Faculty Bibliography

Recent literature has reported a higher occurrence of cognitive impairment among individuals with Age-related Macular Degeneration (AMD) compared to older adults with normal vision. This pilot study explored potential links between single nucleotide polymorphisms (SNPs) in AMD and cognitive status. Individuals with AMD (N = 21) and controls (N = 18) were genotyped for the SNPs CFHY402H, ARMS2A69S and FADS1 rs174547. Cognitive status was evaluated using the Montreal Cognitive Assessment. The two groups differed significantly on which subscales were most difficult. The control group had difficulty with delayed recall while those with AMD had difficulty on delayed recall in addition to abstraction and orientation. Homozygous carriers of the FADS1 rs174547 SNP had significantly lower scores than heterozygotes or non-carriers on the MoCA. The results suggest that the FADS1 SNP may play a role in visual impairment/cognitive impairment comorbidity as reflected in the poorer cognitive scores among homozygotes with AMD compared to those carrying only one, or no copies of the SNP.

Importance/UNASSIGNED:Patients with vision loss who are hospitalized for common illnesses are often not identified as requiring special attention. This perception, however, may affect the outcomes, resource use, and costs for these individuals. Objective/UNASSIGNED:To assess whether the mean hospitalization lengths of stay, readmission rates, and costs of hospitalization differed between individuals with vision loss and those without when they are hospitalized for similar medical conditions. Design, Setting, and Participants/UNASSIGNED:This analysis of health care claims data used 2 sources: Medicare database and Clinformatics DataMart. Individuals with vision loss were matched 1:1 to those with no vision loss (NVL), on the basis of age, years from initial hospitalization, sex, race/ethnicity, urbanicity of residence, and overall health. Both groups had the same health insurance (Medicare or a commercial health plan), and all had been hospitalized for common illnesses. Vision loss was categorized as either partial vision loss (PVL) or severe vision loss (SVL). Data were analyzed from April 2015 through April 2018. Main Outcomes and Measures/UNASSIGNED:The outcomes were lengths of stay, readmission rates, and health care costs during hospitalization and 90 days after discharge. Multivariable logistic and linear regression models were built to identify factors associated with these outcomes among the NVL, PVL, and SVL groups. Results/UNASSIGNED:Among Medicare beneficiaries, 6165 individuals with NVL (with a mean [SD] age of 82.0 [8.3] years, and 3833 [62.2%] of whom were female) were matched to 6165 with vision loss. Of those with vision loss, 3401 (55.2%) had PVL and 2764 (44.8%) had SVL. In the Clinformatics DataMart database, 5929 individuals with NVL (with a mean [SD] age of 73.7 [15.1] years, and 3587 [60.5%] of whom were female) were matched to 5929 individuals with vision loss. Of the commercially insured enrollees with vision loss, 3515 (59.3%) had PVL and 2414 (40.7%) had SVL. Medicare enrollees with SVL, compared with those with NVL, had longer mean lengths of stay (6.48 vs 5.26 days), higher readmission rates (23.1% vs 18.7%), and higher hospitalization and 90-day postdischarge costs ($64 711 vs $61 060). Compared with those with NVL, Medicare beneficiaries with SVL had 4% longer length of stay (estimated ratio, 1.04; 95% CI, 1.01-1.07; P = .02), 22% higher odds of readmission (odds ratio, 1.22; 95% CI, 1.06-1.41; P = .007), and 12% higher costs (estimated cost ratio, 1.12; 95% CI, 1.06-1.18; P < .001). Similar findings were obtained for those with commercial health insurance. When these findings were extrapolated to hospitalizations of patients with vision loss nationwide, an estimated amount of more than $500 million in additional costs annually were spent caring for these patients. Conclusions and Relevance/UNASSIGNED:These findings suggest that opportunities for improving outcomes and reducing costs exist in addressing patients' vision loss and concomitant functional difficulties during hospitalization and thereafter.

SIGNIFICANCE/CONCLUSIONS:This research is significant because, although vision-related quality of life (VRQoL) is improved after vision rehabilitation (VR), patients with certain characteristics respond less positively on VRQoL measures, and this should inform future care. PURPOSE/OBJECTIVE:The purposes of this study were to evaluate how two VRQoL questionnaires compare in measuring change in patient-reported outcomes after VR and to determine if patient characteristics or occupational therapy (OT) predict higher scores after rehabilitation. METHODS:In a prospective clinical cohort study, 109 patients with low vision completed the Impact of Vision Impairment (IVI) and the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) before and after VR. Comprehensive VR included consultation with an ophthalmologist and OT if required. The relationships of six baseline characteristics (age, sex, visual acuity, contrast sensitivity, field loss, diagnosis) and OT were assessed with VRQoL scores using multivariable logistic regression. RESULTS:The mean (SD) age was 68.5 (19.2) years, and 61 (56%) were female. After rehabilitation, increases in scores were observed in all IVI subscales (reading [P < .001], mobility [P = .002], well-being [P = .0003]) and all NEI VFQ-25 subscales (functional [P = .01], socioemotional [P = .003]). Those who were referred to OT but did not attend and those who had hemianopia/field loss were less likely to have higher VRQoL in IVI mobility and well-being. Those attending OT for more than 3 hours were less likely to have better scores in emotional NEI VFQ. Men were less likely to have increased scores in functional and emotional NEI VFQ, whereas those with diagnoses of nonmacular diseases had higher odds of having increased scores on the emotional NEI VFQ (all, P < .05). CONCLUSION/CONCLUSIONS:Both the IVI and the NEI VFQ-25 detected change in patients' VRQoL after rehabilitation. Most of the patient characteristics we considered predicted a lower likelihood of increased scores in VRQoL.

SIGNIFICANCE/CONCLUSIONS:Systematic lighting assessments should be part of low vision evaluations. The LuxIQ has gained popularity as an assessment tool, but its reliability has not been examined independently and is necessary for evidence-based vision rehabilitation. PURPOSE/OBJECTIVE:Besides magnification, improved lighting levels are a common intervention in reading rehabilitation for individuals with low vision. Determining the appropriate lighting can be a complex and time-consuming task. The LuxIQ is a portable lighting assessment tool that can be used to systematically measure lighting preferences; however, there is little independent evidence to support its reliability in low vision rehabilitation. METHODS:One hundred nine control subjects (age, 18 to 85 years) and 64 individuals with low vision (age, 27 to 99 years) adjusted both the luminance and color temperature parameters on the LuxIQ while viewing a sentence on the MNREAD at their preferred print size for continuous reading. After 30 minutes, they were asked to repeat the same measurements. RESULTS:Using Bland-Altman plots, test-retest variability was calculated using the limits of agreement (LOAs). For illuminance, the LOA width was 2806 lux for control subjects and 2657 lux for visually impaired participants. For color temperature, the LOA width was 2807 K for control subjects and 2364 K for those with a visual impairment. Difference scores were centered near zero, indicating overall accuracy. CONCLUSIONS:The measurement of lighting preference lacks the precision necessary for clinical utility, given that the LOA for luminance ranged more than 2600 lux, with normally sighted and low vision participants. Such variability translates into a range of approximately ±40 or 50 W in an incandescent light bulb, depending on the luminance level, making it clinically difficult to narrow down the options for evidence-based lighting recommendations. Next steps are to examine whether the reading behavior of low vision clients is positively affected by interventions that are based on LuxIQ recommendations.

SIGNIFICANCE/CONCLUSIONS:Fundus-guided perimetry is a common clinical tool used to measure visual field sensitivities. Comparisons between perimeters are often made despite relative differences in hardware parameters. We directly compared two perimeters using Weber contrast, which allowed us to assess the clinical gain associated with the extended stimulus range of the macular integrity assessment (MAIA). PURPOSE/OBJECTIVE:The purpose of this study was to directly compare sensitivity thresholds for two microperimeters, the MAIA and Optos optical coherence tomography/scanning laser ophthalmoscope, using Weber contrast values. We also examined the clinical utility of the extended stimulus range of the MAIA. METHODS:Six normally sighted adults with no visual field loss and 16 adults with low vision were recruited. Thresholds were measured on the MAIA and Optos using the same threshold algorithm and test points. To compare equivalent units, decibel thresholds were converted to light increments in apostilbs and then to delta increment intensities relative to each instrument's background luminance. Repeatability was assessed for normally sighted adults by testing both instruments on 3 separate days. RESULTS:For normally sighted observers, mean thresholds were similar on both instruments, and repeatability within microperimeters was high. The MAIA has a 0.3-log lower contrast range and 1.37 higher contrast range. The lower contrast values did not result in lower thresholds for the normally sighted observers on the MAIA. There was a 25% increase in the number of measurable thresholds owing to the higher contrast values in low-vision observers. CONCLUSIONS:The higher contrast range in the MAIA yielded only a small increase in detectable thresholds for participants with visual field loss.

OBJECTIVE:We sought to determine under what conditions brighter lighting improves reading performance. METHOD:Thirteen participants with typical sight and 9 participants with age-related macular degeneration (AMD) read sentences ranging from 0.0 to 1.3 logMAR under luminance levels ranging from 3.5 to 696 cd/m². RESULTS:At the dimmest luminance level (3.5 cd/m²), reading speeds were slowest at the smaller letter sizes and reached an asymptote for larger sizes. When luminance was increased to 30 cd/m², reading speed increased only for the smaller letter sizes. Additional lighting did not increase reading speeds for any letter size. Similar size-related effects of luminance were observed in participants with AMD. CONCLUSION:In some instances, performance on acuity-limited tasks might be improved by brighter lighting. However, brighter lighting does not always improve reading; the magnitude of the effect depends on the text size and the relative changes in light level.

PURPOSE/OBJECTIVE:To examine whether individuals with Stargardt disease macular dystrophy (STGD) change the location of fixation with instruction. DESIGN/METHODS:Case-control study. PARTICIPANTS/METHODS:Thirteen normally sighted and 37 STGD participants. METHODS:Using an Optos scanning laser ophthalmoscopy/OCT microperimeter (Optos plc, Dunfermline, UK), fixation was measured under 2 different instructions: "look at the cross" (LC) and "look straight ahead, even if you do not see the cross" (LS). Visual acuity, contrast sensitivity, disease duration, and age at disease onset were obtained from medical records. MAIN OUTCOME MEASURE/METHODS:Change in fixation with instruction. RESULTS:Mean age of the STGD participants was 39.2 years, and 24 were women. Mean acuity was 1.01±0.29 logarithm of the minimum angle of resolution (logMAR), and mean contrast sensitivity was 1.16±0.41 log. The largest number of fixations under the LC condition were in the superior retina. Patients with STGD were divided into 3 groups, depending on the change in fixation locus when asked to look straight ahead: those having fixation closer the fovea, those with no change in the location of fixation, and those looking farther away from the fovea. Fifty-one eyes of 32 participants had fixations closer to the fovea when asked to look straight ahead (average change, -6.3°), whereas 13 eyes of 11 participants did not change fixation. There were no significant differences between groups in age, visual acuity, contrast sensitivity, bivariate contour ellipse area, and age at disease onset. CONCLUSIONS:Despite having eccentric fixation, most STGD participants did not have a complete directional re-referencing from the fovea to the eccentric location, and moved fixation when asked to look straight ahead. This finding emphasizes that reliable assessment of visual function during evaluations of disease progression or in therapeutic intervention trials requires consistent instructions and monitoring of fixation. Otherwise, a patient's interpretation of fixation instruction may confound the results.