RESUMEN

Purpose: To analyze binocular vision of individuals aged 18 to 35 years diagnosed with keratoconus, utilizing spectacles and rigid gas-permeable (RGP) contact lenses. Research was led by the Universidad Autónoma de Aguascalientes, México and Fundación Universitaria del Área Andina Pereira, Colombia. Methods: A single center, prospective non-randomized, comparative, interventional, open-label study, in which the differences in binocular vision performance with both spectacles and RGP contact lenses was carried out from December 2018 to December 2019. Sampling was performed according to consecutive cases with keratoconus that met the inclusion criteria until the proposed sample size was reached. Results: Rigid gas-permeable (RGP) contact lenses notably enhanced distance and near visual acuity in keratoconus patients compared to spectacles. Visual alignment analysis shows exophoria at both distances and is slightly higher with RGP contact lenses. The difference was statistically significant (p<0.05), with 82.5 % presenting compensated phoria with spectacles and pnly 42.50% with RGP contact lenses. Stereoscopic vision improved while wearing RGP contact lenses (42.59 %), although accommodation and accommodative flexibility remained within normal ranges. Conclusions: Patients with keratoconus fitted with RGP contact lenses have improved binocular vision skills such as visual acuity, stereopsis, and accommodative flexibility. However, even when the vergence and motor system is decompensated with respect to normal ranges, the range between break and recovery points for both fusional reserves and the near point of convergence (NPC) improves with the use of RGP contact lenses, giving indications of an adaptive condition of the motor system from the medium to the long term.(AU)

Asunto(s)

RESUMEN

Optical methods for studying the brain offer powerful approaches for understanding how neural activity underlies complex behavior. These methods typically rely on genetically encoded sensors and actuators to monitor and control neural activity. For microendoscopic calcium imaging, injection of a virus followed by implantation of a lens probe is required to express a calcium sensor and enable optical access to the target brain region. This two-step process poses several challenges, chief among them being the risks associated with mistargeting and/or misalignment between virus expression zone, lens probe and target brain region. Here, an adeno-associated virus (AAV)-eluting polymer coating is engineered for gradient refractive index (GRIN) lenses enabling the expression of a genetically encoded calcium indicator (GCaMP) directly within the brain region of interest upon implantation of the lens. This approach requires only one surgical step and guarantees alignment between GCaMP expression and lens in the brain. Additionally, the slow virus release from these coatings increases the working time for surgical implantation, expanding the brain regions and species amenable to this approach. These enhanced capabilities should accelerate neuroscience research utilizing optical methods and advance the understanding of the neural circuit mechanisms underlying brain function and behavior in health and disease.

RESUMEN

PURPOSE: To gain insight into patients' visual experiences and satisfaction when using different forms of myopia control lenses. METHODS: PubMed, Cochrane Library, Embase, Scopus and Web of Science databases were searched for articles assessing subjective visual quality with myopia control lenses compared with single-vision lenses (SVLs) up to July 10, 2023. Eight-hundred-and-three articles were retrieved, reviewed and any questionnaire items on subjective impressions of lens wear were meta-analysed. Subgroup analyses were based on the magnitude of defocus (add power) of multifocal soft contact lenses (MFSCLs) and age groups. A random-effects model was employed for meta-analysis, and I2 statistic used to assess the statistical heterogeneity. RESULTS: Nineteen articles fit the criteria, but only six articles involving MFSCLs had relevant data. MFSCLs were associated with lower subjective ratings of vision at different distances compared to SVLs (p < 0.001), but the differences were less than one unit. MFSCLs also yielded lower ratings when moving or walking and/or climbing stairs at -0.38 (-0.69 to -0.07, p = 0.02; I2 = 85 %, p < 0.001) and for subjective comfort (difference of -0.23, -0.41 to -0.05, p = 0.01; I2 = 63 %, p < 0.001). Subjective ratings for playing sports were not different between groups. Experience with MFSCLs was rated lower by young adults compared to children for all variables. In both children and young adults, ratings were lower with higher add compared to lower add MFSCLs. CONCLUSION: Although subjective ratings for vision and comfort were lower with MFSCLs compared to SVLs, the difference was mostly less than one unit. Importantly, young adults rated their visual experience lower compared to children.

RESUMEN

Bacterial keratitis (BK) is a severe eye infection commonly associated with Staphylococcus aureus (S. aureus), posing a significant risk to vision, especially among contact lens wearers. This research introduces a novel smart nanoplatform (deMS@cNF), developed from demineralized mussel shells (deMS) and reinforced with chitin (CT) nanofibrils, specifically designed for portable photothermal disinfection of contact lenses. The nanoplatform leverages the photothermal properties of eumelanin in mussel shells (MS), which, when activated by a simple bike flashlight, rapidly heats to temperatures up to 95 °C, effectively destroying bacterial contamination. In vitro tests demonstrate that the nanoplatform is biocompatible and non-toxic, making it suitable for medical applications. This study highlights an innovative approach to converting marine biowaste into a safe, effective, and low-cost portable method for disinfecting contact lenses, showcasing the potential of the deMS@cNF platform for broader antimicrobial applications.

RESUMEN

PURPOSE: The aim of this study was to develop a methodology, based on profilometer measurements to assess the optical behaviour of Intraocular Lenses (IOls). The "Modulation Transfer Function through-object" (MTF through-object) based on vergence object displacement was calculated for different pupil sizes and pseudophakic eyes. Tilt and decentration were also analysed in a realistic cornea eye model. METHODS: For comparison between the different IOLs, an optical quality criterion based on a minimum value the MTF through-object and the recognition of simulated vision optotypes was introduced. Five IOLs were used in this study: Tecnis Eyhance, Mini Well, Tecnis Symfony, Tecnis Synergy and RayOne EMV. RESULTS: The technique was validated with previous methodologies. A general narrowing of the through-object MTF curve compared to the through-focus MTF curve was shown, resulting in greater distances between near and intermediate points and less depth of field around the far peak. The comparison between the IOLs showed that variations in corneal aberrations, pupil size and decentration caused relevant changes in IOL performance. A decrease of the SA produced a hypermetropic shift of the far focus between + 0.3 D and + 0.4 D. Most of IOLs worsen the optical quality as pupil size increased, even the MTF through-object shape changed. Decentration was an important factor in IOL implantation, causing a significant change in MTF through-object shape in most of IOLs. CONCLUSIONS: This study highlights the need to evaluate pre-operative patients for corneal aberrations and pupillary size to have the best optical success after cataract surgery in multifocal or extended depth of focus IOLs. KEY MESSAGES: What is known MTF(Modulation Transfer Function) through-focus curves (calculated in image space by moving the detector plane) can be obtained from optical bench assembly or from commercial devices. Recently, some studies proposed to characterize the lens surface design based on the profilometric measurements What is new A novel methodology based on profilometer measurements to assess the optical behaviour of Intraocular Lenses (IOls) was shown. The "Modulation Transfer Function through-object" based on vergence object displacement was introduced in order to analyse five premium IOLs. MTF through-object curve is more appropriate for studying clinical behaviour, as it provides further near and intermediate points distances and lower depth of focus around far peak compare to MTF through-focus curves. The optical behaviour of the five IOLs can vary considerably depending on the eye model and pupil size. The effect of tilt and decentration on the MTF through-object the IOLs was analysed.

RESUMEN

Contact lens (CL) use is growing rapidly, with a current estimate of over 100 million wearers worldwide. Vast improvements in materials and designs have occurred over the past decades with advancements in the understanding of ocular surface health with CL wear. However, the potential impact of CL on neural structures and function of the ocular surface, particularly in relation to the richly innervated cornea, remain poorly understood. Problems with sensation such as CL discomfort and conditions that may be associated with lens wear including dry eye disease also remain pervasive. This narrative review discusses the findings from studies involving soft or rigid CL wearers, assessed with c linical techniques designed for examining the neural integrity of the cornea, namely in vivo confocal microscopy and esthesiometry. While the collective findings remain equivocal in terms of the changes in corneal nerve morphology and function with conventional CL wear, more specialised CLs, namely orthokeratology lenses, which mechanically manipulates the structure of the cornea seem to produce more prominent changes in nerve distribution and sensitivity reduction. Given the intricate relationship between neural and immune mechanisms in maintaining balanced ocular surface health, the potential links between these structural and functional findings with parainflammation and neuroinflammation, as well as clinical issues including CL discomfort and dry eye disease, are also explored.

RESUMEN

Keratoplasty is a radical surgical method for treating various corneal pathologies. Today, there are many types of keratoplasty, each aiming to restore the integrity and transparency of the cornea. However, keratoplasty-induced ametropia often prevents achieving high visual acuity and makes impossible the use of conventional optical correction methods such as glasses or soft and traditional rigid contact lenses. In this regard, the use of scleral contact lenses is the most optimal method for optical correction of postoperative refractive anomalies, ensuring successful visual rehabilitation and preventing the need for additional keratorefractive interventions.

Asunto(s)

RESUMEN

BACKGROUND: To explore intraocular lens (IOL) preferences of United Kingdom-based (UK) refractive surgeons in cataract and refractive lens exchange (RLE) surgery. METHODS: An online survey on IOL preferences (and reasons for their choice) in cataract and RLE surgery was distributed. It also enquired about implementing mini-monovision with extended depth of field (EDoF) IOLs, about utilising IOL mix-and-match (different IOL types in each eye), and at what level of corneal astigmatism they prefer toric lenses. RESULTS: Following an 81.6% response rate, thirty responses were analysed; median years of refractive surgery experience was 12.5. The most popular IOL choices for cataract surgery were EDoF lenses (30%), monofocals (20%), and trifocals (20%). The most cited reason for each was better overall visual outcomes (88.9%), fewer unwanted symptoms (66.7%) and best spectacle independence (66.7%), respectively. For RLE, EDoF remained most popular (36.7%), followed by trifocals (30%), and multifocals (16.7%) with the same reasons for choice cited above. Mini-monovision with EDoF lenses was well-regarded (83% recommend for most/select patients), unlike utilising IOL mix-and-match (60% did not recommend). 40% prefer toric IOLs for astigmatism of 1 dioptre (D) or higher, whilst 30% opt for them at < 1D. CONCLUSIONS: Experienced UK refractive surgeons prefer newer IOLs with enhanced optics; ≥50% of respondents favoured either EDoF or trifocals for a 'typical' cataract or RLE patient. Notably, respondents have a low corneal astigmatism threshold for toric lenses. Mini-monovision with EDoF IOLs was well-regarded, whilst mix-and-match of different IOL types was less recommended.

Asunto(s)

RESUMEN

The advent of drug-eluting contact lenses (DECLs) has opened up new avenues for the treatment of eye diseases. DECLs is expected to partially overcome the shortcomings of eye drops due to single-dose packaging, accurate dosing, prolonged drug elution behavior, and simplified dosing procedures. Currently, a significant proportion of the DECLs design effort has been directed towards enhancing the compatibility of contact lenses with drugs. The appropriate elution time for the drug remains unclear. Additionally, it is ambiguous for which ophthalmic diseases DECLs offers the greatest therapeutic advantage. To rationally design DECLs in practice, it is necessary to understand the acceptance of DECLs by patients and practitioners and to clarify the indications for DECLs. This review will first focus on the acceptance of DECLs by different patients and practitioners and discuss the factors that influence its acceptance. Secondly, this review presents an overview of the current effectiveness of DECLs treatments in animals and in the clinical phase, with a particular focus on the suitability of DECLs for the treatment of ophthalmic diseases. Overall, patients and practitioners expressed positive attitudes towards DECLs. However, this is related to factors such as DECLs' treatment cycle, safety, and price. In addition, DECLs has good application prospects for ocular wound healing, postoperative management, and treatment of contact lenses-related complications. Furthermore, chronic diseases such as glaucoma that necessitate long-term medication and intraocular diseases that require implants or injections represent additional potential applications for DECLs. It is hoped that this review will facilitate a deeper understanding of DECLs acceptance and indications, thereby supporting the rational design of DECLs. At the same time, this review provides a reference for the design of other drug-device combination products.

RESUMEN

PURPOSE: To assess alterations in the tear Transforming Growth Factor (TGF)-ß1 and Interleukin (IL1)-ß concentration in new contact lens wearers; and explore correlations with tear film stability, and ocular physiological response. METHODS: In this clinical setting, 12 neophytes (5 males), with an average age of 24.0 ± 5.0 years were fitted with delefilcon A contact lenses. Physiological responses (bulbar and limbal hyperemia), Pre-corneal (NIBUT), Pre-lens (PL-NIBUT) non-Invasive Break-Up Times, and tear samples were collected in the morning (before lens insertion; 9 - 10 a.m.) and afternoon (before lens removal; 7 - 8p.m.) of the same day. NIBUT and PL-NIBUT were measured using a tearscope. Tear samples were assayed for TGF-ß1 and IL1-ß concentrations using Enzyme-Linked Immunosorbent Assay kits. An 11-members control group (6 males) aged 25.0 ± 5.0, served to assess biomarker levels in non-contact lens wearers' tears. RESULTS: Subjects wore lenses for an average of 7 h and 20 min (range: 6 to 9 h). Bulbar and limbal hyperemia increased significantly throughout the day (p < 0.001). PL-NIBUT were lower than NIBUT (4.7 ± 2.0 Vs. 12.2 ± 8.8 s; p < 0.001). The IL1-ß levels were higher in neophytes than controls (3.2 ± 4.7 Vs. 0.1 ± 0.1 pg/ml; p = 0.05), correlating significantly with bulbar (r = 0.405, p = 0.008) and limbal hyperemia (r = 0.499, p = 0.027). No substantial changes were reported for TGF-ß1. CONCLUSION: The presence of TGF-ß1 in tears does not appear significantly affected by lens wear. The association between physiological parameters and IL1-ß levels suggests that lenses may disrupt ocular surface homeostasis by altering cytokine regulatory mechanisms. However, due to its low concentration, IL1-ß's role in the subclinical inflammatory response to lens wear is limited.

RESUMEN

OBJECTIVE: To assess the efficacy and safety of using the adjustable flanged technique for secondary implantation of four-point scleral­fixated posterior chamber intraocular lenses with two parallel 6-0 polyglactin sutures. METHODS: Two parallel 6-0 polyglactin sutures were passed separately through the two haptics on the horizontal line of the 4-haptic IOL. The four externalized sutures were then trimmed and cauterized to form flanges. The best corrected visual acuity, intraocular pressure, and complications in all patients were observed and recorded. RESULTS: The flanged technique using two parallel 6-0 polyglactin sutures was applied to 14 aphakic eyes. The average preoperative best corrected visual acuity was 1.00 ± 0.88 LogMAR (Snellen 20/200), which improved to 0.42 ± 0.38 LogMAR (Snellen 20/48) at the final follow-up (P = 0.004). None of the patients experienced vitreous hemorrhage, low intraocular pressure, or issues with exposed or broken sutures. CONCLUSION: The simplicity of the technique, along with its ability to accommodate adjustments post-implantation, allows for optimal positioning and reduces risks like IOL tilt or dislocation. Overall, this is a promising approach to secondary IOL implantation, with potential benefits for both patient outcomes and surgical efficiency.

Asunto(s)

RESUMEN

OBJECTIVES: This retrospective analysis evaluates the treatment success of "Defocus Incorporated Multiple Segments" (DIMS) spectacle lenses in a real-life clinical setting in Germany. MATERIALS AND METHODS: Axial length (AL) and objective refraction of 166 eyes treated with DIMS at baseline and 12-month follow-up were analyzed. Annual AL growth rate within the range of physiological growth rate was considered a successful treatment. Myopia progression of ≥ -0.5 D/yr accounted as treatment success. Differences in percentages of treatment success of subgroups depending on baseline AL and age against treatment success of the total population were investigated. RESULTS: Considering all eyes, treatment success regarding AL growth and myopia progression was achieved in 46% and 65%, respectively. Male eyes with moderate AL showed treatment success in a higher proportion (73%, p < 0.01; 89%, p < 0.01); eyes with high AL showed treatment success in a lower proportion (25%, p < 0.01; 51%, n.s.). Female eyes showed the same trend but without statistical significance (moderate AL: 49%; 68%; high AL: 40%; 62%). Younger children showed treatment success in a lower proportion (male: 11%, p < 0.01; 38%, p < 0.05; female: 25%, p < 0.01; 42%, p < 0.01). Older children showed treatment success in a higher proportion (male: 60%, p < 0.05; 78% p < 0.05; female: 53%, n.s.; 77% p < 0.05). CONCLUSIONS: Eyes with moderate baseline AL and of older children showed treatment success after 12 months of DIMS treatment. Eyes with a high baseline AL and of younger children showed treatment success in a smaller proportion, therefore combination treatment should be considered. In future studies, males and females should be assessed separately.

Asunto(s)

RESUMEN

Objectives: It was aimed to compare the clinical results of the mini-monovision technique (MMV) with enhanced monofocal intraocular lens (IOL) and trifocal IOL applications and to evaluate the intereye differences in the MMV group. Materials and Methods: This retrospective observational study evaluated the results of cataract surgeries performed on 48 eyes of 24 patients. Surgeries in Group I were performed for MMV using the RayOne EMV IOL targeting emmetropia in dominant eyes (Group IA) and -0.70 diopter (D) myopia in non-dominant eyes (Group IB), while those in Group II were performed with the AcrySof® IQ PanOptixTM TNFT00 IOL targeting emmetropia. After the surgeries, uncorrected and corrected distance, intermediate, and near distance visual acuities, contrast sensitivity measurements, and defocus curves were determined. Subjective evaluation was made with the National Eye Institute Visual Function Questionnaire (NEI VFQ-25). The groups were compared statistically. Results: Postoperative refraction mean spherical equivalent was -0.25±0.22 D, -0.67±0.33 D, and -0.16±0.31 D in the three groups, respectively. A statistical difference was identified in favor of Group IA for uncorrected distance vision and in favor of Group IB for near vision (p<0.05). There was no difference in bilateral uncorrected visions in Groups I and II (p>0.05). While contrast sensitivity was better in Group I at all spatial frequencies (p<0.05), better vision was achieved in the defocus curve at distance in Group IA and at near in Group IB. In the binocular evaluation, it was seen that Groups I and II had similar results. In the subjective evaluation, NEI-VFQ-25 scores were 94.1±4.2/100 in Group I and 91.5±3.0/100 in Group II at 6 months (p>0.05). Photic complaints were significantly more common in Group II. Conclusion: With the MMV technique, it was observed that enhanced monofocal lenses provided better visual acuity at all distances and less dysphotopsia than trifocal lenses, whereas trifocal lenses were better at providing independence from glasses.

Asunto(s)

RESUMEN

Microbial keratitis associated with contact lenses (CLs) wear remains a significant clinical concern. Antibiotic therapy is the current standard of care. However, the emergence of multidrug-resistant pathogens necessitates the investigation of alternative strategies. Antibiotic-free antimicrobial contact lenses (AFAMCLs) represent a promising approach in this regard. The effectiveness of CLs constructed with a variety of antibiotic-free antimicrobial strategies against microorganisms has been demonstrated. However, the impact of these antimicrobial strategies on CLs biocompatibility remains unclear. In the design and development of AFAMCLs, striking a balance between robust antimicrobial performance and optimal biocompatibility, including safety and wearing comfort, is a key issue. This review provides a comprehensive overview of recent advancements in AFAMCLs technology. The focus is on the antimicrobial efficacy and safety of various strategies employed in AFAMCLs construction. Furthermore, this review investigates the potential impact of these strategies on CLs parameters related to wearer comfort. This review aims to contribute to the continuous improvement of AFAMCLs and provide a reference for the trade-off between resistance to microorganisms and wearing comfort. In addition, it is hoped that this review can also provide a reference for the antimicrobial design of other medical devices.

Asunto(s)

RESUMEN

Amendment to the Regulation of Minister of Labour and Social Policy of 1 December 1998 on safety and occupational hygiene at positions equipped with display monitors, adopted on October 18th, 2023, entered the long-awaited by employees possibility of reimbursement for corrective contact lenses, adjusting the Polish legislation to European directive regulating working conditions with display screen equipment. Contact lenses in many cases of refractive errors can be an alternative to prescription glasses method of correcting the visual impairment. There are however many clinical conditions, in which contact lenses can provide a better corrective effect on visual acuity. The information contained in medical databases of articles and scientific journals (PubMed, Biblioteka Nauki), online publications (Lippincott Journals), books, applicable legal regulations (available in Internetowy System Aktów Prawnych) and guidelines published by organizations and associations (Nofer Institute of Occupational Medicine in Lódz, Occupational Safety and Health Administration, Tear Film & Ocular Surface Society) were analyzed, covering the discussed issues over the years 2000-2023. Non-correction or suboptimal correction of a refractive error can cause a wide variety of troublesome symptoms, such as eye pain, headache, double vision, balance disorders, nausea, disturbances in the perception of the surroundings, contributing to poorer work efficiency, faster fatigue or an increased risk of error. This article, which is a narrative review, aims to present these conditions, as well as provide a brief overview of the types of contact lenses used, complications that may result from their use and contraindications to the use of this type of correction. Med Pr Work Health Saf. 2024;75(4):383-390.

Asunto(s)

RESUMEN

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.

RESUMEN

Recent advancements in cataract surgery have broadened its scope from mere vision restoration to include correction of refractive errors and presbyopia. This evolution has introduced multifocal and extended depth-of-focus (EDOF) intraocular lenses (IOLs), allowing enhanced vision across multiple distances. However, the influence of these advanced IOLs on stereopsis remains controversial. Factors influencing stereopsis after surgery include visual acuity, interocular differences, residual astigmatism, and the type of IOL, etc. Binocular vision integration and neuroadaptation further affect stereopsis, especially in cases of presbyopia-correcting IOLs. It is widely acknowledged that bilateral implantation of presbyopia-correcting IOLs yield superior stereopsis compared to unilateral implantation. However, there remains no consensus on whether binocular implantation of multifocal or monofocal IOLs provides superior stereopsis. Most studies suggest no significant difference in stereopsis between these two types of implants. Among different types of multifocal IOLs, refractive multifocal IOLs may offer better stereopsis than diffractive multifocal IOLs when implanted bilaterally. Emerging EDOF and hybrid multifocal-EDOF IOLs also demonstrate promising postoperative stereopsis. Additionally, a mix-and-match strategy with different types of IOLs implanted in each eye may result in interocular differences in visual acuity at certain distances, potentially affecting stereopsis. Nevertheless, with appropriate selection, most patients can achieve satisfactory postoperative stereopsis. This review synthesizes current literature on the effects of presbyopia-correcting IOLs on postoperative stereopsis recovery following cataract surgery. Studies on stereopsis outcomes with different IOLs have yielded mixed results, urging further investigation for optimized surgical strategies and patient outcomes.

RESUMEN

[This corrects the article DOI: 10.3389/fnins.2024.1349436.].

RESUMEN

OBJECTIVE: This systematic review and meta-analysis aims to assess the refractive outcomes of the Yamane technique for intrascleral fixation of intraocular lenses (SF-IOL) and compare the predictive ability of the various intraocular lens power calculation formulae commonly used in conjunction with the technique. METHODS: A literature search was conducted in the Medline, Scopus, and Cochrane Library databases for articles published from January 2014 to May 2023. Studies that met the predetermined inclusion criteria were included and subjected to analysis. The primary outcome evaluated was the refractive predictive error, defined as the difference between predicted refraction and post-operative manifest refraction. RESULTS: Eleven studies met the inclusion criteria, with a cumulative sample size of 615 patients (mean age: 66.6 years). Various IOL formulae were used, with SRK/T being the most frequently adopted formula. The overall mean refractive predictive error for all formulae combined was -0.02 D, which was not statistically significant (p = 0.99). Subgroup analysis for individual formulae also showed no significant difference from predicted error for any formula (p > 0.05). CONCLUSION: The Yamane technique for SF-IOL shows promising refractive outcomes, and the choice of IOL power calculation formula should be tailored based on patient characteristics and surgeon preference. No formula demonstrated superior predictive ability over others. Further research is needed to develop formulae specifically for eyes with secondary aphakia and poor capsular support.

RESUMEN

PURPOSE: Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered gold standard in the treatment of posterior capsule opacification (PCO). In this laboratory study, we measured spectral transmission to evaluate the image contrast and analyze the impact of Nd:YAG associated defects in presbyopia-correcting intraocular lenses (IOLs). METHODS: Two hydrophobic, acrylic IOLs as classic multifocal lenses with diffractive ring segments and different amount of near addition (A, B), one hydrophilic, trifocal IOL (C), one sector-shaped, plate haptic IOL (D) and one hydrophobic, enhanced depth of focus (EDOF) IOL (E) were studied. Measurements included surface topography characterization, United States Air Force resolution test chart (USAF) analysis, spectral transmittance measurements and through focus contrast measurement. Measurements were done with unaltered samples, damages (n = 7) were intentionally created in the central 3.5 mm zone using a photodisruption laser (2.0 mJ) and measurements were repeated. RESULTS: Significant differences were shown between unmodified samples and samples with YAG pits. The YAG-pits decreased the image contrast and spectral transmission and changed results of USAF test images. The imaging contrast decreased to 66%, 64%, 60%, 52% and 59% with the YAG shots in samples (A-E). The light transmission decreased to 88%, 87%, 92%, 79% and 91% (A-E) on average between 400 nm to 800 nm. In all IOLs a reduction of the relative intensity of transmitted light was observed. CONCLUSION: The image performance of all tested presbyopia-correcting IOLs is significantly influenced and disturbed by YAG-pits. The intensity of transmitted light is reduced in the wavelength between 450-800 nm. USAF test targets show worse results compared to unmodified samples and contrast is significantly deteriorated. No ranking/rating among tested IOLs should be made as many other factors play a role in real world scenario. High care should be taken when performing Nd:YAG capsulotomy on premium IOLs to avoid any damages.