Eyeworld

EW GLAUCOMA 64 October 2017 central depth of the anterior cham- ber but also showed more enhanced improvement of the pathologic area in angle closure disease," Dr. Lin said. According to a review on lens- based glaucoma surgery by Reay Brown, MD, angle closure occurs in short eyes with shallow anterior chambers. The increasing thickness of the aging lens may contribute to a progressive narrowing of the angle. LPI widens the angle, but some iridotrabecular contact persists in most patients, and angle clo- sure may progress despite a patent iridectomy. Performing cataract surgery may anatomically improve the PACG eye more profoundly than an iridotomy because removing the lens mass causes a greater deepening of the chamber and opening of the angle. This may reduce or eliminate the risk of blindness from an acute attack as well as a chronic increase in IOP. 5 Experience tells Apart from the persuasive evidence from randomized clinical trials, ex- perienced clinicians gather a wealth of experience from the day-to-day. Dana Wallace, MD, Thomas Eye Group, Sandy Springs, Georgia, told EyeWorld that cataract surgery is a critical component of treating angle closure, as removal of the lens not only resolves lens-related angle closure (phacomorphic or from lens subluxation), but also relieves pupil- lary block, which can worsen after laser PI. She thinks that the shallow anterior chamber and choroidal ef- fusions that often follow trabeculec- tomy further support lens extraction as the better option in patients with angle closure. Cataract surgery, however, may not always be enough or be the best first choice. "If the angle closure has been prolonged in duration, for sev- eral months perhaps, there is always the possibility that the angle will not deepen with cataract surgery and that the PAS cannot be freed. In those cases, cataract surgery alone may not be sufficient, and a com- bined procedure with trabeculecto- my may be necessary," Dr. Wallace said. "On the other hand, patients with acute attacks often have significant corneal edema. In these patients, medical treatment and la- ser PI are often needed to lower the pressure first to provide sufficient visibility for cataract surgery." assessed with the European QoL– 5Dimensions questionnaire was 0.052 higher (95% CI, 0.015–0.088, P=.005) than standard care, and the mean IOP of 16.6 ±3.5 mm Hg was 1.18 mm Hg lower (95% CI, –1.99 to –0.38, P=.004) than in the standard care patients. Dr. Chansangpetch noted that although removing the lens could reverse appositional angle closure and theoretically prevent synechial closure—which might subsequently lead to primary angle closure and/ or primary angle closure glaucoma —she thinks there may be a lack of evidence at this point to recom- mend cataract surgery in primary angle closure suspects (PACS), the milder form within the angle closure disease spectrum. According to Shan Lin, MD, director of the glaucoma service, University of California, San Fran- cisco, the outcomes of several key studies make the case for cataract surgery even though there are also benefits to performing laser PI. One prospective interventional trial stud- ied the change of angle parameters measured by anterior segment OCT before and after laser PI in 52 cases of medically resolved acute angle closure attacks. The results showed a significant increase of all parameters, including anterior chamber depth at 6 weeks, as well as reductions in lens vault and iris curvature, after laser PI. 2 Similarly, data from the Zhong- shan Angle Closure Prevention (ZAP) trial reported a significant increase of key anterior segment parameters, including angle width, at 2 weeks af- ter laser PI in PACS patients. 3 In each study patient, LPI was performed in one eye and the fellow eye served as a control. Angle width was assessed using gonioscopy, and various angle configurations were obtained by an- terior segment OCT. The angle width was stable for 6 months, however, all studied parameters then revealed a slow decline in angle width over time after 2 weeks up to 18 months in the laser PI eyes (P<.001 for all variables). According to Dr. Lin, who was one of the investigators in the first study, current evidence seems to support the role of clear lens extraction in angle closure patients. "Our group studied the change in angle parameters before and after LPI in resolved acute angle clo- sure attacks resulting in significant increases," Dr. Lin said. "However, the rebound effect seen in the ZAP trial is likely caused by an increase in the lens vault and/or lens thick- ness; thus, lens extraction possibly provides further widening of the angles. In support of this assump- tion, studies on anatomical effects of cataract surgery in PACG eyes with a patent laser PI showed substan- tial additional ACD widening after surgery, from baseline 1.8–2.4 mm to 3.2–3.5 mm." A head-to-head study compar- ing laser PI and cataract surgery in 28 primary angle closure patients re- ported significantly greater improve- ment in trabecular iris space area and trabecular iris circumference volume, as measured by anterior chamber OCT, in the cataract sur- gery group compared to the laser PI group. 4 "Thus, cataract surgery not only had better improvement of the Removing continued from page 62 ACRYSOF ® IQ TORIC IOL IMPORTANT PRODUCT INFORMATION CAUTION: Federal (USA) law restricts this device to the sale by or on the order of a physician. INDICATIONS: The AcrySof ® IQ Toric posterior chamber intraocular lenses are intended for primary implantation in the capsular bag of the eye for visual correction of aphakia and pre-existing corneal astigmatism secondary to removal of a cataractous lens in adult patients with or without presbyopia, who desire improved uncorrected distance vision, reduction of residual refractive cylinder and increased spectacle independence for distance vision. WARNING/PRECAUTION: Careful preoperative evaluation and sound clinical judgment should be used by the surgeon to decide the risk/benefit ratio before implanting a lens in a patient with any of the conditions described in the Directions for Use labeling. Toric IOLs should not be implanted if the posterior capsule is ruptured, if the zonules are damaged, or if a primary posterior capsulotomy is planned. Rotation can reduce astigmatic correction; if necessary lens repositioning should occur as early as possible prior to lens encapsulation. All viscoelastics should be removed from both the anterior and posterior sides of the lens; residual viscoelastics may allow the lens to rotate. Optical theory suggests that high astigmatic patients (i.e. > 2.5 D) may experience spatial distortions. Possible toric IOL related factors may include residual cylindrical error or axis misalignments. Prior to surgery, physicians should provide prospective patients with a copy of the Patient Information Brochure available from Alcon for this product informing them of possible risks and benefits associated with the AcrySof ® IQ Toric Cylinder Power IOLs. Studies have shown that color vision discrimination is not adversely affected in individuals with the AcrySof ® Natural IOL and normal color vision. The effect on vision of the AcrySof ® Natural IOL in subjects with hereditary color vision defects and acquired color vision defects secondary to ocular disease (e.g., glaucoma, diabetic retinopathy, chronic uveitis, and other retinal or optic nerve diseases) has not been studied. Do not resterilize; do not store over 45° C; use only sterile irrigating solutions such as BSS ® or BSS PLUS ® Sterile Intraocular Irrigating Solutions. ATTENTION: Reference the Directions for Use labeling for a complete listing of indications, warnings and precautions.* © 2016 Novartis 11/16 US-TOR-16-E-4883 Advancing CATARACT SURGERY AcrySof ® IQ Toric ASTIGMATISM-CORRECTING IOL 98442 US-TOR-16-E-4883_PI EW.indd 1 7/13/17 2:26 PM

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