Lens Wear Research Articles

Quantifying tear exchange during rigid contact lens wear using corneoscleral profilometry: A proof of concept study.

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. 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. 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. 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.

Repeatability of lipid layer thickness using LipiView® following removal of contact lenses and its relationship to comfort.

To assess the repeatability of lipid layer thickness (LLT) measurement using the LipiView® interferometer after daily disposable contact lens (CL) wear and correlation with ocular comfort in soft contact lens wearers. A prospective study was conducted over two consecutive months, wherein CL wearers (n = 20) wore either Somofilcon A or Verofilcon A daily disposable CLs in a crossover design, switching lenses after 1 month. The pre-corneal tear film LLT was measured at the end of each month after CLs had been worn for at least 6 h. Using the LipiView® interferometer, three measurements of the LLT (average, maximum and minimum) were recorded. Subjects' symptoms were evaluated with the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and correlations sought between post-lens pre-corneal tear film LLT and symptoms. The average, maximum and minimum intraclass correlation coefficients (ICC) of LLT measurements at baseline were 0.57, 0.39 and 0.66, respectively, indicating poor (ICC < 0.4) to moderate (≥0.4, <0.75) repeatability. Coefficients of repeatability (CR) were 20.4, 24.8 and 20.8, respectively. After daily disposable CL wear, the ICC values were 0.66, 0.72 and 0.63 (indicating moderate repeatability), with CR values of 25.7, 32.0 and 23.3, respectively. Although all the ICC values of the pre-corneal LLT increased after daily disposable lens wear indicating improved repeatability, the CR values also increased, indicating larger spread of data. However, in both cases, these increases were not significantly different from baseline. There were no significant differences in pre-corneal LLT between the two lens types and no significant correlation with comfort scores (baseline: r = -0.11, p = 0.67; Verofilcon A lenses: r = 0.19, p = 0.45; Somofilcon A lenses r = 0.13, p = 0.62) for either lens. The repeatability of average, maximum and minimum LLT measurements performed by LipiView remained stable during CL wear. There was no significant correlation between LLT and comfort scores.

Axial Growth and Myopia Progression After Discontinuing Soft Multifocal Contact Lens Wear

For myopia control to be beneficial, it would be important that the benefit of treatment (slowed eye growth) is not lost because of faster than normal growth (rebound) after discontinuing treatment. To determine whether there is a loss of treatment effect (rebound) after discontinuing soft multifocal contact lenses in children with myopia. The Bifocal Lenses in Nearsighted Kids 2 (BLINK2) cohort study involved children with myopia (aged 11-17 years at BLINK2 baseline) who completed the BLINK Study randomized clinical trial. Enrollment was from September 2019 through January 2021; follow-up was completed in January 2024. In the BLINK2 Study, all children wore high-add (+2.50 diopter [D]) multifocal soft contact lenses for 2 years and single-vision soft contact lenses during the third year to determine if rebound occurred. High-add multifocal soft contact lenses and single-vision soft contact lenses. Eye length (optical biometry) and refractive error (cycloplegic autorefraction) were measured annually. Of 248 participants enrolled in BLINK2, 235 completed the study. The median age at the baseline visit was 15 years (range, 11-17 years); 146 participants (59%) were female, and 102 (41%) were male. At baseline for BLINK2, mean (SD) axial length and spherical equivalent refractive error were 25.2 (0.9) mm and -3.40 (1.40) D, respectively. After participants switched from multifocal to single-vision contact lenses, axial elongation increased by 0.03 mm per year (95% CI, 0.01 to 0.05) regardless of their original BLINK treatment assignment (P = .81). There was also an increase in myopia progression after switching to single-vision lenses of -0.17 D per year (95% CI, -0.22 to -0.12) that did not depend on the original BLINK treatment assignment (P = .57). There continued to be a difference in axial length and refractive error throughout BLINK2 based on the BLINK Study treatment assignment with the original high-add group having shorter eyes and less myopia than the original medium-add (+1.50 D) and single-vision groups. The BLINK2 Study found no evidence of a loss of treatment effect after discontinuing multifocal contact lenses in older teenagers. These data suggest eye growth and myopia progression returned to faster but age-expected rates and support continuing multifocal lenses until cessation of elongation and progression.

Quarter of a century of contact lens prescribing trends in Australia (2000–2024)

ABSTRACT Clinical relevance Knowledge of contact lens prescribing trends can (a) assist practitioners to benchmark their own prescribing habits, (b) help the contact lens industry understand preferred products, and (c) support academics in scholarly writings. Background This work aims to document contact lens prescribing trends in Australia over the past quarter of a century. Methods An annual survey of contact lens prescribing trends was conducted in Australia each year from 2000 to 2024, inclusive, by asking optometrists to provide information relating to 10 consecutive contact lens fits undertaken between January and March. Results Over the 25-year survey period, a total of 20,281 contact lens fits were reported. Lens wearers were 34.4 ± 14.7 years of age and 65% were female. Over the survey period, rigid lenses increased from 13% to 21% of all lens fits. Of all soft lens fits, silicone hydrogel lenses increased from 22% to 96%; soft torics increased from 24% to 30%; daily disposables increased from 7% to 63%; soft extended wear decreased from 16% to 5%; multifocals increased from 5% to 26%; and myopia control (first fit in 2011) reached 3% by 2024. Rigid lens extended wear (primarily orthokeratology) increased from 0.3% to 17% of rigid lens fits, primarily for myopia control. Multi-purpose lens care solutions are ubiquitous, and peroxide systems are seldom prescribed. Rigid lenses and monthly replacement soft lenses are largely worn full time, whereas daily disposables are worn full time and part time in equal measure. Australian and global prescribing trends are broadly consistent. Conclusions Contact lens fitting trends this century can be characterised as: soft lenses – significant increase in silicone hydrogels, daily disposables, torics and multifocals; rigid lenses – dominance of high-Dk materials, and recent resurgence in scleral and orthokeratology fits. There is little extended wear fitting. Multi-purpose care systems are ubiquitous.

Refractive Changes and Corneal Thickness in Healthy Mountaineers at High Altitude: The Korzhenevskoi Experience (7105 m).

The purpose of this study was to investigate the effect of hypoxia and hypobaric conditions on refraction and central corneal thickness on healthy corneas during an ascent without oxygen supplementation above 7000 m (23 000 ft). Twelve multinational mountaineers were included in a prospective observational cohort study during an expedition to the Korzhenevskoi Peak (7105 m). The two patients excluded from the study had a history with keratoconus or were current wearers of rigid contact lenses. None had a history of refractive surgery or ocular disease. The central corneal thickness (CCT), the oxygen saturation, and the refraction have been recorded for each patient using portable equipment. The highest measurement has been taken at 6356 m of altitude which is the highest ophthalmologic measurement ever done. Longitudinal analysis revealed a significant increase of CCT during altitude exposure (CCTbaseline = 542± 36 μm; CCTC3 = 633 ± 30 μm) due to stromal edema reversible upon descent. The amount of decrease in oxygen saturation paralleled the increase in CCT. The refraction measurements showed a myopic shift (-1.14D) with the altitude (RBaseline = -0.41 ±2.25D; RC3 = -1.55 ± 2.41D P < 0.05). Significant stromal edema was found during exposure to high altitude in healthy mountaineers. This is due to hypoxia and decreased atmospheric pressure leading to a deficiency of adenosine triphosphate. A significant and clinically relevant myopic shift, due to the stroma edema, appears above 6500 m which can explained the blurry far vision in high altitude for mountaineers without oxygen supplementation.

Scleral lens wear and fluid reservoir turbidity in eyes with ocular surface disorders.

To investigate changes in fluid reservoir turbidity parameters over time and its influence on visual performance in eyes with ocular surface disorders (OSD) wearing scleral contact lenses (SL). Thirteen eyes with OSD were assessed for corrected distance visual acuity, contrast sensitivity (CS) and fluid reservoir turbidity using anterior segment optical coherence tomography at baseline, after 5 min and 0.5, 1, 2, 3 and 4 h of SL wear on day 1 and after 1 month. A significant reduction in CS was noted at 0.5, 1, 2, 3 and 4 h of SL wear compared to 5 min (p < 0.001) and a similar trend was noted after 1 month (p < 0.001). The average number of particles on day 1 showed a significant increase over 4 h of SL wear (p < 0.001), with a same trend noted at 1 month (p = 0.001). However, the percentage of particles decreased from 88% ± 4% to 75% ± 12% (p = 0.004) after 1 month of SL wear. Average particle size showed a significant increase at all time points over 4 h compared with 5 min of SL wear (p < 0.003) and after 1 month (p < 0.001). The percentage of average particle size decreased from 73% ± 9% to 67% ± 8% after 1 month of lens wear (p = 0.003). The mean percentage turbid area increased from 0.6% ± 0.5% to 24% ± 16% over 4 h of lens wear on day 1 (p < 0.006) and from 0.7% ± 0.5% to 11% ± 8% at 1 month (p = 0.001). The mean difference in percentage turbid area at the first and follow-up visits decreased from 96% ± 3% to 89% ± 9% (p = 0.01). A gradual increase in fluid reservoir turbidity parameters was noted with the reduction in CS; however, all these parameters improved after 1 month of SL wear.

Translation and validation of the 8-item contact lens dry eye questionnaire (CLDEQ-8) among Chinese soft contact lens wearers.

To develop a Chinese version of the 8-item Contact Lens Dry Eye Questionnaire (CLDEQ-8) with cross-cultural adaption and clinical validation among soft contact lens wearers (SCL) in China. The translation and adaptation of the Chinese CLDEQ-8 (C-CLDEQ-8) followed a rigorous methodological process based on cross-cultural research guidelines consisting of three main phases: 1) forward and backward translation of original CLDEQ-8 into Chinese, 2) cross-cultural adaptation performed by medical advising committee, and 3) clinical validation and repeatability test of the translated questionnaire on Chinese SCL wearers. Rasch analysis was also performed to investigate the psychometric properties of C-CLDEQ-8. 134 experienced SCL wearers aged 18-45 completed the C-CLDEQ-8. C-CLDEQ-8 score was linearly related to the overall opinion of SCLs (beta=2.16, p=0.002), gestalt eye dryness response (beta=2.90, p<0.001), and sensitivity response (beta=1.83, p=0.001). The questionnaire showed excellent test-retest repeatability with an intra-class correlation coefficient (ICC) of 0.95 and great internal consistency with a Cronbach's alpha of 0.83. The corrected index of homogeneity for each item was more significant than 0.5. In Rasch analysis, the infit and outfit values for eight items were all within 0.6-1.4, suggesting a good fit for the Rasch model. Martin-Löf test result indicated that the Rasch model was unidimensional (p=1.0). Item characteristics curves suggested combining categories 3-4 and 5-6 in item 5 of C-CLDEQ-8. This study produced a Chinese version of CLDEQ-8 with great validity and reliability and proved capable of evaluating SCL-related symptoms.

Diversity and composition of ocular microbiota in contact lens wearers: Efficacy of liposomal ozonated oil.

To characterize the ocular surface microbiota in regular contact lens wearers with dry eyes and assess the effectiveness of reducing bacterial load using a liposomal ozonated oil solution. This prospective, longitudinal, controlled study randomized subjects into two groups. Group A (45 subjects) received hydroxypropylmethylcellulose (HPMC, Artific®), while Group B (41 subjects) received ozonated sunflower seed oil with soybean phospholipids (OSSO, Ozonest®). Microbial communities were analyzed via DNA metabarcoding of the 16S rRNA gene, and statistical analyses (alpha and beta diversity) were performed in R. Both groups predominantly harbored Staphylococcus caprae, Streptococcus oralis, and Corynebacterium spp., with OSSO and HPMC users showing distinct bacterial profiles. Alpha diversity showed no significant differences, but beta diversity revealed differences in bacterial composition between the groups. The results seem to indicate that the use of ozonized oil reduces the bacterial load compared to the solution used as a control.

Association between axial elongation and corneal topography in children undergoing orthokeratology with different back optic zone diameters

PurposeTo explore the associations between myopia defocus dosage (MDD), aberration coefficients (primary spherical aberration and coma), and axial elongation in children undergoing orthokeratology (ortho-k) with back optic zone diameters (BOZD) of 5 mm and 6 mm over 2 years.MethodsData from 80 participants from two ortho-k studies were analyzed: 22 and 58 children wore lenses with 5-mm and 6-mm BOZD, respectively. Four MDD metrics were calculated from corneal topography data over a 5-mm pupil for the 1-month and 24-month visits: the circumferential, flat, steep, and volumetric MDD. Corneal primary spherical aberration and comatic aberrations were also extracted from topography data over a 5-mm pupil. Linear mixed modelling was performed to explore the associations between the MDD, corneal aberrations, and axial elongation over 2 years, while controlling for confounding factors (e.g., baseline age and sex).ResultsParticipants in the 5-mm BOZD group displayed less axial elongation than the 6-mm BOZD group over 2 years (0.15 ± 0.21 mm vs. 0.35 ± 0.21 mm, P < 0.001). A greater volumetric MDD was observed in the 5-mm BOZD group compared with the 6-mm BOZD group at the 1- and 24-month visits (both P < 0.001). No significant differences were observed between the two groups for the other MDD metrics or corneal aberration coefficients (all P > 0.05). Less axial elongation was associated with a greater volumetric MDD at the 1- and 24-month visits (both β = –0.01, P < 0.001 and P = 0.001), but not with any other MDD metrics or corneal aberrations (all P > 0.05).ConclusionsThe volumetric MDD over a 5-mm pupil after 1 month of ortho-k lens wear was associated with axial elongation after 24 months, and may be a useful predictor of future axial elongation in children undergoing ortho-k.

Effects of computer-generated patterns with different temporal and spatial frequencies on choroidal thickness, retinal dopamine and candidate genes in chickens wearing lenses

PurposeChanges in choroidal thickness (ChT) are proposed to predict myopia development but evidence is mixed. We investigated time courses of choroidal responses, following different types of dynamic artificial stimulation in chicks with and without spectacle lenses, as well as changes in retinal dopamine metabolism and expression of candidate genes.MethodsChicks were kept in an arena surrounded by computer monitors presenting dynamic checkerboard fields of small, medium and large size. Fields were displayed with different cycle frequencies, as ON (rapid rise, slow decay) or OFF (slow rise, rapid decay) temporal luminance profile. Refractive errors, ocular biometry and ChT were assessed. Dopamine metabolism and candidate gene expression levels were also measured. Stimuli were applied for (1) 3 h with no lens, (2) 3 h and monocular treatment with −7D or +7D lenses, (3) 3 or 7 days.Results(1) The smallest fields caused the largest decrease in ChT. (2) Negative lens treatment induced on average 11.7 μm thinner choroids. ChT thinning was enhanced by 10 Hz-ON medium field size flicker which also reduced choroidal thickening with positive lenses. (3) With prolonged treatment, the choroid recovered from initial thinning in all groups although to varying degrees which were dependent on stimulus parameters. Relative ChT changes were positively correlated with the vitreal level of dopamine metabolites. Retinal EGR-1 mRNA level was positively correlated with choroidal thickness. Retinal melanopsin mRNA was increased by 10 Hz-ON stimulation and choroidal BMPR1A mRNA increased with 10 Hz-OFF stimulation. On average, early choroidal thinning did not predict the amount of negative lens-induced eye growth changes after 7 days, whereas later ChT changes showed a weak association.ConclusionNegative lenses caused long-lasting choroidal thinning, with some recovery during lens wear, especially after stimulation with 10 Hz. The dynamic stimuli modulated choroidal thinning but effects were small. There was little difference between ON and OFF stimulation, perhaps because the checkerboard patterns were too coarse. 10 Hz cycle frequency increased dopamine release. Less dopamine was correlated with thinner choroids. Result do not exclude a predictive value of choroidal thickening for future refractive development since we almost exclusively tested choroidal thinning effects.

Variation of Bruch's membrane opening in response to intraocular pressure change during scleral lens wear, in a population with keratoconus.

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. 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. 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. 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.

Contact Lens Wear Alters Transcriptional Responses to Pseudomonas aeruginosa in Both the Corneal Epithelium and the Bacteria.

Healthy corneas resist colonization by virtually all microbes yet contact lens wear can predispose the cornea to sight-threatening infection with Pseudomonas aeruginosa. Here, we explored how lens wear changes corneal epithelium transcriptional responses to P. aeruginosa and its impact on bacterial gene expression. Male and female C57BL/6J mice were fitted with a contact lens on one eye for 24 h. After lens removal, corneas were immediately challenged for 4 h with P. aeruginosa. A separate group of naïve mice were similarly challenged with bacteria. Bacteria-challenged eyes were compared to uninoculated naive controls as was lens wear alone. Total RNA-sequencing determined corneal epithelium and bacterial gene expression. Prior lens wear profoundly altered the corneal response to P. aeruginosa, including: upregulated pattern-recognition receptors (tlr3, nod1), downregulated lectin pathway of complement activation (masp1), amplified upregulation of tcf7, gpr55, ifi205, wfdc2 (immune defense) and further suppression of efemp1 (corneal stromal integrity). Without lens wear, P. aeruginosa upregulated mitochondrial and ubiquinone metabolism genes. Lens wear alone upregulated axl, grn, tcf7, gpr55 (immune defense) and downregulated Ca2+-dependent genes necab1, snx31 and npr3. P. aeruginosa exposure to prior lens wearing vs. naïve corneas upregulated bacterial genes of virulence (popD), its regulation (rsmY, PA1226) and antimicrobial resistance (arnB, oprR). Prior lens wear impacts corneal epithelium gene expression altering its responses to P. aeruginosa and how P. aeruginosa responds to it favoring virulence, survival and adaptation. Impacted genes and associated networks provide avenues for research to better understand infection pathogenesis.

Pediatric Scleral Lenses: 21-Year Retrospective Review.

Retrospective study to review scleral lens outcomes in the pediatric population over a 21-year period, at a single clinical center. A total of 209 pediatric eyes (108 males and 101 females), distributed between 97 right and 112 left eyes, of which 147 eyes had ocular surface disease and 62 eyes had irregular cornea/refractive conditions, were treated with scleral lenses over a 21-year period. The mean age at the time of treatment initiation was 10.6 ± 2.6 years and at the time of the last evaluation recorded was 14.7 ± 4.0 years. One hundred and forty-seven eyes (70%) continued to wear scleral lenses at the time of review, with a mean duration of lens wear of 8.2 ± 4.6 years. Sixteen eyes (8%) discontinued lens wear, and of these, challenges with application and removal were the predominant reason for discontinuation. The lens wearing status of forty-six eyes (22%) was unknown. Mean LogMAR visual acuity at presentation for the entire cohort was 0.93 ± 0.74 and improved to 0.43 ± 0.58, p < 0.05 with scleral lens wear. LogMAR visual acuity at the last evaluation recorded was 0.4 ± 0.6, p < 0.05. The mean initial lens diameter of the full study cohort was 17.7 ± 1.2 mm, with a mean increase of 1.3mm (p = 0.0004) over the study period, to end with a mean final diameter of 18.2 ± 1.5 mm, at the time of the last evaluation recorded. Scleral lenses are a viable option for therapeutic and visual rehabilitation applications in the pediatric population for both ocular surface disease and irregular cornea/refractive conditions. Most eyes continued to wear lenses over a 21-year review period. The mean final lens diameter was 18.2mm, suggesting that larger diameters do not appear to be a deterrent or obstacle for successful long-term outcomes in the pediatric population.

Validation and repeatability assessment of the Chinese version of the Ocular Surface Disease Index (OSDI), 5-item dry eye (DEQ-5), and contact lens dry eye questionnaire-8 (CLDEQ-8) questionnaires.

This prospective study aimed to validate the translated Chinese versions of the Ocular Surface Disease Index (OSDI), 5-Item Dry Eye (DEQ-5), and Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) questionnaires and test their repeatability. From August 2022 to July 2023, online (qualtrics.com) English and Chinese versions of OSDI, DEQ-5, and CLDEQ-8 questionnaires were distributed to residents of Hong Kong, mainland China, Taiwan, and Singapore≥18years old who could understand both written Chinese and English. Subjects who were regular contact lens wearers (wear contact lenses>5 days/week and>8h/day) were invited to complete the English and Chinese versions of the CLDEQ-8 questionnaire. Those who were not regular contact lens wearers were requested to complete the English and Chinese OSDI and DEQ-5 questionnaires. Subjects who completed the questionnaires were invited to participate for the second time three days later. Cronbach's alpha coefficient and intraclass correlation coefficient were used to test the internal consistency test-retest reliability of the translated questionnaires, respectively. A total of 141 subjects completed the OSDI and DEQ-5 (50 (35%) completed the second attempt) and 96 completed the CLDEQ-8 questionnaires (52 (54%) completed the second time). All Chinese versions of the questionnaires showed adequate internal consistency (Cronbach's alpha coefficient≥0.872) and high reliability. There were no significant differences between the two attempts for Chinese OSDI and DEQ-5, but a statistically (not clinically) significant difference for the Chinese CLDEQ-8. This indicates that the Chinese version is clinically comparable to the English version. The Chinese versions of OSDI, DEQ-5, and CLDEQ-8 questionnaires showed adequate internal consistency and high reliability. Despite not being identical in measured scores, the translated Chinese questionnaires could effectively provide information about dry eye conditions and be used as alternative tools for assessing and diagnosing dry eye in clinical practice.

2024 Charles F. Prentice Medal award lecture: Moments of inspiration.

In this Prentice Medal Award lecture, I shall recount my career in vision science in the context of three types of inspiration-"being inspired," "personal inspiration," and "inspiring others." My research has derived inspiration from a variety of sources, such as contemporary and historical research doyens in the ophthalmic field and beyond, artists, Greek philosophers, and abstract constructs such as principles and adages. A given moment of inspiration can range from being a profound experience to a subtle realization during a quiet moment of reflection. Here I shall recount the primary research domains of vision science that have defined my academic career in the context of the three types of inspiration defined above. These research domains are ophthalmic markers of diabetic neuropathy, ocular response to contact lens wear, contact lens-induced parainflammation, contact lens-associated microbial keratitis, grading scales for contact lens complications, contact lens prescribing surveys, material properties of contact lenses, contact lens compliance, history of contact lenses, ocular thermography, and ophthalmic bibliometrics. The notions of "being inspired" and "personal inspiration" are necessarily subjective, although I have endeavored to present them here in a scientific context. Conversely, the notion of "inspiring others" can be objectively gauged, at least in part, by counting article citations or the number of times articles are read online or downloaded from a journal website. In conclusion, my research in the vision sciences has been inspired by others, derived from personal ideas, and perhaps in turn has inspired others.

International trends in prescribing multifocal and monovision soft contact lenses to correct presbyopia (2000–2023): An update

PurposeNumerous multifocal soft contact lenses have been introduced into clinical practice over the past half century. The purpose of this work is to update earlier surveys by describing international trends in multifocal and monovision soft lens fitting for presbyopia between 2000–2023, inclusive. MethodAn annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000–2023. Data relating to 52,580 soft daily wear lens fits to presbyopes (those ≥45 years of age) undertaken in 20 countries returning reliable longitudinal data were analysed in respect of multifocal and monovision soft daily wear lens fits. ResultsOverall, multifocal and monovision soft daily wear lens prescribing to presbyopes has more than doubled over the course of this survey, from 26.4 % of standard soft daily wear lens fits in 2000 to 61.1 % in 2023 (p < 0.0001). There were significant differences between countries in presbyopia soft daily wear lens prescribing (p < 0.0001). Of all soft daily wear fits to males, 45.1 % were multifocal and monovision soft lenses, compared with 52.7 % for females (p < 0.0001). When considered as the proportion of lenses fitting by age, multifocal soft lens fitting peaked between 50–65 years, followed by a precipitous drop until 85–90 years of age, and then an increase beyond 90 years of age. Analysis of 13,014 recent soft lens fits to presbyopes (2019–2023) revealed the following fitting proportions: multifocal lenses – 51 %; monovision – 10 %; and non-presbyopia fitting – 39 %. ConclusionThere has been a substantial increase in soft contact lens correction of presbyopia using multifocal and monovision corrections throughout the 24 years of this survey. A significant number of soft contact lens-wearing presbyopes are not receiving a presbyopia contact lens correction.

Decision-making tree to support sustainable waste management in optometric clinical practice and healthcare training programmes

ABSTRACT Clinical relevance Waste management strategies are well documented for employee safety, legal compliance and infection control measures; however, appropriate waste disposal is equally important to minimise adverse environmental impacts. Knowledge on best practices related to the disposal of healthcare-generated waste is crucial for environmental sustainability. Background Global healthcare contributes significantly to greenhouse gas emissions, thereby extending the pervasiveness of climate change. Urgent action is required by the healthcare sector to minimise these impacts. Proper waste management is an alleviation measure that can be easily implemented in healthcare practice. The aim of this study was to calculate the approximate mass of plastic waste generated through lens wear and develop an easy-to-use decision-making tree to support optometrists with sustainable waste management. Methods Data were analysed, from an online survey directed to ophthalmic lens wearers, to determine the mass of annual plastic waste associated with lens wear. Information collated from published studies and clinical experience of the researchers, supplemented by a literature search from online databases, EBSCOhost, Google Scholar, ScienceDirect and PubMed, were used to develop the waste decision-making tree. Results Approximately 48 kg of plastic waste was generated from annual lens wear, of which approximately 83% of recyclable materials were landfilled. The waste management decision-making tree was created to guide optometrists regarding sustainable waste management practices. Conclusion Although this study focused on Optometry, its findings and recommendations have applicability across the healthcare field. Environmental stewardship is a joint responsibility of all healthcare professionals. This study highlighted the importance of incorporating and promoting sustainable clinical measures as well as the embedding and regular updating of clinical evidence on waste management best practices into healthcare training programmes. In doing so, the broader healthcare sector can contribute significantly towards reducing healthcare waste and associated emissions and improving health outcomes, thereby safeguarding the planet and its inhabitants.

Concomitant Potentially Contagious Factors Detected in Poland and Regarding Acanthamoeba Strains, Etiological Agents of Keratitis in Humans.

Diseases in humans caused by amphizoic amoebae that can result in visual impairment and even blindness, have recently been identified more frequently worldwide. Etiologically complex incidents of keratitis, including those connected with Acanthamoeba strains detected in Poland, were evaluated in this study. Corneal samples from cases resistant to antimicrobial therapy assessed for epidemiological, microbiological and parasitological aspects were investigated by phase-contrast microscope, slit lamp and by confocal microscopy. In vitro techniques were applied for detection of bacteria and fungi, and corneal isolates cultured under axenic condition using BSC medium-for detection of Acanthamoeba spp.; molecular techniques were applied for amoeba species identification. Most etiologically complicated keratitis cases, detected in ~84% of incidents, was due to exposure of contact lenses to tap water or pool water; trophozoites and cysts of Acanthamoeba, concomitant bacteriae, e.g., Pseudomonas aeruginosa, fungi and microfilariae were identified in contact lens users. In samples from contact lens wearers where microbial keratitis is identified along with some connection with the patient's exposure to contaminated water environments, a risk of Acanthamoeba spp. infections should be considered. Understanding the complicated relationship between Acanthamoeba spp., co-occurring pathogens including associated endosymbionts is needed. In vivo confocal microscopy and in vitro cultivation were necessary to identify potentially contagious concomitant factors affecting the complex course of the keratitis.

Scleral Contact Lens Benefits for Myopic Patients With Regular Corneas: A Prospective Randomized Study.

To evaluate the impact of scleral contact lens (SL) wear on the visual quality and the ocular surface wettability in myopic patients with regular corneas. This prospective, randomized, controlled study enrolled a total of 80 myopes with regular corneas. Subjects were randomly allocated to wear SL or rigid corneal lens (RCL) for 3 months. The objective optical quality parameters were detected using the Optical Quality Analysis System-II, and the ocular surface wettability was assessed using the Keratograph 5M noninvasive ocular surface analyzer. The National Eye Institute 25-Item Visual Function Questionnaire and Ocular Surface Disease Index questionnaire were performed. Both SL and RCL wear could obtain good best-corrected visual acuity. Strehl ratio, modulation transfer function cutoff frequency, objective scattering index, and Optical Quality Analysis System values (Optical Quality Analysis System values at 100%, 20%, and 9% contrasts) in the SL group significantly improved from baseline to the third month (both P<0.05), but not in the RCL group. At the third month, tear meniscus height and noninvasive tear break-up time showed a significant increase in the SL wearers from baseline (both P<0.05), but exhibited no significant changes in the RCL group. At the third month, SL wearers had significantly higher noninvasive tear break-up time compared with RCL wearers (P<0.05). Besides, after 3-month SL wear, the National Eye Institute 25-Item Visual Function Questionnaire score and the Ocular Surface Disease Index score both remarkably improved from baseline (both P<0.05). Short-term SL wear could provide satisfactory visual quality, ocular comfort, and stable tear film for myopic patients.

A New Method to Measure Ocular Surface Sensitivity: Repeatability and Reproducibility of the Liquid Jet Esthesiometer.

To assess the reliability of the liquid jet esthesiometer (LJA) for measurement of corneal sensitivity. Two separate studies were conducted to assess intrasession repeatability (study 1) and intersession reproducibility (study 2) of corneal sensitivity measured using the LJA. Thirty participants (13 female and 17 male participants, age 23±6 years) participated in study 1 and another 30 (18 female and 12 male participants, 35±10 years) participated in study 2. For study 1, mechanical sensation threshold of the central cornea was measured three times on the same day, with a 30-min break between repeats. For study 2, central corneal sensation threshold was measured on five different days by one of eight randomly assigned examiners. Corneal sensation thresholds obtained in studies 1 and 2 were 2.3±1.0 and 2.5±1.2 μL, respectively. No significant differences between repeated measurements were obtained in either study (P≥0.19). Thresholds were lower (i.e., corneal sensitivity was higher) in female than male participants (2.1±1.0 vs. 2.7±0.9 μL in male participants, P=0.02) but were not affected by contact lens wear. Clinical reliability of the LJA was good for intrasession repeatability (coefficient of repeatability ±1.6 μL, intraclass correlation coefficient 0.74, within-subject coefficient of variation (CVW) 24%) and moderate for intersession reproducibility (Coefficient of Reproducibility ±2.2 μL, CVW 32%). Measurement variability was independent of threshold level (P=0.84). The LJA offers good clinical repeatability and is a reliable tool to measure corneal sensitivity in different population groups, regardless of stimulus thresholds. Day-to-day fluctuations in corneal sensitivity probably account for the relatively lower reproducibility.