Ophthalmic and Physiological Optics最新文献

Purpose: To assess the ability of the Dolphin air-pulse aesthesiometer to present multiple stimuli, which are separated temporally (in sequence) or spatially (simultaneously).

Methods: Two studies were performed to explore the cooling effects induced by double air-puff stimuli generated by a novel aesthesiometer composed of two micro-blower integrated units. The stimuli were delivered sequentially or simultaneously at the same or different spatial locations to an in vitro eye model monitored using thermography. The model eye was based on a 2-cm LED dome light mounted on a circuit board with an 8-V supply producing a baseline 32°C temperature. Single and repeated air-pulse stimuli varying in intensity, duration, inter-stimulus delay and stimulus location were presented to the model. The cooling effect produced was observed using a thermal camera and quantified using image analysis software.

Results: The instrument can deliver single stimuli, repeated single stimuli with a variable time delay or multiple stimuli either simultaneously or with a time delay between them. The thermal effects of stimuli were evaluated by measuring (relative to pre-stimulus baseline) the local temperature change and the diameter of the model eye surface region with ≥1°C reduction. Repeated stimuli at the same location produced a significantly greater effect than a single stimulus of the same intensity (larger area of cooling after the second stimulus compared to the first [|M|{SE} = 1.48 mm {0.06}, p < 0.001]). Spatially separated stimuli produced separate cooling zones, with the amount of cooling relative to stimulus intensity (rm-ANOVA, F_2,8 = 276.01, p < 0.001, $\omega$ ² = 0.96).

Conclusions: The combined use of two micro-blower units allows increased options for modification of stimulus intensity and timing of delivery that enables the production of alternative stimulus presentations and intensity compared to a single stimulus. This adaptability may enable future in vivo study of corneal sensory nerve summation.

Purpose: The present study aimed to determine the potential impact of scleral lenses on intraocular pressure (IOP) by analysing the Bruch's membrane opening-minimum rim width (BMO-MRW) while the lenses are worn, in a population with keratoconus.

Methods: Participants were required to have keratoconus and be successfully fitted with scleral lenses for at least 3 months. A new pair of optimised scleral lenses was provided before the study. During the first session, corneal biomechanics was assessed using an air tonometer, coupling Scheimpflug technology. Then, a scan of the optic nerve was carried out using optical coherence tomography (OCT) at 2 h intervals for 6 h. Particular attention was paid to identifying the BMO-MRW, which represents the smallest distance between the BMO and the internal limiting membrane. These tests were repeated, respecting the time at which the initial measurements were taken, while the scleral lens was worn. Results from only one eye were analysed.

Results: A statistically significant change of 10.5 ± 3.6 μm (95% CI [241.3-473.1]; p = 0.02) in BMO-MRW was observed after 6 h of scleral lens wear, compared to measurements without lenses (4.8 ± 3.4 μm; 95% CI [285.1-439.7]; p = 0.18). The fluctuation was greater in participants with keratoconus than found in a previous study of regular corneas.

Conclusion: BMO-MRW became significantly thinner after 6 h of scleral lens wear compared with measurements without lenses. These variations may be associated with a rise in IOP during lens wear. Close monitoring for optic head changes should be carried out for patients at risk. These results should be compared with future longer-term studies including a larger cohort of patients.

Purpose: This case-control study investigated whether defects in visual field contrast sensitivity are associated with exposure to occupational levels of pesticides in agricultural workers.

Methods: Twenty-seven individuals exposed to occupational levels of pesticides (exposed group) from 14 agricultural systems and 27 non-exposed individuals (non-exposed group) were measured using standard automated perimetry (30-2 full threshold). Visual sector analysis, targeting regions of the optic nerve head, was performed to examine for potential region-specific sensitivity differences. Participants also underwent comprehensive assessments, including general optometric examinations and demographic surveys. Symptoms and signs of neurotoxicity were assessed using the modified Q16 neurotoxic symptom questionnaire and biological testing for abnormal levels of Substance P in tears (an inflammatory marker associated with chemical exposure) and cholinesterase (which is inhibited by pesticides) in blood samples.

Results: Signs of chemical exposure were found as indicated by significantly higher levels of neurotoxic symptoms, higher concentrations of Substance P and lower levels of cholinesterase in the exposed group. Visual field global indices showed differences in contrast sensitivity between the exposed and non-exposed groups, with the exposed group demonstrating significantly lower means and larger pattern-standard deviations. Notably, visual field sector analysis revealed comparatively lower contrast sensitivity at nasal locations surrounding the optic nerve head in the exposed group.

Conclusion: This study found deficits in visual field contrast sensitivity to be associated with pesticide exposure, and selective loss at nasal locations centred on the optic nerve head may indicate retinal toxicity. These findings suggest the utility of visual field assessment as a potential method to evaluate pesticide-related health implications. The results highlight the need for ongoing monitoring and protective measures for agricultural workers exposed to pesticides to prevent potential visual and neurological damage.

Introduction: To evaluate the long-term effect of corneal transplantation on mental health outcomes and to assess potential predictors of these outcomes.

Methods: For this multicentre prospective cohort study, patients awaiting corneal transplantation were recruited from 11 (academic) hospitals and eye clinics in the Netherlands. Participants (n = 238) completed the Centre for Epidemiological Studies Depression scale (CES-D), the Hospital Anxiety and Depression Scale-Anxiety subscale (HADS-A) and the Dutch ICF Activity Inventory Emotional Health subscale (DAI-EH) and Fatigue subscale (DAI-F) 1 month prior and 3, 6, 12 and 24 months after corneal transplantation. Sociodemographic and clinical characteristics, as well as coping styles as measured with the Utrecht Coping List, were considered as potential predictors for mental health outcomes (depression, anxiety, emotional health problems and fatigue). Linear mixed models were used to analyse and predict symptoms of depression, anxiety, emotional health problems and fatigue over time.

Results: Scores on the CES-D and HADS-A improved significantly from baseline to 24-months (mean scores CES-D: 8.6 vs. 7.7, p = 0.03; mean scores HADS-A: 3.7 vs. 3.2, p = 0.002). Scores on the DAI-EH and DAI-F also improved significantly from baseline to 24-months (mean scores DAI-EH: 10.7 vs. 7.5, p < 0.001; mean scores DAI-F: 17.4 vs. 11.3, p < 0.001). Male sex and Fuchs' dystrophy were important predictors of better mental health outcomes, whereas comorbidity, (dry) eye complaints and a passive reacting coping style were important predictors of worse mental health outcomes.

Conclusion: Corneal transplantation had a positive impact on mental health outcomes and important predictors were identified. This study may improve the understanding of patients and eyecare practitioners about the effects of corneal transplantation, leading to realistic communication about corneal transplantation expectations.

Introduction: Understanding barriers to seeking eye care and providing evidence-based theory-informed solutions can improve the uptake of eye care services. Therefore, in this cross-sectional study, we aim to report and analyse barriers to seeking eye care services among individuals with vision impairment in the Akividu region of Andhra Pradesh, India.

Methods: Out of the 3000 enumerated participants, a total of 2587 were examined. All participants with vision impairment were asked to report barriers for not seeking eye care despite noticing reduced vision using a validated questionnaire. The reported barriers were mapped to the theoretical domains framework (TDF) to explore potential individual and environmental influences on the uptake of eye care services.

Results: Barriers to seeking eye care services are most frequently mapped to the 'beliefs about capabilities', 'environmental context and resources' and 'social influences' domains of the TDF. The most frequently reported barrier was 'aware of the problem but can manage' (beliefs about capabilities), expressed by 43.4% (n = 156) and 55.7% (n = 337) of participants with distance and near vision impairment, respectively. 'No one to accompany' for an appointment (social influences) was a significant barrier for participants with distance vision impairment (n = 44, 12.2%) in comparison to participants with near vision impairment (n = 19, 3.1%). Additionally, fear of losing eyesight or operation or consultation (emotion) was a major deterrent for seeking eye care services, particularly among participants with distance vision impairment (n = 31, 8.6%) when compared with near vision impairment (n = 17, 2.8%).

Conclusion: The uptake of eye care services is influenced by a complex set of interacting factors. Identification of potentially modifiable target behaviours provides an opportunity to develop theory-informed solutions to improve uptake of services and prevent avoidable vision loss.

Purpose: Reliable assessment is critical for diagnosing and managing meibomian gland dysfunction. Multi-functional diagnostic devices, such as meibographers, streamline clinical workflows by integrating multiple ocular assessments. Ensuring reproducibility across examiners is vital for accurate diagnosis and monitoring of treatment. This prospective study determined the inter-examiner reproducibility (IER), inter-rater reproducibility (IRR) and within-subject variability (WSV) of the Huvitz HRK-9000A meibographer.

Methods: Meibomian glands (MGs) of both eyelids of healthy participants were captured during the same session by Examiner 1 (E1) and Examiner 2 (E2) in a counter-balanced design. The images were rated offline by E1, E2 and an Independent rater (R1). The inter-examiner reproducibility (IER between E1 vs. E2) and inter-rater reproducibility (IRR between E1 vs. R1 and E2 vs. R1) were determined based on non-parametric Bland-Altman plots, intraclass correlation coefficients (ICCs) and weighted Kappa (κ) values. Within-subject variability (WSV) was determined using ICCs.

Results: Mean MG loss of the upper (E1: 1.0 ± 0.8 vs. R1: 0.9 ± 0.8, E2: 1.2 ± 0.8 vs. R1: 0.9 ± 0.7) and lower eyelids (E1: 1.9 ± 0.9 vs. R1: 2.1 ± 1.1, E2: 1.5 ± 1.0 vs. R1: 1.8 ± 1.0) of 35 participants (mean age 22 ± 3 years, range 19-30) was significantly correlated (p < 0.001) for all pairs of examiners (E1-E2, E1-R1 and E2-R1), but was significantly different for the upper eyelids of E2 vs. E1 (p < 0.002) and E2 vs. R1 (p < 0.003). Median differences between pairs of raters for both eyelids were close to zero, with >74% of comparisons falling within the interquartile range, except for the upper eyelids of E2 vs. E1 and E2 vs. R1 (63% and 66%, respectively). IRR demonstrated moderate agreement (0.43-0.57) with good reliability (ICC range 0.76-0.86) for the upper eyelids and good agreement (0.60-0.65) with good reliability (ICC range 0.85-0.88) for the lower eyelids. The WSV was excellent (ICCs for repeated measurements > 0.90).

Conclusions: The HRK-9000A meibographer demonstrated excellent reliability, with good inter-examiner and inter-rater reproducibility. It is suitable for meibographic assessment, follow-up or treatment.

Purpose: This study evaluated the effects of orthokeratology and 0.01% atropine on corneal biomechanical properties (CBPs) and myopia progression in children, focusing on their association with axial length (AL) changes and treatment outcomes.

Methods: In this 1-year prospective study, 53 children (aged 8-17 years) were enrolled, with 30 undergoing orthokeratology and 23 receiving 0.01% atropine. CBP parameters, including the Corvis Biomechanical Index (CBI), central corneal thickness (CCT), biomechanically corrected intraocular pressure (bIOP) and stress-strain index (SSI), were assessed at baseline and during follow-ups at 1, 3, 6, 9 and 12 months. The orthokeratology group was further stratified into good and poor responders based on early myopia reduction.

Results: The orthokeratology group exhibited a significant increase in CBI over time, particularly among good responders, while CCT, bIOP and SSI remained stable. In contrast, no significant changes in CBPs were observed in the atropine group. AL elongation showed no significant correlation with CBP changes in either group. The orthokeratology group achieved superior control of myopia progression compared to the atropine group at 12 months, with poor responders exhibiting better long-term AL control.

Conclusions: Both orthokeratology and 0.01% atropine were effective in controlling myopia. While atropine had no impact on CBPs, the increase in CBI with orthokeratology may predict early treatment outcomes. However, the initial response to orthokeratology did not guarantee long-term effectiveness, highlighting the need for individualised treatment monitoring.

Purpose: To investigate the influence of the corneal epithelium on corneal power, particularly in special cases such as post-refractive surgery and keratoconus.

Methods: A retrospective observational study. Measurement data were obtained from a high-resolution anterior segment analyser (CSO MS-39). Corneal curvature and power data, as well as surface height data, were organised in a cylindrical coordinate system. Calculations considered one, two and three refractive surfaces, examining the role of epithelial thickness and stromal curvature.

Results: The effect of the epithelium on corneal power was minimal (<0.1 D) in normal corneas, but it was considerable in keratoconus and post-refractive surgery cases, with differences up to 0.9 D. The effect decreased for larger measurement zones.

Conclusion: Incorporating epithelial thickness and stromal curvature into corneal power calculations is a crucial next step in accurate corneal power and intraocular lens calculation in eyes with previous refractive surgery or keratoconus. This study highlights the need for advanced diagnostic and calculation methods in complex cases.