Central contrast sensitivity perimetry discriminates between glaucomatous and non-glaucomatous eyes.

Background: Glaucoma is an optic neuropathy which causes irreversible vision loss. Standard perimetry, which is essential for glaucoma diagnosis, can only detect glaucomatous visual filed loss when considerable structural damage has occurred. Contrast sensitivity is one of the visual function tests that is reduced in eyes with glaucoma. It is known to be affected in pre-perimetric stages of glaucoma. Objective: The objective of this study was to investigate the discriminating ability of central contrast sensitivity perimetry in eyes with and without glaucoma. Design: The study employed a cross-sectional study design. Methods: The study participants were made of two groups; eyes diagnosed with glaucoma by an ophthalmologist based on visual field test and optical coherence tomography (OCT) and age- and sex-matched controls who were declared free from glaucoma. Static contrast sensitivity (CS) was measured in the central 10° of visual field using a custom psychophysical test. Results: There were 45 eyes with glaucoma and 45 age- and sex-matched controls in this study. The static CS in the glaucoma group was significantly reduced in 9 out of the 13 tested locations in the central 10° of the visual field. The mean static CS at 5°, 10°, superior hemifield and inferior hemifield were all significantly reduced in the glaucoma patients compared to the controls. Conclusion: Static CS measurement is a sensitive approach that can be utilized to aid in the detection of glaucoma. The use of static CS can be adopted in the development of a cost-effective yet sensitive screening tool for the detection of glaucoma.

Accuracy and stability of accommodation and vergence responses during sustained near tasks in uncorrected hyperopes.

This study investigated the accuracy and stability of accommodative and vergence functions in children with and without hyperopia while engaged in two sustained near tasks. The sustained accommodative and vergence characteristics of participants without refractive correction (n = 92, aged 5-10 years) with and without hyperopia (defined as cycloplegic retinoscopy ≥ + 1.00D and less than + 5.00D) were measured using eccentric infrared photorefraction (PowerRef 3; PlusOptix, Germany). Binocular measures of accommodation and eye position were recorded while participants engaged in 2 tasks at 25 cm for 15 min each: (1) reading small print on an Amazon Kindle and (2) watching an animated movie on liquid crystal display screen. Comprehensive visual assessment, including measurement of presenting visual acuity, amplitude of accommodation, and stereoacuity was conducted. The magnitude of accommodative and vergence responses was not related to refractive error (P > 0.05). However, there were inter-task differences in the accuracy and stability of the accommodative responses across refractive groups (P < 0.05). The relationship between accommodation and vergence was not significant in both tasks (P > 0.05). However, increased accommodative and vergence instabilities were associated with total accommodative response (P < 0.05). Despite having greater accommodative demand, uncorrected hyperopes accommodate comparably to emmetropic controls. However, uncorrected hyperopes have increased instabilities in their accommodative and vergence responses, which may adversely impact their visual experience.

The effect of filters and varying illumination on contrast sensitivity in eyes with moderate to severe visual impairment.

PURPOSE: To investigate the effect of filters and illumination on contrast sensitivity in persons with cataract, pseudophakia, maculopathy and glaucoma to provide a guide for eye care providers in low vision rehabilitation. MATERIALS AND METHODS: A within-subjects experimental design with a counter-balanced presentation technique was employed in this study. The contrast sensitivity of eyes with cataract, pseudophakia, maculopathy and glaucoma was measured with filters (no filter, yellow, pink and orange) combined with increasing illumination levels (100 lx, 300 lx, 700 lx and 1000 lx) using the SpotChecks™ contrast sensitivity chart. The data were analyzed using descriptive statistics and two-way repeated measures ANOVA. RESULTS: The yellow filter at 100 lx significantly improved contrast sensitivity in the maculopathy group. There were no significant improvements with either intervention in the rest of the groups. There was, however, a significant interaction between filters and illumination in the cataract group. CONCLUSION: There were small improvements in contrast sensitivity at low illumination levels with the yellow filter in the maculopathy group, and this could be considered in clinical practice and low vision rehabilitation. Overall, filters at most illumination levels did not benefit most groups.

Associations between personality traits and adherence to treatment in patients with primary open-angle glaucoma in an African population.

CLINICAL RELEVANCE: Inclusion of personality profile assessment and appropriate psychotherapeutic regimen in glaucoma diagnosis and management protocols could prove useful for enhanced medication adherence in patients living with glaucoma. BACKGROUND: There is poor adherence to medication among patients with glaucoma, especially in people of African ancestry. The present study assessed the influence of personality traits on adherence to glaucoma medication among patients living with primary open-angle glaucoma (POAG) from an African population. METHODS: A clinic-based cross-sectional study was conducted among patients with POAG attending a specialist eye-care facility. Adapted and validated questionnaires for personality trait (The Big Five Inventory) and medication adherence (Medication Adherence Report Scale 5) were used. RESULTS: Self-reported adherence to glaucoma medication was 60.8%. The personality traits conscientiousness and agreeableness significantly predicted medication adherence but accounted for only 30.3% and 13.3% of the variance, respectively. Non-adherence to glaucoma medication was significantly predicted by the personality profiles neuroticism, extraversion and openness which, respectively, accounted for 61.7%, 20.3% and 13.3% of the variance in the personality trait assessment. Old age and longer use of glaucoma medications were also significantly associated with non-adherence to glaucoma medication. CONCLUSIONS: Personality trait dimensions were significantly associated with glaucoma medication adherence in this at-risk population.

Assessment of four validated questionnaires for screening of dry eye disease in an African cohort.

PURPOSE: To evaluate the 5-item dry eye questionnaire (DEQ-5) for measurement precision and unidimensionality, and assess the ability of Ocular Surface Disease Index (OSDI), McMonnies Dry Eye Questionnaire (MQ), Ocular Comfort Index questionnaires (OCI), and DEQ to predict clinical measures of DED in an African population. METHOD: Participants (n = 113; mean age 24.7 ± 5.4 years) completed all four questionnaires administered in a randomized order. Internal consistency and test-retest reliability of the instruments were assessed. A masked examiner performed clinical dry eye tests in both eyes of participants and the results used to classify into either "dry" or "non-dry" groups. The diagnostic criteria for dry eye disease were tear break up time (TBUT) < 10 s plus at least one of Schirmer <15 mm in 5 min., > 5 corneal staining spot, or > 9 conjunctival staining spots. Rasch analysis was performed to assess the DEQ for unidimensionality and measurement precision, and receiver operating characteristic curve (AUC) analysis was used to assess the ability of the four questionnaires to predict clinical measures of DED. RESULTS: The responses from the DEQ-5 met the Rasch analysis criterion of unidimensionality with infit and outfit values of between 0.74-1.43 mean-square and 0.69-1.49 mean-square, respectively, and measurement precision of 2.33. Internal consistency and test-retest reliability of each test was high, with Cronbach alpha >0.70 for the questionnaire and their respective subscales but internal consistency reliability of the MQ was poor (Cronbach's alpha = 0 .29-0 0.52). Each test segregated the "dry" and "non-dry" groups with moderate (all AUC 0.70-0.80) and similar accuracy (P > .05). CONCLUSION: The DEQ -5 demonstrated adequate measurement precision and unidimensionality. Each of the four questionnaires showed psychometric validity for clinical use in the African population, and modest and similar accuracy when screening for dry eye signs but the performance of the McMonnies questionnaire was limited in terms of internal consistency reliability.

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.

Contact Lens- and Patient-related Factors Associated with Contact Lens Discomfort among Contact Lens Wearers in an African Cohort.

SIGNIFICANCE: No information is available on contact lens discomfort in any African population. Such information may be helpful in developing the scope and priorities for intervention. PURPOSE: The purpose of the study was to examine contact lens- and patient-related factors associated with contact lens discomfort among wearers in Ghana. METHODS: In this multicenter cross-sectional study, contact lens wearers 18 years and older were recruited. The Contact Lens Dry Eye Questionnaire-8 and a standardized scripted interview were administered to 72 contact lens wearers at five clinical sites, and 40 participants' lens storage cases were collected and cultured. A variety of patient- and contact lens-related factors were examined. Univariate and multivariate logistic regression modeling were used to assess risk factors associated with contact lens discomfort. RESULTS: Seventy-two contact lens wearers aged 18 to 45 years completed the study. The mean age was 27.5 ± 6.4 years, 65.3% of them were females, 86.1% wore soft contact lens, and 13.9% wore rigid gas-permeable lens. Contact lens discomfort was reported by 66.7% of the subjects. Most frequent lens storage cases isolates were Bacillus species (40%) and fungi (31.1%). Significant association was found between disinfecting with tap water (5.98; 95% confidence interval [CI], 1.22 to 29.27; P = .03), heavy visual display terminal use (3.39; 95% CI, 1.01 to 11.34; P = .05), high water content (1.16; 95% CI, 1.02 to 1.33; P = .03), and contact lens discomfort. Demographic factors, wear modality, and care solutions were not significant (all P > .05). CONCLUSIONS: In considering the use of contact lenses for refractive correction in this population, strategies for preventing contact lens discomfort that should be targeted include use of low-water-content lenses, disinfecting with multipurpose solutions, and reducing the time spent daily on visual display terminal use.

Application and repeatability of ocular biometric measures for gaze position calibration in children.

PURPOSE: The purpose of this study was to investigate the utility of two ocular biometric measurements to obtain Hirschberg ratios (HRs) in a binocularly normal paediatric population, and to assess the repeatability of this approach. METHODS: Ocular biometry data from 80 participants (aged 5 to 14 years) was obtained using the KM-1 LED manual keratometer and the Tomey Biometer AL-100 A-scan. HRs were calculated from corneal curvature and anterior chamber depth measurements in the horizontal and vertical meridians of each eye using a regression equation based on a geometric optics model. To assess intrasubject variability in the HRs obtained from biometry, measurements were repeated approximately 1 h later. RESULTS: At the initial measurement, mean (SD, range) HRs were 10.77 (0.79, 9.14-12.73) and 11.02 (0.82, 9.48-13.32) °/mm for the horizontal and vertical meridians, respectively. There was a significant difference between the horizontal and vertical HRs (p < 0.0001). Mean intrasubject variability of HR was 0.06 °/mm (95% Limit of Agreement [LOA]: -0.82 to 0.94 °/mm), and 0.05 °/mm (95% LOA: -1.05 to 1.15 °/mm) for the horizontal and vertical meridians, respectively. CONCLUSION: The results indicated that HRs obtained through ocular biometry in a binocularly normal paediatric population are consistent with previous studies in both strabismic children and adult cohorts. The HRs obtained with this technique were highly repeatable in this study population. This approach to gaze position calibration could be used in lieu of other empirical techniques in children.

Assessment of infection prevention and control measures adopted by eye care practitioners in Ghana and South Africa against COVID-19.

This study investigated the infection prevention and control measures adopted by eye care practitioners in Ghana and South Africa during the lockdown phase of the COVID-19 pandemic. A descriptive, cross-sectional study was used to investigate infection prevention and control measures by eye care practitioners in Ghana (n = 189) and South Africa (n = 92) during the extended lockdown phase (01 April-30 June 2020) by both countries, immediately following the WHO declaration of COVI9-19 as a pandemic. Participants from both countries included Ophthalmologists, Optometrists, Ophthalmic nurses, and Opticians who were invited via email and social media platforms to complete an online questionnaire. The questionnaire assessed practitioners' general knowledge on the COVID-19, viral exposure, infection prevention and control measures adopted during eye examinations. The majority of the practitioners from Ghana 140 (74%) and 43 (47%) South Africa reported COVID-19 screening at their facilities before the commencement of eye examinations. Few practitioners 77 (41%) and 9 (10)% from Ghana and South Africa, respectively had received any form of training (seminars and workshops) in COVID-19 infection prevention and control measures. Practitioners frequently practiced hand washing - Ghana (125, 66%), South Africa (70, 76%) -, wearing of nose masks - Ghana 126 (67%), South Africa 51 (55%), alcohol-rub on equipment - Ghana 115 (61%), South Africa 45(49%) as a means of sterilizing the hand and equipment against COVID-19 during close contact examinations. The majority of practitioners from the two countries adhered to basic safety protocols despite receiving no additional training on COVID-19 infection prevention. Maintenance of universal safety precautions in eye care facilities is key to preventing nosocomial infections.

Correction of Low-Moderate Hyperopia Improves Accommodative Function for Some Hyperopic Children During Sustained Near Work.

Purpose: This study investigated whether refractive correction improved accommodative function of hyperopic children while engaged in two sustained near activities. Methods: Sustained accommodative function of 63 participants (aged 5-10 years) with varying levels of uncorrected hyperopia (>/= +1.00 D and < + 5.00 D spherical equivalent in the least hyperopic eye) was measured using eccentric infrared photorefraction (PowerRef 3; PlusOptix, Germany). Binocular accommodation measures were recorded while participants engaged in 2 tasks at 25 cm for 15 minutes each: an "active" task (reading small print on an Amazon Kindle), and a "passive" task (watching an animated movie on liquid crystal display [LCD] screen). Participants also underwent a comprehensive visual assessment, including measurement of presenting visual acuity, prism cover test, and stereoacuity. Reading speed was assessed with and without hyperopic correction. Refractive error was determined by cycloplegic retinoscopy. Results: Hyperopic refractive correction significantly improved accuracy of accommodative responses in both task (pairwise comparisons: t = -3.70, P = 0.001, and t = -4.93, P < 0.001 for reading and movie tasks, respectively). Accommodative microfluctuations increased with refractive correction in the reading task (F(1,61) = 25.77, P < 0.001) but decreased in the movie task (F(1,59) = 4.44, P = 0.04). Reading speed also significantly increased with refractive correction (F(1,48) = 66.32, P < 0.001). Conclusions: Correcting low-moderate levels of hyperopia has a positive impact on accommodative performance during sustained near activity in some schoolchildren. For these children, prescribing hyperopic correction may benefit performance in near vision tasks.

Epidemiology and visual outcomes of ocular injuries in a low resource country.

BACKGROUND: Ocular injury is a major cause of ocular morbidity and unilateral visual impairment and represents a considerable public health concern especially in low resource societies. OBJECTIVE: To evaluate the epidemiology and visual outcomes of ocular injuries in southern Ghana. METHODS: A retrospective hospital-based case series was conducted. Information on new cases of ocular injuries were retrieved and parameters including time between injury occurrence and reporting to the clinic, presenting visual acuity (VA), and the best corrected final VA were investigated and visual outcomes were assessed Results: Most (50.2%) of the patients reported to the hospital after a day of sustaining an ocular injury; workplace injuries, older patients and farm-related injuries were most likely to report after a day of sustaining an injury. A significant proportion (40.4%) of patients reported with good presenting vision (6/6-6/18) which increased to 56.7% after treatment; 45.3% of patients reported with visual impairment (<6/18) and reduced to 42.4% after treatment. Farming (AOR = 4.5, p = 0.02), reporting after a day of sustaining injury (AOR = 78, p< 0.001), workplace injuries (AOR = 3.1, p = 0.007) and roadside injuries (AOR = 3.1, p = 0.02) were associated with poor visual outcomes. Initial VA 6/18 or better was the highest predictor of good visual outcome. CONCLUSION: There is a shift in the pattern of ocular injury occurrence from work-related to home- related.

Comparison of Three Gaze-position Calibration Techniques in First Purkinje Image-based Eye Trackers.

SIGNIFICANCE: This study highlights potential differences that can arise in gaze-position estimates from first Purkinje image-based eye trackers based on how individual Hirschberg ratios (HRs) are calculated. PURPOSE: The purpose of this study was to evaluate the accuracy and repeatability of eccentric-viewing, prism-based, and theoretical techniques that are routinely used to calibrate HR in first Purkinje image-based eye trackers. METHODS: Hirschberg ratios of 28 participants (18 to 40 years old) were obtained using the PlusOptix PowerRef 3 photorefractor and eye tracker. In the gold standard eccentric-viewing technique, participants viewed eccentric targets (±12°, 4° steps) at 2 m. In the prism-based technique, 4 to 16Δ-D base-out and base-in prisms were placed in 4Δ-D steps before an eye occluded with an infrared filter; the fellow eye fixated a target at 1 m. Each participant's HR was calculated as the slope of the linear regression of the shift in Purkinje image relative to the pupil center for each target eccentricity or induced prism power. Theoretical HR was calculated from the participant's corneal curvature and anterior chamber depth measures. Data collection was repeated on another visit using all three techniques to assess repeatability. Data were also obtained from an Indian cohort (n = 30, 18 to 40 years old) using similar protocols. RESULTS: Hirschberg ratio ranged from 10.61 to 14.63°/mm (median, 11.90°/mm) in the eccentric-viewing technique. The prism-based and theoretical techniques demonstrated inaccuracies of 12 and 4% relative to the eccentric-viewing technique. The 95% limits of agreement of intrasubject variability were ±2.00, ±0.40, and ±0.30°/mm for the prism-based, eccentric-viewing, and theoretical techniques, respectively (P > .05). Intraclass correlation coefficients (95% confidence interval) were 0.99 (0.98 to 1.00) for eccentric, 0.99 (0.99 to 1.00) for theoretical, and 0.88 (0.74 to 0.94) for prism-based techniques. Similar results were found for the Indian cohort. CONCLUSIONS: The prism-based and theoretical techniques both demonstrated relative inaccuracies in measures of HR compared with the eccentric-viewing technique. The prism-based technique exhibited the poorest repeatability.

Near vision spectacle coverage and barriers to near vision correction among adults in the Cape Coast Metropolis of Ghana.

PURPOSE: To determine the near vision spectacle coverage and barriers to obtaining near vision correction among adults aged 35 years and older in the Cape Coast Metropolis of Ghana. METHODS: A population-based cross-sectional study design was adopted and 500 out of 576 participants aged 35 years and older were examined from 12 randomly selected clusters in Cape Coast, Ghana. All participants underwent a comprehensive eye examination which included: distance and near visual acuities measurements and external and internal ocular health assessments. Distance and near refractions were performed using subjective refraction technique. Information on participants' demographics, near vision correction status, near visual needs and barriers to acquiring near vision correction were obtained through a questionnaire administered as part of the study. RESULTS: The mean age of participants was 52.3±10.3 years of whom 280 (56%) were females and 220 (44%) were males. The near vision spectacle coverage was 25%, 33% "met need" for near vision correction in the presbyopic population, and 64% unmet need in the entire study population. After controlling for other variables, age (5th and 6th decades) and educational level were associated with "met need" for near vision correction (OR=2.7 (1.55-4.68), p =0.00, and OR=2.36 (1.18-4.72), p=0.02 respectively). Among those who needed but did not have near vision correction, 64 (26%) did not feel the need for correction, 55 (22%) stated that they were unaware of available interventions, and 53 (21%) found the cost of near vision correction prohibitive. CONCLUSION: There was a low near vision spectacle coverage in this population which suggests the need for strategies on health education and promotion to address the lack of awareness of spectacle need and cost of services.

A case of leukemic retinopathy mimicking common ischemic retinopathies.

Reported case of leukemic retinopathy mimicking common ischemic retinopathies in a young adult where ophthalmic visit was the first step to the diagnosis of chronic myeloid leukemia. It highlights the importance of routine eye exams and that clinicians should suspect leukemia in an otherwise healthy patient presenting with ischemic retinopathy.

Fasting Plasma Sugar: A Predictor of Accommodative Function in Diabetes.

BACKGROUND: Diabetes has been associated with decline in accommodative function in some ethnic groups. This outcome, however, could differ since ethnic variations in accommodation have been noted. This study investigated the relationship between plasma sugar level on subjective accommodative amplitude and accommodative lag in black Africans with type-1 diabetes. METHODS: An examiner-blind study of subjective accommodative amplitude and accommodative lag between 45 diabetic subjects (15 males, 30 females) aged 12-39 years and 45 age- and sex-matched healthy non-diabetic controls was conducted. Accommodative amplitude was measured by the push-up to blur/push-down to clear methods using a RAF rule, the accommodative lag by the MEM retinoscopy, and the fasting plasma sugar (FPS) by a glucose meter. RESULTS: Comparatively, the diabetic subjects had significantly lower accommodative amplitude (10.1 ± 2.7 D versus 11.5 ± 2.4 D, respectively; p = 0.010) and greater accommodative lag (1.1 ± 0.4 D versus 0.7 ± 0.2 D; p < 0.001, respectively) than the controls. Multiple regression analyses showed that after adjusting for age, FPS concentration significantly predicted accommodative amplitude (R(2 )= 0.05, p = 0.022) and accommodative lag (R(2 )= 0.30, p < 0.001) in diabetes. Duration of diabetes was not significantly related to accommodative amplitude and accommodative lag. CONCLUSION: Diabetes mellitus in black Africans was associated with lower accommodative amplitude and greater accommodative lag. An adequate control of the plasma sugar concentration may be vital to maintain proper accommodative function.

A cross-sectional survey of optometrists and optometric practices in Ghana.

PURPOSE: The study was conducted to profile optometrists and optometric practices in Ghana. METHODS: An online survey was conducted among 146 optometrists, who were registered with the Ghana Optometric Association (GOA). It included questions on their demographics, equipment, ophthalmic procedures routinely conducted and the barriers to providing a full scope of optometric services. RESULTS: Ninety registered optometrists (62 per cent) responded, their mean age being 28.97 ± 3.36 years. There were more males (68.9 per cent) than females and most had the Doctor of Optometry (OD) degree, the profession's highest degree in Ghana. There were more practitioners in urban centres (71.1 per cent) and most practices had basic optometric instruments, such as direct ophthalmoscopes, slitlamp biomicroscopes and retinoscopes. Many optometrists routinely conducted direct ophthalmoscopy (100 per cent), slitlamp biomicroscopy (87.5 per cent) and contact tonometry (55.7 per cent); however, few provided contact lens (10.2 per cent) and low vision (9.1 per cent) assessments, with 76 per cent stating that it was due to the unavailability of low vision devices, poor sources of contact lenses (27 per cent) and perceived insufficient training (11.2 per cent). Many practitioners (97 per cent) reported the use of diagnostic pharmaceutical agents and therapeutic pharmaceutical agents (96.6 per cent). Most practitioners (52.9 per cent) preferred conferences for the delivery of continuous professional development over publications (26.4 per cent) and internet resources (12.6 per cent). CONCLUSION: The data elicited in this study provide a basis for addressing the country's unmet eye-care needs and can be used to determine training and support guidelines for the profession.

Toward eliminating blindness due to uncorrected refractive errors: assessment of refractive services in the northern and central regions of Ghana.

PURPOSE: This study sought to document current refractive services in the northern and central regions of Ghana as a first step toward evidence-based planning of refractive services. METHODS: A descriptive cross-sectional survey was carried out in health facilities in the northern and central regions of Ghana, which provided eye-care services. A semi-structured questionnaire was administered to gather information on each facility type, human resources providing refractive services, assessment of refraction and spectacle dispensing output and provider barriers to the services. RESULTS: Current outputs of refraction in the northern and central regions were 0.5 and 1.2 per cent of the estimated refractive needs, respectively. Spectacle dispensing services were below the outputs of refraction. Lack of equipment (36.8 per cent) and cost of providing spectacles frames (31.6 per cent), were identified as the main barriers to providing refractive services. CONCLUSION: The provision of refractive services in the study regions was inadequate. Lack of infrastructure and inadequate human resource were the major reasons for the limited service provision. This should be considered for planning refractive services in the study regions and Ghana as a whole.

The effect of caffeine on tear secretion.

PURPOSE: Caffeine, probably the most widely consumed psychoactive substance, is claimed to have conflicting effects on some tear film dynamics. This study sought to investigate the effect of orally ingested caffeine on tear secretion. METHODS: In an examiner-masked, placebo-controlled, crossover experimental model, the effect of caffeine intake on tear secretion was studied in 41 healthy volunteers aged 20 to 26 years (mean, 23.0 ± 2.1 years). Participants were randomly assigned into two groups, A and B, to receive two different treatments in two sessions. Subjects in group A were exposed to 5.0 mg/kg body weight of caffeine dissolved in 200 mL of water on their first visit, whereas those in group B were exposed to 200 mL of water. On the second visit, however, the order of treatment was reversed. Schirmer 1 scores were measured repeatedly at 45, 90, 135, and 180 minutes after treatment. The baseline Schirmer 1 scores were compared with posttreatment scores. RESULTS: Schirmer 1 scores increased after caffeine intake. The increase was statistically significant at 45 and 90 minutes (p < 0.05) after caffeine intake. Age, body mass, and blood pressure had no correlation with Schirmer 1 scores (Spearman correlation test, p > 0.05). There was no influence of gender in caffeine's effect on tear secretion (F = 0.994, p = 0.399). CONCLUSIONS: From our study, orally ingested caffeine appears to stimulate tear secretion in healthy non-dry eye subjects.