EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/87458
October 2012 Challenging cataract cases February 2011 Diving in deep: Unexpected problems with a shallow eye by Maxine Lipner Senior EyeWorld Contributing Writer Coping with patient reaction, iris expulsion, and more I t was a case that appeared at first to be nothing more than "routinely" problematic—cer- tainly nothing that the resi- dent handling the cataract removal would have difficulty with, according to Saras Ramanathan, M.D., who oversaw the procedure. The patient had bilateral cataracts in eyes marked by shallow anterior chambers with very small palpebral fissure width, said Dr. Ramanathan, associate clinical professor of oph- thalmology, University of California, San Francisco, and teaching faculty, California Pacific Medical Center, San Francisco. The first eye, which had a dense cataract, was done using both a sub- Tenon's and a lid block under MAC anesthesia. All seemed to be going well until the resident handling the case began irrigating out the trypan blue used to stain the capsule. "While we irrigated the trypan out, the patient valsalvaed (involun- tarily clenched down) and the iris came out of the sideport," Dr. Ramanathan said. "Pressure inside the eye was so high that 'burping' the sideport was difficult, and repo- sitioning the iris back into the eye took a surprisingly long time." Fluid was let out of the eye so that the iris could be put back in. Then more viscoelastic was used to make more space. The pupil also needed to be expanded because it was too small. Next the cataract was taken out, but this was not without a hitch. As the procedure continued, the capsule tore, resulting in loss of half the nucleus. "After that we ended up putting a lens in the sulcus, and sending her for retina evaluation," Dr. Ramanathan said. The patient ulti- mately underwent a vitrectomy with removal of the retained nucleus and went on to see 20/25 uncorrected. For the second cataract, under- taken by another resident, a new approach was used. "We gave the pa- tient mannitol, put her to sleep, and did a canthotomy and cantholysis," Dr. Ramanathan said. Putting the patient to sleep assured that she would not valsalva, while the man- nitol helped to increase space. "It completely decompresses the vitre- ous, so this shrinks in volume," Dr. Ramanathan said. Likewise, the canthotomy and cantholysis de- creases the tightness from the eye- lids, giving the eyeball more room to move forward, she observed. Next, Healon GV (Abbott Med- ical Optics, AMO, Santa Ana, Calif.) and Viscoat (Alcon, Fort Worth, Texas) with the Arshinoff soft shell technique were used to make space. With this technique, a dispersive viscoelastic coats the cornea and protects it, and then the Healon GV underneath pushes the anterior capsule down posteriorly, Dr. Ramanathan explained. From there the case proceeded normally. Begin- ning on post-op day 1 the patient had 20/25 acuity and by the 1- month mark attained 20/20 vision. Monday morning quarterbacking Looking back, Dr. Ramanathan recalls that while there were some concerns about the shallow anterior chamber with the small palpebral fissure width, initially these had seemed quite manageable. "Hon- estly, I didn't think that it would be as hard as it was," she said. "I think it was a combination of us being at the edge of what is possible and the patient being slightly uncomfort- able." Dr. Ramanathan sees the take- continued on page 76 AT A GLANCE • Cataract removal in a small eye with a shallow chamber takes an unforeseen turn with iris expulsion following patient valsalva • In the second eye, four different approaches were used to avoid similar complications • Other practitioners consider the best precautionary maneuvers to take here home message here as learning from the first eye and realistically pursu- ing as many options as possible to ensure that history is not repeated. "You should do as many things as are reasonable to do," she said. "We did four different things to decrease pressure and make space—maybe that was overkill, but it worked out great and there was no downside." Bennie H. Jeng, M.D., assistant professor, University of California, thinks the sub-Tenon's block used initially may have been an issue. "Any kind of block is going to in- crease the pressure from behind the eye, and that will contribute to problems with the multi-palpebral EW FEATURE 75 Performing a canthotomy cantholysis decreases the tightness from the eyelids Source: Saras Ramanathan, M.D.