EyeWorld Asia-Pacific March 2014 Issue

17 March 2014 EWAP FEAturE It is important for cataract surgeons to be aware of any previous vitreoretinal conditions that patients have had surgery for, Dr. Huang said. “Preoperative retinal consultation may be considered, and patients should be aware that factors may exist that can retard recovery.” Additionally, “surgical techniques that limit zonular stress and stabilize the capsule should be employed.” Using the vertical chop, a capsular tension ring, viscoelastic, and meticulous attention to fluidics can aid in avoiding complications. “Patients and staff should be educated about symptoms not typically associated with routine surgery, especially the onset of new photopsia, floaters, and decreased peripheral vision,” Dr. Huang said. “In the event of complications, a team approach to management may optimize therapy.” Dr. Fram offered several pearls for the factors contributing to complications that she mentioned, which include fluidics, white or brunescent cataracts, posterior capsule rent, and zonular weakness. For an excessively deep anterior chamber, she suggested lowering the bottle height. “Lowering the bottle height allows for more stable fluidics in the setting of an eye without vitreous support,” Dr. Fram said. “In addition, one should lower the aspiration rate accordingly to maintain a stable chamber.” However, she noted that it is important to remember that fluidic controls can vary from machine to machine. Reverse pupillary block (Iris Retropulsion Syndrome) is a common occurrence during cataract surgery in post-vitrectomy eyes. This is syndrome is caused by altered fluidics leading to posterior apposition of the iris to the anterior capsule. 1,2 It is helpful to place a second instrument under the iris and gently lift anteriorly to release the reverse pupillary block. In eyes with low scleral rigidity (high myopes) reverse pupillary block may be a repeated occurrence during surgery. Placing one iris hook to break prolonged pupillary block is sometimes necessary. 3 Diffuse zonulysis can lead to a floppy bag. If the eye is soft and the capsular bag is floppy one can fill the capsular bag with a dispersive viscoelastic to push the bag posteriorly and allow for safe removal of the final lens fragments during phacoemulsification. Similarly, inflating the bag with a dispersive viscoelastic and performing a bimanual irrigation and aspiration approach during cortical cleanup can ease removal in the setting of a floppy bag. An alternative approach is to place a capsular tension ring to reestablish a taut capsule. When dealing with posterior capsule rent, Dr. Fram recommended attempting to make a generous capsulorhexis, around 5.5 to 6.0 mm, to help facilitate the removal of the lens. “The goal is to deliver the lens into the anterior chamber for nuclear disassembly and removal,” she said. “Copious use of dispersive viscoelastic in front and behind the lens with gentle viscodissection is also useful in this scenario.” What postop anti- inflammatory regimen do you use in non-diabetic, post-vitrectomy eyes? Dr. Huang said that inflammation can exacerbate most complications of ocular surgery, including proliferative vitreoretinopathy. “I typically use sub-Tenon’s dexamethasone 10 mg and cefazolin 50 mg at the end of the case, tobramycin/ dexamethasone ointment and homatropine 5% with patch and shield, and a combination drop/ homatropine 5% QID,” he said. “If inflammation is a particular concern, I add a nonsteroidal anti- inflammatory therapy.” Dr. Braga-Mele said her postop routine for these eyes is no different from the treatment she would use in a standard cataract case, unless the case has presented difficulties. “If it’s all gone well, then it’s my standard routine of using a nonsteroidal anti- inflammatory for a total of four to six weeks and a steroid as well,” she said. Dr. Fram said that patients who have a history of pars plana vitrectomy may benefit from pre-treatment one week prior to surgery with a topical steroid and NSAID. “Preoperative topical NSAID use can potentially improve perioperative stability of pupillary dilation and address pre-existing retinal pathology such as subclinical macular edema,” she said. “Typically, this can be continued for four to six weeks postoperatively.” This postoperative regimen correlates with evidence that it could take up to six weeks or longer for the blood-aqueous barrier to recover. 4,5 “Careful evaluation of the retina postoperatively for macular edema and peripheral retinal pathology is warranted in all eyes undergoing cataract surgery after vitrectomy,” Dr. Fram said. EWAP Editors’ note: Dr. Huang has no financial interests related to this article. Dr. Braga-Mele has no financial interests related to the article. Dr. Fram has no financial interests related to this article. References 1. Wilbrandt HR, Wilbrandt TH. Pathogenesis and management of the lens-iris diaphragm retropulsion syndrome during phacoemulsification. J Cataract Refract Surg. 1994 Jan;20(1):48-53. 2. Cionni RJ, Barros MG, Osher RH. Management of lens-iris diaphragm retropulsion syndrome during phacoemulsification. J Cataract Refract Surg. 2004 May;30(5):953-6. 3. Nahra D, Pazos-Lopez M, Castilla- Cespedes M. Iris hook as a management technique for lens-iris diaphragm retropulsion syndrome. J Cataract Refract Surg. 2007 Feb;33(2):177. 4. Miyake K, Asakura M, Kobayashi H. Effect of intraocular lens fixation on the blood-aqueous barrier. Am J Ophthalmol. 1984; 98:451-5. 5. Ferguson VM and Spalton DJ. Recovery of the blood-aqueous barrier after cataract surgery. Br J Ophthalmol. 1991 February; 75(2):106–110. Contact information Braga-Mele: +1-650-948-9123, dceye@earthlink.net Fram : nicfram@yahoo.com Huang : Suber.Huang@UHhospitals.org Phaco - from page 15