EyeWorld India December 2013 Issue

19 EWAP CAtArACt/IOL December 2013 YAO Ke, MD Eye Institute of Zhejiang University and Eye Center, Second Affiliated Hospital of Zhejiang University College of Medicine 88 Jiefang Road, Hangzhou, China, 310009 Tel. no. +86-571-87783897 Fax no. +86-571-87783897 xlren@zju.edu.cn T here is a large number of Chinese patients suffering from primary angle closure glaucoma (PACG). Doctors in poverty-stricken areas used to treat these patients with 1% pilocarpine; however, long-term use of pilocarpine has been found to relate withmiotic pupils and posterior synechiae. Therefore, it is common to encounter the small and scarred pupil as Dr. Waltz mentioned among Chinese cataract patients with PACG or previous filtering surgery. For example, I often deal with 1 or 2 such patients on every surgery day in our hospital. I adopt different methods to treat these special cases, depending on the pupil size. 1. For the pupil larger than 4 mm, I usually use viscoelastic to separate the posterior synchiae and enlarge the pupil. Pupillary organization membrane radial resection will be performed before the viscomydriasis if the membrane restricts the expansion of pupil. After the pupil expands to 5 mm, I just do phacoemulsification directly. 2. For the pupil around 3 mm or smaller, iris hooks seem more efficient than viscoelastic. With four iris hooks (Synergetics USA, Inc., O’Fallon, Mo., USA), I smoothly stretch the pupil to a 5 x 5 mm square, which is eligible for phacoemulsification. In order to avoid damage to the pupillary sphincter, the pupil should not be over-stretched or stretched too quickly. It is also critical to locate incisions, for example, on the right eye with superior filtering bleb; usually I make a corneal incision at the 10:30 and a stab incision at 1:30 clock positions. Then iris hooks are inserted through other four side-ports at 3, 6, 9, 12 o’clock to fully expose the surgical field. Such incisions could avoid damaging the functional filtering bleb and meet the habits of most Chinese surgeons. Nowadays, microincision cataract surgery (MICS) has been promoted in our hospital. For patients with previous filtering surgery, a 1.8- or 2-mm corneal incision has a small influence on filtering blebs. Moreover, such incisions minimize surgically induced astigmatism (SIA), and, according to our study, this value is only 0.4 D. Toric IOLs are suitable for that kind of patient to diminish the residual astigmatism, and in MICS, implantation of a toric IOL will provide more precise astigmatism correction. Editors’ note: Prof. Yao has no financial interests related to his comments. Views from Asia-Pacific impressive, enabling a focused and effective removal of the lens that can comfortably be completed with a compromised eye. I use a Dewey Radius Phaco Tip (Innova Medical, Toronto, Canada), which helps me control the entire process. After the cataract was removed, I scanned the eye using the ORA intraoperative aberrometer (WaveTec Vision, Aliso Viejo, Calif., USA) to measure the net astigmatism power and visual axis. These new measurements allowed me to select the correct toric lens, which was different from what the preoperative measurements indicated should be used. Once the lens was implanted, I used the ORA system again to confirm the axis and power. Follow-up care for this patient was routine, with exams at one day, one week, and one month. By the day after surgery, the patient achieved 20/20 vision and his IOP was in the mid-teens, slightly lower than preoperatively. Surgeons understand that great outcomes are possible in very complicated cases, but there is no margin for error. Good results from a toric IOL already require great precision, and a small pupil and preexisting filtering bleb add further complexity. If the viscoelastic is unable to perform as needed or choppy fluidics create too much trauma, a surgical plan may have to be modified and the use of a toric lens abandoned. Confidence and comfort with my tools and equipment are paramount for me prior to beginning any complicated surgery. EWAP reference 1. Ramulu PY, Corcoran KJ, Corcoran SL, Robin AL. Utilization of various glaucoma surgeries and procedures in Medicare beneficiaries from 1995 to 2004. Ophthalmol . 2007;114(12): 2265-2270. Editors’ note: Dr. Waltz is a partner with Eye Surgeons of Indiana. He has financial interests with AMO. Contact information Waltz: kwaltz56@gmail.com