Maximal incremental exercise improves macular photostress recovery time and lowers intraocular pressure in healthy athletes

OBJECTIVES

Better visual performance in athletes compared to non-athletes could suggest improved macular function through physical exertion. The study aimed to investigate the effect of maximal incremental treadmill (MIT) exercise on macular function.

DESIGN

An interventional study comparing the effect of maximal incremental treadmill (MIT) exercise until volitional exhaustion between athletes (n = 26) and non-athletes (n = 26).

METHODS

Participants underwent an ophthalmological assessment involving repeated measurements of the photostress recovery time (PSRT) at baseline and post-exercise. PSRT was recorded after a 10-second exposure of the macular to an intense light source from an ophthalmoscope positioned 2 cm in front of the eye. Secondary outcome measures also recorded included the best-corrected visual acuity (BCVA) and the intraocular pressure (IOP).

RESULTS

Compared to the baseline, MIT exercise markedly improved the PSRT of athletes from 42.7 ± 1.6 s to 39.6 ± 1.4 s (P < 0.001), while having no significant changes in the PSRT of non-athletes. After adjusting for exercise duration, the exercise intervention showed significant effects on the PSRT improvement in the athletes compared to non-athletes after exercise [F(1,49) = 16.941, P < 0.001], with estimated marginal means of 3.00 s and 0.47 s, respectively. Also, the exercise intervention resulted in significant improvements in IOP (P < 0.001) and BCVA (P < 0.01) of both groups.

CONCLUSIONS

MIT exercise improves macular function, BCVA, and reduced IOP in healthy athletes. Maximal incremental exercise may be recommended for competitive sports athletes seeking optimal visual performance, as long as it does not adversely impact other relevant non-visual factors.

TFEB is a central regulator of the aging process and age-related diseases

Old age is associated with a greater burden of disease, including neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease, as well as other chronic diseases. Coincidentally, popular lifestyle interventions, such as caloric restriction, intermittent fasting, and regular exercise, in addition to pharmacological interventions intended to protect against age-related diseases, induce transcription factor EB (TFEB) and autophagy. In this review, we summarize emerging discoveries that point to TFEB activity affecting the hallmarks of aging, including inhibiting DNA damage and epigenetic modifications, inducing autophagy and cell clearance to promote proteostasis, regulating mitochondrial quality control, linking nutrient-sensing to energy metabolism, regulating pro- and anti-inflammatory pathways, inhibiting senescence and promoting cell regenerative capacity. Furthermore, the therapeutic impact of TFEB activation on normal aging and tissue-specific disease development is assessed in the contexts of neurodegeneration and neuroplasticity, stem cell differentiation, immune responses, muscle energy adaptation, adipose tissue browning, hepatic functions, bone remodeling, and cancer. Safe and effective strategies of activating TFEB hold promise as a therapeutic strategy for multiple age-associated diseases and for extending lifespan.

In vitro methods in autophagy research: Applications in neurodegenerative diseases and mood disorders

Background

Autophagy is a conserved physiological intracellular mechanism responsible for the degradation and recycling of cytoplasmic constituents (e.g., damaged organelles, and protein aggregates) to maintain cell homeostasis. Aberrant autophagy has been observed in neurodegenerative diseases, including Alzheimer's Disease (AD), Parkinson's Disease (PD), Amyotrophic Lateral Sclerosis (ALS), and Huntington's Disease (HD), and recently aberrant autophagy has been associated with mood disorders, such as depression. Several in vitro methods have been developed to study the complex and tightly regulated mechanisms of autophagy. In vitro methods applied to autophagy research are used to identify molecular key players involved in dysfunctional autophagy and to screen autophagy regulators with therapeutic applications in neurological diseases and mood disorders. Therefore, the aims of this narrative review are (1) to compile information on the cell-based methods used in autophagy research, (2) to discuss their application, and (3) to create a catalog of traditional and novel in vitro methods applied in neurodegenerative diseases and depression.

Methods

Pubmed and Google Scholar were used to retrieve relevant in vitro studies on autophagy mechanisms in neurological diseases and depression using a combination of search terms per mechanism and disease (e.g., "macroautophagy" and "Alzheimer's disease"). A total of 37 studies were included (14 in PD, 8 in AD, 5 in ALS, 5 in %, and 5 in depression).

Results

A repertoire of traditional and novel approaches and techniques was compiled and discussed. The methods used in autophagy research focused on the mechanisms of macroautophagy, microautophagy, and chaperone-mediated autophagy. The in vitro tools presented in this review can be applied to explore pathophysiological mechanisms at a molecular level and to screen for potential therapeutic agents and their mechanism of action, which can be of great importance to understanding disease biology and potential therapeutic options in the context of neurodegenerative disorders and depression.

Conclusion

This is the first review to compile, discuss, and provide a catalog of traditional and novel in vitro models applied to neurodegenerative disorders and depression.

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.

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.

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.

Autophagy in the control and pathogenesis of parasitic infections

Background

Autophagy has a crucial role in the defense against parasites. The interplay existing between host autophagy and parasites has varied outcomes due to the kind of host cell and microorganism. The presence of autophagic compartments disrupt a significant number of pathogens and are further cleared by xenophagy in an autolysosome. Another section of pathogens have the capacity to outwit the autophagic pathway to their own advantage.

Result

To comprehend the interaction between pathogens and the host cells, it is significant to distinguish between starvation-induced autophagy and other autophagic pathways. Subversion of host autophagy by parasites is likely due to differences in cellular pathways from those of ‘classical’ autophagy and that they are controlled by parasites in a peculiar way. In xenophagy clearance at the intracellular level, the pathogens are first ubiquitinated before autophagy receptors acknowledgement, followed by labeling with light chain 3 (LC3) protein. The LC3 in LC3-associated phagocytosis (LAP) is added directly into vacuole membrane and functions regardless of the ULK, an initiation complex. The activation of the ULK complex composed of ATG13, FIP200 and ATG101causes the initiation of host autophagic response. Again, the recognition of PAMPs by conserved PRRs marks the first line of defense against pathogens, involving Toll-like receptors (TLRs). These all important immune-related receptors have been reported recently to regulate autophagy.

Conclusion

In this review, we sum up recent advances in autophagy to acknowledge and understand the interplay between host and parasites, focusing on target proteins for the design of therapeutic drugs. The target host proteins on the initiation of the ULK complex and PRRs-mediated recognition of PAMPs may provide strong potential for the design of therapeutic drugs against parasitic infections.

Controlled blood sugar improves the eye's accommodative ability in type-1 diabetes

PURPOSE

To evaluate the impact of blood sugar level on ocular measures, including refractive error (RE), amplitude of accommodation (AoA), and lag of accommodation (LoA), in pre-presbyopes with type-1 diabetes.

METHOD

The fasting blood sugar (FBS) and ocular measures of type-1 diabetes patients (age: 14-39 years; n = 30) on insulin treatment was recorded while they fasted on two separate visits, at baseline and 3 months later. The AoA and LoA was measured with the appropriate spectacle correction worn. The Welch's t-test was used for comparison of the baseline measures between the normal FBS ≤ 7 (n = 10) and higher FBS > 7 (n = 20) patients, and the paired t-test used to investigate for differences between the baseline and follow-up data in patients with changes in FBS.

RESULTS

On average, the spectacle correction for the normal FBS group was marginally more myopic (RE: -0.30 ± 0.67 D vs. +0.18 ± 1.00 D, p = 0.032), and they showed greater AoA (5.38 ± 1.08 D vs. 3.68 ± 1.43 D, p < 0.001) and lower LoA (1.00 ± 0.30 D vs. 1.30 ± 0.38 D, p = 0.004) compared with the higher FBS group at baseline. On the follow-up visit attended by 25 patients, the FBS of 15 patients was reduced by an average of 7.0 mmol/L, 8 patients had an average increase of 5.2 mmol/L, while 2 patients recorded no changes relative to the baseline. The patients whose FBS was reduced showed improvement in the mean AoA from 3.78 ± 1.58 D to 4.88 ± 1.61 D (p < 0.001) and a reduction in the mean LoA from 1.37 ± 0.40D to 0.87 ± 0.19D (p < 0.001), whereas those with deteriorated control of the FBS showed an opposite trend.

CONCLUSIONS

Controlling hyperglycemia improves ocular accommodation in type-1 diabetes.

Central Role of Oxidative Stress in Age-Related Macular Degeneration: Evidence from a Review of the Molecular Mechanisms and Animal Models

Age-related macular degeneration (AMD) is a common cause of visual impairment in the elderly. There are very limited therapeutic options for AMD with the predominant therapies targeting vascular endothelial growth factor (VEGF) in the retina of patients afflicted with wet AMD. Hence, it is important to remind readers, especially those interested in AMD, about current studies that may help to develop novel therapies for other stages of AMD. This study, therefore, provides a comprehensive review of studies on human specimens as well as rodent models of the disease, to identify and analyze the molecular mechanisms behind AMD development and progression. The evaluation of this information highlights the central role that oxidative damage in the retina plays in contributing to major pathways, including inflammation and angiogenesis, found in the AMD phenotype. Following on the debate of oxidative stress as the earliest injury in the AMD pathogenesis, we demonstrated how the targeting of oxidative stress-associated pathways, such as autophagy and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, might be the futuristic direction to explore in the search of an effective treatment for AMD, as the dysregulation of these mechanisms is crucial to oxidative injury in the retina. In addition, animal models of AMD have been discussed in great detail, with their strengths and pitfalls included, to assist inform in the selection of suitable models for investigating any of the molecular mechanisms.

Inter-regional trends in causes of childhood blindness and low vision in Ghana

BACKGROUND

Inter-regional trends of visual loss in most developing countries remain largely unknown. We compared the causes of childhood blindness among children attending blind schools in the northern (one school) and southern (two schools) regions of Ghana and assessed their need for spectacles and low-vision devices.

METHODS

Using a standardised methodology, children were examined by an ophthalmologist and optometrists in each location. Causes of visual loss were classified anatomically and by time of onset, and avoidable causes identified. Children identified with functional low vision were assessed and provided with low-vision devices.

RESULTS

A total of 252 children under 16 years of age were examined in the schools. The overall prevalence of total blindness was 73 (29.0 per cent), with similar proportions (p = 0.87) in the north (29 [28.4 per cent]) and south (44 [29.3 per cent]); 92 (36.5 per cent) had functional low vision. Two children improved with spectacles and 35 benefited from low-vision devices. Corneal scarring was significantly (p = 0.045) more prevalent in southern Ghana (n = 150) than in the north (n = 102), responsible for visual loss in 36 (24.0 per cent, 95% CI 17.2-30.8 per cent) and 14 (13.7 per cent, 95% CI 7.0-20.4 per cent) cases, respectively. No significant difference (p = 0.321) was observed in the prevalence of cataract between northern (28: 27.5 per cent, 95% CI 18.3-36.2 per cent) and southern Ghana (33: 22.0 per cent, 95% CI 15.4-28.6 per cent). Over 87 per cent of children had 'avoidable' causes of visual loss, with a higher proportion being treatable (124: 49.2 per cent) than preventable (96: 38 per cent).

CONCLUSION

Cataract was the major cause of visual loss in the overall population. The south had a higher proportion of corneal scarring and late-onset blindness compared with the north. More than one-third of blindness in blind schools in Ghana could have been prevented by primary care interventions and nearly half could have been treated surgically to prevent visual loss. Two in five children in blind schools in Ghana could benefit from optical intervention.

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 (5^th and 6^th 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.

Knowledge, usage and barriers associated with contact lens wear in Ghana

BACKGROUND

Despite findings that contact lens wear for vision correction provides better quality of life than spectacles, contact lens use in developing countries is low. This study evaluated knowledge, usage and barriers associated with contact lens wear among spectacle wearers in Cape Coast, Ghana.

METHOD

A cross-sectional survey using a structured questionnaire was conducted on an adult population of spectacle wearers to assess their knowledge of contact lens wear for vision correction. The participants were proportionately sampled from three eye clinics in the Cape Coast Metropolis, Ghana. Questionnaires were either self-administered or completed with the help of a research assistant.

RESULTS

Of the 422 participants, only 147 (34.8%) knew of contact lens wear for vision correction. The proportion of spectacle wearers reporting history of contact lens wear was 14 (3.3%). Barriers to contact lens wear reported were satisfaction with vision through spectacles 102 (25.0%), lack of adequate information 111 (27.2%), fear of side effects 94 (23.0%) and cost 78 (19.1%). The younger adults and those with higher number of changes of spectacles were more likely to know of contact lenses.

CONCLUSION

Knowledge and usage of contact lenses among spectacle wearers was low. Contact lens education and demonstration of visual performance through fitting of trial contact lenses on potential candidates may help overcome barriers to contact lens wear.

Caffeine intake is associated with pupil dilation and enhanced accommodation

PurposeIt is purported that caffeine, an autonomic stimulant, affects visual performance. This study sought to assess whether caffeine intake was associated with changes in pupil size and/or amplitude of accommodation.Patients and methodsA double-masked, crossover study was conducted in 50 healthy subjects of age range 19 to 25 years. Subjects were randomized to treatments such that subjects consumed either 250 mg caffeine drink or vehicle on separate days. Amplitude of accommodation was measured by the push-up technique, and pupil size using a millimeter ruler fixed to a slit lamp biomicroscope in dim illumination (5 lux). Amplitude of accommodation and pupil size were taken at baseline, and at 30, 60 and 90 min time points post treatment. Repeated measures one-way ANOVA and paired t-test were used in analyzing data.ResultsAmplitude of accommodation and pupil size after caffeine intake were significantly greater than vehicle (P<0.001) at each time point. Consumption of the caffeine beverage was associated with significant increases in amplitude of accommodation and pupil size with time (P<0.001). Amplitude of accommodation rose from 12.4 (±2.2 D) at baseline to 15.8(±2.6 D) at 90 min. Similarly, pupil size increased from 3.4 (±0.4 mm) at baseline to 4.5 (±0.72 mm) at 90 min. Consumption of vehicle was not associated with increase in amplitude of accommodation or pupil size with time.ConclusionPupil size and accommodation are affected after ingestion of caffeine. This study suggests caffeine may have some influence on visual functions.

Prevalence and Causes of Visual Impairment and Blindness among Cocoa Farmers in Ghana

PURPOSE

To determine the prevalence and causes of visual impairment and blindness among cocoa farmers in Ghana in order to formulate early intervention strategies.

METHODS

A cross-sectional study using multistage random sampling from four cocoa growing districts in Ghana was conducted from November 2013 to April 2014. A total of 512 cocoa farmers aged 40 years and older were interviewed and examined. The brief interview questionnaire was administered to elicit information on the demographics and socioeconomic details of participants. The examination included assessment of visual acuity (VA), retinoscopy, subjective refraction, direct ophthalmoscopy, slit-lamp biomicroscopy and intraocular pressure (IOP). For quality assurance, a random sample of cocoa farmers were selected and re-examined independently.

RESULTS

Moderate to severe visual impairment (VA <6/18 to 3/60 in the better-seeing eye) was present in 89 participants (17.4%) and 27 (5.3%) were blind (presenting VA <3/60 in the better eye) defined using presenting VA. The main causes of visual impairment were cataract (45, 38.8%), uncorrected refractive error (42, 36.2%), posterior segment disorders (15, 12.9%), and corneal opacity (11, 9.5%).

CONCLUSION

The prevalence of visual impairment and blindness among cocoa farmers in Ghana is relatively high. The major causes of visual impairment and blindness are largely preventable or treatable, indicating the need for early eye care service interventions.

Effect of preserved and preservative-free timolol eye drops on tear film stability in healthy Africans

Background:

Preserved versus nonpreserved formulations for ophthalmic use have been well described in the literature although not specifically in the African population where beta blockers are frequently used as the first-line therapy due to economic and availability issues. This study sought to determine the effect of preserved and preservative-free Timolol eye drops on tear film stability in healthy black Africans.

Materials and Methods:

Sixty healthy nondry eye subjects aged 19–25 years were randomly assigned into four groups (n = 15) and differently treated with eye drops of phosphate buffered saline (PBS), preservative-free timolol (PFT), benzalkonium chloride (BAK) only, and BAK-preserved timolol (BPT). Noninvasive tear break-up time (NITBUT) was measured using the keratometer at baseline and 30, 60, and 90 min after drop application.

Results:

No significant decline in NITBUT was observed following treatment with PFT and PBS. However, BAK treatment showed a positive time-dependent significant decline in NITBUT (P < 0.001) while a significant decline in the BPT-treated group was only found at 90 min (−3.52 s; P < 0.001). In comparison to the PFT-treated group, treatment with BAK and BPT showed significantly lower NITBUT (P < 0.001).

Conclusion:

BPT is associated with a significant decline in tear film stability in black Africans. This finding has implications in the management of glaucoma in patients with high-risk of dry eyes in this population.

Visual impairment attributable to uncorrected refractive error and other causes in the Ghanaian youth: The University of Cape Coast Survey

PURPOSE

To determine the prevalence of visual impairment attributable to refractive error and other causes in a youthful Ghanaian population.

METHODS

A prospective survey of all consecutive visits by first-year tertiary students to the Optometry clinic between August, 2013 and April, 2014. Of the 4378 first-year students aged 16-39 years enumerated, 3437 (78.5%) underwent the eye examination. The examination protocol included presenting visual acuity (PVA), ocular motility, and slit-lamp examination of the external eye, anterior segment and media, and non-dilated fundus examination. Pinhole acuity and fundus examination were performed when the PVA≤6/12 in one or both eyes to determine the principal cause of the vision loss.

RESULTS

The mean age of participants was 21.86 years (95% CI: 21.72-21.99). The prevalence of bilateral visual impairment (BVI; PVA in the better eye ≤6/12) and unilateral visual impairment UVI; PVA in the worse eye ≤6/12) were 3.08% (95% CI: 2.56-3.72) and 0.79% (95% CI: 0.54-1.14), respectively. Among 106 participants with BVI, refractive error (96.2%) and corneal opacity (3.8%) were the causes. Of the 27 participants with UVI, refractive error (44.4%), maculopathy (18.5%) and retinal disease (14.8%) were the major causes. There was unequal distribution of BVI in the different age groups, with those above 20 years having a lesser burden.

CONCLUSION

Eye screening and provision of affordable spectacle correction to the youth could be timely to eliminate visual impairment.

Antiallergic effect of an aqueous leaf extract of Pistia stratiotes in murine model of ovalbumin-induced allergic conjunctivitis

Aim:

The aim was to investigate the antiallergic effect of an aqueous leaf extract of Pistia stratiotes (ALPS) in a murine model of ovalbumin (OVA)-induced allergic conjunctivitis (AC).

Materials and Methods:

Prior to topical challenge (instillation of 1.5 mg OVA in 10 μL phosphate buffered saline into their conjunctival sacs) to induce AC, groups of sensitized Imprinting Control Region mice (injected IP, on day 1 and 7, with 0.2 ml solution of 100 μg OVA and 0.01 mg aluminum hydroxide in phosphate buffered saline), were treated with 5 mg/kg cetirizine, 10, 50 or 100 mg/kg of ALPS, or 2 ml/kg normal saline per os. Conjunctival redness, lid edema, tearing and lid scratching (clinical symptoms of AC) were scored. Serum OVA specific immunoglobulins were determined using ELISA. Histopathological assessment of the conjunctival mucosal tissue was conducted. The extract was screened for secondary plant metabolites.

Results:

Pretreatment with the extract significantly (P ≤ 0.05–0.01) and dose-dependently reduced the scores for clinical symptoms, which were marked in vehicle-pretreated mice. Pretreatment also lowered (P ≤ 0.01–0.001) serum OVA specific immunoglobulins. Mast cell infiltration and degranulation in conjunctival stroma (measured by an inflammatory score) in histopathological studies was also significantly low (P ≤ 0.05–0.01) on pretreatment.

Conclusion:

The ALPS exhibited interesting antiallergic activity and hence could be useful in managing AC.

Knowledge of diabetes and its associated ocular manifestations by diabetic patients: A study at Korle-Bu Teaching Hospital, Ghana

Background:

Diabetes mellitus is a significant cause of visual impairment, hence adequate knowledge on this condition and its ocular manifestations is of immense importance to diabetic patients.

Aim:

To assess the knowledge of diabetic patients on the disorder and its ocular manifestations, and their attitude towards ocular examinations.

Materials and Methods:

A cross-sectional survey involving the use of a structured interview was conducted among diabetic patients attending the Diabetic Clinic of the Korle-Bu Teaching Hospital. Using Fishers Exact Chi-square (χ²) and Odds Ratios (ORs), data obtained was analyzed.

Results:

Only 103 (26.4%) patients knew the type of diabetes mellitus they were suffering from. Knowledge on ocular effects of diabetes mellitus was low and only 15 (3.8%) knew that it could affect the ocular refraction with no patient mentioning that diabetes mellitus could cause cataract or diabetic retinopathy. Attitude to routine eye examination was poor. As much as 135 (34.6%) had never had an eye examination since being diagnosed of diabetes. Knowledge of the type of diabetes mellitus the individual had or any ocular complication of this disorder was significantly related (OR: 4.22; P < 0.001 and OR: 2.55; P < 0.001) respectively to their attitude to seeking eye care.

Conclusion:

Diabetic patients’ knowledge on diabetes mellitus and its ocular manifestations, and the attitude of diabetic patients towards eye examination were poor. Intensive health education by diabetes care givers and leaders of the Ghana Diabetic Association for diabetic patient is therefore required to improve attitude towards eye care to prevent visual impairment.