Correction Of Refractive Errors Research Articles

Chinese expert consensus on the perioperative medication in laser corneal refractive surgery (2024)

With the increasing incidence of myopia year by year and the continuous progress of various treatment techniques, laser corneal refractive surgery has become one of the important ways to correct refractive errors. The rational drug use in the perioperative period is important for the success of surgery and reduction of complications. In 2019, based on the development of laser corneal refractive surgery in China, experts from the Refractive Surgery Experts Group of Ocular Microcirculation Branch of Chinese Society of Microcirculation and the Ophthalmology Branch in the Chinese Medical Association formed the "Chinese Expert Consensus on the Perioperative Medication in Laser Corneal Refractive Surgery (2019)". To further promote the expansion of new clinical technologies and surgical methods, and to improve surgical efficacy, the Refractive Surgery Experts Group of Ocular Microcirculation Branch of Chinese Society of Microcirculation, according to the latest domestic and foreign research results, has recently updated the consensus after a collective discussion.

Stereopsis Following Implantation of Presbyopia-Correcting Intraocular Lenses: A Narrative Review.

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.

Investigation of current guidelines for prescribing spectacles to children using a modified Delphi approach and the AGREE II tool.

This study aimed to identify clinical guidelines that provide recommendations on prescribing refractive error correction in children, evaluate the overall quality of these guidelines using the Appraisal of Guidelines for REsearch and Evaluation II (AGREE II) tool and subsequently gain consensus on the prescribing recommendations from high-quality guidelines using the modified Delphi technique. A comprehensive search for prescribing guidelines was conducted using databases and professional websites. The quality appraisal of eligible guidelines was undertaken by scoring the six AGREE II domains. Subsequently, the modified Delphi technique was used by 10 experts (sub-specialist optometrists, ophthalmologists and orthoptists) to gain consensus on the prescribing recommendation statements extracted from guidelines that had been identified as high quality. Three rounds were conducted in which agreement of these statements were scored using a 9-point Likert scale with a free-text option for any additional comments. Five eligible guidelines were identified. The AGREE II tool demonstrated that the guidelines varied substantially in quality, with only one guideline identified as being of high quality. A total of 168 prescribing statements were reviewed in the Delphi procedure. Of these, 95 statements reached expert consensus as being appropriate prescribing recommendations. There is significant scope for improving current guidelines for prescribing refractive error correction in children. We used the modified Delphi technique to find points of agreement on prescribing recommendations to support professionals prescribing refractive error correction in children. We recommend that further work is needed to address gaps in the guidelines.

Safety and Effectiveness of Smooth Incision Lenticular Keratomileusis (SILK™) Using the ELITA™ Femtosecond Laser System for Correction of Myopic and Astigmatic Refractive Errors [Letter

Safety and Effectiveness of Smooth Incision Lenticular Keratomileusis (SILK™) Using the ELITA™ Femtosecond Laser System for Correction of Myopic and Astigmatic Refractive Errors [Letter

Analysis of Treatment Discontinuation in Orthokeratology: Studying Efficacy, Safety, and Patient Adherence Over Six Months.

This study aimed to evaluate the efficacy, safety, and participant compliance of orthokeratology treatment for the correction of myopic refractive errors over a six-month prospective study and to define the potential reasons for early treatment discontinuation. A total of 32 participants with low-to-moderate myopia were fitted with the spherical model of corneal refractive therapy (CRT) orthokeratology lenses (Paragon Vision Sciences) and followed over six months, with specific attention to alterations in refractive error, corneal topography, and epithelial thickness. Concurrently, participant feedback and reasons for any treatment discontinuation were documented. Significant changes in refractive error and in corneal topography were observed, with approximately 50% of the refractive error being corrected on the first night of use and 100% by the first two weeks (P<0.001). Central epithelial thickness experienced substantial thinning, reducing to 15.65±4.49 μm (67.38%) (P<0.001) after 6 months of lens use. Six participants withdrew from this study for varied reasons, including unmet visual expectations and difficulty adhering to the lens-wearing regimen. Notably, the dropout group exhibited higher baseline low-order aberrations and less prolate corneas than those who persisted with the treatment (P<0.05). Orthokeratology with CRT is efficacious and safe for the correction of low-to-moderate myopia in adults, but a portion of patients discontinue the treatment in the first 6 months of contact lens wear. Special care should be taken when recommending orthokeratology in patients with higher levels of myopia and corneas with less prolate shape, providing more realistic expectations and even changing to dual axis or more sophisticated designs.

Approaches for delivery of refractive and optical care services in community and primary care settings.

Uncorrected refractive error is a leading cause of vision impairment which, in most cases, can be managed with the appropriate spectacle correction. In 2021, the World Health Assembly endorsed a global target of a 40-percentage-point increase in effective coverage of refractive error by 2030. To achieve this global target, equitable access to refractive and optical services within community and primary care settings needs to be strengthened. This review will inform the development of technical guidance to support improvements in the testing and correction of refractive error among World Health Organization (WHO) member states. To determine the range of approaches for delivery of refractive and optical care services in community and primary care settings, and the methods employed for their evaluation. We searched CENTRAL, MEDLINE, Embase and Global Health databases, grey literature, and annual reports and websites of relevant organizations involved in eye-care delivery from January 2002 to November 2022 to identify approaches for refractive and optical service delivery. We included observational and interventional studies, reviews, and reports from relevant organizations related to delivering refractive services and optical services for preschool and school-aged children and adults in community and primary care settings published between January 2002 and November 2022. We searched for studies and reports published within the last 20 years because vision impairment due to uncorrected refractive error has only recently become a public health and eye health priority, therefore we did not expect to find much relevant literature until after 2002. Two review authors screened titles, abstracts and full texts, and extracted data. We resolved any discrepancies through discussion. We synthesized data, and presented results as tables, figures, and case studies. This project was led by the World Health Organization (WHO) Vision and Eye Care Programme. We identified 175 studies from searches of databases and grey literature, 146 records from company reports, and 81 records from website searches of relevant organizations that matched our inclusion criteria. Delivery approaches for refractive and optical services in community care included school-based, pharmacy, and outreach models, whereas primary care approaches comprised vision centre, health centre, and a combination of vision or health centre and door-to-door delivery. In community care, school-based and outreach approaches were predominant, while in primary care, a vision-centre approach was mainly used. In the WHO African region, the school-based and outreach approaches were mainly reported while, in the Americas, the outreach approach was mostly used. Very few approaches for service delivery were reported in the WHO Eastern Mediterranean region. Prominent gaps exist in the evaluation of the approaches, and few studies attempted to evaluate the approaches for delivery of refractive and optical care services. We comprehensively describe a range of approaches for delivery of refractive and optical services in community and primary care. Further evaluation of their effectiveness will better inform the application of these service-delivery approaches. The study outcomes will help guide WHO member states in strengthening refractive and optical services at community and primary care levels. This scoping review was supported by the Vision and Eye care Programme, World Health Organization and ATscale Global Partnership. The protocol of this scoping review was published in the Open Source Framework.

Second harmonic generation microscopy of electromechanical reshaping on corneal collagen

Refractive errors remain a global health concern, as a large proportion of the world's population is myopic. Current ablative approaches are costly, not without risks, and not all patients are candidates for these procedures. Electromechanical reshaping (EMR) has been explored as a viable cost-effective modality to directly shape tissues, including cartilage. In this study, stromal collagen structure and fibril orientation was examined before and after EMR with second-harmonic generation microscopy (SHG), a nonlinear multiphoton imaging method that has previously been used to study native corneal collagen with high spatial resolution. EMR, using a milled metal contact lens and potentiostat, was performed on the corneas of five extracted rabbit globes. SHG was performed using a confocal microscopy system and all images underwent collagen fibril orientation analysis. The collagen SHG signal in controls is uniform and is similarly seen in samples treated with pulsed potential, while continuous EMR specimens have reduced, nonhomogeneous signal. Collagen fibril orientation in native tissue demonstrates a broad distribution with suggestion of another peak evolving, while with EMR treated eyes a bimodal characteristic becomes readily evident. Pulsed EMR may be a means to correct refractive errors, as when comparing its SHG signal to negative control, preservation of collagen structures with little to no damage is observed. From collagen fiber orientation analysis, it can be inferred that simple DC application alters the structure of collagen. Future studies will involve histological assessment of these layers and multi-modal imaging analysis of dosimetry.

Prevalence of visual impairment and estimation of refractive errors among school children in Kakamega, Kenya.

To investigate the prevalence of visual impairment (VI) and provide an estimation of uncorrected refractive errors in school-aged children, conducted by optometry students as a community service. The study was cross-sectional. Totally 3343 participants were included in the study. The initial examination involved assessing the uncorrected distance visual acuity (UDVA) and visual acuity (VA) while using a +2.00 D lens. The inclusion criteria for a subsequent comprehensive cycloplegic eye examination, performed by an optometrist, were as follows: a UDVA<0.6 decimal (0.20 logMAR) and/or a VA with +2.00 D ≥0.8 decimal (0.96 logMAR). The sample had a mean age of 10.92±2.13y (range 4 to 17y), and 51.3% of the children were female (n=1715). The majority of the children (89.7%) fell within the age range of 8 to 14y. Among the ethnic groups, the highest representation was from the Luhya group (60.6%) followed by Luo (20.4%). Mean logMAR UDVA choosing the best eye for each student was 0.29±0.17 (range 1.70 to 0.22). Out of the total, 246 participants (7.4%) had a full eye examination. The estimated prevalence of myopia (defined as spherical equivalent ≤-0.5 D) was found to be 1.45% of the total sample. While around 0.18% of the total sample had hyperopia value exceeding +1.75 D. Refractive astigmatism (cil<-0.75 D) was found in 0.21% (7/3343) of the children. The VI prevalence was 1.26% of the total sample. Among our cases of VI, 76.2% could be attributed to uncorrected refractive error. Amblyopia was detected in 0.66% (22/3343) of the screened children. There was no statistically significant correlation observed between age or gender and refractive values. The primary cause of VI is determined to be uncorrected refractive errors, with myopia being the most prevalent refractive error observed. These findings underscore the significance of early identification and correction of refractive errors in school-aged children as a means to alleviate the impact of VI.

Creation of a Corneal Flap for Laser In Situ Keratomileusis Using a Three-Dimensional Femtosecond Laser Cut: Clinical and Optical Coherence Tomography Features

Laser in situ keratomileusis (LASIK) is the most frequently used technique for the surgical correction of refractive errors on the cornea. It entails the creation of a superficial hinged corneal flap using a femtosecond laser, ablation of the underlying stromal bed using an excimer laser, and repositioning of the flap. A corneal flap with an angled side cut reduces the risk of flap dislocation and infiltration of epithelial cells and confers unique biomechanical properties to the cornea. A new laser software creating three-dimensional (3D) flaps using a custom angle side cut was retrospectively evaluated, comparing optical coherence tomography 3D (with intended 90° side cut) and 2D flaps (with tapered side cuts) as well as respective intra- and early postoperative complications. Four hundred consecutive eyes were included, two hundred for each group. In the 3D group, the mean edge angle was 92°, and the procedure was on average 5.2 s slower (p = 0). Non-visually significant flap folds were found in thirteen eyes of the 2D group and in seven eyes of the 3D group (p = 0.17). In conclusion, the creation of a LASIK flap using a 3D femtosecond laser cut, although slightly slower, was safe and effective. The side cut angle was predictable and accurate.

Surgical options and clinical outcomes for high myopia.

Higher degrees of myopia are currently being treated with refractive surgery. However, there is limited characterization and outcomes data for this cohort. This article aims to review the literature on highly myopic patients who had refractive surgery and present a retrospective analysis of 149 patients (270 eyes) with high to extreme myopia (≤-5.0D SE) who underwent refractive surgery [laser-assisted subepithelial keratomileusis (LASIK), photorefractive keratectomy (PRK), or implantable collamer lense (ICL)] at a single practice. There is substantial literature on the efficacy of LASIK, PRK, and phakic intraocular lenses for refractive error correction, but a dearth of studies on patients with high to extreme myopia undergoing different types of refractive surgery. Our study reveals that this cohort of patients has excellent outcomes with minimal complications. Our study reveals that the average preoperative myopia was highest in ICL patients (-10.03D), followed by PRK (-7.21D), and LASIK (-7.04D) patients. Not surprisingly, eyes with high myopia and thin corneas were offered and elected ICLs for their procedure. Highly myopic patients achieved outcomes consistent with data reported in the literature- average postoperative uncorrected visual acuity was 20/20 for LASIK and ICL eyes and 20/25 for PRK eyes.

Ten-year follow-up of posterior chamber phakic intraocular lens with central port design in patients with low and normal vault.

To assess the clinical outcomes and postoperative complications of the implantable collamer lens (ICL) with a central port throughout 10 years of follow-up in patients with low and normal vault. Fernández-Vega Ophthalmological Institute, Oviedo, Spain. Retrospective and comparative case series. This study included eyes that underwent a V4c ICL implantation with 10 years of follow-up. The eyes were divided into 2 groups according to the vault at 1 year postoperatively: vault <250 μm and between 250 μm and 800 μm. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), intraocular pressure (IOP), endothelial cell density (ECD), vault, complications, and secondary surgeries were analyzed. 37 and 90 eyes were enrolled in the low and normal-vault groups, respectively. No differences in UDVA, CDVA, and refraction were found between the groups over 10 years of follow-up. No cases developed ICL-induced anterior subcapsular opacity over the follow-up period. 2 (5.4%) and 8 (8.9%) eyes in the low and normal-vault groups, respectively, required ICL exchange. 1 (2.8%) and 2 (2.2%) eyes in the low and normal-vault groups, respectively, required excimer laser to correct residual refractive error. The IOP remained stable throughout the 10-year follow-up. The loss in ECD from that preoperatively to 10 years postoperatively was 3.8% and 4.5% in the low and normal-vault groups, respectively ( P = .4). No pigment dispersion glaucoma or other vision-threatening complications were reported. This study shows good long-term outcomes of the V4c ICL, supporting that the central hole provides safety to the procedure and prevents the potential risk associated with low vault.

Femtosecond laser-assisted in situ keratomileusis versus small-incision lenticule extraction: current approach based on evidence.

Laser keratorefractive surgery achieves excellent visual outcomes for refractive error correction. With femtosecond laser, small incision lenticule extraction (SMILE) is an increasingly viable alternative to laser-assisted in situ keratomileusis (LASIK). Comparative studies demonstrate similar efficacy and predictability between SMILE and LASIK, making it difficult for clinicians to choose which to use. This review thus compares femtosecond-LASIK (FS-LASK) and SMILE in various scenarios, to assist clinicians in deciding which refractive surgery procedure to recommend. SMILE may be superior for highly myopic eyes due to a smaller decrease in functional optical zone. SMILE further induces less spherical aberration and less overall higher order aberrations in mesopic conditions. SMIILE also has less postoperative dry eye, making it suitable those with preexisting dry eye. For low to moderate myopic astigmatism correction, FS-LASIK has less undercorrection compared to SMILE. Lastly, SMILE has not yet received Food and Drug Administration or Conformité Européenne approval for hyperopic correction, rendering FS-LASIK the choice of procedure for hyperopic correction. Both FS-LASIK and SMILE demonstrate good efficacy and predictability. Understanding specific clinical scenarios where one may be superior to the other will aid clinicians in choosing the most suitable procedure for personalized care.

Femtosecond thin-flap laser assisted in situ keratomileusis for correction of post-penetrating keratoplasty ametropia: long-term outcome

PurposeTo evaluate the long-term clinical outcomes of femtosecond thin-flap LASIK (femto-LASIK) for correction of refractive error after penetrating keratoplasty in keratoconus-affected eyes.Settinga private ophthalmology clinic.DesignProspective interventional case series.MethodsThis prospective interventional case series enrolled 22 eyes of 22 patients who underwent femto-LASIK for the management of post-penetrating keratoplasty ametropia. The refractive error, uncorrected (UDVA), and corrected (CDVA) distance visual acuities and vector analysis were reported in short-term and long-term period after surgery.ResultsThe mean age was 32.7 ± 7.5 years (range, 23 to 47 years) at the surgery time. The average time between PK and femto-LASIK was 42.5 ± 31.7 months. The average follow-up duration after femto-LASIK was 81.2 ± 18.6 months. The mean preoperative UDVA significantly improved from 0.47 ± 0.15 logMAR to 0.35 ± 0.14 logMAR at 12 months (P = 0.048) and 0.4 ± 0.17 at final follow-up exam (P = 0.007). CDVA was 0.22 ± 0.1 at baseline which improved to 0.18 ± 0.15 and 0.15 ± 0.1 logMAR at 12 and 81 months, respectively. (Ps = 0.027, 0.014). The mean cylinder before surgery was − 5.04 ± 1.4D which significantly decreased to -1.5 ± 0.8 D at 12 months postoperatively. (P < 0.001). There was a significant increase in refractive astigmatism from 12 months to 81 months postoperatively (-3.1 ± 2.0, P = 0.002). At the final visit, the efficacy index was 0.83, and the safety index was 1.16.ConclusionsDespite the short-term outcome indicated that femo-LASIK was effective for correction of post-keratoplasty ametropia during short-term period, a notable regression in its effect was observed in the long-term follow-up. Therefore, the predictability of this technique might decrease in the long-term.

Refractive Lens Exchange after Implanted Collamer Lens: A Case Report

Introduction: Myopia stands as a prevalent ametropic condition. Posing ongoing challenges for ophthalmologists. Surgery to correct refractive errors is a primary intervention for severe myopia, encompassing procedures like the removal of the crystalline lens coupled with the placement of an intraocular lens (IOL), and the insertion of phakic IOL. The Implantable Collamer Lens (ICL) is commonly utilized in the posterior chamber but carries potential risks including the disruption of the eye’s normal function, potentially leading to conditions like cataracts and glaucoma. Methods and Purpose: This case report explains a single case patient with ICL that includes previous clinical condition, current condition, steps of surgical procedure, and follow-up after procedure. Case Illustration: We present the case of a 66-year-old male patient who came to the hospital for refractive surgery due to a cataract with a history of implantable collamer lens (ICL) for high myopia. Cataract surgery was performed after an explanation of the ICL followed by an implanted capsular tension ring (CTR) and IOL. Discussion: Several cases of patients using ICL will have complications such as glaucoma and cataracts. Determining ICL design will influence the progression of these complications. An explanation procedure by tuck and pull method is needed for age-related cataract patients. Conclusion: ICL is a safe procedure for high myopia patients. Explanation of ICL can be performed by several medical conditions.

IJCM_230A: Obstacles Faced by Medical Undergraduates Wearing Spectacles In A Medical College In Mangalore

Background: Spectacle compliance is vital among the young population to combat visual impairment arising from untreated refractive errors. Encouraging spectacle use is crucial, despite the challenges they present, such as fogging, scratches, and discomfort when prescribed wrong Objectives: 1. To study the obstacles faced by medical undergraduates while using spectacles. 2. To find out the various factors associated with the obstacles faced by undergraduates while wearing spectacles. Methodology: The study protocol was submitted for the approval from the Institutional Ethics Committee (IEC) of Kasturba Medical College, Mangalore. After obtaining the approval from ethics committee, permission was obtained from the Dean of Kasturba Medical College, Mangalore and data collection was done after receiving informed consent from the participants. A semi- structured questionnaire was distributed to the participants Results: 72.7% faced obstacle of dependency on spectacles and 71.5% faced difficulty of adjusting spectacles with gloved hands. · Out of 60(34.9%) study participants who ride two-wheeler, 21(35%) participants faced difficulties while riding due to spectacle use and wearing helmet(42.8%), glaring(19.1%) and fogging(14.2%) were the major difficulties faced. · Among 54(32%) study participants who drive 4-wheeler, 9(16.6%) participants faced difficulties while driving due to spectacle use and the major difficulties encountered were glaring(55.5%) and restricted field of vision(22.2%). · A statistically significant association with P value of 0.001 was established between duration of spectacle usage and dependency on spectacles Conclusion: Based on our study, we have found that most of the participants have been using spectacles for 1-10 years mainly for correction of refractive errors like myopia and thus use spectacles throughout the day.

Awareness and Knowledge About RefractiveSurgery Among Medical Students in Baghdad

Purpose: Refractive error represents a common eye disorder that can significantly impact an individual's visual function and overall well-being. There are several methods of correcting refractive errors and objective of this study was to assess the awareness of refractive surgery and the preferred methods of refractive error correction among medical students in Baghdad. Study Design: Cross sectional survey. Place and Duration of Study: University of Baghdad Al-Kindy College of Medicinefrom November 2022 to March 2023. Methods: Medical students from six Baghdad medical colleges with total sample size of 350 were included. Students who had undergone refractive surgeries and fifth and sixth year medical students were also excluded. Level of knowledge was categorized as; &lt;50% (0-5) poor knowledge, 50-70% (6-8) moderate knowledge and &gt;70% (9-12) good knowledge. Results: Among the students with refractive errors, 82% had knowledge about their refractive error. Forty percent had myopia, 12% had astigmatism, 15 % had myopia and astigmatism, 10% had hyperopia, 5% had hyperopia and astigmatism. Among them 57.8% were not willing to undergo refractive surgery due to fear of complications. Forty eight percent had poor knowledge,43.1% had moderate and only 8.26% had a good knowledge of refractive surgeries. The majority preferred eyeglasses (82.6%) followed by both eyeglasses and contact lenses. Conclusion: Students had good awareness about refractive surgery but their familiarity and knowledge about it remained poor because of complications. An overwhelming majority of students still preferred spectacles as the method for vision correction.

Physiological Changes in the Cornea When Wearing Rigid Gas Permeable Contact Lenses

Rigid gas permeable (RGP) contact lenses are made of materials with excellent oxygen permeability and wettability, so they not only improve oxygen permeability compared to existing lenses, but also provide correction of refractive errors and improved vision in irregular corneas such as keratoconus. However, the hard material of the lens along with hypoxia and hypercapnia of the cornea caused by wearing RGP contact lenses cause various physiological changes in the cornea. Physiological changes in the cornea that may occur when wearing RGP contact lenses include mucin balls, decreased corneal epithelial thickness and increased size, decreased epithelial barrier function, corneal erosion and staining, decreased keratocyte density, decreased corneal sensitivity, and stromal opacities, contact lens‐induced peripheral ulcers, endothelial blebs, increased endothelial polymegethism, and changes in corneal shape. It is necessary to know the performance of the RGP contact lenses being prescribed, be aware of the physiological changes in the cornea caused by wearing RGP contact lenses, and provide the correct lens prescription along with appropriate education to the patient.

Низкоэнергетическая лентикулярная лазерная хирургия в коррекции миопии

Purpose. To improve the efficiency and safety of SMILE-type lenticular surgery procedure in correction of different degrees myopia based on the use of low-energy laser parameters. Material and methods. This study includes a comparative analysis of data from 193 patients (288 eyes) operated for different degrees myopia including a number of cases with myopic astigmatism using SMILE technology with different FSL energy levels from 130 to 150 nJ. The parameters were analyzed on the 1st day and after 1 week, 1 month, 3, 6 and 12 months after surgery with assessment of NCVA, quality of life (QIRC questionnaire), general corneal wavefront aberrations (RMS), densitometry and pachymetry. Results. According to visometry, quality of life assessment, RMS, densitometry and pachymetry, the best functional results were obtained in subgroups with mild and moderate myopia on the 1st day after SMILE using an energy level in the range of 130 nJ. And in subgroups with a high degree of myopia, when using an energy level in the range of 140 nJ, no direct effect of energy on other indicators was found. Conclusion. According to the results of the study, it was found that the correction of myopic refractive error using the SMILE technology with a FSL energy level in the range of 130–140 nJ in its effectiveness on the 1st day after surgery exceeds the previously used energy levels (150 nJ) in terms of the quality of restoration of visual functions and does not have a negative effect on other parameters of the cornea. Key words: myopia, lenticular surgery, femtosecond laser energy, SMILE

Relationship Between Personality Traits and Perceived Pain After Photorefractive Keratectomy: A Cross-Sectional Study in Hamadan

Background: Photorefractive keratectomy (PRK) is a common procedure to correct refractive errors. However, postoperative pain is one of the most common drawbacks of PRK. Evidence shows that individual`s personality traits could impact postoperative perceived pain. Hence, this study aimed to investigate the severity of postoperative pain and personality traits after PRK.Materials and Methods: This cross-sectional study was performed on 300 patients who attended to Mahdieh Surgical Clinic (Hamadan, Iran) and underwent PRK. Persian version of the NEO Five-Factor Inventory (NEO-FFI) was applied to assess personality traits, and postoperative pain was measured using the visual analog scale (VAS) score.Results: The mean age of patients was 31.8 ±5.51 years, and most (68%) were female. The most common personality trait was neuroticism, and the mean refractive errors of the right and left eyes of the patients were 1.2±2.67 and 1.3±2.75, respectively. Regarding the VAS score, patients with neuroticism traits perceived the most severe postoperative pain (VAS=6±2.2). Also, the Pearson correlation test indicated a positive correlation between perceived pain and neuroticism personality traits (r=0.059, P˂0.001). In contrast, a significant negative correlation was observed between extraversion and conscientiousness with pain perception (r= -0.737 and r= -0.307, respectively).Conclusion: Our findings showed a positive and significant correlation between three personality traits and pain perception in these patients. Postoperative pain perception in patients undergoing PRK depends on the personality traits of these patients. Groups with less personality stability feel more pain than groups with stable personalities.

Unregulated Decorative Lenses: A Brief Definitive Review.

Contact lenses are US Food and Drug Administration-regulated medical devices that are a safe and effective method for the correction of refractive error. They are worn by an estimated 45 million Americans. Decorative contact lenses (DCLs) can be used for patients with medical conditions such as failed corneas or aniridia. However, DCLs have also gained popularity in the young, contact lens-naïve population. DCL users often buy lenses through unregulated sources without a clinical examination and education on proper use by an eye care professional. These lenses have a significantly higher risk of infection when compared with contact lenses for the correction of refractive error. To reduce the incidence of microbial keratitis, regulators and eye care professionals must make coordinated efforts to generate and disseminate prevention messages to all contact lens users. In addition, physician and patient reporting of contact lens-related complications to regulatory agencies enhances the pathway to risk reduction. This article reviews DCL use and supply, with a specific focus on the increased risk of contact lens-related complications in unsupervised DCL use.