Oral docosahexaenoic acid in the prevention of exudative age-related macular degeneration: the Nutritional AMD Treatment 2 study.

OBJECTIVE: To evaluate the efficacy of docosahexaenoic acid (DHA)-enriched oral supplementation in preventing exudative age-related macular degeneration (AMD). DESIGN: The Nutritional AMD Treatment 2 study was a randomized, placebo-controlled, double-blind, parallel, comparative study. PARTICIPANTS: Two hundred sixty-three patients 55 years of age or older and younger than 85 years with early lesions of age-related maculopathy and visual acuity better than 0.4 logarithm of minimum angle of resolution units in the study eye and neovascular AMD in the fellow eye. METHODS: Patients were assigned randomly to receive either 840 mg/day DHA and 270 mg/day eicosapentaenoic acid (EPA) from fish oil capsules or the placebo (olive oil capsules) for 3 years. MAIN OUTCOME MEASURES: The primary outcome measure was time to occurrence of choroidal neovascularization (CNV) in the study eye. Secondary outcome measures in the study eye were: incidence of CNV developing in patients, changes in visual acuity, occurrence and progression of drusen, and changes in EPA plus DHA level in red blood cell membrane (RBCM). RESULTS: Time to occurrence and incidence of CNV in the study eye were not significantly different between the DHA group (19.5±10.9 months and 28.4%, respectively) and the placebo group (18.7±10.6 months and 25.6%, respectively). In the DHA group, EPA plus DHA levels increased significantly in RBCM (+70%; P<0.001), suggesting that DHA easily penetrated cells, but this occurred unexpectedly also in the placebo group (+9%; P = 0.007). In the DHA-allocated group, patients steadily achieving the highest tertile of EPA plus DHA levels in RBCM had significantly lower risk (-68%; P = 0.047; hazard ratio, 0.32; 95% confidence interval, 0.10-0.99) of CNV developing over 3 years. No marked changes from baseline in best-corrected visual acuity, drusen progression, or geographic atrophy in the study eye were observed throughout the study in either group. CONCLUSIONS: In patients with unilateral exudative AMD, 3 years of oral DHA-enriched supplementation had the same effect on CNV incidence in the second eye as did the placebo. However, RBCM fatty acid measurements revealed that CNV incidence was significantly reduced in DHA-supplemented patients showing a steadily high EPA plus DHA index over 3 years. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Suppression of drusen formation by compstatin, a peptide inhibitor of complement C3 activation, on cynomolgus monkey with early-onset macular degeneration.

For the past 10 years, number of evidence has shown that activation of complement cascade has been associated with age-related macular degeneration (AMD). The genome wide association study in American population with dominantly dry-type AMD has revealed strong association with single nucleotide polymorphism (SNP) of complement genes. Protein composition of drusen, a deposit observed in sub-retinal space between Bruch's membrane and retinal pigment epithelial (RPE), contains active complement molecules in human and monkey. These evidences have leaded us to consider the possibility of suppressing complement cascade in the retina to delay or reverse the onset of AMD. To test is hypothesis we used the C3 inhibitor Compstatin on primate model with early-onset macular degeneration which develop drusen in less than 2 years after birth. Our preliminary result showed drusen disappearance after 6 months of intravitreal injection.

Grading of age-related maculopathy: slit-lamp biomicroscopy versus an accredited grading center.

PURPOSE: To compare clinical age-related maculopathy (ARM) grading using slit-lamp biomicroscopy (SLB) versus photographic grading of stereoscopically captured fundus photographs (FP) using a high-resolution fundus camera. METHODS: A subset (129) of participants in the Carotenoids in ARM study were clinically graded for ARM signs and the corresponding FPs were graded in an accredited reading center. RESULTS: Drusen were said to be present in 192 (94.5%) eyes graded by FP, and in 165 (82.5%) eyes examined by SLB (agreement = 84%, k = 0.23). A good and modest degree of agreement was observed between SLB and FP for quantification of total drusen number (agreement = 81%, k = 0.33) and for classification of drusen subtypes (agreement = 60%, k = 0.33), respectively. Localization of drusen to either the inner zone or the outer zone was comparable for both techniques of ARM grading (inner zone: agreement = 89%; outer zone: agreement = 88%, k = 0.39). Agreement between SLB and FP was 76% (k = 0.46) for identification of any pigment abnormality; however, agreement was less for hypo-pigmentation abnormalities (agreement = 64%, k = 0.21). CONCLUSIONS: From the statistical perspective, SLB grading of ARM is generally comparable with findings from standardized grading of FP. However, the lower levels of agreement for classification of drusen subtypes and detection of hypo-pigmentation suggest these features may go unrecorded in a study which relies on SLB for grading ARM.

The relationship of dietary omega-3 long-chain polyunsaturated fatty acid intake with incident age-related macular degeneration: AREDS report no. 23.

OBJECTIVE: To examine the association of dietary omega-3 long-chain polyunsaturated fatty acid and fish intake with incident neovascular age-related macular degeneration (AMD) and central geographic atrophy (CGA). METHODS: Multicenter clinic-based prospective cohort study from a clinical trial including Age-Related Eye Disease Study (AREDS) participants with bilateral drusen at enrollment. Main outcome measures were incident neovascular AMD and CGA, ascertained from annual stereoscopic color fundus photographs (median follow-up, 6.3 years). We estimated nutrient and food intake from a validated food frequency questionnaire (FFQ) at baseline, with intake of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), combined EPA and DHA, and fish as primary exposures. RESULTS: After controlling for known covariates, we observed a reduced likelihood of progression from bilateral drusen to CGA among people who reported the highest levels of EPA (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.23-0.87) and EPA+DHA (OR, 0.45; 95% CI, 0.23-0.90) consumption. Levels of DHA were associated with CGA in age-, sex-, and calorie-adjusted models (OR, 0.51; 95% CI, 0.26-1.00); however, this statistical relationship did not persist in multivariable models. CONCLUSIONS: Dietary lipid intake is a modifiable factor that may influence the likelihood of developing sight-threatening forms of AMD. Our findings suggest that dietary omega-3 long-chain polyunsaturated fatty acid intake is associated with a decreased risk of progression from bilateral drusen to CGA.

Intake of zinc and antioxidant micronutrients and early age-related maculopathy lesions.

BACKGROUND: Macular degeneration, the end stage of age-related maculopathy (ARM), is the leading cause of legal blindness worldwide, and few modifiable risk factors are known. The high concentration of carotenoids in the macula, plus evidence linking oxidative stress to ARM and carotenoids to antioxidation, generated the hypothesis that higher antioxidant intakes can prevent ARM. Results of observational and intervention studies have been inconsistent. OBJECTIVE: To evaluate associations between intakes of zinc and antioxidant micronutrients and early ARM. METHODS: Between 1993 and 1995, ARM was assessed in 398 Boston-area women aged 53-74 y using the Wisconsin Age-related Maculopathy System of grading retinal fundus photographs. The women were a subset of the Nurses' Health Study cohort. Micronutrient intake was assessed by semi-quantitative food frequency questionnaires administered four times between 1980 and the baseline eye examinations. RESULTS: After multivariate adjustment for potential confounders, 1980 energy-adjusted intakes of alpha-carotene, beta-carotene, lycopene, total retinol, total vitamin A, and total vitamin E were significantly inversely related to the prevalence of pigmentary abnormalities (PA). Furthermore, increasing frequency of consuming foods high in alpha-or beta-carotene was associated with lower odds of PA; compared to women consuming these foods < 5 times/wk, odds ratios (95% CI) were 0.7 (0.3-1.6) for 5-6 times/wk, 0.6 (0.2-1.3) for 7-9.5 times/wk, and 0.3 (0.1-0.7)for > or =10 times/wk. Lutein/zeaxanthin intakes and more recent intakes of most carotenoids were unrelated to PA, and intakes of zinc and antioxidant micronutrients were unrelated to having large or intermediate drusen alone.

Risk factors for choroidal neovascularization and vision loss in the fellow eye study of CNVPT.

PURPOSE: To identify risk factors for the development of choroidal neovascularization (CNV) and vision loss in the Fellow Eye Study of the Choroidal Neovascularization Prevention Trial. METHODS: Retrospective review of 121 patients enrolled in a multicentered, randomized, controlled trial. Patients had neovascular age-related macular degeneration in one eye and more than 10 large drusen in the other eye. Records of patients randomly assigned to laser treatment or observation were reviewed through 4 years of follow-up. Three candidate risk factors for the development of CNV and vision loss were evaluated. RESULTS: Eyes with hyperfluorescent drusen on fluorescein angiography at 3 minutes appeared to have a decreased risk of CNV. Patchy choroidal filling was seen in 14% of patients. Eyes with patchy choroidal perfusion showed a higher risk of developing CNV that was not statistically significant, and the increased risk was present only in treated eyes. Reticular pseudodrusen were present in only three eyes. CONCLUSIONS: Reticular pseudodrusen were rare. Late drusen fluorescence may protect against the development of CNV.

Influence of laser photocoagulation on choroidal capillary cytoarchitecture.

AIM: To identify if laser photocoagulation induces morphological changes specifically related to the choroidal capillary endothelial processes that protrude into Bruch's membrane. METHODS: Two human eyes and one adult macaque monkey eye received retinal laser photocoagulation that was just suprathreshold, before enucleation or exenteration. They were examined by electron microscopy to determine the length of the endothelial processes emanating from the choroidal capillaries in the region around the laser burn. One human and two monkey untreated eyes were used for comparison. RESULTS: In human eyes, there was no increase in the number of processes 15 hours after laser treatment but at 5 days the processes were more numerous and longer within 400-500 microm of the burn than in the untreated half of the same eye. The processes were longer 9 days after photocoagulation in the monkey, when compared with untreated monkeys, and some breached the elastic lamina, a phenomenon not seen in the untreated eyes. Qualitative differences were also noted in the endothelial cell processes following photocoagulation. Neovascularisation was not observed. CONCLUSIONS: Protrusion of choroidal endothelial cell processes into Bruch's membrane is a normal anatomical feature but the number, length, and morphology of the processes change following mild photocoagulation. It is plausible that these processes may play a part in the clearance of debris from Bruch's membrane, and represent an early stage of angiogenesis. If the latter is true prophylactic laser photocoagulation at just suprathreshold levels may carry a risk of inducing choroidal neovascularisation.

The VECAT study: methodology and statistical power for measurement of age-related macular features. Vitamin E, Cataract, and Age-related Maculopathy Study.

PURPOSES: (1) To develop the methodology for the grading of macular one-frame stereoslides and to assess the reliability of the system. (2) To determine the prevalence of soft drusen (> 63 microm) and pigment abnormalities synonymous with age-related maculopathy (ARM) at baseline, in a clinical trial of volunteers aged between 55 and 80 years of age. (3) To ascertain the power of the study to detect the 4-year incidence and progression of ARM in vitamin E versus placebo treated participants, given the baseline prevalence. METHODS: The 1204 participants enrolled in the Vitamin E, Cataract, and Age-related Maculopathy Study (VECAT) had colour stereoslides of their fundus taken using the Nidek 3-DX mydriatic fundus camera. The stereoslides were graded by two masked graders according to the "International Classification System for ARM and AMD". Assessment of inter- and intra-observer reliability was carried out on a regular basis on 15% of randomly selected slides. Anticipated rates of incidence and progression were based on results reported by the Beaver Dam Eye Study and the Chesapeake Bay Waterman Study. Power estimations were determined using the "nQuery Advisor" software program. Analyses were carried out on the worse affected eye. RESULTS: Inter-observer reliability was moderate to substantial (Kappa 0.5-0.88) whilst intra-observer agreement was high (0.6-1.0). The prevalence of any soft drusen was 32%. Significant associations were found between soft large indistinct drusen, hypopigmentation, hyperpigmentation and age (p = 0.0001, 0.024 and 0.0001, respectively). The study has at least 87% power to detect an odds ratio equal to two for the progression of soft distinct, soft indistinct, hyperpigmentation and hypopigmentation. CONCLUSIONS: The VECAT study methodology appears to be highly reliable and to have sufficient power to detect the differences in the four-year progression of soft distinct and indistinct drusen and pigment abnormalities between the treatment groups.