Optometry And Vision Science[JOURNAL]

PURPOSE: This study investigated how obstacle contrast altered gait behavior of healthy younger and older adults. METHODS: Twenty normally sighted adults, 11 older (mean [standard deviation] age, 68.1 [5.1] years) and 9... PURPOSE: This study investigated how obstacle contrast altered gait behavior of healthy younger and older adults. METHODS: Twenty normally sighted adults, 11 older (mean [standard deviation] age, 68.1 [5.1] years) and 9 younger (mean [standard deviation] age, 21.1 [2.1] years), walked along a 6-m, black carpeted walkway and stepped over a single obstacle positioned 4 m from the start. The obstacle varied in height (0 [no obstacle], 1, and 19 cm) and contrast (6% ["low"] and 90% ["high"] Michelson contrast). Each subject completed 10 trials for each of the 5 conditions in an unblocked, random order. Lower limb kinematics were recorded using 13 motion capture cameras. Visual acuity and contrast sensitivity were measured. A repeated-measures analysis of variance was used to assess age group differences in trail toe position before crossing, lead and trail foot clearance over the obstacle, lead heel position after crossing, and obstacle crossing speed. Planned comparisons were done with Bonferroni correction. Independent t tests were used to compare vision and survey variables between groups. RESULTS: Visual acuity was similar in both groups (p=0.17), although contrast sensitivity was better in the younger than older adults (p=0.001). Main effects were found for age: compared with younger adults, older adults showed a farther back trail foot position, greater trail foot clearance, closer lead heel position, and slower obstacle crossing speed (p<0.001 for all effects). Main effects were found for obstacle contrast: compared with low-contrast obstacles, for high-contrast obstacles, the trail foot position was farther back, both lead and trail foot clearance were greater, and lead heel position was closer (p<0.024 for all effects). CONCLUSIONS: Obstacle contrast impacts gait behavior for younger and older adults. It is possible that the visual characteristics of an obstacle are enhanced for high-contrast obstacles, causing changes to gait behavior that may increase safety.

Get PDF PubMed ↗

Epidemiology of epiretinal membranes using spectral-domain optical coherence tomography in an Iranian elderly population.

Hashemi H, Nabovati P, Aghamirsalim M … +3 more , Hajizadeh F, Hashemi A, Khabazkhoob M

Optom Vis Sci · 2025 Feb · PMID 39792892 · Publisher ↗

SIGNIFICANCE: Epidemiological information about the epiretinal membrane is important for better clinical management and understanding of the nature and burden of this disease. There are some gaps in our understanding of... SIGNIFICANCE: Epidemiological information about the epiretinal membrane is important for better clinical management and understanding of the nature and burden of this disease. There are some gaps in our understanding of the epidemiology of epiretinal membranes, particularly in Africa and the Middle East. PURPOSE: This study aimed to determine the prevalence and risk factors of epiretinal membrane using spectral-domain optical coherence tomography (OCT) in an Iranian elderly population. METHODS: This report is a part of a population-based study conducted on the elderly population 60 years and older from Tehran, the capital of Iran, using multistage stratified random cluster sampling. Study participants underwent measurement of visual acuity, autorefraction, subjective refraction, and slit-lamp biomicroscopy. The epiretinal membranes were diagnosed by a retinal specialist from OCT images (Spectralis OCT). RESULTS: A total of 1298 individuals were analyzed for this report. Of these, 58.9% were female, and the mean age of the participants was 67.4 ± 6.4 years. The prevalence rates of all epiretinal membranes, primary epiretinal membrane, and secondary epiretinal membrane were 6.0% (95% confidence interval [CI], 4.6 to 7.5%), 4.7% (95% CI, 3.0 to 6.3%), and 10.1% (95% CI, 6.6 to 13.6%), respectively. According to the multiple logistic regression model, the interaction between age and diabetes (odds ratio [OR], 1.09; 95% CI, 1.01 to 1.18, p=0.048) and the presence of posterior vitreous detachment (OR, 2.89; 95% CI, 1.45 to 5.78, p=0.003) were significantly linked to a higher prevalence of primary epiretinal membrane. Additionally, a significant inverse relationship was found between the prevalence of primary epiretinal membrane and the number of years of education (OR, 0.91; 95% CI, 0.85 to 0.97; p=0.002). CONCLUSIONS: The prevalence of primary epiretinal membrane in Tehran, Iran, was found to be lower than that reported in the majority of earlier studies. Posterior vitreous detachment, interaction between age and diabetes, and lower education level were risk factors of primary epiretinal membrane in this study.

Get PDF PubMed ↗

Internal validation of a convolutional neural network pipeline for assessing meibomian gland structure from meibography.

Scales C, Bai J, Murakami D … +10 more , Young J, Cheng D, Gupta P, Claypool C, Holland E, Kading D, Hauser W, O'Dell L, Osae E, Blackie CA

Optom Vis Sci · 2025 Jan · PMID 39792877 · Full text

SIGNIFICANCE: Optimal meibography utilization and interpretation are hindered due to poor lid presentation, blurry images, or image artifacts and the challenges of applying clinical grading scales. These results, using t... SIGNIFICANCE: Optimal meibography utilization and interpretation are hindered due to poor lid presentation, blurry images, or image artifacts and the challenges of applying clinical grading scales. These results, using the largest image dataset analyzed to date, demonstrate development of algorithms that provide standardized, real-time inference that addresses all of these limitations. PURPOSE: This study aimed to develop and validate an algorithmic pipeline to automate and standardize meibomian gland absence assessment and interpretation. METHODS: A total of 143,476 images were collected from sites across North America. Ophthalmologist and optometrist experts established ground-truth image quality and quantification (i.e., degree of gland absence). Annotated images were allocated into training, validation, and test sets. Convolutional neural networks within Google Cloud VertexAI trained three locally deployable or edge-based predictive models: image quality detection, over-flip detection, and gland absence detection. The algorithms were combined into an algorithmic pipeline onboard a LipiScan Dynamic Meibomian Imager to provide real-time clinical inference for new images. Performance metrics were generated for each algorithm in the pipeline onboard the LipiScan from naive image test sets. RESULTS: Individual model performance metrics included the following: weighted average precision (image quality detection: 0.81, over-flip detection: 0.88, gland absence detection: 0.84), weighted average recall (image quality detection: 0.80, over-flip detection: 0.87, gland absence detection: 0.80), weighted average F1 score (image quality detection: 0.80, over-flip detection: 0.87, gland absence detection: 0.81), overall accuracy (image quality detection: 0.80, over-flip detection: 0.87, gland absence detection: 0.80), Cohen κ (image quality detection: 0.60, over-flip detection: 0.62, and gland absence detection: 0.71), Kendall τb (image quality detection: 0.61, p<0.001, over-flip detection: 0.63, p<0.001, and gland absence detection: 0.67, p<001), and Matthews coefficient (image quality detection: 0.61, over-flip detection: 0.63, and gland absence detection: 0.62). Area under the precision-recall curve (image quality detection: 0.87 over-flip detection: 0.92, gland absence detection: 0.89) and area under the receiver operating characteristic curve (image quality detection: 0.88, over-flip detection: 0.91 gland absence detection: 0.93) were calculated across a common set of thresholds, ranging from 0 to 1. CONCLUSIONS: Comparison of predictions from each model to expert panel ground-truth demonstrated strong association and moderate to substantial agreement. The findings and performance metrics show that the pipeline of algorithms provides standardized, real-time inference/prediction of meibomian gland absence.

Free PDF PubMed ↗

Topical review: Ocular surface abnormalities in neurodegenerative disorders.

Waller SE, Stockwell JB, Fung VSC … +4 more , Anstey KJ, Colebatch JG, Markoulli M, Krishnan AV

Optom Vis Sci · 2025 Feb · PMID 39792646 · Publisher ↗

SIGNIFICANCE: In an aging population, the number of people living with neurodegenerative disease is projected to increase. It is vital to develop reliable, noninvasive biomarkers to detect disease onset and monitor progr... SIGNIFICANCE: In an aging population, the number of people living with neurodegenerative disease is projected to increase. It is vital to develop reliable, noninvasive biomarkers to detect disease onset and monitor progression, and there is a growing body of research into the ocular surface as a potential source of such biomarkers. BACKGROUND: This article reviews the potential of in vivo corneal confocal microscopy and tear fluid analysis as tools for biomarker development. Corneal confocal microscopy, traditionally used for studying corneal health, offers high-resolution imaging of corneal nerves and has shown promise for examining systemic diseases such as Alzheimer disease and Parkinson's disease. Complementarily, tear fluid analysis, known for its ease of collection, reflects systemic changes in neurodegenerative conditions. CONCLUSION: Together, these noninvasive techniques provide insights into disease onset and progression and hold potential for advancing diagnostic and treatment strategies.

Get PDF PubMed ↗

2024 AAO Select Meeting Papers and Posters.

Optom Vis Sci · 2024 Dec · PMID 39729539 · Publisher ↗

Abstract loading — click title to view on PubMed.

Get PDF PubMed ↗

Effect of different artificial tears on tear film parameters in dry eye disease.

Maity M, Allay MB, Ali MH … +2 more , Basu S, Singh S

Optom Vis Sci · 2025 Jan · PMID 39729080 · Full text

SIGNIFICANCE: Artificial tears remain the cornerstone for managing dry eye disease. The current study's real-world efficacy test of carboxymethylcellulose (CMC), polyethylene glycol (PEG) 400, or sodium hyaluronate (SH)-... SIGNIFICANCE: Artificial tears remain the cornerstone for managing dry eye disease. The current study's real-world efficacy test of carboxymethylcellulose (CMC), polyethylene glycol (PEG) 400, or sodium hyaluronate (SH)-based lubricants highlights their similar effects on noninvasive tear film parameters over the short term. However, patients reported better relief with SH-based lubricants. PURPOSE: This study aimed to compare the short-term impact of different artificial tear formulations on tear film in moderate dry eye disease patients. METHODS: A prospective, double-masked, controlled study randomly allocated moderate dry eye disease patients into five groups of artificial tears: 0.5% CMC, 1% CMC, 0.1% SH-trehalose, 0.4% PEG 400-0.3% propylene glycol (PG), and 0.1% SH-0.4% PEG 400-0.3% PG. Noninvasive tear breakup time (NIBUT), tear meniscus height, and bulbar redness (Keratograph 5M; OCULUS Optikgeräte, Wetzlar, Germany) were assessed (in a controlled environment chamber 68 to 70°F; 35% relative humidity) at baseline and every 15 minutes for 1 hour after a drop instillation in the left eye. The right eye was an internal control. At 1 hour, subjects were asked for a change in subjective symptomatology (scales 0 to 4). A linear mixed-effect model was used for analysis. RESULTS: Each artificial tear group had 20 patients (100 patients). All groups had similar dry eye disease types and durations, baseline ocular surface disease index scores, and tear film parameters. All artificial tears showed significant improvement in NIBUT values at all time points from baseline compared with contralateral eyes. The change in NIBUT values was similar between different artificial tears at all time points. Bulbar redness scores and tear meniscus height showed no significant change in either eye with time or artificial tears. All patients reported improvement in dry eye disease symptomatology, with significant differences observed between 1% CMC and SH-PEG-PG (p=0.01), 0.5% CMC and SH-PEG-PG (p<0.0001), and 0.5% CMC and 0.1% SH-trehalose (p=0.01), where SH-based tear drops performed better. CONCLUSIONS: Tear film stability improves following a single drop of CMC, SH, and PEG-based artificial tears, although these artificial tears do not differ in their short-term effect.

Free PDF PubMed ↗

Refrigeration reduces instillation discomfort of a 0.09% cyclosporine A solution.

Ngo W, Nagaarudkumaran N, Huynh CB

Optom Vis Sci · 2025 Jan · PMID 39704709 · Publisher ↗

SIGNIFICANCE: Topical cyclosporine A (CsA) for the treatment of dry eye disease is often associated with instillation discomfort, which may negatively influence patient adherence to therapy. This study found that refrige... SIGNIFICANCE: Topical cyclosporine A (CsA) for the treatment of dry eye disease is often associated with instillation discomfort, which may negatively influence patient adherence to therapy. This study found that refrigerating topical CsA reduced instillation discomfort compared with instillation of warm CsA. Thus, refrigerating CsA prior to instillation may improve patient experience when using CsA to manage dry eye disease. PURPOSE: This study aimed to quantify instillation discomfort associated with cold or warm instillation of a 0.09% CsA. METHODS: Forty participants with symptomatic aqueous deficient dry eye were enrolled. A drop of cold (4°C) CsA was instilled in one eye, and a drop of warm (23°C) CsA was instilled in the other eye. The order and eye receiving the cold drop were randomized. Participants rated the discomfort of each eye (0, no discomfort; 10, maximal discomfort) prior to drop instillation, immediately post-instillation, and at each subsequent minute for 10 minutes. Area under the curve was used to quantify cumulative discomfort. RESULTS: Forty participants (39.6 ± 18.9 years old, 82% female) completed the study. A majority of participants (n = 24, 60%) experienced reduced cumulative discomfort with cold CsA, whereas the remainder experienced minimal difference (n = 10, 25%) or increased cumulative discomfort (n = 6, 15%). For those with reduced discomfort (n = 24), cumulative discomfort associated with cold instillation (median, 11.5 [2.2, 20.0]) was significantly lower (p<0.01) than cumulative discomfort associated with warm instillation (median, 17.5 [11.2, 32.2]). Cold instillation was associated with a median reduction of 1 discomfort point immediately post-instillation and at all subsequent time points (all p≤0.04, but not significant at t = 10), compared with warm instillation. CONCLUSIONS: Up to 60% of participants found that cold instillation of CsA solution induced less discomfort than warm instillation, lasting up to 9 minutes post-instillation. In contrast, although 15% of participants found reduced discomfort with warm instillation, the magnitude of discomfort associated with warm instillation was not significantly different than cold instillation.

Get PDF PubMed ↗

Randomized clinical trial: MGrx versus standard debridement and expression for meibomian gland dysfunction.

Semp DA, Dutta D, Wolffsohn JS

Optom Vis Sci · 2025 Jan · PMID 39670548 · Publisher ↗

SIGNIFICANCE: Evaporative dry eye disease, due to meibomian gland dysfunction, causes significant suffering for millions of people globally, yet satisfactory long-term treatment remains elusive for many. Investigation of... SIGNIFICANCE: Evaporative dry eye disease, due to meibomian gland dysfunction, causes significant suffering for millions of people globally, yet satisfactory long-term treatment remains elusive for many. Investigation of potential therapies for meibomian gland dysfunction is therefore of high importance to clinicians and their patients. PURPOSE: This study aimed to compare the efficacy of a new device for meibomian gland debridement and expression to that of the conventional way of providing this treatment. METHODS: Thirty participants (mean age, 36.4 ± 15.4 years; 77% female) fulfilling current Tear Film & Ocular Surface Society diagnostic criteria for dry eye disease and meibomian gland dysfunction were recruited (Research Registry, 10340). Fifteen participants each were randomized to receive a single treatment with either traditional debridement (using a golf-club spud), heating (10 minutes of Blepha EyeBag, Théa Laboratories, Clermont-Ferrand, France) and expression (with forceps), or the multimodal MGrx, which comprises a handheld device with heated debridement, massage, and expression attachments. Symptomatology, tear film, and ocular surface measures were assessed at baseline and at 4 and 8 weeks post-treatment. RESULTS: Ocular Surface Disease Index, 5-Item Dry Eye Questionnaire, and Symptom Assessment in Dry Eye symptom questionnaire scores all improved significantly with both treatments (all p<0.001), with no subsequent deterioration for at least 8 weeks. The improvement was similar between treatment groups (all p>0.05). Clinical signs, of blink rate, tear film quality and quantity, ocular surface characteristics, and meibomian gland expressibility, were all unchanged with both treatments (all p>0.05) except for noninvasive tear breakup time, which deteriorated in the conventional treatment group (p=0.006) between 4 and 8 weeks post-treatment. No adverse reactions were reported, and all participants were able to tolerate treatment. CONCLUSIONS: A single application of meibomian gland debridement and expression resulted in sustained improvements in the symptoms of dry eye disease, in both treatment groups. The MGrx device provides a safe and effective in-office treatment for evaporative dry eye disease, and has time and space advantages compared with conventional treatment.

Get PDF PubMed ↗

The effect of transient increase in intraocular pressure on subfoveal choroidal thickness.

Niyazmand H, Jeyakumar V, Feng I … +4 more , Jansen L, Mahindra A, Menage A, Alam K

Optom Vis Sci · 2025 Jan · PMID 39670547 · Publisher ↗

SIGNIFICANCE: Myopia prevalence has increased over the last few decades. Studies have documented that the choroid is considered an important biomarker in myopia development. As myopia and choroidal thinning are associate... SIGNIFICANCE: Myopia prevalence has increased over the last few decades. Studies have documented that the choroid is considered an important biomarker in myopia development. As myopia and choroidal thinning are associated with increased glaucoma risk, understanding the role of the choroid in myopia and glaucoma is imperative. PURPOSE: This study investigates the effect of transiently elevated intraocular pressure on axial length, subfoveal choroidal thickness, and central retinal thickness in emmetropes, low myopes, and high myopes. METHODS: This study involved 29 young adults (23 ± 1 years), including 10 emmetropes (-0.50 D < SE < +0.50 D), 10 low myopes (-6.00 D < SE ≤ -0.50 D), and 9 high myopes (SE ≤ -6.00 D). Participants were fitted with modified swimming goggles for 5 minutes to transiently change intraocular pressure. Noncontact tonometry, optical biometry, and optical coherence tomography were used to measure intraocular pressure, axial length, central retinal thickness, and subfoveal choroidal thickness, respectively. Measurements were taken at before, during goggle wear, immediately after, and 3 minutes after goggles removal. Repeated-measures analysis of variance with Bonferroni adjustment was used to assess the effect of transiently changed intraocular pressure and to elucidate any differences between refractive groups in response to the intraocular pressure change. RESULTS: Intraocular pressure increased by 1.7 ± 2.1 mmHg (p=0.002) from baseline, accompanied by axial elongation of 14 ± 21 μm (p = 0.012) and subfoveal choroidal thinning of 13 ± 15 μm (p=0.01). However, central retinal thickness did not change significantly (p>0.05). Most of the changes in the axial length were due to changes in the choroidal thickness. Observed changes returned to baseline immediately following goggles removal. There was no significant difference between refractive error groups' changes associated with the transient increase in intraocular pressure (p>0.05). CONCLUSIONS: Transiently increased intraocular pressure caused temporary axial elongation and subfoveal choroidal thinning, with no significant differences between refractive groups. Further studies are required to assess the impact of long-term increased intraocular pressure on ocular components.

Get PDF PubMed ↗

Feature Issue: Advances in Refractive Error Research.

Optom Vis Sci · 2024 Nov · PMID 39602288 · Publisher ↗

Abstract loading — click title to view on PubMed.

Get PDF PubMed ↗

Where next for contact lens research?

Papas EB

Optom Vis Sci · 2024 Nov · PMID 39602286 · Publisher ↗

This editorial fronts the second virtual issue for Optometry & Vision Science. Virtual issues are a collection of papers from previously published issues of the journal that are brought together in a single, online publi... This editorial fronts the second virtual issue for Optometry & Vision Science. Virtual issues are a collection of papers from previously published issues of the journal that are brought together in a single, online publication. They highlight the important contribution the journal has made in supporting myopia research. All the papers referenced and previously published in Optometry & Vision Science will be made free access for 1-month. The collection can be accessed here: https://journals.lww.com/optvissci/pages/collectiondetails.aspx?TopicalCollectionId=18.

Get PDF PubMed ↗

Psychometric properties and diagnostic performance of three dry eye questionnaires in Italian: OSDI, OSDI-6, and SPEED.

Facchin A, Boccardo L

Optom Vis Sci · 2024 Sep · PMID 39514738 · Publisher ↗

SIGNIFICANCE: Psychometric questionnaires are highly valuable instruments in clinical practice as they make subjective symptoms easier to measure. Recently, a short version of the Ocular Surface Disease Index (OSDI) ques... SIGNIFICANCE: Psychometric questionnaires are highly valuable instruments in clinical practice as they make subjective symptoms easier to measure. Recently, a short version of the Ocular Surface Disease Index (OSDI) questionnaire was developed, named OSDI-6. PURPOSE: This study aimed to assess the psychometric properties and compare the diagnostic criteria of three questionnaires, available in the Italian language, designed for assessing dry eye disease: Standard Patient Evaluation of Eye Dryness (SPEED), OSDI-12, and specifically the new shortened version, OSDI-6. METHODS: Psychometric evaluations were conducted on 250 adult participants aged 20 to 83 years. Classic and Rasch psychometric analyses were performed on the three questionnaires. The repeatability of the questionnaires was assessed by retesting 120 participants. RESULTS: The exploratory factor analysis of OSDI-6 indicated saturation on two factors. Repeatability was optimal for all three questionnaires. Based on the reference OSDI-12, the cutoff for OSDI-6 was 5 points and 7 for SPEED. Rasch analysis showed that OSDI-6 and OSDI-12 present disordered response categories and thresholds. Conversely, the SPEED questionnaire shows the optimal item characteristic curve. CONCLUSIONS: The OSDI-12 is a reference questionnaire used in dry eye disease studies and clinics, but OSDI-6 does not represent a perfect shortened version, primarily for the absence of one factor measured and secondarily for the same problem of category response order and thresholds. Conversely, SPEED focusing only on symptoms showed better psychometric properties.

Get PDF PubMed ↗

Corneal hypersensitivity to cold stimuli in symptomatic computer users.

Talens-Estarelles C, Golebiowski B, Ehrmann K … +3 more , García-Lázaro S, Cerviño A, Stapleton F

Optom Vis Sci · 2024 Sep · PMID 39514737 · Publisher ↗

SIGNIFICANCE: Prolonged computer use may result in repeated stimulation of the ocular surface due to ocular dryness, potentially leading to alterations in its sensitivity. PURPOSE: This study aimed to evaluate the relati... SIGNIFICANCE: Prolonged computer use may result in repeated stimulation of the ocular surface due to ocular dryness, potentially leading to alterations in its sensitivity. PURPOSE: This study aimed to evaluate the relationship between ocular symptoms and corneal sensitivity to cold and mechanical stimuli in computer users. METHODS: Fifty-two young (31 ± 6 years), frequent computer users, including symptomatic and asymptomatic users, participated in this study. Mechanical and cold sensation thresholds were determined at the central cornea of one randomly selected eye of each participant using the UNSW Liquid Jet Aesthesiometer. Ocular surface symptoms and digital eye strain were assessed using the Ocular Surface Disease Index, Ocular Comfort Index, Instant Ocular Symptom Survey, and Computer Vision Syndrome Questionnaire (CVS-Q). Associations between central corneal sensation thresholds and demographic variables, patterns of digital device use, and symptom scores were analyzed using Pearson (r) or Spearman (ρ) correlations and linear regression models. RESULTS: Age (ρ = 0.24), CVS-Q score (ρ = -0.33), CVS-Q dry eye score (ρ = -0.28), and mechanical sensation threshold (ρ = 0.63) were significantly associated with cold sensation threshold (p≤0.04). Conversely, there were no significant relationships with Ocular Surface Disease Index, Ocular Comfort Index, or Instant Ocular Symptom Survey or with other demographic variables (p≥0.34). In multiple linear regression models, age and mechanical sensation threshold were significant predictors of cold sensitivity (p=0.04 and p<0.001, respectively) (adjusted R2 = 0.459). There were no significant correlations between mechanical sensitivity and symptom scores (p≥0.09). CONCLUSIONS: Symptoms of digital eye strain, particularly those related to dry eye, were associated with higher corneal cold sensitivity. Corneal hypersensitivity to cold stimuli as a marker of ocular discomfort during computer use requires further investigation.

Get PDF PubMed ↗

Advances in Ocular Surface Research Feature Issue.

Craig JP, Wolffsohn JS, Advances in Ocular Surface Research Feature Issue Editorial Team

Optom Vis Sci · 2024 Sep · PMID 39514735 · Publisher ↗

Abstract loading — click title to view on PubMed.

Get PDF PubMed ↗

Extended release of ciprofloxacin from commercial silicone-hydrogel and conventional hydrogel contact lenses containing vitamin E diffusion barriers.

Al Atrach M, Phan CM, Jones LW

Optom Vis Sci · 2024 Nov · PMID 39514398 · Publisher ↗

SIGNIFICANCE: Vitamin E could be used as a coating with commercial silicone hydrogel lenses to extend the release of various ophthalmic drugs. This concept could provide a promising approach to improve overall ocular the... SIGNIFICANCE: Vitamin E could be used as a coating with commercial silicone hydrogel lenses to extend the release of various ophthalmic drugs. This concept could provide a promising approach to improve overall ocular therapeutic outcomes for topical ocular drugs. PURPOSE: This study aimed to develop a contact lens-based ocular drug delivery system using vitamin E as a diffusion barrier to extend the release duration of ciprofloxacin. METHODS: Five commercial lenses were soaked for 24 hours in various concentrations of vitamin E dissolved in ethanol (0.0125 to 0.2 g/mL). The lenses were loaded with ciprofloxacin for 24 hours in 3 mL of 3 mg/mL of ciprofloxacin/acetic acid solution. The drug release was evaluated in 3 mL of phosphate-buffered saline solution. At t = 0.5, 1, 2, 4, 6, 8, 12, 16, and 24 hours, the amount of ciprofloxacin released was measured using a UV-VIS spectrophotometer at 270 nm. RESULTS: There was a decrease in ciprofloxacin loading with increasing amounts of vitamin E loaded into the silicone hydrogel lenses. For each lens type, there was an optimal amount of vitamin E loaded that extended the release duration of the drug from 1 hour (without vitamin E) to as long as 16 hours. In contrast, vitamin E loaded into hydrogel lenses had no effect on the amounts of drugs loaded or the release duration. CONCLUSIONS: Vitamin E can be used as a diffusion barrier with commercially available silicone hydrogel lenses to provide sustained release of ciprofloxacin. The results suggest that vitamin E may form blockages in channels within a silicone hydrogel lens material, thereby forcing a longer path for drugs to diffuse into and out of the lens material. There is an optimal amount of vitamin E that needs to be loaded to extend the release duration, and this is lens material dependent.

Get PDF PubMed ↗

A pilot study of the impact of repeated blink refrainment on ocular surface temperature and the interblink period.

Li W, Graham AD, Lin MC

Optom Vis Sci · 2024 Nov · PMID 39514397 · Publisher ↗

SIGNIFICANCE: This study examines a potential stress test of repeated blink refrainment and its effects on the interblink period and the rate of evaporative ocular surface cooling. Such a test could aid in the study of c... SIGNIFICANCE: This study examines a potential stress test of repeated blink refrainment and its effects on the interblink period and the rate of evaporative ocular surface cooling. Such a test could aid in the study of computer vision syndrome, in which screen users unconsciously delay blinking, leading to onset of symptoms. PURPOSE: This study aimed to examine the relationship between the length of the maximum achievable interblink time and the rate of ocular surface cooling under stress test conditions of repeated refrainment from blinking for as long as possible. METHODS: Subjects acclimated to the examination room for 10 minutes before measurement and then were asked to hold the eyes open and refrain from blinking for as long as possible (the maximum blink interval), while ocular surface temperature was recorded using an infrared thermographic video camera. Subjects completed 20 trials with four successive blinks separating each trial. RESULTS: Fifteen subjects (8 female and 7 male subjects) completed the study. The grand mean ocular surface cooling rate was -0.027°C/s (range, -0.338 to +0.014°C/s). A faster ocular surface cooling rate was significantly related to an exponentially shorter maximum blink interval (p<0.001). An increasing number of trials was related to a clinically insignificant increase in the length of the maximum blink interval overall, and a post hoc analysis revealed subject subgroups for whom the stress test was effective or ineffective. CONCLUSIONS: The ocular surface evaporatively cools exponentially during periods of blink refrainment. With a subgroup of subjects with initially stable tear films and normal lipid layer thickness, cumulative tear film stress from repeated, longer-term blink refrainment could contribute to tear evaporation and symptoms of computer vision syndrome.

Get PDF PubMed ↗

Case report: Acute macular neuroretinopathy post-COVID-19 infection.

Mohamad NA, Yong MH, Mohd Khialdin S … +1 more , Bastion MC

Optom Vis Sci · 2024 Nov · PMID 39514396 · Publisher ↗

SIGNIFICANCE: Acute macular neuroretinopathy (AMN) is a rare disease that causes transient or permanent visual disturbance. The exact etiology remains unknown, but vascular compromise of the deep retinal capillary plexus... SIGNIFICANCE: Acute macular neuroretinopathy (AMN) is a rare disease that causes transient or permanent visual disturbance. The exact etiology remains unknown, but vascular compromise of the deep retinal capillary plexus was postulated as the main mechanism. Retinal vascular event post-coronavirus disease 2019 (COVID-19) infection is recently highlighted during the pandemic, which includes AMN. PURPOSE: To report a case of AMN post-COVID-19 infection. CASE REPORT: A 24-year-old Indian woman presented with acute-onset painless bilateral central scotoma for a day. The symptom was preceded by a history of COVID-19 infection 3 weeks prior. Ocular examination revealed a near-normal visual acuity for both eyes. Fundus examination showed bilateral dull foveal reflex with mild scattered cotton wool spot and vascular tortuosity. Optical coherence tomography macula revealed a distinct short hyperreflective band involving the outer plexiform and outer nuclear layers nasal to the fovea. The Bjerrum perimetry test revealed central scotoma temporal to the fixation. Optical coherence tomography lesions and scotomas are identical and congruous in both eyes. Serial fundus photographs are captured showing the evolving changes of near-normal macula to pigmented wedge-shaped petaloid lesions around the fovea. The patient was diagnosed as bilateral AMN and treated with oral prednisolone. On subsequent follow-up, the central scotoma improved. CONCLUSIONS: This case illustrates a clear temporal and possible causal relationship of COVID-19 infection with AMN. Further studies and data are required to justify its association, but the rising cases of AMN shall be anticipated as COVID-19 infections have become endemic worldwide.

Get PDF PubMed ↗

Optometry And Vision Science[JOURNAL]

About