LASIK has better long-term results than photorefractive keratoplasty for treating myopia, according to a comparative case series evaluating the outcomes of both procedures at the Centre for Eye Research
The study evaluated 389 eyes (229 patients). In the PRK group, the mean preoperative spherical equivalent (SE) was -4.05 D ±1.17 in eyes with low to moderate myopia and -7.97
±2.00 D in eyes with high myopia (p=0.009). For the LASIK group, SE was -3.98 ±1.27 D and -7.64 ±1.66 D, respectively (p=0.008). At the last visit, the mean SE in the PRK group was -0.64 ±0.83 D in eyes with low to moderate myopia and -1.06 ±1.74 D in eyes with high myopia (p=0.73); the LASIK group was at -0.33 ±0.59 D and -0.63 ±0.90 D, respectively (p=0.68). At the end, 45.9 percent of eyes with low to moderate myopia and 25 percent with high myopia in the PRK group and 64.8 percent and 37.3 percent, respectively, in the LASIK group were within ±0.50 D of the attempted correction, showing that LASIK had better stability than PRK for up to six to nine years.
J Cataract Refract Surg 2010;36:1709-17
Dirani M, Couper T, Yau J, et al.
DuraSite Proves Detrimental to Animal Eyes
DuraSite bioadhesive (InSite Vision) has been shown to block the trabecular meshwork and may be additionally toxic when introduced as a large bolus in the anterior segment of rabbit eyes. In a randomized, masked, placebo-controlled animal study to determine whether Besivance (Bausch + Lomb), AzaSite (Inspire Pharmaceuticals)—both used with DuraSite—and ciprofloxacin are toxic inside the anterior chamber, researchers at the John A. Moran Eye Center, University of Utah, Salt Lake City, observed 20 New Zealand white rabbits (40 eyes) that were randomized to one of four study groups: Besivance, AzaSite, ciprofloxacin and balanced salt solution. Each eye was injected with 0.1 mL of the study medication. Clinical slit-lamp examinations were conducted at 24 and 48 hours after injection. After the animals were sacrificed, the eyes were randomized to either corneal vital staining or histopathologic examination. The main outcome measures were clinical and pathological signs of toxicity.
The DuraSite-based study groups showed clinically and pathologically significant differences when compared with the ciprofloxacin and balanced salt solution groups. Besivance and AzaSite eyes exhibited significantly similar and severe clinical damage, including severe corneal edema. Ciprofloxacin and balanced salt solution eyes appeared similar and had only mild conjunctival injection and limbal vascularity. Vital staining and histopathologic evaluation revealed glaucomatous and toxic damage in eyes given DuraSite-based medications, whereas non-DuraSite groups showed minimal changes. Until the safety of these medications is established with further studies using smaller injection volumes, the authors of the study recommend placing a suture over a clear corneal wound if DuraSite-based medications are used.
Am J Ophthalmol 2010;150:498-504.
CER Model Applicable to POAG
Research at
The 45 clinical questions were derived from the POAG PPPs. Of the 620 AGS members invited to participate in the survey, 169 completed the round one survey; 105 of 169 completed round two. Authors observed four response patterns to the individual questions. Nine clinical questions were ranked as the most important: four questions on medical intervention; four questions on filtering surgery; and one question on adjustment of therapy. The authors concluded that the theoretical model for priority setting for CER questions is a feasible and pragmatic approach that merits testing in other medical settings.
Ophthalmology 2010;117:1937-45.
Li T, Ervin AM, Scherer R, et al.
Abnormal Antibody Levels and Age Accelerate VF Change
Results from the Canadian Glaucoma Study Group have shown that patients with abnormal anticardiolipin antibody levels and increasing age had faster visual field change during glaucoma progression. During the course of a study designed to determine rates of visual field change associated with risk factors for progression (abnormal anticardiolipin antibody level, age, female sex and mean follow-up intraocular pressure) as well as to evaluate the effect of IOP reduction on subsequent rates of visual field change in progressing patients, researchers followed 216 patients (median age: 65.2 years) at four-month intervals with perimetry while monitoring for progression. Patients reaching an endpoint based on total deviation analysis underwent 20 percent or greater reduction in IOP. Rates of mean deviation (MD) change were calculated.
Patients with zero, one and two end-points had a median of 18, 23 and 25 examinations, respectively. The median MD rate in progressing patients prior to the first endpoint was significantly worse compared with those with no progression (-0.35 and 0.05 dB/y, respectively). An abnormal anticardiolipin antibody level was associated with a significantly worse MD rate compared with a normal anticardiolipin antibody level (-0.57 and -0.03 dB/y, respectively). Increasing age was associated with a worse MD rate, but female sex and mean follow-up IOP were not. After the first endpoint, the median IOP decreased from 18 to 14.8 mmHg (20 percent in individual patients), resulting in a significant MD rate change from -0.36 to -0.11 dB/y, showing that modest IOP reduction in progressing patients significantly ameliorated the rate of visual field decline.
Arch Ophthalmol 2010;128:1249-55.
Bevacizumab and Ranibizumab Pose Little Risk in AMD Treatment
Bevacizumab and ranibizumab use is not associated with increased risks of mortality, myocardial infarction, bleeding or stroke compared with photodynamic therapy or pegaptanib use, say researchers at Duke University School of Medicine. The two-year, retrospective, cohort study of 146,942 Medicare beneficiaries 65 years or older with a claim for age-related macular degeneration evaluated the risks of AMD therapies. On the basis of claims for the initial treatment, beneficiaries were assigned to four groups: an active control group including patients who received photodynamic therapy; and patients who received intravitreous pegaptanib octasodium, bevacizumab or ranibizumab. Patients data were eliminated if they received a therapy different from the initial therapy. The main outcome measures were associations between photodynamic, pegaptanib, bevacizumab and ranibizumab therapies and the risks of all-cause mortality, incident myocardial infarction, bleeding and incident stroke.
After adjustment for baseline characteristics and comorbid conditions, the authors found significant differences in the rates of mortality and myocardial infarction by treatment group. Specifically, the hazard of mortality was significantly lower with ranibizumab therapy than with photodynamic therapy (hazard ratio, 0.85; 99 percent confidence interval, 0.75 to 0.95) or pegaptanib use (0.84; 0.74 to 0.95), and the hazard of myocardial infarction was significantly lower with ranibizumab use than with photodynamic therapy (0.73; 0.58 to 0.92). There were no significant differences in the hazard of mortality or myocardial infarction between bevacizumab use and the other therapies. No statistically significant relationship between treatment group and bleeding events or stroke was found.
Arch Ophthalmol 2010;128:1273-9.
Curtis LH, Hammill BG, Schulman KA, Cousins SW.
