunctival accumulation of fluids and to minimize such pooling in the operative field, tilting the head, usually to the temporal side, will effect natural drainage of fluid from the ocular surface. Drainage may be enhanced by using a drainage wick. Conjunctival ballooning secondary to subconjunctival irrigating solution or a local anesthetic agent can also be drained by making small incisions, occasionally multiple, in the conjunctiva at the meridians of maximal elevation and about 5.0 to 10.0 mm behind the limbus, bearing in mind that collections of fluid may be loculated. The potential problems outlined in the above cases can be avoided by ensuring that entry sections and side ports into the anterior chamber are not made too peripherally but are through clear cornea. The potential increased risk of ocular infection secondary to contaminated irrigation solution remains unsubstantiated but may form the subject of a more detailed study. André R Ismail MB, BS Haralabos Eleftheriadis MD Athanasios Vakalis MD Christopher S.C Liu FRCOphth aBrighton, United Kingdom