Retinal Nerve Fiber Layer Loss and Quality of Life in Glaucoma
April JAMA Ophthalmology
To better characterize the relationship between structural changes and disease disability, Gracitelli et al. examined the correlation between rates of retinal nerve fiber layer (RNFL) loss and longitudinal changes in quality of life in glaucoma. Their observational cohort study included 130 patients (260 eyes) with glaucoma who were followed for a mean (SD) of 3.5 (0.7) years.
At baseline, all patients had repeatable visual field defects on standard automated perimetry (SAP). The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was administered annually, and spectral-domain optical coherence tomography and SAP were performed at six-month intervals. A joint model was used to investigate the association between change in NEI VFQ-25 Rasch-calibrated scores and change in RNFL thickness, adjusting for confounding socioeconomic and clinical variables.
Progressive binocular RNFL thickness loss was associated with worsening of NEI VFQ-25 scores over time. In a multivariable model adjusting for baseline disease severity and the rate of change in binocular SAP sensitivity, each 1 μm/year loss of RNFL thickness was associated with a decrease of 1.3 units (95 percent CI, 1.02-1.56) per year in NEI VFQ-25 scores (p < .001). After adjustment for the contribution from SAP, 26 percent (95 percent CI, 12-39) of the variability of change in NEI VFQ-25 scores was associated uniquely with change in binocular RNFL thickness.
The authors concluded that progressive binocular RNFL thickness loss is associated with longitudinal loss in quality of life, even after adjustment for progressive visual field loss. These findings suggest that rates of binocular RNFL change are valid markers for the degree of neural loss in glaucoma and have a strong relationship with glaucoma-associated disability.
Assessment of Online Patient Education Materials
April JAMA Ophthalmology
Patients are increasingly using the Internet to obtain medical information. Huang et al. assessed the reading levels of patient education materials (PEMs) available on ophthalmologic association websites to see if they conform to the fourth- to sixthgrade reading level recommended by the American Medical Association and National Institutes of Health. PEMS from major ophthalmology websites were downloaded from June 1, 2014, through June 30, 2014, and assessed for level of readability using 10 scales. Text from each article was pasted into Microsoft Word. These documents were analyzed using the software Readability Studio professional edition for Windows.
A total of 339 online PEMs from seven ophthalmologic associations were assessed. The mean Flesch Reading Ease score was 40.7 (range, 17.0-51.0), which is defined as difficult. The mean readability grade levels on the other nine scales were as follows: 10.4 to 12.6 for the Flesch-Kincaid Grade Level; 12.9 to 17.7 for the Simple Measure of Gobbledygook test; 11.4 to 15.8 for the Coleman-Liau Index; 12.4 to 18.7 for the Gunning Fog Index; 8.2 to 16.0 for the New Fog Count; 11.2 to 16.0 for the New Dale-Chall Readability Formula; 10.9 to 12.5 for the FORCAST scale; 11.0 to 17.0 for the Raygor Readability Estimate Graph; and 12.0 to 17.0 for the Fry Readability Graph.
The authors concluded that online PEMs on major ophthalmologic association websites are written well above the recommended reading level and that consideration should be given to revision of these materials to allow greater comprehension among a wider audience.
Changes in Microperimetry and Low Luminance VA in AMD
April JAMA Ophthalmology
Wu et al. investigated whether microperimetry and low luminance visual acuity (LLVA) could serve as sensitive measures of disease activity in intermediate-stage age-related macular degeneration.
Their prospective longitudinal study included 49 participants with AMD (41 with intermediate-stage AMD and eight with nonfoveal geographic atrophy due to AMD) and 10 control participants at a research clinic from May 1, 2012, to Dec. 31, 2013. Participants underwent microperimetry examinations in one eye during a 12-month period (at six-month intervals for participants with AMD and at baseline and 12 months for control participants). Best-corrected visual acuity (BCVA) and LLVA were measured at baseline and at 12 months in all participants. Side-by-side comparisons of color fundus photographs from the initial and final visit were used to assess the pathological features of intermediate-stage AMD and to grade each participant’s status as worsened, stable, or improved.
A reduction in mean microperimetric point-wise sensitivity was identified at 12 months compared with the baseline in eyes with intermediate-stage AMD graded as stable (−0.31 dB; p = .003) or worsened (−0.42 dB; p < .001). An increase in mean pointwise sensitivity was identified in eyes graded as improved (1.13 dB; p < .001). A reduction in mean pointwise sensitivity was identified in eyes with nonfoveal geographic atrophy at both six months (−1.41 dB; p < .001) and 12 months compared with the baseline (−2.56 dB; p <.001). Among the control participants, no change in mean pointwise sensitivity was detected over the 12-month period (−0.11 dB; p = .34). In all groups, no changes in BCVA or LLVA were identified over the 12-month period (p ≥ .07).
The authors concluded that in eyes with intermediate-stage AMD, microperimetry detected subtle changes in visual function over a 12-month period that were not identified on VA measures. This technique warrants further study as a way to assess efficacy of in new treatments for intermediate-stage AMD, potentially allowing a shorter follow-up period.
JAMA Ophthalmology summaries are based on authors’ abstracts as edited by senior editor(s).
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