Differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability in athletes and non-athletes.

The study investigated the differential response to a single bout of maximal incremental treadmill exercise between athletes and non-athletes without dry eyes regarding tear secretion, tear film stability, visual acuity (VA), and stereoacuity. Additionally, the study examined the effect of gender and the duration of exercise on exercise-induced changes. Study participants included young university students aged 18-25 years who were athletes (male/female: 13/13) or non-athletes (male/female: 17/9). Participants underwent an aerobic exercise session using a treadmill and following the laid down Bruce treadmill test protocol till exhaustion. Measurements were taken in the order of distance VA, stereopsis, non-invasive tear break-up time (TBUT), and phenol red thread test, at baseline and after the exercise regimen. Within- and between-subject analyses using multiple t-tests with correction for multiple comparisons were performed to determine differences before and after exercise in athletes and non-athletes. Subsequently, ANCOVA was used to assess the influence of gender and the duration of exercise. The mean age (SD) of the athletes and the non-athletes was 22.4 ± 2.1 years and 21.8 ± 2.1 years, respectively (p = 0.357). Before exercise, the athletes had higher TBUT than non-athletes (14.6 ± 2.9 s vs. 11.9 ± 3.8 s; p = 0.021), but no difference was observed in any other ocular measurements. After exercise, the athletes showed significant improvement in tear secretion with the basal tear secretion increasing from 22.3 ± 2.5 mm to 25.8 ± 1.7 mm (p < 0.001). The non-athletes on the other hand had a borderline increase in tear secretion from 21.42 ± 2.85 mm to 23.73 ± 2.68 mm (p = 0.08). Also, the TBUT was much improved in the athletes after exercise compared to the non-athletes (17.7 ± 2.7 s vs. 14.8 ± 2.9 s, p = 0.004). Additionally, exercise improved the VA indifferently between the groups, while stereoacuity was unchanged after exercise in either group. Gender had no influence on the differences in the tear function measures between athletes and non-athletes after exercise. The duration of exercise, however, showed a borderline effect on the tear film stability (p = 0.068) after exercise. Our findings support the differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability between athletes and non-athletes. Thus, increased physical fitness and the duration of exercise might be crucial in the improvement of tear function through aerobic exercise.

Visual function, spectacle independence, and patients' satisfaction after cataract surgery- a study in the Central Region of Ghana.

BACKGROUND: Reduced visual function is associated with diminished quality of life as well as decreased physical and mental health. Poor visual function related to cataracts is also a risk factor for falls and traffic accidents, which may lead to hospital admissions and limit independence. OBJECTIVE: To evaluate patients' satisfaction, visual functions and spectacle independence among patients in the Central Region of Ghana who had cataract surgery in one eye. METHODS: A hospital-based prospective cohort study was carried out on 146 patients booked for cataract surgery: 16 were lost through follow-ups whilst 130 completed the study. Visual functions including visual acuity, contrast sensitivity, stereopsis and colour vision were assessed before and after a month of cataract surgery. Objective and subjective refractions were performed to determine the post-surgery refractive status of the participants. Participants completed the NEI-VFQ 25 questionnaire and the scores obtained were used as a construct of their satisfaction. RESULTS: The NEI-VFQ 25 questionnaire scores indicated patients' satisfaction was high with an average quality of life score of 77.46. Patients satisfaction was strongly correlated with contrast sensitivity (r=0.653, p<0.001) but moderately correlated with visual acuity (r=-0.554, p<0.001), stereopsis (r=0.490, p<0.001) and colour vision (r=0.466, p<0.001). Contrast sensitivity was a better predictor of patients' satisfaction than visual acuity and stereopsis. Spectacle independence at distance was achieved in only 44.6% of the participants and 5.4% at near. There was a significant (p>0.001) association between spectacle independence and the two types of cataract surgery performed which included Small Incision Cataract Surgery (SICS) and Extracapsular Cataract Extraction (ECCE). Among those who were spectacle independent, 53.4% of them were low vision patients. CONCLUSION: Satisfaction of patients after cataract surgery was high but was greatly influenced by visual functions with contrast sensitivity being a better predictor of satisfaction than visual acuity and stereopsis. Spectacle independence after cataract surgery was low at distance and extremely low at near. The type of cataract surgery performed influenced thespectacle independence.