Methods for detecting age-related maculopathy: a comparison between photographic and clinical assessment

Diagnostic sensitivity and specificity of dark adaptometry for detection of age-related macular degeneration

PURPOSE

Difficulty with night vision is a common complaint of patients with age-related macular degeneration (AMD). Consistent with this complaint, dark adaptation (DA) is substantially impaired in these patients. Because of the severity of the deficit, measurement of DA has been suggested as a means for the diagnosis of AMD. Previous methods for measurement of DA were time intensive (>30 minutes), which made them unsuitable for clinical use. This study evaluated a rapid DA test (≤ 6.5 minutes) for the detection of AMD.

METHODS

Dark adaptation was measured by using the AdaptDx dark adaptometer in two groups: subjects with normal retinal health and subjects with AMD. Subjects were assigned to their group by clinical examination and grading of fundus photographs. Subjects were classified as having DA consistent with normal retinal health (rod intercept ≤ 6.5 minutes) or having dark adaptation consistent with AMD (rod intercept > 6.5 minutes).

RESULTS

The eligible sample for analysis included 21 normal adults and 127 AMD patients. The rapid test was found to have a diagnostic sensitivity of 90.6% (P < 0.001) and specificity of 90.5% (P < 0.027). Thus, abnormal DA was detected in 115 of 127 AMD patients, and normal DA was found in 19 of 21 normal adults.

CONCLUSIONS

The high diagnostic sensitivity and specificity compared favorably to long-duration research methods for the measurement of DA, and slit lamp biomicroscopy performed by a retina specialist. These results suggest that a rapid DA test is useful for the detection of AMD.

The cost-effectiveness of Welcome to Medicare visual acuity screening and a possible alternative welcome to medicare eye evaluation among persons without diagnosed diabetes mellitus

OBJECTIVE

To estimate the cost-effectiveness of visual acuity screening performed in primary care settings and of dilated eye evaluations performed by an eye care professional among new Medicare enrollees with no diagnosed eye disorders. Medicare currently reimburses visual acuity screening for new enrollees during their initial preventive primary care health check, but dilated eye evaluations may be a more cost-effective policy.

DESIGN

Monte Carlo cost-effectiveness simulation model with a total of 50 000 simulated patients with demographic characteristics matched to persons 65 years of age in the US population.

RESULTS

Compared with no screening policy, dilated eye evaluations increased quality-adjusted life-years(QALYs) by 0.008 (95% credible interval [CrI], 0.005-0.011) and increased costs by $94 (95% CrI, −$35 to$222). A visual acuity screening increased QALYs in less than 95% of the simulations (0.001 [95% CrI, −0.002 to 0.004) and increased total costs by $32 (95% CrI, −$97 to $159) per person. The incremental cost-effectiveness ratio of a visual acuity screening and an eye examination compared with no screening were $29 000 and$12 000 per QALY gained, respectively. At a willingness-to-pay value of $15 000 or more per QALY gained, a dilated eye evaluation was the policy option most likely to be cost-effective.

CONCLUSIONS

The currently recommended visual acuity screening showed limited efficacy and cost-effectiveness compared with no screening. In contrast, anew policy of reimbursement for Welcome to Medicare dilated eye evaluations was highly cost-effective.

The cost-effectiveness of three screening alternatives for people with diabetes with no or early diabetic retinopathy

OBJECTIVE

To determine whether biennial eye evaluation or telemedicine screening are cost-effective alternatives to current recommendations for the estimated 10 million people aged 30-84 with diabetes but no or minimal diabetic retinopathy.

DATA SOURCES

United Kingdom Prospective Diabetes Study, National Health and Nutrition Examination Survey, American Academy of Ophthalmology Preferred Practice Patterns, Medicare Payment Schedule.

STUDY DESIGN

Cost-effectiveness Monte Carlo simulation.

DATA COLLECTION/EXTRACTION METHODS

Literature review, analysis of existing surveys.

PRINCIPAL FINDINGS

Biennial eye evaluation was the most cost-effective treatment option when the ability to detect other eye conditions was included in the model. Telemedicine was most cost-effective when other eye conditions were not considered or when telemedicine was assumed to detect refractive error. The current annual eye evaluation recommendation was costly compared with either treatment alternative. Self-referral was most cost-effective up to a willingness to pay (WTP) of U.S.$37,600, with either biennial or annual evaluation most cost-effective at higher WTP levels.

CONCLUSIONS

Annual eye evaluations are costly and add little benefit compared with either plausible alternative. More research on the ability of telemedicine to detect other eye conditions is needed to determine whether it is more cost-effective than biennial eye evaluation.

C-reactive protein levels and complement factor H polymorphism interaction in age-related macular degeneration and its progression

PURPOSE

To determine the effect of elevated level of C-reactive protein (CRP) and its joint effect with the complement factor H (CFH) polymorphism on prevalent age-related macular degeneration (AMD) and its progression.

DESIGN

Two-arm case-control study: (a) Study on prevalent AMD cases and population-based controls; (b) longitudinal study on AMD progression, comparing those in whom AMD progressed with those with no progression.

PARTICIPANTS

(a) A cross-sectional sample of 544 participants, of whom 312 had features of early or late AMD and 232 were controls; (b) a sample of 254 early AMD cases, followed for 7 years.

METHODS

The study was conducted in Melbourne, Australia. Macular stereo photographs were graded for AMD according to the International Classification and Grading System. High-sensitivity CRP was measured in fresh serum, and genotyping was performed through the Australian Genome Research Facility. The association of CRP with outcomes was tested using multivariate logistic regression analysis adjusted for age, smoking, anti-inflammatory medications, and the CC genotype of the CFH gene. Risk factor interaction was explored using an additive model.

MAIN OUTCOME MEASURES

Prevalent early AMD, prevalent late AMD, progressed AMD, and measures of risk factor interaction.

RESULTS

Elevated CRP levels were associated with late AMD: odds ratio (OR), 3.12; 95% confidence interval (CI), 1.38-7.07. An association of elevated CRP with AMD progression was weaker: OR, 1.90 (95% CI, 0.88-4.10). A combination of elevated CRP and the CC (Y402H) genotype resulted in a super-additivity of the risks, with odds ratios of 19.3 (95% CI, 2.8-134) for late AMD, and 6.8 (95% CI, 1.2-38.8) for AMD progression, with the attributable proportion of risk owing to CRP-CFH interaction calculated at 26% for prevalent late AMD and 22% for AMD progression.

CONCLUSIONS

Synergistic influence of CRP levels and the at risk genotype of the CFH gene resulted in a super-additive risk for prevalent late AMD and AMD progression. Testing for the combination of these 2 risk factors to predict a high risk of AMD and its progression would allow for targeted trials of new intervention strategies.

Interobserver and intraobserver reliability of detecting age-related macular degeneration using a nonmydriatic digital camera

PURPOSE

To evaluate the interobserver and intraobserver reliability of detecting early and late age-related macular degeneration (AMD) using a nonmydriatic digital camera in two distinct groups of older people.

DESIGN

Prospective study.

METHODS

The two groups consisted of a series of patients older than 70 years hospitalized in a geriatric unit and a younger series of people older than 55 years. In both groups, nonmydriatic color fundus photographs were obtained and graded independently by two ophthalmologists (V.L. and M.S.). No ophthalmic examination was performed. Main outcome measures were frequencies of early and late AMD and interobserver and intraobserver agreement.

RESULTS

Among 233 patients in group 1 (mean age, 84.6 years), only 119 patients (51%) could undergo photography because of associated multiple morbidities. Mean age of group 2 was 63.8 years. In group 1, 35 (14.5%) of 238 pictures were ungradable. In series 2, 65 (9.1%) of 716 pictures were ungradable. Frequencies of early and late AMD were 30.3% and 5.9% vs 12.6% and 2.6% in series 1 and 2, respectively. Interobserver and intraobserver agreement was good or excellent (kappa > 0.6) in both groups.

CONCLUSIONS

In the entire geriatric cohort, 43% of the patients had gradable pictures allowing a diagnosis. These patients would otherwise have had no access to any form of funduscopy. In the younger population, nonmydriatic pictures permitted a diagnosis in 90% of the individuals. Detection of AMD with a nonmydriatic digital camera may lead to large-scale screening and specific management.

Dietary lutein, zeaxanthin, and fats and the progression of age-related macular degeneration

BACKGROUND

To estimate the effect of dietary intake of lutein and zeaxanthin (L/Z) and fats on the progression of age-related macular degeneration (AMD).

METHODS

Two hundred and fifty-four subjects identified with early age-related macular degeneration (AMD) were re-examined to determine 7-year AMD progression. Intakes of L/Z and fatty acids were estimated from food frequency questionnaires. Progression was defined by 3 different definitions, 2 quantitative and 1 qualitative, which varied in the stringency of the change required for the AMD to be deemed to have progressed. Covariates included age, smoking, AMD family history, source study, and follow-up duration.

RESULTS

Energy-adjusted L/Z intake as a continuous variable was associated with AMD progression in the worse affected eye when defined by the most stringent criterion (odds ratio [OR] = 2.65, 95% confidence interval [CI] 1.13-6.22, p = 0.02). Similar associations were observed for the 2 other progression definitions (p = 0.18 and p = 0.13). Energy-adjusted omega-3 fatty acid intake modelled as a quintile median was associated with AMD progression only in the side-by-side assessment (OR = 2.56, 95% CI 1.11-5.91, p = 0.03), with borderline significance in the other 2 definitions (p = 0.05 and p = 0.08). No association of AMD progression was observed with the intake of either total fat or other subgroups: saturated, polyunsaturated, or monounsaturated fats; trans fatty acids; or omega-6 fatty acids.

INTERPRETATION

The findings of the study are counterintuitive, suggesting that increased intakes of dietary L/Z and omega-3 fatty acids are associated with progression of AMD. These results may indicate that too much of a good thing might be harmful. It is possible that in this study participants adopted a more healthy diet, having been aware of their AMD status at the beginning of the study. This healthy diet was then reflected in the dietary questionnaire completed at the end of study. However, this explanation may not adequately explain why those whose AMD had progressed, on the basis of fundus signs and not symptoms such as visual acuity decline, adopted a healthier lifestyle more aggressively than those without progression.

Characteristics of dynamic processing in the visual field of patients with age-related maculopathy

Purpose

To investigate the characteristics of dynamic processing in the visual field of patients with age-related maculopathy (ARM) by measuring motion sensitivity, double-pulse resolution (DPR), and critical flicker fusion.

Methods

Fourteen subjects with ARM (18 eyes), 14 age-matched controls (19 eyes), and 7 young controls (8 eyes) served as subjects. Motion contrast thresholds were determined by a four-alternative forced-choice (4 afc) staircase procedure with a modification by Kernbach for presenting a plaid (size = 3.8°) moving within a stationary spatial and temporal Gaussian envelope in one of four directions. Measurements were performed on the horizontal meridian at 10°, 20°, 30°, 40°, and 60° eccentricity. DPR was defined as the minimal temporal gap detectable by the subject using a 9-fold interleaved adaptive procedure, with stimuli positioned on concentric rings at 5°, 10°, and 20° eccentricity on the principal and oblique meridians. Critical flicker fusion thresholds (CFF) and the Lanthony D-15 color vision test were applied foveally, and the subjects were free to use their fovea or whatever retinal area they needed to use instead, due to their retinal lesions caused by ARM. All measurements were performed under photopic conditions.

Results

Motion contrast sensitivity in subjects with ARM was pronouncedly reduced (0.23–0.66 log units, p < 0.01), not only in the macula but in a region up to 20° eccentricity. In the two control groups, motion contrast sensitivity systematically declined with retinal eccentricity (0.009–0.032 log units/degree) and with age (0.01 log units/year). Double-pulse thresholds in healthy subjects were approximately constant in the central visual field and increased outside a radius of 10° (1.73 ms/degree). DPR thresholds were elevated in subjects with ARM (by 23–32 ms, p < 0.01) up to 20° eccentricity, and their foveal CFFs were increased by 5.5 Hz or 14% (p < 0.01) as compared with age-matched controls.

Conclusions

Dynamic processing properties in subjects with ARM are severely impaired in the central visual field up to 20° eccentricity, which is clearly beyond the borders of the macula.

Associations of ambient illumination with mood: contribution of ophthalmic dysfunctions

Evidence suggests that ocular pathology could reduce light-stimulated neuronal signaling to the suprachiasmatic nuclei. This study investigated associations of ambient illumination with moods, while considering the contribution of ophthalmic dysfunctions. Seventy Black (59%) and White (41%) Americans participated in the study. Their average age was 68.27+/-5.97 years; 73% were women. Baseline data included: physical health, mood, and sociodemographics. Ophthalmic factors including visual acuity, visual field defects, intraocular pressure, vertical and horizontal cup-to-disk ratios, and nerve-fiber-layer thickness were assessed at SUNY Downstate's eye clinic. The following week, participants wore the Actiwatch-L at home to monitor ambient illumination and sleep. Cosine analyses were performed on the logarithm of measured illumination, yielding the mesor and acrophase of daily illumination exposure. Sleep was estimated with an automatic scoring algorithm. Of the sample, 25% reported visual impairment and 85% reported good to excellent health; 27% were visually impaired according to American criteria. Partial correlation analyses showed an inverse correlation of daily illumination levels to depressed mood [r(p)=-0.33, P<0.05], when age, sex, ethnicity, income, BMI, diabetes, hypertension, respiratory disease, and habitual sleep duration were controlled. With further control for ophthalmic factors, the magnitude and significance of the correlation diminished [r(p)=-0.26, NS]. Individuals receiving daily illumination later in the day reported more depressed moods [r(p)=0.36, P<0.01]; of note, this correlation was not significant after control for the covariates [r(p)=0.18, NS]. Regression analysis indicated that the ophthalmic factors explained 13% of the variance in depression. Our results show that both the level and timing of ambient illumination are associated with mood. Furthermore, they suggest that visual impairment has a mediating effect on the associations of ambient illumination with depression, supporting the notion that ocular pathology lessens the efficacy of daily illumination in promoting positive moods.

Cataract surgery in patients with age-related maculopathy: preoperative diagnosis and postoperative visual acuity

PURPOSE

To report the reliability in detecting age-related maculopathy (ARM) lesions before cataract surgery and postoperative visual acuity (VA) in cataract surgery patients with ARM.

METHODS

Medical records of surgical patients in a large public hospital, west of Sydney, were reviewed retrospectively. Detection of ARM lesions was compared before and after surgery to determine sensitivity and specificity of preoperative diagnoses. Postoperative VA was assessed 4 weeks after surgery.

RESULTS

Data were available for 721/784 eyes (92.0%) of 656 patients aged 60 years or older. ARM lesions were detected in 98 eyes (13.6%) before and 92 eyes (12.8%) after surgery. Sensitivities for detecting late ARM lesions, soft drusen and retinal pigment epithelium abnormalities preoperatively were 100%, 94% and 69%, respectively. Corresponding specificities were 100%, 100% and 77%, respectively. Postoperative VA achieved or remained 6/12 or better in 81.6% of eyes.

CONCLUSION

A high sensitivity and specificity in detecting late ARM lesions and soft drusen preoperatively, and a good postoperative VA outcome is achievable in patients with preoperative early ARM lesions.

Comparison of stereoscopic digital imaging and slide film photography in the identification of macular degeneration

BACKGROUND

This study compared the sensitivity and specificity of stereoscopic digital photography of the retina through a dilated pupil with a 45 degrees nonmydriatic camera and Joint Photographic Experts Group (JPEG) compression of the images with the sensitivity and specificity of 35-mm slide film photography in the identification of age-related macular degeneration (AMD).

METHODS

Consecutive patients with a diagnosis of AMD were enrolled. Stereoscopic retinal images of the disc, macula and temporal macula were captured with a digital 45 degrees nonmydriatic camera (then compressed into JPEG format) and with a standard fundus camera and slide film. A single retinal specialist graded both image formats in masked fashion, at least 1 month apart, using a modified Age-Related Eye Disease Study (AREDS) severity scale. The digital images were displayed on a monitor and viewed with the use of liquid crystal display shutter glasses and stereo imaging software. The film images were mounted on a light box and graded with the use of a stereoviewer. Primary outcome measures included the presence or absence of AMD pathological features. Positive and negative predictive values (PPVs and NPVs), sensitivity, specificity and weighted kappaw statistics were calculated.

RESULTS

We photographed 203 eyes (of 103 patients) with both digital and slide film cameras. Correlation of the 2 image formats was substantial in identifying AREDS level 3a or greater (kappaw=0.64, standard error=0.08, PPV=0.95, NPV=0.66, sensitivity=0.93, specificity=0.74) and excellent in identifying level 4b or greater (kappaw=0.83, standard error=0.05, PPV=0.81, NPV=0.98, sensitivity=0.94, specificity=0.94).

INTERPRETATION

High-resolution stereoscopic, mydriatic, 45 degrees digital images captured with a nonmydriatic camera and JPEG compressed correlate well with stereoscopic slide film photographs in the identification of moderate to advanced AMD (AREDS level 3a or greater).

Exposure to Chlamydia pneumoniae infection and progression of age-related macular degeneration

Recent studies have found an association between exposure to Chlamydia pneumoniae infection and risk of age-related macular degeneration (AMD). To assess a potential risk of AMD progression posed by exposure to C. pneumoniae, the authors reexamined Australian residents in 2001-2002 who were aged 51-89 years with early AMD at baseline (1992-1995). Examination included macular photography and an enzyme-linked immunosorbent assay to determine antibody titers to the elementary bodies from C. pneumoniae AR39. AMD progression was assessed quantitatively, using both coarse and fine progression steps following an international classification for AMD grading, and also qualitatively, by side-by-side comparison of baseline and follow-up macular photographs. Serologic data were available for 246 of 254 (97%) subjects. AMD progression was associated with a higher antibody titer. After adjustment for age, smoking, family history of AMD, history of cardiovascular diseases, and source study, the subjects in the upper tertiles of antibody titers were 2.1 (95% confidence interval: 0.92, 4.69), 2.6 (95% confidence interval: 1.24, 5.41), and 3.0 (95% confidence interval: 1.46, 6.37) times more at risk of progression than those in the lowest tertile, using three definitions of progression, respectively. The fact that seroreactivity to C. pneumoniae was independently associated with the risk of AMD progression suggests that C. pneumoniae infection may be an additional risk factor for AMD progression.

Vitamin E supplementation and macular degeneration: randomised controlled trial

OBJECTIVE

To determine whether vitamin E supplementation influences the incidence or rate of progression of age related maculopathy (AMD).

DESIGN

Prospective randomised placebo controlled clinical trial.

SETTING

An urban study centre in a residential area supervised by university research staff.

PARTICIPANTS

1193 healthy volunteers aged between 55 and 80 years; 73% completed the trial on full protocol.

INTERVENTIONS

Vitamin E 500 IU or placebo daily for four years.

PRIMARY OUTCOME

development of early age related macular degeneration in retinal photographs. Other measures included alternative definitions of age related macular degeneration, progression, changes in component features, visual acuity, and visual function

RESULTS

The incidence of early age related macular degeneration (early AMD 3) was 8.6% in those receiving vitamin E versus 8.1% in those on placebo (relative risk 1.05, 95% confidence interval 0.69 to 1.61). For late disease the incidence was 0.8% versus 0.6% (1.36, 0.67 to 2.77). Further analysis showed no consistent differences in secondary outcomes.

CONCLUSION

Daily supplement with vitamin E supplement does not prevent the development or progression of early or later stages of age related macular degeneration.