Ophthalmic and Physiological Optics最新文献

Purpose: Scotland has comprehensive child vision screening at age 3.5-5.5 years of age, with ~85% participation (40,000-50,000 screening episodes annually). Orthoptists deliver the screening, including presenting vision, cover test and other tests. Screening failures are referred for eye examinations, including cycloplegic refraction. The study aims to report refractive error data from these examinations (~5000-6000 annually) for 3 years before and 2 years following the COVID-19 pandemic, and to investigate correlations between myopia and socio-economic factors.

Methods: Right eye data from eight Scottish health boards (HB) are reported for spherical equivalent refraction (SER) for the years 2013-14, 2014-15, 2015-16, 2020-21 and 2021-22. Associations were investigated between the proportion of the sample in each HB with myopia and the proportion of the population in each HB with different levels of deprivation index, classification on a rural/urban continuum and dwelling type.

Results: Refractive error frequency distributions revealed a myopic shift in SER over the 5 years. Median SER (interquartile range) in 2013-14, 2014-15, 2015-16, 2020-21 and 2021-22 was +1.38 D (+0.50 to +2.75), +1.38 D (+0.25 to +2.63), +1.38 D (+0.50 to +2.75), +1.13 D (+0.25 to +2.25) and +1.25 D (+0.38 to +2.25), respectively. The increase in myopia was statistically significant in each of the last 2 years compared with each of the first 3 years (p < 0.0005). The proportion of myopes (≤-0.50 D) increased from <7.8% annually in 2013-16 to 11.51% in 2020-21 and 10.65% in 2021-22 (linear trend: r² = 0.94, p = 0.006). Associations between the proportion of children in each HB with myopia and: (1) deprivation index was low and not statistically significant; (2) the proportion of the population in the most urban environments was high (r² = 0.79; p = 0.003); (3) the proportion of dwellings that were flats/apartments was also high (r² = 0.83, p = 0.002).

Conclusions: In this predominantly Caucasian population, the proportion of children with myopia has increased post-COVID. A strong association exists between myopia and living in flats/apartments and urbanicity, but not with a deprivation index.

Purpose: The onset and progression of myopia can occur during adulthood, suggesting that myopia should be managed in young adults. Low-concentration atropine eye drops have shown promising efficacy in myopia control. This study aimed to evaluate the impact of 0.01% and 0.05% atropine eye drops on the visual performance of university students.

Methods: Twenty-six myopic students aged 18-30 years received 0.01% and 0.05% atropine in random order. Atropine eye drops were administered once a night in both eyes for 14 days, with a minimum 14-day washout period between concentrations. Visual assessments, including the modulation transfer function (MTF) cut-off, Strehl ratio (SR), objective scattering index, contrast sensitivity (CS) and glare disability, were conducted 1, 2, 7 and 14 days after atropine administration and corresponding time points after cessation. A questionnaire was used to evaluate ocular and general symptoms.

Results: After 1 day of treatment with 0.05% atropine, the MTF cut-off (β = -8.75, p < 0.001) and SR (β = -0.05, p < 0.001) decreased significantly to their lowest levels. The area under the log CS function also decreased significantly (all p < 0.05) during administration of the 0.05% eye drops, especially in the mesopic with glare condition, and reached its lowest point 1 day after administration (β = -0.20, p < 0.001). However, all parameters returned to baseline levels 2 weeks after 0.05% atropine was stopped (all p > 0.05). Additionally, 40.91% of the young adults reported experiencing excessive daytime sleepiness and nocturnal glare during 0.05% atropine use. Treatment with 0.01% atropine had minimal effects on both visual performance and subjective symptoms.

Conclusions: Administration of 0.05% atropine had a significant but temporary effect on the visual performance of young adult myopic patients, whereas 0.01% atropine had a minimal effect.

Purpose: The apparent contrast of a visible central grating can be reduced by the presence of a surrounding grating-an effect known as surround suppression of contrast. Surround suppression is strong when the orientation of the surround matches that of the central probe and is strongest in the periphery. There is evidence that surround suppression at the fovea increases in strength with age, and that the orientation dependence of surround suppression is weakened. However, the range of visual stimuli that can produce this effect (and the implicated underlying mechanisms) requires further examination. This study aimed to characterise surround suppression at the fovea and its dependence on age. Visual stimuli with previously unexplored spatiotemporal parameters were used, designed to minimise contributions from spatially short-range overlay masking and temporally transient masking mechanisms.

Methods: In 20 younger (<30 years) and 17 older (>60 years) observers, psychophysical contrast-matching thresholds were measured using stimuli centred on the fovea. Grating stimuli were presented with either no surround, a collinearly oriented surround or an orthogonally oriented surround. Using a staircase procedure, observers matched the contrast of these central target stimuli to the contrast of a separate reference stimulus. The points of subjective equality between target and reference stimuli were compared between the two surround orientations and between younger and older age groups.

Results: Across all observers, weak foveal surround suppression was found that had little orientation tuning. No evidence for the strength of surround suppression increasing with age is reported.

Conclusions: These findings suggest that the age-related effects of surround suppression may be dependent on the spatiotemporal parameters of the stimulus used and encourage further exploration of the contrast masking mechanisms affected by age. The mild and weakly orientation-tuned suppression may have been produced by a weak and temporally sustained suppression mechanism.

Aim: This study aimed to quantify the internal, corneal and total higher order aberrations (HOAs) in the healthy human eye using ray tracing technology in bright and dim light conditions. The study also aimed to evaluate the retinal image quality and contrast modulation at different spatial frequencies, objectively using image-quality metrics derived from wavefront aberrations.

Methodology: A cross-sectional prospective observational study was conducted on 521 emmetropic young adults. HOAs including coma, trefoil, spherical aberration and secondary astigmatism were measured separately for the cornea, internal and total eye using a ray-tracing wavefront aberrometer at mesopic and photopic pupil sizes. The Strehl ratio, derived from the point spread function (PSF), was used to evaluate the retinal image quality of the eye. Contrast modulation at spatial frequencies of 5, 10 and 15 cycles per degree was assessed through the modulation transfer function (MTF).

Results: Mean age of participants was 25.4 ± 4.8 years (54.5% male). The total HOAs of internal, corneal and total eye were 0.186 ± 0.075, 0.191 ± 0.112 and 0.222 ± 0.075 μ, respectively for a 5-mm pupil (dim light condition), and 0.069 ± 0.031, 0.061 ± 0.094 and 0.076 ± 0.031 μ, respectively, for a 3-mm pupil (bright light condition). The Strehl ratio was 0.16 ± 0.124 (5 mm pupil) and 0.601 ± 0.19 (3 mm pupil). A normative database was created and correlations drawn for the HOAs, PSF and MTF (using image quality metrics) for the cornea, internal and total eye at mesopic and photopic pupil sizes.

Conclusion: These findings provide normal population (young healthy adults) reference ranges for HOAs, retinal image quality and contrast modulation at higher spatial frequencies using ray tracing technology. The presence of these natural wavefront aberrations enhances the visual performance and may not need to be corrected. The separate assessment of aberrations and derived image quality metrics for the cornea, internal and total eye can serve as a benchmark for diagnosing and monitoring ocular conditions and allows targeted treatment planning.

Introduction: Tear exchange during contact lens wear is essential for ocular surface integrity, facilitating debris removal, and maintaining corneal metabolism. Fluorophotometry and fluorogram methods are typically used to measure tear exchange, which require hardware modifications to a slit lamp biomicroscope. This manuscript introduces an alternative method using a corneoscleral profilometer, the Eye Surface Profiler (ESP), to quantify tear exchange during corneal and scleral rigid lens wear by assessing fluorescence intensity changes over time.

Methods: As a proof of concept, a healthy participant wore a corneal and a scleral rigid lens on separate days. After lens application, 2% sodium fluorescein was instilled, and ESP images were captured at intervals over a 30-min period for corneal and a 90-min period for the scleral lens. Fluorescence intensity data were extracted and analysed using MATLAB, restricted to a region of interest centred on the contact lens. The fluorescence intensity was fitted with an exponential decay curve to quantify tear exchange.

Results: Fluorescence intensity decreased over time for both lenses, with a faster decay rate being observed for the corneal lens. The scleral lens showed an initial ingress of fluorescein into the fluid reservoir, then a slow decay in fluorescence intensity due to limited tear exchange. The decay rate for the corneal lens was approximately four times faster than the scleral lens, with the time to reach 50% decay of ~42 min for the corneal lens compared to ~157 min for the scleral lens.

Conclusion: A new method was developed to quantify tear exchange using a commercially available corneoscleral profilometer, offering a wider field of view than existing techniques. This approach has clinical potential in scleral lens practice for identifying landing zone misalignment and improving the understanding of post-lens tear dynamics, particularly in cases involving scleral lens modifications or patients experiencing midday fogging.

Purpose: To compare the magnitude of central, mid-peripheral and peripheral stromal corneal oedema induced during short-term fenestrated and non-fenestrated scleral lens wear.

Methods: Nine healthy participants wore a non-fenestrated and a fenestrated (0.3-mm diameter limbal fenestration) scleral lens (KATT™, Capricornia Contact Lenses), hexafocon B material (Dk 141 × 10^-11 cm³ O₂(cm)/[(s) (cm²) (mmHg)]) in one eye under open-eye conditions for 90 min on two separate days. Scleral lens thickness, fluid reservoir thickness and stromal corneal oedema were measured using high-resolution optical coherence tomography. Stromal oedema was quantified across the central (0-2.5 mm from the corneal apex), mid-peripheral (-3.0 to -1.0 mm from the scleral spur) and peripheral (-1.0 to 0 mm from the scleral spur) cornea with the lens in situ. The magnitude of oedema was corrected based on variations in fluid reservoir thickness between the lens conditions.

Results: There was a significant effect of lens type (p = 0.04) on stromal oedema, with less oedema observed with the fenestrated (0.36 ± 0.45%) compared to the non-fenestrated lenses (1.24 ± 0.27%), averaged across all corneal locations. A significant lens type by corneal location interaction was also observed (p = 0.05), with less oedema observed in the peripheral region for the fenestrated (-0.15 ± 0.98%) compared to the non-fenestrated lenses (1.81 ± 0.57%) (p = 0.048). A fenestration location by corneal location interaction was also observed (p = 0.02), indicating a greater reduction in oedema closer to the fenestration.

Conclusions: Central and mid-peripheral stromal oedema was similar during fenestrated and non-fenestrated lens wear; however, fenestrated lenses displayed significantly less oedema in the peripheral cornea. This is most likely due to increased oxygen delivery in proximity to the fenestration.

The ageing process of adults with a disability may differ from the typical ageing process, yet few studies have addressed ageing of adults who are blind. However, a broad scope of literature exists on ageing with a visual impairment that includes adults who are blind. People who are blind may age differently than people with a visual impairment. Furthermore, it cannot be inferred from studies on the ageing of visually impaired adults that changes are due to the ageing process alone, since vision may decline further as well. This article presents a scoping review of studies on the ageing of adults who are blind, examining the areas of decline due to ageing, differences compared to non-blind adults, additional contributing factors and support. A systematic literature search was performed from inception up to July-October 2023 in Scopus, Medline, Embase, CINAHL, APA PsycInfo and Web of Science. Thirteen articles met the eligibility criteria. Analysis led to four broad areas: physical, sensory, cognitive and psychological. In several of these areas, the decline due to ageing was similar for people who were blind or non-blind. Declines specific to people who were blind were in spatial memory and engagement to the outer world. Two abilities were identified where blind people outperformed sighted people: attention and working memory and active tactile acuity. Overall, ageing blind adults were shown to have additional risks and hence need extra support. Interventions may focus on physical and cognitive exercise, braille training, risk screening, education and social activities. More research is needed to replicate studies and disambiguate results, to include areas that have not been investigated specifically for this group, to differentiate between different types of blindness and to investigate systematically the needs and support of blind adults who are ageing.

Purpose: Alternative non-standard paediatric visual field (VF) tests have been developed to address the challenges associated with standard approaches. However, diagnostic accuracy of these new VF tests has not yet been rigorously evaluated. This systematic review aims to explore diagnostic accuracy and feasibility of non-standard VF tests in paediatric patients.

Methods: The following databases were searched for English language studies comparing a non-standard paediatric VF test to standard methods, such as standard automated perimetry (SAP), manual kinetic perimetry (MKP) and confrontation testing (CT): EMBASE, PubMed, Ovid MEDLINE, Web of Science, Scopus, VisionCite, Cochrane Library, ClinicalTrials.gov, African Index Medicus, LILACS, Trip and grey literature databases. Studies included were of children ≤18 years old with suspected or known VF defects (n > 3). Case reports, case series, editorials and letters were excluded. This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.

Results: Thirty studies (n = 2074 children, age range: 2 months to 18 years) published between 1990 and 2023 met the inclusion/exclusion criteria. Twenty index tests were reported, sorted into four categories of methods: behavioural/observational (5), electrophysiological (2), modifications of standard perimetry (11) and eye tracking (2). Risk of bias, based on the QUADAS-2 results, was unclear or high for most studies. Sensitivities of 10 studies (behavioural/observational [2]; electrophysiological [2]; modifications of standard perimetry [2] and eye tracking [4]) were 60%-100%, 75%, 80%-94% and 70%-100%, and specificities were 98%-100%, 86%-88%, 68%-100% and 50%-100%, respectively.

Conclusions: Alternative non-standard paediatric VF tests, and behavioural/observational methods in particular, show potential for adequate diagnostic accuracy and feasibility, although limited to certain conditions and ages. Studies with complete reporting and low risk of bias are needed to determine the diagnostic accuracy and feasibility of non-standard paediatric VF tests.

Purpose: To evaluate the repeatability and agreement of established and newer methods for measuring the amplitude of accommodation in non-presbyopic and early presbyopic individuals.

Methods: The amplitude of accommodation of 81 participants was measured using five different methods (two push-up techniques, two minus lens techniques and one objective technique) with different measurement principles. Among these, two new techniques were introduced: an electronic push-up and a minus lens technique with a tunable lens. Three repeated measurements were performed with each method. The repeatability limit and non-parametric Bland-Altman analysis were used to describe the repeatability and agreement of each method.

Results: The repeatability limit was between ±0.7 D and ±1.4 D for the minus lens techniques, around ±1.8 D for the push-up methods and ±1.4 D for the objective procedure. The largest differences in median values were found between the push-up and objective methods.

Conclusions: Push-up methods are most likely to overestimate accommodation, while the objective method gives the lowest results. New techniques show good repeatability for measuring the amplitude of accommodation. Among the subjective methods, the minus lens technique with the tunable lens gives the best repeatability, is one of the fastest and gives results most similar to the objective method.

Purpose: To increase recognition of Charles Bonnet Syndrome (CBS) beyond its conventional association with 'significant vision loss', which is indicated in the current literature as a diagnostic criterion.

Methods: Clinical observation of CBS associated with unilateral visual loss following enucleation due to choroidal melanoma. Comprehensive visual assessments were performed. The cognitive function was assessed with the Montreal Cognitive Assessment (MoCA)-BLIND. The phenomenology, occurrence and impact of visual hallucinations were evaluated using the University of Miami Parkinson's Disease Hallucinations Questionnaire (UM-PDHQ). A critical literature review of CBS cases associated with vision loss in one eye only was conducted.

Results: In this case and in an additional nine reported cases in the literature, CBS hallucinations occurred following unilateral vision loss despite preserved visual function in the fellow eye. These hallucinations are phenomenologically consistent with those observed after severe bilateral vision loss, indicating that both conditions can lead to the development of CBS.

Conclusions: CBS should be screened in all patients who have experienced any degree of vision loss.