Characteristics of Medicare Beneficiaries With Glaucoma
To better understand the effect of glaucoma on nonglaucomatous medical conditions and resultant secondary health care costs, Prager et al. assessed self-reported medical conditions, the use of medical services, and total health care costs among Medicare beneficiaries with glaucoma. The researchers found that patients with glaucoma had higher health care costs and use of health aides and services.
In this longitudinal observational study, self-reported health status, use of health care services, adjusted mean annual total health care costs per person, and adjusted mean annual nonoutpatient costs per person were extracted from the Medicare Current Beneficiary Survey for 72,587 Medicare beneficiaries. Participants were 65 years or older with (n = 4,441) or without (n = 68,146) a glaucoma diagnosis in the year before collection of survey data from 2004 to 2009. Their mean age was 76.9 years, and 43.2% were men. Patients with glaucoma who responded to survey questions on visual disability were stratified into those with (n = 1,748) and without (n = 2,639) self-reported visual disability.
The authors found that Medicare beneficiaries with glaucoma had higher adjusted odds of inpatient hospitalizations (odds ratio [OR], 1.27; 95% CI, 1.17-1.39) and home health aide visits (OR, 1.27; 95% CI, 1.13-1.43) compared with Medicare beneficiaries without glaucoma. Furthermore, patients with glaucoma who had self-reported visual disability were more likely to report depression (OR, 1.47; 95% CI, 1.26-1.71), falls (OR, 1.34; 95% CI, 1.09-1.66), and difficulty walking (OR, 1.22; 95% CI, 1.02-1.45) compared with those who did not report visual disability. In the risk-adjusted model, Medicare beneficiaries with glaucoma incurred an additional $2,903 (95% CI, $2,247-$3,558) in annual total health care costs and $2,599 (95% CI, $1,985-$3,212) in costs for nonoutpatient services than those without glaucoma.
The authors concluded that glaucoma is associated with greater use of inpatient and home health aide services and with higher annual total and nonoutpatient medical costs. Self-reported visual disability among patients with glaucoma may be associated with depression, falls, and difficulty walking. Reducing the prevalence and severity of glaucoma may result in improvements in associated nonglaucomatous medical conditions and a reduction in health care costs.
Automated Quantification of Capillary Nonperfusion From OCT Angiography
Macular ischemia is recognized as a key feature of diabetic retinopathy (DR). Hwang et al. studied the feasibility of using automated quantification of capillary nonperfusion via optical coherence tomography (OCT) angiography as a potential biomarker for DR.
In an observational study conducted in a tertiary subspecialty academic practice, the researchers evaluated macular nonperfusion with 6 × 6-mm OCT angiography obtained with commercially available 70-kHz OCT versus fluorescein angiography (FA) from Jan. 22 to Sept. 18, 2014. Participants included 12 individuals with normal vision (mean age, 54.2 years) serving as controls and 12 patients with various levels of DR (mean age, 55.1 years). Preplanned primary measures were parafoveal and perifoveal vessel density, total avascular area, and foveal avascular zone as detected with 6 × 6-mm OCT angiography and analyzed using an automated algorithm. Secondary measures included the agreement of the avascular area between the OCT angiogram and FA.
Compared with the 12 healthy controls, the 12 DR patients had parafoveal and perifoveal vessel density that was reduced by 12.6% (95% CI, 7.7%-17.5%) and 10.4% (95% CI, 6.8%-14.1%), respectively. Total avascular area and foveal avascular zone area, respectively, were greater in eyes with DR by 0.82 mm2 (95% CI, 0.65-0.99 mm2) and 0.16 mm2 (95% CI, 0.05-0.28 mm2). The agreement between the vascular areas in the OCT angiogram and FA had a κ value of 0.45 (95% CI, 0.21-0.70). Total avascular area in the central 5.5-mm-diameter area distinguished eyes with DR from control eyes with 100% sensitivity and specificity.
The authors concluded that avascular area analysis with an automated algorithm using OCT angiography, although not equivalent to FA, detected DR reliably in this small pilot study. Further study is needed to determine the usefulness of the automated quantification in clinical practice.
Risk for Cataract After Treatment of Childhood Cancer
Few studies have been published on the association of the radiotherapy (RT) dose applied to the eyes for childhood cancer and the risk for later cataract; thus, Allodji et al. investigated the risk for cataract after treatment of nonretinoblastoma solid cancer in childhood.
They found a significantly increased risk of cataract in patients who had received RT, especially at higher doses.
The study used data from the Euro2K cohort that includes 4,389 5-year survivors of solid tumors treated from Jan. 1, 1945, to Dec. 31, 1985. In this group 3,172 patients had been treated in France and were sent a self-reported questionnaire starting on Sept. 1, 2005; the response period ended Dec. 31, 2012, when follow-up was considered complete.
From the French patients, 1,833 questionnaires were analyzed (the rest of the patients had died, had retinoblastoma or enucleation, could not be located, or did not return the questionnaire or consent form). Among the 1,833 patients, 52.4% were men, and the mean (SD) age was 37.0 (8.5) years.
Radiation doses in both eyes were estimated for all patients who had received RT. The role of the radiation dose in cataract risk was investigated using the Cox proportional hazard regression model and the excess relative or the absolute risk model. The role of cytotoxic chemotherapy was also investigated.
After a mean follow-up of 32 years, 33 patients with unilateral or bilateral cataract were identified, for a total of 47 cataract events. The 47 events were validated by medical record review and by contacting the patients and their medical physician or ophthalmologist to obtain copies of diagnostic examinations or surgical reports.
Overall, in a multivariable Cox proportional hazard regression analysis, patients who had received RT had a 4.4-fold (95% CI, 1.5- to 13.0-fold) increased risk for cataract compared with patients who did not receive RT. Exposure to radiation doses of at least 10 Gy to the eyes increased the hazard ratio 39-fold (95% CI, 12.0- to 127.9-fold), relative to no radiation exposure. Treatment with melphalan hydrochloride was associated with a strong increase in cataract risk (hazard ratio, 26.3; 95% CI, 7.1-96.6), although this finding was based on few patients. The authors noted that these results could aid in developing guidelines for long-term follow-up for cataract.
JAMA Ophthalmology summaries are based on authors’ abstracts, as edited by senior editor(s).
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