To examine resource consumption and the direct costs of treating glaucoma at different disease severity levels. Design: Observational, retrospective cohort study based on medical record review. Participants: One hundred fifty-one records of patients with primary open-angle or normal-tension glaucoma, glaucoma suspect, or ocular hypertension (age Ն18 years) were randomly selected from 12 sites in the United States and stratified according to severity based on International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients had to have been followed up for a minimum of 5 years. Patients with concomitant ocular disease likely to affect glaucoma treatment-related resource consumption were excluded. Methods: Glaucoma severity was assessed and assigned using a 6-stage glaucoma staging system, modified from the Bascom Palmer (Hodapp-Anderson-Parrish) system. Clinical and resource use data were collected from the medical record review. Resource consumption for low-vision care and vision rehabilitation was estimated for patients with end-stage disease based on specialist surveys. For each stage of disease, publicly available economic data were then applied to assign resource valuation and estimate patientlevel direct costs from the payer perspective. Main Outcome Measures: Average annual resource use and estimated total annual direct cost of treatment were calculated at the patient level and stratified by stage of disease. Direct costs by specific resource types, including ophthalmology visits, glaucoma surgeries, medications, visual field examinations, and other glaucoma services, were also assessed. Results: Direct ophthalmology-related resource use, including ophthalmology visits, glaucoma surgeries, and medication use, increased as disease severity worsened. Average direct cost of treatment ranged from $623 per patient per year for glaucoma suspects or patients with early-stage disease to $2511 per patient per year for patients with end-stage disease. Medication costs composed the largest proportion of total direct cost for all stages of disease (range, 24%-61%). Conclusions: The study results suggest that resource use and direct cost of glaucoma management increase with worsening disease severity. Based on these findings, a glaucoma treatment that delays the progression of disease could have the potential to significantly reduce the health economic burden of this chronic disease over many years.

To determine whether motion sensitivity varies with age, we measured motion discrimination in visual normals 25 to 80 years of age and found that motion thresholds increased linearly with age and were approximately two times higher in those 70 to 80 years old than in participants under thirty. This increase was not attributable to pupil size or retinal image distortion, but probably reflects neurodegeneration in the primary visual pathway. We compared the motion sensitivity of patients with senile dementia of the Alzheimer type (SDAT) with results from a subset of the visual normals of similar age. In SDAT patients, there were significant threshold elevations, which were more pronounced in the patients with more severe dementia. These findings confirm previous reports of visual system involvement in SDAT and indicate motion testing may reveal preclinical visual system involvement in SDAT.

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Although automated perimetry requires considerable patient cooperation, many patients with SDAT can produce reliable visual field results. These patients exhibit significant reductions in global sensitivity. Visual field loss in SDAT is most pronounced in the inferonasal and inferotemporal arcuate regions of the visual field but also involves the central field.

Patients with senile dementia of the Alzheimer type frequently have difficulty performing visual tasks. These difficulties may be due, at least partially, to degenerative changes in both the primary visual pathway and the visual association areas. To determine whether retinal ganglion cell dysfunction contributes to visual loss in senile dementia of the Alzheimer type, we tested a group of patients with this disease (n = 13) using the pattern-reversal electroretinogram to both low (4.0 reversals per second) and high (16.0 reversals per second) temporal frequency checkerboard patterns (1.0 degree checks). Significant amplitude reductions were noted for the patients relative to age-matched control subjects (n = 30). In addition, the observed amplitude reductions were most pronounced for the high temporal frequency condition. Therefore, the results are consistent with retinal ganglion cell dysfunction and support the notion that optic nerve damage induced by senile dementia of the Alzheimer type preferentially affects the larger, faster-conducting retinal ganglion cells along with their retinocortical projections.