EW Weekly, April 15, 2016

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April 15, 2016
Volume 21 , Number 14

BromSite granted FDA approval

The U.S. Food and Drug Administration has granted approval for BromSite (bromfenac ophthalmic solution) 0.075% for the treatment of postoperative inflammation and prevention of ocular pain in patients undergoing cataract surgery, marketer Sun Ophthalmics (Princeton, New Jersey) said in a press release. BromSite is the first nonsteroidal anti-inflammatory drug approved in the U.S. to prevent pain. The compound is the first bromfenac solution formulated in DuraSite, a polymer-based formulation that can be used to improve solubility, absorption, bioavailability, and residence time as compared to conventional topical therapies, developed by InSite Vision (now a subsidiary of Sun Pharma, Mumbai, India). BromSite's approval was based on data from 2 multicenter, randomized, placebo-controlled phase 3 studies, where a significantly higher proportion of BromSite-treated patients were pain-free at day 1 post-surgery (77% and 82%) compared to patients treated with vehicle control (48% and 62%; p<0.001). Additionally, a significantly higher proportion of subjects administered BromSite were inflammation-free at day 15 post-cataract surgery (57% and 38%), compared to a vehicle control group (19% and 22%; p<0.001 and p=0.035, respectively).

Largest eye study on Chinese&nbsp;Americans published

The largest eye study on those with Chinese ancestry living in the U.S. found a higher percentage (85%) of neovascular or "wet" age-related macular degeneration (AMD) than geographic atrophy or "dry" AMD (15%), according to researchers at University of Southern California (USC) Roski Eye Institute, Los Angeles; this is almost directly opposite of what has been found in whites or other ethnic groups. The study found the prevalence of AMD is higher among Chinese Americans as compared to the Chinese population living in urban/rural China, suggesting the influence of environmental or behavioral factors should be considered. The other substantial finding in the study is that participants with diabetes (17.4%) were 3 times more likely than those without the disease to have significant visual impairment. This increase was found in the Chinese American study participants with type 2 diabetes who had cataracts or macular edema resulting in visual impairments. While 41% of these Chinese American study participants had diabetic retinopathy, this is a lower percentage than has been reported among Chinese people living in rural China (46%) and Latinos living in Los Angeles (48%).

VEGF-A plays role in AMD and cataract

Increased expression of the angiogenic factor VEGF-A promotes 3 common age-related eye conditions, both versions of age-related macular degeneration (AMD) and also cataracts, in an animal model, according to a press release from Massachusetts General Hospital, Boston. Using a mouse model in which VEGF-A is expressed at 2-3 times the normal level, similar to what is seen in aging humans, Alexander Marneros, MD, found this level of increased VEGF-A expression in the retina led to the kind of damage seen in both wet and dry AMD. A "surprising finding" was that VEGF-A was also expressed in the lens, which has no vascular system, and that its overexpression in the mouse model increased markers of oxidative stress in the lens and accelerated the formation of cataracts. IL-1β activation was found to be involved in dry AMD-like retinal damage seen in the mouse model, even at areas with no vascular overgrowth. But in strains of mice with both overexpression of VEGF-A and inactivation of certain genes essential to the NLRP3 inflammasome, the characteristic retinal degeneration did not appear, Dr. Marneros found. Overexpression of IL-1β was also seen in the lenses of mice with VEGF-A-induced cataracts.

RESEARCH BRIEFS

  • A new paper in the American Journal of Ophthalmology evaluated the magnitude, with-the-rule (WTR) or against-the-rule (ATR) orientation, and vector components (Jackson astigmatic vectors [J0 and J45] and blurring strength) of the anterior and posterior corneal astigmatism (ACA and PCA) in patients with keratoconus. Mohammad Naderan, MD, and colleagues evaluated Pentacam (Oculus, Arlington, Washington) images to compare 1,273 patients with keratoconus and 1,035 normal age- and sex-matched participants. The mean magnitude of the ACA and PCA was 4.47±2.14 and 0.90±0.43 D, respectively. The dominant astigmatism orientation of the ACA was ATR in keratoconus patients and WTR in normal participants (p<0.001), while for the PCA it was WTR in keratoconus patients and ATR in normal participants (p<0.001). There was a significant agreement between the axis orientations of ACA and PCA in keratoconus patients (ĸ=0.077, p<0.001), but not in the normal group (p=0.626). ACA and PCA magnitude, M, J0, J45, and blur significantly increased by increasing keratoconus severity. There was a trend for increasing anterior ATR and posterior WTR and decreasing oblique astigmatism on both corneal surfaces by increasing the keratoconus severity according to the Amsler-Krumeich classification. A cutoff value of 1.8 D for ACA had 90.2% sensitivity and specificity, and that of 0.4 D for PCA had 89.5% sensitivity and 85.0% specificity for discriminating keratoconus from normal corneas.
  • Errors in IOL calculation for normal eyes after laser refractive treatment are related to the ratio of posterior-to-anterior corneal radius, according to a retrospective data analysis and validation study from A.K. Schuster and colleagues. They tested a new method of IOL calculation after corneal refractive surgery using Scheimpflug imaging (Pentacam HR) and partial coherence interferometry (PCI, IOLMaster, Carl Zeiss Meditec, Jena, Germany) that does not require historical data, the Schuster/Schanzlin-Thomas-Purcell (SToP) IOL calculator. The regression analysis study included 61 eyes (39 patients) that had LASIK (57 eyes) or photorefractive keratectomy (4 eyes) and subsequent cataract. Two factors were found that explained the deviation of the target refraction using the Holladay 1 formula; that is, the ratio of the corneal radii and the axial length and the ratio of corneal radii for the SRK/T formula. A new IOL adjustment calculator was derived and validated at a second center using 14 eyes (10 patients). The study is published in the Journal of Cataract & Refractive Surgery.
  • Coaxial micro-incision cataract surgery (C-MICS) was associated with less surgically induced astigmatism (SIA) 1 month after surgery than standard 2.75 mm incision cataract surgery (SICS), but differences were not statistically significant at final follow-up, indicating a faster refractive recovery with C-MICS than with SICS, according to prospective study from M.P. Czajka and colleagues. They evaluated 30 eyes (30 patients) scheduled to undergo combined phacoemulsification and 23-G vitrectomy and randomized them 1:1 to either C-MICS or SICS. Incision leakage occurred in 2 eyes (7%: 1 per group) and retinal break in 9 (30%: 4 in C-MICS, 5 in SICS). Fibrin in the anterior chamber occurred at day 1 in 3 eyes (10%: 2 C-MICS and 1 SICS). Posterior capsule opacification developed in 22 eyes (78%: 13 C-MICS, 9 SICS, p=0.1). A myopic shift of -0.63±0.7 was noted (-0.59±0.8 C-MICS, -0.68±0.6 SICS, p=0.74). SIA was significantly smaller in the C-MICS group at 1 month but not at final follow-up. The study is published in Acta Ophthalmologica.

EYEWORLD WEEK Online is edited by Stacy Majewicz and Michelle Dalton.

EyeWorld Week Online (ISSN 1089-0319), a digital publication of the American Society of Cataract and Refractive Surgery and the American Society of Ophthalmic Administrators, is published every Friday, distributed by email, and posted live on Friday.

Medical Editors: Eric Donnenfeld, MD, chief medical editor; Rosa Braga-Mele, MD, cataract editor; Clara Chan, MD, cornea editor; Nathan Radcliffe, MD, glaucoma editor; and Vance Thompson, MD, refractive editor.

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