The influence of age, refractive error, visual demand and lighting conditions on accommodative ability in Malay children and adults.

PURPOSE: Near work, accommodative inaccuracy and ambient lighting conditions have all been implicated in the development of myopia. However, differences in accommodative responses with age and refractive error under different visual conditions remain unclear. This study explores differences in accommodative ability and refractive error with exposure to differing ambient illumination and visual demands in Malay schoolchildren and adults. METHODS: Sixty young adults (21-25 years) and 60 schoolchildren (8-12 years) were recruited. Accommodative lag and accommodative fluctuations at far (6 m) and near (25 cm) were measured using the Grand Seiko WAM-5500 open-field autorefractor. The effects of mesopic room illumination on accommodation were also investigated. RESULTS: Repeated-measures ANOVA indicated that accommodative lag at far and near differed significantly between schoolchildren and young adults [F(1.219, 35.354) = 11.857, p < 0.05]. Post hoc tests using the Bonferroni correction showed that at near, there was a greater lag in schoolchildren (0.486 ± 0.181 D) than young adults (0.259 ± 0.209 D, p < 0.05). Repeated-measures ANOVA also revealed that accommodative lag at near demands differed statistically between the non-myopic and myopic groups in young adults and schoolchildren [F(3.107, 31.431) = 12.187, p < 0.05]. Post hoc tests with Bonferroni correction showed that accommodative lag at near was significantly greater in myopic schoolchildren (0.655 ± 0.198 D) than in non-myopic schoolchildren (0.202 ± 0.141 D, p < 0.05) and myopic young adults (0.316 ± 0.172 D, p < 0.05), but no significant difference was found between myopic young adults (0.316 ± 0.172 D) and non-myopic young adults (0.242 ± 0.126 D, p > 0.05). Accommodative lag and fluctuations were greater under mesopic room conditions for all ages [all p < 0.05]. CONCLUSION: Greater accommodative lag was found in myopes than in emmetropes, in schoolchildren than in adults, and under mesopic conditions than under photopic conditions. Accommodative fluctuations were greatest in myopes and in mesopic conditions. These results suggest that differences exist in the amount of blur experienced by myopes and non-myopes at different ages and under different lighting conditions.

Myopes have significantly higher serum melatonin concentrations than non-myopes.

PURPOSE: Experimental animal models of myopia demonstrate that higher melatonin (Mel) and lower dopamine (DA) concentrations actively promote axial elongation. This study explored the association between myopia and serum concentrations of DA and Mel in humans. METHODS: Morning serum concentrations of DA and Mel were measured by solid phase extraction-liquid chromatography-tandem mass spectrometry from 54 participants (age 19.1 ± 0.81 years) in September/October 2014 (phase 1) and March/April 2016 (phase 2). Axial length (AL), corneal radii (CR) and spherical equivalent refraction (SER) were also recorded. Participants were defined as myopic if non-cycloplegic spherical equivalent refractive error ≤-0.50 DS at phase 1. RESULTS: Nine participants were lost to follow up. Mel concentrations were measurable for all myopes (phase 1 n = 25, phase 2 n = 22) and non-myopes (phase 1 n = 29, phase 2 n = 23). SER did not change significantly between phases (p = 0.51). DA concentrations were measurable for fewer myopes (phase 1 n = 13, phase 2 n = 12) and non-myopes (phase 1 n = 23, phase 2 n = 16). Myopes exhibited significantly higher Mel concentrations than non-myopes at phase 1 (Median difference: 10 pg mL-1 , p < 0.001) and at phase 2 (Median difference: 7.3 pg mL-1 , p < 0.001) and lower DA concentrations at phase 2 (Median difference: 4.7 pg mL-1 , p = 0.006). Mel concentrations were positively associated with more negative SER (all r ≥ -0.53, all p < 0.001), longer AL (all r ≥ 0.37, all p ≤ 0.008) and higher AL/CR ratio (all r ≥ 0.51, all p < 0.001). CONCLUSION: This study reports for the first time in humans that myopes exhibit higher serum Mel concentrations than non-myopes. This may indicate a role for light exposure and circadian rhythm in the human myopic growth mechanism. Further research should focus on younger cohorts exhibiting more dynamic myopic progression and explore the profile of these neurochemicals alongside evaluation of sleep patterns in myopic and non-myopic groups.

The use of conjunctival ultraviolet autofluorescence (CUVAF) as a biomarker of time spent outdoors.

PURPOSE: Conjunctival ultraviolet autofluorescence (CUVAF) has been used in previous Southern Hemisphere myopia research as a marker for time spent outdoors. The validity of CUVAF as an indicator of time spent outdoors is yet to be explored in the Northern Hemisphere. It is unclear if CUVAF represents damage attributed to UV exposure or dry eye. This cross-sectional study investigated the association between CUVAF measures, self-reported time spent outdoors and measures of dry eye. METHODS: Participants were recruited from University staff and students (n = 50, 19-64 years; mean 41). None were using topical ocular medications (with the exception of dry eye treatments). Sun exposure and dry eye questionnaires (Ocular Surface Disease Index and McMonnies) were completed by the participant. Dryness was also assessed using slit lamp biomicroscopy and invasive tear break up time. Images of the temporal and nasal conjunctiva from the right and left eye were captured using a bespoke photography system. The total CUVAF area, average CUVAF pixel intensity per mm(2) and total CUVAF pixel intensity were analysed using MATLAB R2013a (The MathWorks Inc). RESULTS: Of the 50 participants, 42% were classified as having dry eye. Self-reported sunglasses use was negatively associated with all CUVAF measures (Kruskal Wallis total CUVAF area, p = 0.04, ptrend  = 0.03, average CUVAF pixel intensity p = 0.02, ptrend  = 0.02, total CUVAF pixel intensity: p = 0.04, ptrend  = 0.02). Time spent outdoors was positively associated with all CUVAF measures (Spearman's correlation coefficients, total CUVAF area: r = 0.37, p = 0.01, average CUVAF pixel intensity: r = 0.36, p = 0.01, total CUVAF pixel intensity: r = 0.37, p = 0.01) and remained significant when sunglasses use was controlled for (partial correlation, total CUVAF area: r = 0.32, p = 0.03, average CUVAF pixel intensity: r = 0.39, p = 0.01, total CUVAF pixel intensity: r = 0.39, p = 0.03). Neither CUVAF area nor intensity measures were associated with any dry eye measure (Ocular Surface Disease Index: all p ≥ 0.41, corneal staining: all p ≥ 0.38, McMonnies: all r ≤ 0.09 all p ≥ 0.52, slit lamp biomicroscopy: all r ≤ 0.20 all p ≥ 0.17, invasive tear break up time: all r ≤ -0.07 all p ≥ 0.31). CONCLUSIONS: CUVAF area and intensity were not associated with clinical measures of dry eye. Greater CUVAF area and intensity were associated with wearing sunglasses less frequently and spending more time outdoors. If sunglass wear is accounted for, CUVAF may be a useful biomarker of time spent outdoors in future myopia studies.

Retinal Fractal Dimension Is a Potential Biomarker for Systemic Health-Evidence From a Mixed-Age, Primary-Care Population.

Purpose: To investigate whether fractal dimension (FD), a retinal trait relating to vascular complexity and a potential "oculomics" biomarker for systemic disease, is applicable to a mixed-age, primary-care population. Methods: We used cross-sectional data (96 individuals; 183 eyes; ages 18-81 years) from a university-based optometry clinic in Glasgow, Scotland, to study the association between FD and systemic health. We computed FD from color fundus images using Deep Approximation of Retinal Traits (DART), an artificial intelligence-based method designed to be more robust to poor image quality. Results: Despite DART being designed to be more robust, a significant association (P < 0.001) between image quality and FD remained. Consistent with previous literature, age was associated with lower FD (P < 0.001 univariate and when adjusting for image quality). However, FD variance was higher in older patients, and some patients over 60 had FD comparable to those of patients in their 20s. Prevalent systemic conditions were significantly (P = 0.037) associated with lower FD when adjusting for image quality and age. Conclusions: Our work suggests that FD as a biomarker for systemic health extends to mixed-age, primary-care populations. FD decreases with age but might not substantially decrease in everyone. This should be further investigated using longitudinal data. Finally, image quality was associated with FD, but it is unclear whether this finding is measurement error caused by image quality or confounded by age and health. Future work should investigate this to clarify whether adjusting for image quality is appropriate. Translational Relevance: FD could potentially be used in regular screening settings, but questions around image quality remain.

Socio-economic differences in accessing NHS spectacles amongst children with differing refractive errors living in Scotland.

BACKGROUND/OBJECTIVES: Adults living in more deprived areas are less likely to attend an eye examination, resulting in greater visual impairment from undiagnosed eye disease and a widening of health inequalities. It is unknown if the introduction of free NHS eye examinations and help with spectacle costs has benefited children in Scotland. This study aimed to explore factors associated with accessing NHS spectacles including level of deprivation, refractive error, urbanity and age. SUBJECTS/METHODS: NHS-financed General Ophthalmic Services (GOS) 3 supplement the cost of spectacles for children under 16 years. Administrative data on the spectacle refraction dispensed were obtained from Information Services Division (ISD) for mainland Scotland, 2018, and categorised by: Emmetropes/low hyperopes (reference group), myopes and moderate/high hyperopes. Data were linked to the Scottish Index of Multiple Deprivation (SIMD) quintile. RESULTS: Data included 108, 043 GOS 3 claims. Greater deprivation was associated with greater GOS 3 claims p = 0.041. This was most evident in emmetropic/low hyperopic children and in moderate/high hyperopic children. GOS 3 claims in the myopes group increased with age across all SIMD and decreased with age in the moderate/high hyperope group (all p < 0.001). GOS 3 claims were not associated with urbanity for all Health Boards (p = 0.13). CONCLUSIONS: Children in areas of greater deprivation and in more rural areas are not disadvantaged in accessing NHS spectacles. This did not vary by refractive error group. This suggests that health policy in Scotland is accessible to those from all deprivation levels and refractive errors.

Topical Management of Enterocutaneous and Enteroatmospheric Fistulas: A Systematic Review.

Enterocutaneous (ECF) and enteroatmospheric (EAF) fistulas are associated with considerable morbidity and patient care challenges, including optimal topical management. PURPOSE: A systematic literature review was conducted to identify topical management interventions used in ECF/EAF care and to explore the role of these interventions in fistula closure and long-term fistula management. METHODS: A search of PubMed, the Cumulative Index of Nursing and Allied Health Literature, and Scopus was conducted to identify English-language articles published from January 2004 to January 2019. The keywords enterocutaneous fistula, enteroatmospheric fistula, negative pressure wound therapy, NPWT, vacuum-assisted closure, VAC, pouch or pouching, troughing, bridging, collection device, dressing, and wound care were used to identify all publications pertaining to the topical management of adult and mixed adult/pediatric patients with an ECF or EAF. Single-person case studies, exclusively pediatric studies, surgical treatment-based, and duplicate publications were excluded. Abstracts were screened for relevance to the research questions, and eligible publications were abstracted and categorized using The Oxford Centre for Evidence-Based Medicine Levels of Evidence. The Joanna Briggs Institute (JBI) critical appraisal checklist for case series was used to assess each article for risk of bias and methodological quality. Outcomes of interest included patient demographics, closure rates, fistula classification (type of fistula, fistula output, fistula origin), type of topical treatment, adverse events (pain, new fistula formation, fistula recurrence, mortality), follow-up, long-term management, perifistula skin protection, effluent management, dressing change frequency, and quality of life. Descriptive statistics were presented; no statistical analysis was performed. RESULTS: Of the 983 articles identified, 57 underwent critical appraisal using the JBI checklist for case series. Forty-two (42) did not meet the inclusion criteria, leaving 15, level IV, case-based publications (N = 410 patients). No randomized controlled trials were found. All studies included some form of negative pressure wound therapy. JBI results found that each study was at high risk of bias in more than 2 domains. Interventions were categorized as intubation, occlusion, or isolation of the fistula. Of the 559 fistulas treated, spontaneous closure was reported in 164 cases, with rates ranging from 0% to 100%. Adverse events to treatment included pain (n = 33 patients), new fistula formation (n = 12), and fistula recurrence (n = 1). Sepsis was the leading cause of mortality (n = 29), with reported rates ranging from 0% to 44%. CONCLUSION: Due to the high risk of study bias and low quality of evidence, the exact contribution of any one intervention could not be established. Results also suggest a high risk of publication bias, and patient-centered outcomes were reported in only 1 study. Although topical management might play a role in fistula closure, it is only as part of a comprehensive plan of care. Future research should focus on developing and using standardized reporting tools, classifications, and outcomes and include patient-centered outcomes such as acceptance, tolerability, pain, and quality of life relating to any one intervention. At this time, the evidence base for management recommendations is limited, suggesting that interventions should mainly be based on practical considerations such as resources and clinician skill.

Change in body height, axial length and refractive status over a four-year period in caucasian children and young adults.

INTRODUCTION: Body height and axial length (AL) increase during childhood with excessive axial elongation resulting in myopia. There is no consensus regarding the association between body growth and AL during refractive development. This study explored the association between change in body height, AL and refractive status over 4-years in children and young adults. MATERIAL AND METHODS: Measures were collected biennially (timepoints: t1, t2, t3) (t1 n = 140, aged 5-20years). Non-cycloplegic autorefraction was obtained using the Shin-Nippon openfield autorefractor. AL, corneal curvature (CC) and anterior chamber depth (ACD) were measured by IOL Master. Body height (cm) was measured using a wall mounted tape measure. Refractive status was classified using spherical equivalent refraction (SER): persistent emmetropes (PE) (-0.50D to +1.00D), persistent myopes (PM) (≤-0.50D), progressing myopes (PrM) (increase of ≤-0.50D between timepoints), incident myopes (IM) (subsequent SER≤-0.50D) and persistent hyperopes (PH) (>+1.00D). RESULTS: Change in AL and change in height were correlated in the PE (all t:p ≤ 0.003) and the IM (t1-t2 p = 0.04). For every increase in body height of 1 cm: t1-t2: AL increased by 0.03 mm in the PE, 0.15 in the PM, 0.11 mm in the IM, 0.14 mm in the PrM, -0.006 mm in the PH. T2-t3: AL increased by 0.02 mm in the PE, 0.06 in the PM, 0.16 mm in the PrM, 0.12 mm in the IM and -0.03 mm in the PH. CONCLUSIONS: In emmetropia body growth and axial elongation are correlated. In participants with myopia, body growth appears to stabilise whilst axial elongation continues at a much faster rate indicating dysregulation of normal ocular growth.

Conjunctival ultraviolet autofluorescence area, but not intensity, is associated with myopia.

BACKGROUND: Conjunctival ultraviolet autofluorescence (CUVAF) has been used as a biomarker of time spent outdoors. Smaller CUVAF area is associated with myopia in southern hemisphere cohorts. Further research is required to determine if this association is replicated in northern latitudes and whether average CUVAF intensity is a valuable metric. This prospective study explored the association between myopia, CUVAF (area and intensity) and additional indicators of sun exposure (vitamin D3 and self-reported sun exposure preferences) across seasons at a location of 55° north. METHODS: Young adults (age 18-20) provided blood samples biannually (March/April and September/October) over an 18-month period (four phases) for the assessment of 25-hydroxyvitamin D (25(OH)D3 ) concentrations (liquid chromatography-tandem mass spectrometry). CUVAF (total area, average intensity) and self-reported sun exposure preferences were recorded at each phase. Axial length and corneal radius were measured. Refractive error was measured by autorefractor and spherical equivalent refraction used to classify participants into refractive groups: myopic (spherical equivalent refraction ≤ -0.50 DS) or non-myopic. RESULTS: Fifty-four participants (24 myopes, 30 non-myopes) participated. CUVAF area was negatively associated with the presence of myopia (odds ratio = 0.94, 95 per cent confidence interval = 0.90-0.98, p = 0.002). Myopes = 4.5 mm2 (interquartile range [IQR] 0.95-6.4 mm2 ), non-myopes = 7.0 mm2 (IQR = 2.0-10.7 mm2 ). No significant association was found between CUVAF intensity and refractive group (p = 0.17). There was no significant association between sun exposure preferences or serum concentration of 25(OH)D3 and refractive status (all p ≥ 0.21). CUVAF measures were not associated with ocular biometry measures (all p ≥ 0.084). CUVAF area was unaffected by season (all p ≥ 0.45) and variations in CUVAF area over the study period did not exceed the repeatability of the measurement technique. CONCLUSION: Myopia was associated with smaller areas of CUVAF indicative of less cumulative ultraviolet-B exposure. These findings suggest that CUVAF measures are a useful, non-invasive biomarker of the time spent outdoors in adults in northern hemisphere populations.