Special Considerations in Cataract Surgery: Five Cornea Challenges

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CATARACT Special Considerations in Cataract Surgery: Five Cornea Challenges

by linda roach, contributing writer interviewing preston h. blomquist, md, rosa a. braga-mele, md, kimberly a. drenser, md, phd, herbert e. kaufman, md, marguerite mcdonald, md, and roger f. steinert, md

s the most common surgical choices, said Marguerite McDonald, IOL Selection procedure in ophthalmol- MD, of Lynbrook, N.Y. The device en- ogy, replacement of a cloudy ables the surgeon to directly measure 1 crystalline lens with an the eye’s aphakic refractive power in intraocular lens (IOL) usu- the operating room. Aally presents the ophthalmologist with Using intraoperative aberrometry is familiar sets of surgical routines. But becoming more commonplace, as “it what about those cases that involve may help in achieving more accuracy comorbidities or other complicating with IOL power selection,” Dr. Mc- factors? Donald said. Several experts shared their per- Tips on IOL selection. The chosen spectives on approaching out-of-the- IOL should be shaped to neutralize After an off-center LASIK procedure ordinary cataract surgeries in ways spherical aberrations, said Rosa A. such as this, the irregularity of the that offer the best chance at optimiz- Braga-Mele, MD, at the University of corneal topography indicates that a ing patient outcomes. This month, Toronto. “In anybody who has had multifocal IOL should be avoided. here’s a look at five challenges involv- myopic LASIK or PRK, I think it’s very ing the cornea. important to use a negatively aspheric prior to cataract surgery. 2) A dysfunc- IOL, because these patients have more tional, unstable tear film will affect the Challenge: Prior Refractive Surgery positively aberrant corneas. You don’t visual outcome by introducing error Two decades after the first corneal re- want to use a standard IOL, which will into the measurements on which the fractive surgeries in the United States, increase their aberrations.” IOL power calculations depend, Dr. many laser- or RK-sculpted eyes are Multifocal IOLs also should be Steinert noted. “Mild to moderate dry now developing cataracts. These ablat- avoided. “A multifocal IOL is usually eye can disrupt the tear film enough to ed or weakened corneas defy conven- not recommended for [most of] these affect the optics of the cornea.” tional formulas for determining IOL patients, because the cornea is already Diagnostic clues. “The first step power, said Roger F. Steinert, MD, at multifocal,” Dr. McDonald said. is recognition. It is easy to overlook a the University of California, Irvine. case of mild to moderate dry eye, par- Avoid IOL power errors. Dr. Stein- Challenge: ticularly if the patient is asymptom- ert recommends adjusting IOL power An Unhealthy Ocular Surface atic,” Dr. Steinert said. calculations for postrefractive surgery It’s essential to ensure that the ocular Stepwise use of standard diagnostic eyes with the aid of a free online tool.1 surface is as healthy as possible before tools, such as the Schirmer test of tear “You put in all the info you have about surgery, said Dr. Steinert, for two rea- production, has been proposed by two the eye, and it gives you IOL power sons. 1) Dry eye syndrome and related expert consensus panels.2,3 Dr. Steinert recommendations using as many for- surface-damaging disorders are likely favors corneal staining with lissamine mulas as it can.” It is then up to the to worsen if they are not addressed green or rose bengal, as these agents surgeon to choose from among them. Alternatively, many surgeons use Special Considerations in Cataract Surgery is an occasional series on challenging an intraoperative aberrometer, the situations in cataract surgery. Future installments will cover such topics as cataract Optiwave Refractive Analysis system, surgery in the settings of other comorbidities, such as age-related macular edema,

courtesy of roger steinert, f. md to improve the accuracy of their IOL glaucoma, and diabetic retinopathy.

eyenet 27 Cataract can reveal more subtle surface damage 2 alert to subtle clues that herpes simplex than fluorescein staining can. virus type 1 (HSV-1) infection of the For meibomian gland dysfunction cornea might be the real cause of a (MGD), the key signs are meibomian patient’s reduced acuity, said Kimberly gland dropout, abnormal secretions A. Drenser, MD, PhD, of Royal Oak, when the glands are expressed, and Mich. If this is the case, there will be a changes in lid morphology.3 To detect mismatch between the severity of the blepharitis, it is important to examine cataract and the patient’s visual com- the eyelids and exert mild pressure on plaints. the central third of the lower eyelid to A need for suspicion. When it look for signs of meibomian gland in- comes to HSV-1, cataract surgeons spissation, Dr. McDonald added. BACTERIAL RESISTANCE. MRSA kera- cannot afford to let down their guard. Postpone surgery as needed. Sur- titis with hypopyon in a health care If the virus progresses unnoticed, it gery should be postponed until any worker after sutureless cataract sur- can cause a necrotizing infection that surface damage has been treated and gery. “really wipes out the retina,” said Dr. resolved as much as possible, which Drenser. usually takes two to four weeks, Dr. it takes for the cornea to unmold, so In addition, researchers now sus- Steinert said. that preop biometry is accurate. This pect that most patients—although Make better use of artificial tears. means at least two consecutive visits they may seem uninfected at the Dr. Steinert said that his dry eye pa- where the manifest refraction and to- time—carry HSV-1 in their systems tients get the most benefit—both pre- pography maps are virtually the same,” that could become active if their im- and postoperatively—from artificial Dr. McDonald said. She added, “If the munity were sufficiently compromised tears if they instill preservative-free patient is wearing gas-permeable or by surgery, said Herbert E. Kaufman, tears both liberally and, importantly, soft toric lenses, they should be out MD, at Louisiana State University (see before they experience any discomfort of them for at least one month—and “More Online,” below). related to their dry eye disease. out of soft spherical lenses for three The prophylaxis problem. Periop- Intraoperative tips. Dr. McDonald weeks—before they return for the erative prophylaxis, sometimes with offered the following intraoperative first of at least two visits. I will wait as immunosuppression, in people with tips to help protect the surface from long as necessary to be sure that their prior HSV keratitis remains prudent, surgical stress and minimize the corneas have unmolded and are finally said Dr. Kaufman. However, there still chances of dry eye symptoms after stable.” are no good data on what works best surgery. Reduce astigmatism. The kerato- before cataract surgery. • Use a topical viscoelastic. “Many conic patient will have better pseudo- In general, Dr. Kaufman’s herpes surgeons use viscoelastic on the cornea phakic acuity if the keratome incision prophylaxis regimen is similar to the as a way to keep the eye moist during is placed on the steep axis to reduce one followed by many LASIK sur- cataract surgery,” she said. regular astigmatism, Dr. McDonald geons in patients with prior herpetic • Take care with the speculum. said. Manifest refractions and topo- infections.4 The intensity of the regi- “Opening the speculum only as much graphic maps should be obtained to men (outlined below) varies based on as is necessary, and not more, helps locate the axis accurately, she said. In the prior infection site in the eye, on to avoid lagophthalmos and exposure addition, a toric IOL also is appropri- whether active disease develops despite keratitis postoperatively. These flaccid ate for a keratoconic patient, because prophylaxis, and on the degree of ocu- older lids don’t recover so easily from it can improve postcataract acuity in lar inflammation, he said. the stretching and trauma they receive selected eyes, Dr. Braga-Mele said. He considers the most serious when the speculum is cranked open Rethink cross-linking. “Most kera- threats to vision from HSV-1 to be se- wide,” she said. toconus patients with cataracts are vere inflammation, iritis, and stromal older and their keratoconus is stable; keratitis. “I don’t want the immune re- Challenge: Keratoconus therefore, they will not need cross- sponse in the eye to be too severe, and The experts offered the following tips linking,” Dr. McDonald said. “If they I don’t want the inflammation to dam- for patients with keratoconus. are younger and the keratoconus is still age the endothelial cells of the cornea.” Discontinue contacts. Because of changing, it is best to do cross-linking Prevention and treatment tips. Dr. their highly aberrated corneas, many first, let the cornea stabilize, and then Kaufman offered the following tips patients with keratoconus use cus- do the cataract surgery.” on preventing recurrence and treating tomized, rigid gas-permeable contact new disease. lenses, which mold their corneas to Challenge: Herpes Infections • Preventing recurrence in cases of compensate for the optical distortions. When examining patients before cata- stromal disease or iritis. Before sur-

“Stop contact lenses for as long as ract surgery, the clinician should be gery, Dr. Kaufman prescribes one or courtesy preston of md blomquist, h.

28 may 2014 Cataract two days of oral valacyclovir hydro- tant bacteria from entering the eye and 3 Invest Ophthalmol Vis Sci. 2011;52(4). Free chloride (Valtrex), typically given in causing endophthalmitis. download in multiple languages at www. doses of 500 mg, three times a day.5 A need for suspicion. Certain pa- tearfilm.org/tearfilm-reports.php. The medication is then continued for tients are at increased risk of carrying 4 de Rojas Silva V et al. J Cataract Refract two weeks postoperatively. resistant bacteria asymptomatically, Surg. 2007;33(11):1855-1859. Generic acyclovir can be used, al- said Dr. Blomquist, at the University 5 For a typical dosing regimen, see webeye. though it is not absorbed as readily. of Texas Southwestern Medical Cen- ophth.uiowa.edu/eyeforum/cases/160-HSV. As with valacyclovir, generic acyclovir ter. They include health care workers, htm. (typically prescribed in doses of 400 cataract surgery candidates who were 6 Shorstein NH et al. J Cataract Refract Surg. mg five times a day5) should be taken recently hospitalized or who reside in 2013;39(1):8-14. one or two days before surgery and nursing homes, and those who are part then continued for two weeks postop- of large groups of people who are in Preston H. Blomquist, MD, is professor of eratively. close contact (such as athletes, prison ophthalmology, vice-chairman for education, In addition to the systemic medica- inmates, and military personnel). and director of the ophthalmic residency pro- tion, a topical antiviral, such as ganci- These patients should receive preop gram at the University of Texas Southwestern clovir 0.15 percent gel (Zirgan) or tri- topical gentamicin prophylactically, he Medical Center in Dallas. Financial disclo- fluridine 1 percent solution (Viroptic), said. sure: None. may be used. The prophylaxis problem. Like Rosa Braga-Mele, MD, is professor of oph- If severe intraocular inflammation many ophthalmologists, Dr. Blomquist thalmology at the University of Toronto and or recurrent herpetic disease develops uses a fourth-generation fluoroqui- director of professionalism and biomedical postoperatively, add 80 mg/day of oral nolone drop perioperatively for most ethics and director of cataract surgery at the prednisolone for one week (unless con- cataract patients. However, this rou- Kensington Eye Institute in Toronto. Financial traindicated). Add a topical antiviral tine changes for patients he knows are disclosure: Consults for Alcon and has received (ganciclovir or trifluridine) if it is not colonized with MRSA or MRSE, as lecture fees from Alcon, Allergan, and AMO. already in use. these bacteria are, for the most part, Kimberly A. Drenser, MD, PhD, is clinical • Reducing frequency of recurrence resistant to fourth-generation fluoro- professor of ophthalmology at the William in cases of epithelial ulcers. Use topi- quinolones such as moxifloxacin and Beaumont Oakland University College of cal ganciclovir or trifluridine for one gatifloxacin. Medicine and a partner in Associated Retinal or two days preoperatively and two Instead, Dr. Blomquist prescribes Consultants in Royal Oak, Mich. Financial weeks postoperatively. topical gentamicin, an aminoglycoside disclosure: Has equity interest in FocusROP • Treating new disease in cases of that still works against resistant mi- and Retinal Solutions and has received lecture stromal keratitis or iritis. If the con- crobes, for use three days before and fees from ThromboGenics. dition is severe, treat with two weeks one week after surgery. Herbert E. Kaufman, MD, is professor emeri- of oral valacyclovir hydrochloride or One alternative to the fluoroquino- tus of ophthalmology, pharmacology, and acyclovir, and add one week of oral lones, cefuroxime, has been found to microbiology at Louisiana State University in prednisolone at 80 mg/day (unless reduce endophthalmitis when used New Orleans. Financial disclosure: Holds sev- contraindicated). intracamerally.6 However, the drug eral royalty-generating patents, and consults • Treating new disease in cases of is not readily available in the United for Bausch + Lomb and RPS Diagnostics. epithelial ulcers. Use a topical antivi- States. Moreover, it is not effec- Marguerite McDonald, MD, is clinical profes- ral (ganciclovir or trifluridine) until tive against MRSE or MRSA, Dr. sor of ophthalmology at New York University’s healed. Blomquist said. Some cataract sur- Langone Medical Center and adjunct clinical One last note regarding treatment geons instead routinely use intracam- professor of ophthalmology at Tulane Univer- from Dr. Kaufman: “After cataract eral vancomycin, a practice he discour- sity in New Orleans, and she practices with surgery, herpes recurrences are typi- ages for fear of promoting resistance to Ophthalmic Consultants of Long Island in cally not dendritic and are difficult this last-ditch medication for resistant Lynbrook, N.Y. Financial disclosure: Consults to diagnose from appearance. Any staphylococci. n for 15 ophthalmic companies, including Alcon, prolonged epithelial defect should be Allergan, AMO, Bausch + Lomb, Pfizer, and suspect.” MORE ONLINE. For more about recent re- TearLab. search on herpes keratitis as well as tips on Roger F. Steinert, MD, is professor and chair Challenge: Bacterial Resistance minimizing the risk of a bacterial infection, see of ophthalmology at the University of Cali- After studying the spread of methicil- this article at www.eyenet.org. fornia, Irvine. He also directs the university’s lin-resistant Staphylococcus aureus and Gavin Herbert Eye Institute. Financial dis- S. epidermis (MRSA, MRSE) in the 1 Available at http://iolcalc.org. Accessed closure: Has patent/royalty interests in Rhein United States, Preston H. Blomquist, Feb. 20, 2014. Medical, has received grant support from MD, became convinced that cataract 2 Ocul Surf. 2007;5(2):67-142. Free download AMO, and consults for AMO, OptiMedica, surgeons can do more to prevent resis- in multiple languages at www.tearfilm.org. ReVision Optics, and WaveTec.

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