To investigate the relation between sleep disruption and nuclear cataract, as well as the impact of cataract removal on sleep, in two discrete population-based cohorts.

This is a cross-sectional study of 5070 participants from three large longitudinal epidemiologic studies of age-related eye disease, hearing, olfaction, and cognition. Slit-lamp photos of the lens were obtained to grade nuclear cataract using a standardized protocol. The quality of sleep was assessed using a modified Wisconsin Sleep Cohort Study questionnaire. Multiple linear regression analyses were used to assess the associations between levels of nuclear cataract/cataract extraction and the number of sleep problems. Systemic co-morbidity data were included as potential confounders, including diabetes mellitus, obesity, hypertension, cerebrovascular disease, thyroid disease, tobacco and alcohol use, and physical component summary score and mental component summary score.

The mean age of the cohort was 57.6 years (range 22-95 years). The majority of the cohort demonstrated nuclear cataract levels 2 or 3 (36.8% and 30.1%, respectively). A total of 8% of the cohort had an intraocular lens (IOL) in at least one eye. There was no statistically significant correlation between sleep problems with presence of either nuclear cataract or IOL implant (p>> 0.05).

In this cross-sectional, population-based study, we found no significant association between nuclear cataract or presence of IOL with poor sleep quality after adjusting for potential confounders. Studies of the longitudinal impact of nuclear cataract and cataract removal on sleep are needed to elucidate the role of nuclear cataract and cataract removal on sleep.

The Dichotic Digits test (DDT) has been widely used to assess central auditory processing but there is limited information on observed DDT performance in a general population. The purpose of the study was to determine factors related to DDT performance in a large cohort spanning the adult age range.

The study was cross-sectional and subjects were participants in the Epidemiology of Hearing Loss Study (EHLS), a population-based investigation of age-related hearing loss, or the Beaver Dam Offspring Study (BOSS), a study of aging in the adult offspring of the EHLS members. Subjects seen during the 4th EHLS (2008 to 2010) or the 2nd BOSS (2010 to 2013) examination were included (N = 3655 participants [1391 EHLS, 2264 BOSS]; mean age = 61.1 years, range = 21 to 100 years). The free and right ear-directed recall DDTs were administered using 25 sets of triple-digit pairs with a 70 dB HL presentation level. Pure-tone audiometric testing was conducted and the pure-tone threshold average (PTA) at 0.5, 1, 2, and 4 kHz was categorized using the worse ear: no loss = PTA ≤ 25 dB HL; mild loss = 25 < PTA ≤ 40 dB HL; moderate or marked loss = PTA>> 40 dB HL. Cognitive impairment was defined as a Mini-Mental State Examination score < 24 (maximum = 30) or a self- or proxy-reported history of dementia or Alzheimer's disease. Demographic information was self-reported. General linear models were fit and multiple linear regression was performed.

The mean total free recall DDT score was 76.7% (range = 21.3 to 100%). Less than 10% of the participants had a total free recall score below 60% correct. The mean right ear-directed recall score was 98.4% with 69% of the participants scoring 100% and another 15.5% scoring 98.7% (1 incorrect digit). In multivariable modeling of the total free recall scores, the predicted mean free recall score was 1 percentage point lower for every 5-year increase in age, 2.3 percentage points lower in males than females, 8.7 percentage points lower in participants with less than a high school degree than in those with college degrees, 6.8 percentage points lower in participants with a moderate or marked hearing loss compared with no hearing loss, and 8.3 percentage points lower in participants with cognitive impairment compared with those without cognitive impairment. These 5 factors were independently and significantly related to performance and accounted for 22.7% of the total variability in free recall scores.

Substantial variation in the total free recall DDT scores but very little variation in the right ear-directed recall DDT scores was observed. Age, sex, education, hearing loss severity, and cognitive impairment were found to be significantly related to DDT scores but explained less than 25% of the total variability in total free recall scores. The right ear-directed recall DDT by itself may not be of benefit in assessing central auditory processing in a general population because of its limited variability but further evaluation of factors potentially related to free recall DDT variability may prove useful.

OBJECTIVE

To investigate the longitudinal effects of cataract extraction on sleep quality in two discrete population cohorts.

METHODS

301 participants who had senile cataract in both eyes at the baseline examination were selected from two large longitudinal epidemiologic studies of age-related eye disease, hearing, olfaction, and cognition. The participants were divided into two groups: one had cataract surgery (CS) in both eyes, and the other had no cataract surgery (NCS) in either eye by the follow up examination. Cataract was graded from photos or digital images using a standardized protocol. The quality of sleep was assessed using a modified Wisconsin Sleep Cohort Study Questionnaire. The NCS and CS groups were compared as to the change in the number of sleep problems reported from the baseline to the follow-up examination. Systemic co-morbidity data were included as potential confounders, including diabetes mellitus, obesity, hypertension, cerebrovascular disease, thyroid disease, tobacco and alcohol use, and the SF-12 physical component and mental component summary scores.

RESULTS

The average (mean±SD) age was 71.0±8.8 years in the NCS (n=237) group and 73.4±9.1 years (n=64) in the CS group. There was no statistically significant difference in the change in the number of sleep problems reported between the NCS and CS groups (mean: -0.068 for NCS and 0.016 for CS, p=0.57). The multivariable linear regression models, when adjusted for confounders, yielded similar results.

CONCLUSIONS

In this longitudinal, community-based population study, we found no significant impact of cataract extraction on sleep quality. Studies of the effect of cataract extraction on sleep should allow a longer follow up to demonstrate sustainability.