THE LATEST PUBLISHED RESEARCH

Trials’ Endophthalmitis Rate Low Despite No Antibiotics in Days Before Intravitreal Injection
After 2,009 intravitreal injections in two randomized clinical trials, a low rate of endophthalmitis has been achieved without the prophylactic use of topical antibiotics on the days before the injections.

Since Dec. 31 of last year, 1,378 injections have been administered in the Diabetic Retinopathy Clinical Research Network Diabetic Macular Edema trial and 631 have been administered in the Standard Care vs. Corticosteroid for Retinal Vein Occlusion trial according to a standardized procedure. One case of endophthalmitis has occurred (0.05 percent, 95 percent confidence interval 0.001 percent to 0.277 percent).

Source: Bhavsar AR, Ip MS, Glassman AR. The risk of endophthalmitis following intravitreal triamcinolone injection in the DRCRnet and SCORE clinical trials. Am J Ophthalmol 2007;144:454-456.

Rate of Noninfectious Endophthalmitis Higher with Preserved Triamcinolone Injection
In a retrospective review of 646 intravitreal injections of triamcinolone acetonide (4 mg/0.1 mL) in 471 eyes, noninfectious endophthalmitis occurred more frequently when preserved, rather than nonpreserved, drug was used. Non-infectious endophthalmitis was defined as pseudohypopyon/hypopyon with or without an inflammatory reaction that regressed after treatment with topical steroid. Mean follow-up in the reviewed cases was 13 months (six to 57 months).

Non-infectious endophthalmitis developed in a total of 12 eyes (1.9 percent), but the rates between the two groups varied significantly (p=0.005). The rate in the preserved-drug group was 7.3 percent; the rate in the nonpreserved-drug group was 1.2 percent. One eye developed bacterial endophthalmitis.

Source: Maia M, Farah ME, Belfort RN, et al. Effects of intravitreal triamcinolone acetonide injection with and without preservative. Br J Ophthalmol 2007;91:1122-1124.

Primary vs. Secondary Bevacizumab for AMD
A group of researchers recently compared the effectiveness of primary therapy with bevacizumab (Avastin) and secondary therapy with bevacizumab after multiple injections of pegaptanib sodium (Macugen) for choroidal neovascularization (CNV) due to age-related macular degeneration (AMD). In their study, 18 eyes received primary bevacizumab and 20 eyes received pegaptanib as initial treatment followed by bevacizumab. All of the intravitreal injections were given at six-week intervals.

Primary bevacizumab therapy resulted in significantly greater improvement in visual acuity. At three months, mean visual acuity in the primary group improved by 1.5 ETDRS lines (p=0.0009) and decreased by 0.4 lines (p=0.27) in the secondary group. At six months, mean visual acuity improved by 2.2 lines (p=0.0004) in the primary group and by 0.2 lines (p=0.70) in the secondary group. The mean decrease in retinal thickness was also higher in the primary bevacizumab treatment group at three months and six months.

Source: Falkenstein IA, Cheng L, Morrison VL, et al. Standardized visual acuity results associated with primary versus secondary bevacizumab (Avastin) treatment for choroidal neovascularization in age-related macular degeneration. Retina 2007;27:701-706.

AREDS Report: Lutein, Zeaxanthin Inversely Associated with AMD
According to an assessment of the relationship between diet and AMD in 4,519 participants in the Age-Related Eye Disease Study (AREDS), higher dietary intake of lutein and zeaxanthin was independently associated with decreased likelihood of having neovascular AMD, geographic atrophy and large or extensive intermediate drusen.

Demographic, life style and medical characteristics of the subjects were determined at enrollment in AREDS. Nutrient intake values based on a self-administered questionnaire were energy-adjusted and classified by quintiles. Adjustments were made for non-nutrient-based covariates.

Logistic regression analyses showed that dietary lutein/zeaxanthin intake was inversely associated with neovascular AMD (odds ratio 0.65; 95 percent confidence interval 0.45-0.93), geographic atrophy (odds ratio 0.45; 95 percent confidence interval 0.24-0.86) and large or extensive intermediate drusen (odds ratio 0.73; 95 percent confidence interval 0.56-0.96). In contrast, vitamin A, alpha-tocopherol and vitamin C were not independently related to AMD.

Source: SanGiovanni JP, Chew EY, Clemons TE, et al., for the Age-Related Eye Disease Study Research Group. The relationship of dietary carotenoid and vitamin A, E, and C intake with age-related macular degeneration in a case-control study. AREDS Report No. 22. Arch Ophthalmol 2007;125:1225-1232.

New Research on Smoking and AMD
Researchers in the Blue Mountains Eye Study reported on their recent finding that smoking strongly increased the long-term risk of incident late--but not early--AMD. Of 3,654 Australian subjects age 49 and older at baseline (Jan. 14, 1992-Dec. 18, 1993), 2,454 were examined five years later, 10 years later or both. After controlling for age, sex and other factors, current smokers had a fourfold higher risk of late AMD than subjects who never smoked (relative risk, 3.9; 95 percent confidence interval, 1.7-8.8). Past smokers had a threefold higher risk of geographic atrophy (relative risk, 3.4; 95 percent confidence interval, 1.2-9.7).

The researchers also reported that joint exposure to current smoking and the lowest level of high-density lipoprotein (HDL) cholesterol, the highest total to HDL cholesterol ratio, or low fish consumption was associated with a higher risk of late AMD than the effect of any risk factor alone, although the interactions were not statistically significant.

Source: Tan JSL, Mitchell P, Kifley A, et al. Smoking and the long-term incidence of age-related macular degeneration: The Blue Mountains Eye Study. Arch Ophthalmol 2007;125:1089-1095.

Evaluation of PPV for Retained Lens Material
A recently published retrospective interventional consecutive case series was designed to evaluate the outcomes and complications associated with pars plana vitrectomy (PPV) for retained lens material after cataract surgery. The series consisted of 223 eyes of 223 patients who underwent PPV at Sydney Eye Hospital between July 1, 1998 and Oct. 31, 2003. Mean follow-up after vitrectomy was 20.5 months.

Final best-corrected visual acuity was 6/12 or better in 159 (71.3 percent) patients. Retinal detachment, either before, during or after PPV, occurred in 20 patients (9 percent). Intraocular pressure increased in 10 patients (5 percent), and cystoid macular edema developed in 42 patients (23.2 percent). Poor final visual acuity was associated with retinal detachment (p=.0026) and poor visual acuity at presentation (p=.030). Significant associations were found between retinal detachment and a long interval (more than 30 days) between cataract surgery and vitrectomy (p=.00047) and between retinal detachment and younger age (p=.0070).

Source: Meraniab R, Hunyorab AP, Playfaira TJ, et al. Pars plana vitrectomy for the management of retained lens material after cataract surgery. Am J Ophthalmol 2007;144:364-370.

Systematic Review of Treatments for Diabetic Retinopathy
According to the authors of a review published in the Journal of the American Medical Association, tight glycemic and blood pressure control reduce the incidence and progression of diabetic retinopathy and continue to be the cornerstone in its primary prevention. Meta-analyses and all English-language reports of randomized controlled trials with more than 12 months of follow-up, which were identified via electronic database and manual reference list searching, were considered. Forty-four studies (including three meta-analyses) were included.

The reviewers concluded that panretinal laser photocoagulation reduces the risk of moderate and severe vision loss by 50 percent in eyes with severe nonproliferative and proliferative retinopathy. They also concluded that focal laser photocoagulation reduces the risk of moderate vision loss by 50 to 70 percent in eyes with macular edema. They wrote that, other than early vitrectomy in certain cases and intravitreal steroids in refractory cases, insufficient evidence exists for routine use of other treatments, such as lipid-lowering therapy and antivascular endothelial growth factors.

Source: Mohamed Q, Gillies MC, Wong TY. Management of diabetic retinopathy: a systematic review. JAMA 2007;298:902-916.