Comparison of the refractive prediction errors of artificial intelligence formula with 3 conventional formulas and 11 combination methods in cataract surgery on eyes with short axial length

ABSTRACT Purpose: To compare the refractive prediction error of Hill-radial basis function 3.0 with those of 3 conventional formulas and 11 combination methods in eyes with short axial lengths. Methods: The refractive prediction error was calculated using 4 formulas (Hoffer Q, SRK-T, Haigis, and Hill-RBF) and 11 combination methods (average of two or more methods). The absolute error was determined, and the proportion of eyes within 0.25-diopter (D) increments of absolute error was analyzed. Furthermore, the intraclass correlation coefficients of each method were computed to evaluate the agreement between target refractive error and postoperative spherical equivalent. Results: This study included 87 eyes. Based on the refractive prediction error findings, Hoffer Q formula exhibited the highest myopic errors, followed by SRK-T, Hill-RBF, and Haigis. Among all the methods, the Haigis and Hill-RBF combination yielded a mean refractive prediction error closest to zero. The SRK-T and Hill-RBF combination showed the lowest mean absolute error, whereas the Hoffer Q, SRK-T, and Haigis combination had the lowest median absolute error. Hill-radial basis function exhibited the highest intraclass correlation coefficient, whereas SRK-T showed the lowest. Haigis and Hill-RBF, as well as the combination of both, demonstrated the lowest proportion of refractive surprises (absolute error >1.00 D). Among the individual formulas, Hill-RBF had the highest success rate (absolute error ≤0.50 D). Moreover, among all the methods, the SRK-T and Hill-RBF combination exhibited the highest success rate. Conclusions: Hill-radial basis function showed accuracy comparable to or surpassing that of conventional formulas in eyes with short axial lengths. The use and integration of various formulas in cataract surgery for eyes with short axial lengths may help reduce the incidence of refractive surprises.

Polymerization of hydroxyethyl methacrylate (HEMA) under rotation to form core-annular hydrogels.

HYPOTHESIS: We propose to polymerize high water content hydroxyethyl methacrylate (HEMA) formulations in a rotating cylinder to explore the effect of the rotation on microstructure and critical parameters such as diffusivity of model proteins in porous poly-HEMA gels. EXPERIMENTS: Cylindrical molds were partially filled with water-HEMA-initiator-crosslinker mixtures and exposed to UV light while undergoing rotation to polymerize into a cylindrical tube. The process was repeated multiple times to manufacture a core annular rod with multiple concentric rings, in which at least one ring was porous. The porous gels were imaged by scanning electron microscopy to explore the microstructure. The transport of model proteins bovine serum albumin and human γ-globulin was measured and modeled, in radial and axial directions, to obtain the effective diffusivity and partition coefficient. Also, the true diffusivity of proteins was calculated by accounting for the effects of porosity and tortuosity. FINDINGS: The porous gels exhibited diffusion-controlled release of both model proteins. The hydrogels prepared with 55% water in the monomer mixture were porous with non-isotropic structure likely due to axially oriented pores with minimal radial connectivity. The gels with higher water content were isotropic with interconnected pores in both directions. The pore volume increased with water content, but the partition coefficient was relatively constant and less than one likely due to presence of isolated unconnected pores.

Comparison of visual outcomes in patients with cataracts and high myopia after implantation of a zonal refractive multifocal or diffractive bifocal intraocular lens.

This study compares the optical quality of zonal refractive multifocal and diffractive bifocal intraocular lenses (IOLs) and visual outcomes after implantation in 93 patients(93 eyes) with cataracts and high myopia. A retrospective analysis was conducted to measure visual acuity at far, intermediate, and near distances, defocus curves, wavefront aberrations, modulation transfer function (MTF), a Quality of Vision questionnaire (QoV) and visual quality self-evaluation were examined at 3 months. The results demonstrated the ZMB group showed better uncorrected near visual acuity (P < 0.01), and the MF15 group showed better uncorrected intermediate visual acuity (P < 0.001). The ZMB group provided better MTF than the MF15 group (P < 0.01) but demonstrated a worse QoV score, especially for the severity of glare, halo, and starburst (P < 0.05). The satisfaction score and spectacle independence rate in the ZMB group were higher than in the MF15 group (P < 0.01). LS-313MF15 and TecnisZMB00 offered excellent visual restoration, stable distance visual acuity, and good subjective visual function.

Comparison of bilateral implantation of monofocal intraocular lenses with enhanced intermediate function targeting with - 2.00 D and emmetropia in moderate to high myopic Asian patients.

BACKGROUND: To investigate the outcomes of bilateral implantation of enhanced monofocal intraocular lenses (IOLs, ICB00) with a - 2.00 diopter (D) target in patients with moderate to high myopia and to compare the clinical outcomes of a - 2.00 D binocular target with an emmetropia target in patients who underwent cataract surgery. METHODS: In this retrospective study, we reviewed the medical records of patients who underwent uncomplicated phacoemulsification with ICB00 IOL implantation. Emmetropia (Group 1) and - 2.00 D (Group 2) were targeted in 60 and 20 eyes of 30 and 10 patients, respectively. Three months after surgery, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), and uncorrected near visual acuity (UNVA) were measured. Defocus curves were measured under the photopic condition by intervals of 0.50 D from + 0.50 D to - 4.00 D. RESULTS: The postoperative binocular logMAR UDVA, UIVA, and UNVA were 0.01 ± 0.03, 0.08 ± 0.11, and 0.33 ± 0.15 in Group 1 and 0.31 ± 0.13, 0.04 ± 0.05, and 0.11 ± 0.07 in Group 2, respectively. Group 2 showed a significantly superior postoperative binocular UNVA (P = 0.027) and inferior binocular UDVA (P = 0.003) than Group 1. Binocular UIVA and CDVA did not significantly differ between the groups although UIVA was better in Group 2 than in Group 1. Near glasses were needed by 66% of Group 1 and 0% of Group 2. CONCLUSIONS: Bilateral implantation of ICB00 IOL with - 2.00 D of residual myopia is suitable for patients with moderate to high myopia to improve UDVA, UIVA, and UNVA.

Impact of Scleral Lenses on Visual Acuity and Ocular Aberrations in Corneal Ectasia: A Comprehensive Review.

Corneal ectasias, including keratoconus (KC), pellucid marginal degeneration (PMD), and post-LASIK ectasia, poses significant visual rehabilitation challenges due to the resultant irregular astigmatism, myopia, and higher-order aberrations (HOAs). These conditions often resist traditional corrective methods, necessitating advanced optical solutions. Scleral lenses (SLs) have emerged as a primary non-surgical option for managing these complex corneal irregularities. SLs form a smooth optical interface by forming a tear-filled chamber between the lens and the cornea, effectively mitigating HOAs and improving both high-contrast and low-contrast visual acuity (VA). This review evaluates the efficacy of SLs in enhancing VA and reducing aberrations in patients with corneal ectasia. It also explores the technological advancements in SLs, such as profilometry and wavefront-guided systems, which enable more precise and customized lens fittings by accurately mapping the eye's surface and addressing specific visual aberrations. The current body of evidence demonstrates that custom SLs significantly improve visual outcomes across various ectatic conditions, offering superior performance compared to conventional correction methods. However, challenges such as the complexity of fitting and the need for precise alignment remain. Ongoing innovations in SL technology and customization are likely to further enhance their clinical utility, solidifying their role as an indispensable tool in the management of corneal ectasias.

Myopia control with orthokeratology lenses. A 3-year follow-up study including a cross-over design: Clinical study Of Near-sightedness; TReatment with Orthokeratology Lenses 2 (CONTROL2 study).

PURPOSE: The purpose of this study is to investigate 3-year efficacy of orthokeratology lenses (OKL) in controlling axial length progression in myopic Scandinavian children. Through a cross-over design of the control group to compare the treatment efficacy in younger versus older children, with the latter having higher cycloplegic spherical refractive error (cSEQ) at treatment initiation. Further, the study aimed to evaluate the safety of the treatment. METHODS: This was a continuation of the randomized controlled study Clinical study Of Near-sightedness; TReatment with Orthokeratology Lenses (CONTROL study) in which the follow-up period of the original intervention group, that received OKL, was extended from 18 months to 36 months. Meanwhile, the original control group was crossed-over to OKL after the 18-month follow-up visit and treated for 18 months. Biometry was measured using Lenstar LS900, and contact lens complications were graded according to Efron Grading Scale for Contact Lens Complications (Efron score). Mixed models were used for statistical analysis. RESULTS: Nineteen subjects in the OKL group and 28 in the control group completed the CONTROL study. Hereof, 17 and 24 subjects from the OKL group and control group, respectively, agreed to participate in the CONTROL2 study. In the OKL continue group, the treatment efficacy did not decline during the 3-year study period (p-values for follow-up visits were all ≥0.82). There was no statistically significant difference between treatment efficacy when OKL treatment was initiated in younger versus older children (p-value ≥0.14 for all follow-up visits). Low-grade corneal staining was seen in several subjects at some point during the study, but here were no treatment-requiring or sight-threatening adverse events during the study period. CONCLUSION: The efficacy of myopia control by OKL was stable during 3 years of treatment. Similar treatment efficacies were found regardless of the age at treatment initiation. No severe adverse events occurred during the study period.

Vat photopolymerization of multifunctional fresnel lenses for ocular management.

In this study, multifunctional Fresnel lenses were explored as a potential solution for correcting vision in patients with color vision deficiency (CVD) and high myopia. Current studies have primarily focused on color vision correction through the 3D printing of glasses and contact lenses. However, the potential of 3D-printed multifunctional devices, such as Fresnel lenses, goes beyond addressing a single vision correction issue. For this study, computer-aided design (CAD) model of Fresnel lens with high diopter based on constant height configuration was developed. The CAD model was successfully fabricated using vat photopolymerization 3D printer, employing laboratory-prepared transparent HEMA resin. The resin was modified with two Atto dyes (565 nm and 488 nm), known for their ability to filter out problematic wavelengths (400-500 nm and 540-580 nm) to address color vision deficiency. The printed lenses were characterized by their chemical, physical, and optical properties using various characterization techniques. The focusing performance was evaluated using focal length measurements, and the results obtained were less than 2 mm deviation from the design value, having the potential to assist in higher myopic vision correction. The resulting optical spectra were compared with commercial glasses, revealing close agreement for CVD correction. These results expand the potential applications of multifunctional Fresnel lenses in ophthalmology, demonstrating their effectiveness as vision-correcting lenses and imaging systems.

Refractive and ocular motor status in autistic adults without learning disabilities: an exploratory study.

CLINICAL RELEVANCE: Refractive and ocular motor anomalies may be more prevalent among autistic adults without learning disabilities, compared to a non-autistic clinical population. In line with current guidance, optometrists should exclude these anomalies prior to prescribing tinted lenses. BACKGROUND: Autistic adults report various visual experiences with largely negative consequences on daily living. Some of these overlap with symptoms of refractive and ocular motor anomalies. Therefore, this study investigated refractive and ocular motor status, and pattern glare, in autistic adults without learning disabilities. The impact of appropriate treatment on visual experiences was explored. METHODS: Twenty four autistic adults, aged 19-67 years, underwent an eye examination involving refraction, ocular motor and pattern glare assessments. Based on pre-determined criteria, anomalies were treated with spectacles, orthoptic exercises, or tinted lenses. Participants completed three questionnaires (Glasgow Sensory Questionnaire, Visual Function Index and Convergence Insufficiency Symptoms Survey) at the start and end of the study to assess the impact of treatment. RESULTS: Relative to population norms, a notable proportion of participants had: a significant change in refractive correction (83.3%); accommodative infacility (72.7%); convergence insufficiency (37.5%); uncompensated distance dissociated heterophoria (33.3%); significant accommodative inaccuracy (27.2%); and positive pattern glare (25%). All participants required treatment. 16.7% were given orthoptic exercises only. New spectacles were dispensed to 79.2%, followed by 16.7% requiring orthoptic exercises and 4.2% dispensed tinted lenses. Questionnaire scores did not significantly change post-treatment. CONCLUSION: This exploratory study suggests autistic adults may be more likely to present with refractive, ocular motor and pattern glare issues. Impacts on autistic visual sensory experiences, vision-related quality of life and visual function remain unclear. Pattern Glare Test scores of autistic adults appear to be reduced by appropriate refractive and/or ocular motor management. Therefore, optometrists should take a conservative approach, managing refraction and ocular motor status of autistic patients prior to considering tinted lenses.

Clinical Outcomes of a Trifocal Versus an Extended Depth of Field Intraocular Lens in Chinese Patients With Cataract: A Prospective Cohort Study.

Purpose: To compare the standard outcomes between the PanOptix and Symfony multifocal intraocular lenses (MIOLs) in Chinese patients. Methods: This prospective observational cohort study enrolled patients with cataracts between April 2021 and December 2021 at Xiamen Eye Center Affiliated to Xiamen University. The patients were grouped in the PanOptix (TIOL group) and Symfony (EDF group) according to the IOLs implanted. Uncorrected distant, corrected distance, binocular uncorrected intermediate, and near visual acuity (UNVA), distance-corrected intermediate and near VA (DCNVA) , defocus curve, spectacle independence, contrast sensitivity (CS), and visual disturbances were evaluated after 3 months. Results: Forty patients (80 eyes) were enrolled in the study (20/group). Three months after the operation, UNVA (0.13 ± 0.16) and DCNVA (0.08 ± 0.08) were better in the TIOL group than in the EDF group (0.22 ± 0.08 and 0.22 ± 0.08, respectively, p=0.003 and p < 0.001, respectively). The TIOL group achieved a better-than-0.15-logMAR VA from +0.5 D to -2.5 D (40 cm). VAs of the TIOL group from -1 D (100 cm) to -4 D (25 cm) were better than in the EDF group (p < 0.05). There were no significant differences in the intermediate and far vision outcomes (p > 0.05). Total near-vision spectacle independence was higher in the TIOL group (80%) than in the EDF group (50%) (p=0.039). Conclusion: Compared with EDF, TIOL leads to better near-vision outcomes without significant differences for intermediate and distant vision outcomes. Trial Registration: ClinicalTrials.gov identifier: ChiCTR2100044558.

Epidemiological survey of two morphotypes of Demodex folliculorum (Prostigmata: Demodicidade) in young people from southern Spain.

Different morphotypes of Demodex from humans have been described. Among them, molecular studies have made it possible to discern between the Demodex folliculorum and Demodex brevis. Further studies showed two morphotypes of D. folliculorum harboured two different habits (human skin and human eyelashes), both of them with finger-shaped terminal opisthosoma difficult to differentiate and that can be assigned to D. folliculorum, Thus, a complete morphometric study of the species, which in this study are referred to as Demodex folliculorum species complex, was carried out. From this morphometric and meristic study two distinct morphological forms (short and long) could be identified within the Demodex folliculorum species complex. These forms differ significantly in four out of the six biometric parameters we analysed: gnathosomal length and width, podosomal width, and opisthosomal length. Moreover, a comprehensive survey of the two morphotypes from different habitats (skin and eyelashes), was carried out in young people of Southern Spain. Therefore, an analysis of 104 asymptomatic students, which were contact lens wearers, and the presence of D. folliculorum was carried out. A statistical analysis based on Bayesian zero inflated Poisson GLM has been applied to our sample data. For the age group considered (18-24 years old), the overall D. folliculorum prevalence for skin face or eye infections (at least one of them) was 19.31 % (51 people), with a statistically significant higher prevalence in males men. Furthermore, there is a slight statistical correlation between the presence of Demodex in silicone hydrogel soft contact lens wearers. This study confirms: i) the existence of two morphotypes of D. folliculorum that appear segregated due to the parasitization microhabitats,ii) a higher prevalence of mites in men than in women, iii) the existence of a high number of statistically supported double infections (skin-eyelashes). It also provides epidemiological data on the prevalence of long and short forms of D. folliculorum in a healthy young population.

Visual rehabilitation using rigid gas permeable contact lenses after femtosecond laser-assisted minimally invasive lamellar keratoplasty in patients with keratoconus.

This study aims to observe the clinical efficacy and safety of rigid gas permeable corneal contact lenses (RGP-CLs) wearing after femtosecond laser-assisted minimally invasive lamellar keratoplasty (FL-MILK) in progressive and advanced keratoconus eyes. Twenty-five patients (27 eyes) fitted with RGP-CLs after FL-MILK were enrolled, and 22 grading-matched keratoconus patients (23 eyes) as a control group. Corneal morphological data, diopter, best corrected vision, corneal endothelium, non-invasive tear film rupture time (NIBUT), corneal perception and comfort questionnaire were analysed before and after wearing RGP-CLs. In the FL-MILK group, the flat K, steep K and Kmax of the corneal anterior surface were decreased by 3.05D, 3.48D and 7.17D respectively after surgery (P = 0.011, 0.004 and 0.007). The central corneal thickness increased by 175.29 µm (P < 0.001). The basic curve of RGP-CLs after surgery was about 0.23 mm flatter than that before surgery (P = 0.013). There was no statistical difference in the best corrected vision and the comfort of wearing RGP-CLs before and after FL-MILK (P = 0.923, 0.391). Compared with the control group, there was no significant difference in vision improvement by RGP-CLs (P = 0.669). During the follow-up, the comfort of wearing RGP-CLs in the two groups was good, and no obvious adverse events were observed. This study showed MILK significantly increases corneal thickness and flattens corneal curvature, achieving good RGP-CLs corrected vision.

Investigation of Delefilcon A Contact Lenses for Symptomatic Daily Disposable Contact Lens Wearers with Dry Eye Disease: A Prospective Comparative Study.

Purpose: This prospective comparative study aimed to assess the effects on contact lens comfort, dryness, and wear time when symptomatic daily disposable (DD) contact lens (CL) wearers were refit with delefilcon A (DT1) lenses. Patients and Methods: Thirty five symptomatic DD CL wearers with dry eye disease as determined according to the TFOS DEWS 2 guidelines, were enrolled and completed the study. Participants wore their habitual DD CLs during an initial assessment and were subsequently refit with DT1 for 1 month. Participants were masked to the study lens type. Subjective ratings of end-of-day comfort and dryness, average wear time, and comfortable wear time were evaluated as primary endpoints. Results: Of the 35 participants, two participants were classified as aqueous deficient dry eye, while the remaining participants exhibited symptoms primarily due to evaporative causes. The median CLDEQ-8 score for dryness significantly improved from 17 (fair) with habitual lenses to 13 (good) with DT1 lenses (p < 0.01). Participants reported significantly better end-of-day comfort (p = 0.01) and less end-of-day dryness (p = 0.01) with DT1 compared to their habitual DD lenses. The comfortable wear time was significantly longer with DT1 (8.5 ± 4.1 hours) compared to habitual DD lenses (6.7 ± 3.2 hours) (p = 0.04). No significant differences were observed in vision ratings (p = 0.07). Conclusion: Refitting symptomatic DD CL wearers with DT1 resulted in improved end-of-day comfort, reduced end-of-day dryness, and extended comfortable wear time compared to their habitual lenses. These findings suggest that DT1 may offer benefits for symptomatic DD wearers with dry eye disease.

Short-term changes in the trabecular iris angle and anterior chamber during wear of scleral lenses with different diameters.

CLINICAL RELEVANCE: Scleral lens (SL) compression on the conjunctiva/episclera during wear may alter adjacent structures related to aqueous humour drainage. BACKGROUND: The aim of this work was to assess short-term changes in the four quadrants of trabecular iris angle (TIA) and anterior chamber parameters during SL wear, using anterior segment optical coherence tomography (AS-OCT). METHODS: Prospective study was conducted involving 16 healthy subjects with a mean age of 28 ± 5 years. Two SL of diameter 15.80 mm (L1) and 16.80 mm (L2) with the same parameters were used for 2 hours in different days. The central fluid reservoir (FR), the TIA in superior, inferior, nasal, temporal quadrants, and anterior chamber parameters; anterior chamber depth (ACD), anterior chamber width (ACW), anterior chamber area (ACAr) and anterior chamber volume (ACV) were measured with AS-OCT. These measurements were performed immediately after SL application (0 h), one hour (1 h) and two hours (2 h) of SL wear. RESULTS: TIA decreases significantly in the superior quadrant at 2 hours of L2 wear (-5.19 ± 7.79º) (p = 0.04). In this sector, differences were also observed between the changes induced by both lenses during the 2 hours of wear (p = 0.04) and between first and second hours of wear (p = 0.04). ACD was significantly lower with L1 (-0.09 ± 0.14 mm) relative to L2 (0.00 ± 0.06 mm) between immediately after the application and 2 hours of wear (p = 0.02). A significant reduction in ACAr at 1 hour (-0.65 ± 0.75 mm2) (p = 0.01) and 2 hours of wear (-0.81 ± 1.15 mm2) (p = 0.04), as well as in ACW at 2 hours (-0.11 ± 0.14 mm) (p = 0.02) compared to immediately after application of L1 was found. CONCLUSION: Small changes in TIA and anterior chamber occur during two hours of SL wear, but these changes are of limited clinical relevance in healthy subjects.

Effects of orthokeratology and spectacle lenses with highly aspherical lenslets on unilateral myopic anisometropia control.

PURPOSE: To evaluate the 1-year effects of orthokeratology (OK) lenses and spectacle lenses with highly aspherical lenslets (HALs) on axial length (AL) elongation in children with unilateral myopic anisometropia. METHODS: This ambispective cohort study recruited 81 children aged 8-14 years with unilateral myopic anisometropia. Of these, 42 participants (mean age 11.07 ± 1.54 years; 23 males) were treated with monocular OK lenses (OK group), and 39 (mean age 10.64 ± 1.72 years; 22 males) with binocular HALs (HAL group). Changes in AL and spherical equivalent refraction (SER) from baseline at 3, 6 and 12 months were compared between eyes and groups. Kaplan-Meier estimation and Cox proportional hazard regression were performed to analyse the risk of myopia onset in the initially non-myopic eyes. RESULTS: Mean axial elongation in the myopic and non-myopic eyes at the 12-month follow-up visit were 0.17 ± 0.20 and 0.41 ± 0.26 mm in the OK group (p < 0.001) and 0.10 ± 0.15 and 0.12 ± 0.12 mm in the HAL group (p = 0.32), respectively. Compared with the OK group, the non-myopic eyes in the HAL group had less axial elongation, lower cumulative myopia incidence and percentage of participants with rapid myopic shift at the 6- and 12 month follow-up (all p < 0.05). Cox regression analysis showed that a higher initial SER decreased the risk of myopia onset significantly in the initially non-myopic eyes (B = -2.06; 95% CI, 0.03-0.49; p = 0.003). CONCLUSIONS: Monocular OK lenses suppressed axial elongation in the myopic eye and minimised anisometropia; however, the non-treated contralateral eye may experience faster myopia onset and myopic shift. Binocular HALs can effectively reduce axial elongation in both eyes of children with unilateral myopic anisometropia.

Sustained release of proteins from contact lenses with porous annulus.

Ophthalmic drugs are administered to the front of the eye by eyedrops. The bioavailability of drugs delivered via eye drops is low due to tear turnover. Contact lenses can address some deficiencies of eye drops by sustaining the delivery of drugs, but commercial contact lenses have small pore sizes that cannot load biologics, which are becoming more common for treating ophthalmic diseases. This study aims to investigate novel poly(hydroxyethyl methacrylate) (pHEMA) lenses with transparent center and porous annulus for sustained release of model proteins. A novel hydrogel polymerization process was used to fabricate concentric, porous layer pHEMA hydrogel rods. The hydrogels were lathe cut into contact lenses which were explored for the delivery of proteins and gold nanoparticles. Lenses were characterized by partition coefficient and diffusivity, which was estimated by fitting experimental data to an analytical model. Transmittance measurements were made to compare transparency of porous lens centers to commercial contact lenses. Porous pHEMA lenses consisting of a concentric, porous layer made from 55% water content in precursor were successfully lathe cut into lenses with transparent center and opaque porous annulus. The porous lenses could load large model proteins of bovine serum albumin and human γ-globulin and provide sustained release. The core annular pHEMA contact lenses consisting of an outer annulus of opaque, porous pHEMA and an inner, center layer of clear, nonporous pHEMA can provide sustained delivery of biologics.

Ag/Cu nanoparticles-loaded glycocalyx biomimetic corneal bandage lenses for combatting bacterial keratitis.

Bacterial keratitis is a major cause of blindness, hindered by the rising threat of antibiotic resistance. Although corneal bandage lenses (CBLs) are widely utilized in ophthalmic treatment, their effectiveness in treating bacterial keratitis remains limited due to risks of secondary infections, patient discomfort, and complications. In this study, we developed a novel biomimetic coating on CBLs by grafting Ag/Cu bimetallic nanoparticles (Ag/Cu-NPs) and thiol-functionalized heparin (Hep-SH) using a rapid polydopamine (PDA) deposition technique, effectively mimicking the ocular surface glycocalyx structure. The resulting Ag/Cu-NPs/Hep-SH coated CBLs (PNH-CBLs) exhibited significant antibacterial activity, with over 80 % reduction in Staphylococcus aureus (S. aureus) and 70 % in Escherichia coli (E. coli) due to the sustained release of Ag+ and Cu2+, along with displaying favorable in vitro biocompatibility. Animal experiments conducted on New Zealand white rabbits with bacterial keratitis demonstrated successful treatment therapeutic outcomes, with PNH-CBLs leading to a significant decrease in clinical score. These biomimetic lenses also exhibited selective anti-protein adsorption properties, minimizing inflammation and promoting surface lubrication. Overall, this innovative approach addresses critical challenges in antibiotic resistance and offers a promising therapeutic strategy for managing ophthalmic infectious diseases.

Prediction of refraction error after toric lens implantation with biometric input data uncertainties and power labelling tolerances.

BACKGROUND: The purpose of this study was to simulate the impact of biometric measure uncertainties, lens equivalent and toric power labelling tolerances and axis alignment errors on the refractive outcome after cataract surgery with toric lens implantation. METHODS: In this retrospective non-randomised cross sectional Monte-Carlo simulation study we evaluated a dataset containing 7458 LenStar 900 preoperative biometric measurements. The biometric uncertainties from literature, lens power labelling according to ISO 11979, and axis alignment tolerances of a modern toric lens (Hoya Vivinex) were taken to be normally distributed and used in a Monte-Carlo simulation with 100 000 samples per eye. The target variable was the defocus equivalent (DEQ) derived using the Castrop (DEQC) and the Haigis (DEQH) formulae. RESULTS: Mean/median / 90% quantile DEQC was 0.22/0.21/0.36 D and DEQH was 0.20/0.19/0.32 D. Ignoring the variation in lens power labelling and toric axis alignment the respective DEQC was 0.20/0.19/0.32 D and DEQH was 0.18/0.17/0.29 D. DEQC and DEQH increased with shorter eyes, steeper corneas, equivalent lens power and highly with toric lens power. CONCLUSIONS: According to our simulation results, uncertainties in biometric measures, lens power labelling tolerances, and axis alignment errors are responsible for a significant part of the refraction prediction error after cataract surgery with toric lens implantation. Additional labelling of the exact equivalent and toric power on the lens package could be a step to improve postoperative results.

Raman spectroscopy to investigate early biochemical alterations in human tears caused by contact lenses.

CLINICAL RELEVANCE: The interaction between contact lenses and tear film plays a critical role in lens biocompatibility and can influence discomfort during wear. Early detection of biochemical changes is important for improving ocular surface health, preventing complications, and developing advanced lens materials to enhance long-term comfort. BACKGROUND: The pursuit of biocompatible lens materials requires a thorough understanding of their interaction with tear environment. The aim of this study is to evaluate different approaches to investigate early alterations in tear biomolecular profiles induced by lens wear. METHODS: Two participants wore different CLs and underwent ocular analysis before CL insertion (T0), after 2-hour wear (T2), and two hours after removing the CL (T4), evaluating non-invasive tear break-up time (NIBUT), tear meniscus height (TMH), and osmolarity. Forty CLs were used. At the same time points, tears were collected and analysed by Raman spectroscopy. RESULTS: Tear film stability, as measured by NIBUT, decreased post-lens wear (T0 vs T2, p = 0.034 and 0.025 for S1 and S2, respectively) but showed recovery within 2 hours (T0 vs T4, p > 0.05 for both S1 and S2), while TMH and osmolarity remained unchanged (T0 vs T2 vs T4, p > 0.05 for both S1 and S2). Raman spectroscopy highlighted notable changes in the biomolecular profile of tears after lens wear, particularly in the 2700-3200 cm-1 spectral window related to C-H stretching, which is sensitive to CH, CH2 and CH3 groups, their functional chemistry group, and the surrounding microenvironment. CONCLUSIONS: Contact lens wear induces subtle biochemical, subclinical alterations in tears that can be detected early by Raman spectroscopy. The method is promising for analysing the subject-specific responses to lenses, also with possible individual variability in the timing of these changes. In addition, this approach can provide insights for designing biocompatible materials and for the early detection of subclinical biomarkers.

Knowledge, attitude and the associated factors regarding spectacle use among adults living in Debre Birhan Town, North Shewa, Ethiopia, 2023: a community-based, cross-sectional study.

OBJECTIVE: This study aimed to assess the knowledge, attitude and the associated factors regarding spectacle use among adults living in Debre Birhan Town, North Shewa, Ethiopia. DESIGN: A community-based, cross-sectional study was conducted using a multistage sampling method. SETTING: The study was conducted in Debre Birhan Town, North Shewa, Ethiopia. PARTICIPANTS: The study included 1022 adults aged ≥18 years living in Debre Birhan Town for more than 6 months. MAIN OUTCOME MEASURES: Data were collected using face-to-face interviews completed by an interviewer. RESULTS: The study included 1022 adults with a median age of 45 years. Of the participants, 86.01% (95% CI 83.88, 88.14) had adequate knowledge and 85.32% (95% CI 83.15, 87.50) had favourable attitude towards spectacle use. Older age (adjusted OR (AOR)=1.21, 95% CI 1.17, 1.26), higher educational status (AOR=2.65, 95% CI 1.06, 6.60), history of spectacle use (AOR=3.20, 95% CI 1.31, 7.83) and family history of spectacle use (AOR=4.75, 95% CI 2.31, 9.75) were positively associated with having adequate knowledge of spectacle use. Higher educational status (AOR=2.56, 95% CI 1.26, 5.21), history of spectacle use (AOR=3.22, 95% CI 1.58, 6.55), family history of spectacle use (AOR=1.89, 95% CI 1.13, 3.16) and adequate knowledge about spectacle use (AOR=4.63, 95% CI 2.69, 7.98) were positively associated with having favourable attitude towards spectacle use. CONCLUSION: This study revealed a good proportion of adults with adequate knowledge and favourable attitude towards spectacle use. Higher educational status, history of spectacle use and family history of spectacle use were significantly associated with having adequate knowledge and favourable attitude towards spectacle use.

Antimicrobial and antifouling hyaluronic acid-cobalt nanogel coatings built sonochemically on contact lenses.

The wearing of contact lenses (CLs) may cause bacterial infections, leading in turn to more serious complications and ultimately vision impairment. In this scenario, the first step is the adhesion of tear proteins, which provide anchoring points for bacterial colonization. A possible solution is the functionalization with an antimicrobial coating, though the latter may also lead to sight obstruction and user discomfort. In this study, adipic acid dihydrazide-modified hyaluronic acid-cobalt (II) (HA-ADH-Co) nanogels (NGs) were synthesized and deposited onto commercial CLs in a single-step sonochemical process. The coating hindered up to 60 % the protein adsorption and endowed the CLs with strong antibacterial activity against major ocular pathogens like Staphylococcus aureus and Pseudomonas aeruginosa, reducing their concentration by around 3 logs. Cytotoxicity assessment with human corneal cells demonstrated viabilities above 95 %. The nanocomposite coating did not affect the optical power and the light transmission of the CLs and provided enhanced wettability, important for the wearer comfort.