Post-refractive Surgery Research Articles

Efficacy of gabapentin and pregabalin for treatment of post refractive surgery pain: a systematic review and meta-analysis.

For ophthalmic patients, eye discomfort is a major problem that requires efficient pain treatment techniques. Pregabalin and gabapentin have surfaced as viable treatments for post-refractive surgery pain. To manage pain after refractive surgery, gabapentin and pregabalin were evaluated in this systematic review and meta-analysis. A thorough search of databases including PubMed, Embase, Cochrane Library, and CINAHL was performed until March 2024. Inclusion criteria were randomized controlled trials assessing pregabalin and/or gabapentin's effectiveness in treating pain post-PRK, LASIK, and LASEK surgeries. Six studies met inclusion criteria, comprising a total of 391 patients undergoing various corneal surgeries. The meta-analysis revealed that pregabalin was significantly more effective than placebo in reducing pain on the first and second postoperative days (SMD day 1: -0.32, 95% CI -0.54, -0.09; SMD day 2: -0.55, 95% CI -0.85, -0.25), while gabapentin showed significant pain reduction on the second day only (SMD day 2: -0.42, 95% CI -0.71, -0.13). Combined analysis for both medications showed significant pain reduction on the first- and second-days post-surgery. No significant increase in adverse events was associated with either medication. Publication bias was minimal except for a slight asymmetry noted on day 1 effectiveness. Pregabalin and gabapentin are effective in reducing postoperative pain following refractive surgeries, with pregabalin showing a greater effect. Both medications are safe, with no significant increase in adverse events. Further research with standardized methodologies and long-term follow-up is recommended to optimize postoperative pain management in ocular surgeries.

Lens Factor Choice in IOL Power Calculation after Laser Refractive Surgery: The Right Constant for Advanced Lens Measurement Approach (ALMA).

Background/Objectives: To evaluate the advanced lens measurement approach (ALMA) formula accuracy using different lens constants available on the user group for laser interference biometry (ULIB) and IOL Con platforms. Methods: In this retrospective, comparative, case-series study, 150 eyes of 160 patients with previous myopic Photorefractive Keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK), who underwent uneventful cataract surgery and IOL implantation, were examined. The ALMA formula was evaluated to calculate the refractive prediction error (PE), analysing four different categories of lens constants: both nominal and optimized A-Constant for SRKT, which are available on the ULIB and IOL Con platforms. An additional analysis was carried out in this study, evaluating if a decreased ULIB optimized constant (DUOC) with different fixed factors (-1.2 -1.3 -1.4 -1.5) could improve refractive outcomes. Median absolute error (MedAE) and percentage of eyes within ±0.50 and ±1.00 diopters (D) of prediction error were measured as the main outcomes. Results: Comparing the lens factors available on ULIB and IOL Con platforms, the ALMA formula reported a lower MedAE and higher percentages of eyes with a refractive PE within 1.0 D using ULIB nominal constants (all p < 0.05). Using DUOC (-1.3), and there was a statistically significant improvement of both MedAE and of the percentages of eyes with PE within ±0.50 D with the ALMA method compared to nominal ULIB constants (all p < 0.05). Conclusions: The impact of different lens factors in the IOL power calculation after myopic LRS should be carefully evaluated. The ALMA formula, in the absence of optimized constants by zeroing the mean error, should be used by subtracting 1.3 from the optimized ULIB constants available on the IOL Con website. This finding suggests further studies to test which of these constants could work better with the other post-refractive surgery formulas.

The role of corneal epithelial thickness in ocular surface health

Abstract The corneal epithelium (CE), which is made up of five to seven layers, is crucial for maintaining the integrity of the cornea and the health of the ocular surface. The present review delves into the importance of corneal epithelial thickness (CET) in the identification and treatment of a range of ocular surface diseases (OSDs), such as keratoconus (KCN), dry eye disease (DED), and the aftermath of refractive procedures. Spectral-domain optical coherence tomography (SD-OCT) can be used to provide reliable and precise CET values, providing valuable insights into epithelial remodeling patterns and their correlation with disease severity. In DED, CE irregularities correlate with clinical symptoms, revealing a distinctive thinning pattern in the superior epithelium, especially in severe cases. This is attributed to mechanical friction from frequent blinking. Contrasting studies on overall CET in DED patients highlight the need for standardized assessment protocols. In KCN, epithelial thickness mapping (ETM) demonstrates specific thinning patterns, aiding in early detection and management. Postrefractive surgery, epithelial remodeling contributes to residual refractive errors, emphasizing the epithelium’s role in compensating for stromal irregularities. This review underscores the importance of CET analysis in clinical practice, advocating for the integration of advanced imaging technologies like SD-OCT. Understanding the dynamic changes in CET can enhance early diagnosis, guide surgical decisions, and improve treatment outcomes for various OSDs, ultimately contributing to better ocular health maintenance.

The association between elevated blood estradiol level and corneal ectasia in women.

This study aims to investigate the association between blood estradiol level and two different etiologies of corneal ectasia in premenopausal women. This is an observational case-control study with three groups of women. Group 1 included women with keratoconus. Group 2 included women with post refractive surgery ectasia (PRSE). Group 3 was the control group. Venous blood for the measurement of estradiol was collected in order to assess the relationship between estradiol levels and ectasia. Participant's age, regular cycle (yes/no) and oral contraceptive pills (OCP) use (yes/no) was also documented. We compared the differences in estradiol levels between the 3 groups. Logistic regression was used to detect variables' effect on participants' chance to ectasia. Ninety-six women were enrolled: 36 (37%), 29 (30%), and 31 (32%) in the keratoconus, PRSE, and control group, respectively. The mean age of the participants was 29.8 ± 3.2, 31.9 ± 2.6, and 30.7 ± 3.5 years, respectively (p = 0.04, between groups 1 and 2). Estradiol levels [pg/mL] were 38.0 ± 2.4, 43.4 ± 2.4, and 28.6 ± 3.9, respectively (p < 0.001, between any pair of groups). Two multivariate logistic regression models adjusted to age, regular cycle, and OCP use, indicated that higher blood estradiol levels were associated with an increased risk of ectasia (OR = 2.71 and 2.44, respectively; p < 0.001). Corneal ectasia may be associated with elevated blood estradiol levels. Estradiol measurements could be useful in women with keratoconus or in women who undergo refractive surgery.

Safety and Efficacy of Epithelium-Off Corneal Collagen Cross-Linking for the Treatment of Corneal Ectasia: A Report by the American Academy of Ophthalmology

To review the evidence on the safety and effectiveness of epithelium-off corneal collagen cross-linking (CXL) for the treatment of progressive corneal ectasia. A literature search of the PubMed database was most recently conducted in March 2024 with no date restrictions and limited to studies published in English. The search identified 359 citations that were reviewed in abstract form, and 43 of these were reviewed in full text. High-quality randomized clinical trials comparing epithelium-off CXL with conservative treatment in patients who have keratoconus (KCN) and post-refractive surgery ectasia were included. The panel deemed 6 articles to be of sufficient relevance for inclusion, and these were assessed for quality by the panel methodologist; 5 were rated level I, and 1 was rated level II. There were no level III studies. This analysis includes 6 prospective, randomized controlled trials that evaluated the use of epithelium-off CXL to treat progressive KCN (5 studies) and post-laser refractive surgery ectasia (1 study), with a mean postoperative follow-up of 2.4 years (range, 1-5 years). All studies showed a decreased progression rate in treated patients compared with controls. Improvement in the maximum keratometry (Kmax) value, corrected distance visual acuity (CDVA), and uncorrected distance visual acuity (UDVA) was observed in the treatment groups compared with control groups. A decrease in corneal thickness was observed in both groups but was greater in the CXL group. Complications were rare. Epithelium-off CXL is effective in reducing the progression of KCN and post-laser refractive surgery ectasia in most treated patients with an acceptable safety profile. Proprietary or commercial disclosure may be found after the references.

Post-refractive Surgery Dry Eye: A Systematic Review Exploring Pathophysiology, Risk Factors, and Novel Management Strategies.

Dry eye disease frequently manifests following corneal refractive procedures, significantly impacting patients' quality of life. This review systematically synthesizes current evidence on the pathophysiological mechanisms, risk factors, and therapeutic interventions for post-refractive surgery dry eye. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, a systematic review of literature published until August 2023 was conducted, focusing on post-refractive surgery dry eye. Eighteen relevant studies were identified through screening and eligibility assessment. A qualitative synthesis of outcomes was performed using narrative and thematic analysis methods. Surgically induced neurotrophic deficiency, stemming from nerve transection, triggers a cascade of events including apoptosis, inflammation, and lacrimal dysfunction, ultimately leading to tear film instability. Risk factors such as female gender, thyroid eye disease, meibomian gland dysfunction, higher ablation depths, and the use of LASIK over surface ablation exacerbate the condition. While conventional treatments like artificial tears provide temporary relief, emerging interventions such as nerve growth factors, matrix metalloproteinase inhibitors, serum eye drops, and specialized contact lenses show promise in promoting nerve regeneration and epithelial healing. Strategies such as customized ablation profiles, smaller optical zones, and nerve-sparing techniques like small incision lenticule extraction demonstrate potential advantages. A multifaceted therapeutic approach targeting neuroprotection, anti-inflammatory mechanisms, and tear film stabilization is imperative for effectively managing post-refractive surgery dry eye. Future research should focus on evaluating prognostic biomarkers, exploring precision medicine approaches, and investigating neuroprotective adjuvants to further enhance treatment outcomes.

Orthokeratology fitting in a Post LASIK Patients : A Case Report

Introduction : Refractive surgery patients may have residual refractive eror.. Orthokeratology (OK) lenses are a less common option for correcting refractive eror in post refractive surgery patients. This case discusses OK lens as an alternative to LASIK enhancement, patient selection and fitting.&#x0D; Case Illustration : A 34 years old male complaint of blurred vision in both eye . He presented to our clinic with a refraction in the right eye (RE) of S -2.50 cyl -1.25 x 90 and in the the left eye (LE) of S -2.5.00 cyl -1.00 x 80. He underwent bilateral LASIK surgery 10 years ago with recalled refraction of approximately –6.00D in both eyes. Following one week of lens wear, the residual refraction of RE ?1.50 ?0.50 x 90 and LE ?1.50 ?0.50 x 80. After one month,the refraction in RE ?1.00 ?0.50 x 90 and LE ?1.00 ?0.25 x 80. Following a six months, the refraction of RE was -1.00 cyl?0.25 x 90 and-1.00 cyl -0.25x 80 in the LE. He is well satisfied with the level of uncorrected vision throughout the day&#x0D; Discussion : OK lenses are could be an alternative to LASIK enhancement. The good candidate for post refractive surgery in OK, there were no significant corneal irregularity, BCVA 20/20, and K’s reading between 40-46. It is recommended to wait at least 1 year post Lasik before fitting OK lenses and the process may take longer due to oblate cornea.&#x0D; Conclusion : OK lenses are effective alternative to LASIK enhancement. Proper patients selection are vital to achieve a satisfied patient.

Efficacy of topical 0.05% cyclosporine A and 0.1% sodium hyaluronate in post-refractive surgery chronic dry eye patients with ocular pain

BackgroundThe management of post-refractive surgery dry eye disease (DED) can be challenging in clinical practice, and patients usually show an incomplete response to traditional artificial tears, especially when it is complicated with ocular pain. Therefore, we aim to investigate the efficacy of combined topical 0.05% cyclosporine A and 0.1% sodium hyaluronate treatment in post-refractive surgery DED patients with ocular pain unresponsive to traditional artificial tears.MethodsWe enrolled 30 patients with post-refractive surgery DED with ocular pain who were unresponsive to traditional artificial tears. Topical 0.05% cyclosporine A and 0.1% sodium hyaluronate were used for 3 months. They were evaluated at baseline and 1 and 3 months for dry eye and ocular pain symptoms and objective parameters, including Numerical Rating Scale (NRS), Neuropathic Pain Symptom Inventory modified for the Eye (NPSI-Eye), tear break-up time (TBUT), Schirmer I test (SIt), corneal fluorescein staining (CFS), corneal sensitivity, and corneal nerve morphology. In addition, tear levels of inflammatory cytokines and neuropeptides were measured using the Luminex assay.ResultsAfter 3 months of treatment, patients showed a statistically significant improvement in the ocular surface disease index (OSDI), TBUT, SIt, CFS, and corneal sensitivity (all P < 0.01) using linear mixed models. As for ocular pain parameters, the NRS and NPSI-Eye scores were significantly reduced (both P < 0.05) and positively correlated with the OSDI and CFS scores. Additionally, tear IL-1β, IL-6, and TNF-α levels were improved better than pre-treatment (P = 0.01, 0.03, 0.02, respectively).ConclusionIn patients with post-refractive surgery DED with ocular pain, combined topical 0.05% cyclosporine A and 0.1% sodium hyaluronate treatment improved tear film stability, dry eye discomfort, and ocular pain, effectively controlling ocular inflammation.Trial registrationRegistration number: NCT06043908.

Clinical associations of corneal neuromas with ocular surface diseases.

Corneal neuromas, also termed microneuromas, refer to microscopic, irregularly-shaped enlargements of terminal subbasal nerve endings at sites of nerve damage or injury. The formation of corneal neuromas results from damage to corneal nerves, such as following corneal pathology or corneal or intraocular surgeries. Initially, denervated areas of sensory nerve fibers become invaded by sprouts of intact sensory nerve fibers, and later injured axons regenerate and new sprouts called neuromas develop. In recent years, analysis of corneal nerve abnormalities including corneal neuromas which can be identified using in vivo confocal microscopy, a non-invasive imaging technique with microscopic resolution, has been used to evaluate corneal neuropathy and ocular surface dysfunction. Corneal neuromas have been shown to be associated with clinical symptoms of discomfort and dryness of eyes, and are a promising surrogate biomarker for ocular surface diseases, such as neuropathic corneal pain, dry eye disease, diabetic corneal neuropathy, neurotrophic keratopathy, Sjögren's syndrome, bullous keratopathy, post-refractive surgery, and others. In this review, we have summarized the current literature on the association between these ocular surface diseases and the presentation of corneal microneuromas, as well as elaborated on their pathogenesis, visualization via in vivo confocal microscopy, and utility in monitoring treatment efficacy. As current quantitative analysis on neuromas mainly relies on manual annotation and quantification, which is user-dependent and labor-intensive, future direction includes the development of artificial intelligence software to identify and quantify these potential imaging biomarkers in a more automated and sensitive manner, allowing it to be applied in clinical settings more efficiently. Combining imaging and molecular biomarkers may also help elucidate the associations between corneal neuromas and ocular surface diseases.

The influence of altitude on the differences between Goldmann tonometry and Pascal dynamic contour tonometry: An ecological meta-analysis.

A meta-analysis found that including atmospheric pressure as altitude in generalized linear models reveals higher differences between Goldmann tonometry and Pascal dynamic contour tonometry at higher altitudes, with the difference increasing in thinner corneas. To examine the difference in intraocular pressure (IOP) measurements by using Goldman applanation tonometry (GAT) and dynamic contour tonometer (DCT) tonometry in published literature and determine the influence of central corneal thickness (CCT), age, and altitude on that difference. Articles that compare GAT and DCT were selected for an extensive literature review, and the location and altitude of the research centers were found online. CCT and age were analyzed as covariates, when available. A total of 157 studies including 24,211 eyes of 20,214 patients were included in the study. The results showed that the difference between DCT and GAT was higher at higher altitudes above sea level and increased with thinner corneas. However, the results were different in eyes with corneal transplants, where altitude and CCT had less influence, and in those post-refractive surgery where age was found to influence the difference. Theoretical correction formulas using altitude, CCT, and age were derived from this meta-analysis, but their accuracy and usefulness in clinical practice need validation. The findings suggest that there is a higher risk of underestimating IOP when the Goldmann tonometer is used at a higher altitude, particularly in eyes with glaucoma, thinner corneas, or corneal refractive surgery. Further research is needed to validate the accuracy of the correction formulas derived from this meta-analysis in clinical practice.

Central Toxic Keratopathy After Collagen Cross-Linking: A Case Series.

The aim of this study was to report a case series of central toxic keratopathy (CTK) after collagen cross-linking (CXL) in keratoconus. This is a retrospective case series between January 2020 and September 2021. In this period, CXL was performed for progressive keratoconus in 964 eyes. CXL was performed using the epithelium-off accelerated protocol in all patients with a riboflavin soak time of 20 minutes and a UVA light exposure of 9 mW for 10 minutes using the Avedro KXL (Glaukos Inc, Aliso Viejo, CA) cross-linking system. Twelve of 964 eyes (1.2%) developed CTK within 1 week of CXL. All patients presented with well-circumscribed, central disciform haze that was broader in the anterior stroma and narrower in the posterior stroma. We noted initial flattening in keratometry up to 3 months post-CXL in these patients, which gradually steepened over 12 months, but did not reach preoperative levels. We also noted exuberant flattening in pachymetry in the first 3 months, which improved over 12 months. There was a statistically significant decrease in pachymetry in patients who developed CTK at 3 and 12 months postoperatively when compared to patients who underwent CXL but did not develop CTK. Several reports of CTK postrefractive surgery have been described previously. However, the association of CXL in the development of CTK has not been described previously. Here, we elucidated the clinical features of CTK after CXL and how it differs from corneal scarring or haze that occurs post-CXL.

Research progress on animal models of corneal epithelial-stromal injury.

A corneal epithelial-stromal defect is recognized as a major contributor to corneal scarring. Given the rising prevalence of blindness caused by corneal scarring, increasing attention has been focused on corneal epithelial-stromal defects. Currently, the etiology and pathogenesis of these defects remain inadequately understood, necessitating further investigation through experimental research. Various modeling methods exist both domestically and internationally, each with distinct adaptive conditions, advantages, and disadvantages. This review primarily aims to summarize the techniques used to establish optimal animal models of corneal epithelial-stromal injury, including mechanical modeling, chemical alkali burns, post-refractive surgery infections, and genetic engineering. The intention is to provide valuable insights for studying the mechanisms underlying corneal epithelial-stromal injury and the development of corresponding therapeutic interventions.

Tel-Aviv Protocol for Postrefractive Surgery Corneal Ectasia: A Case Series.

The aim of this study was to describe the safety and efficacy of the Tel-Aviv Protocol (epithelial photorefractive keratectomy and corneal cross-linking) as a treatment for postrefractive surgery corneal ectasia. This study includes 8 eyes from 7 patients, each diagnosed with postrefractive surgery ectasia years after refractive surgery and treated with the Tel-Aviv Protocol. The procedure included transepithelial PRK using the EX500 excimer laser, a 50-μm laser ablation of the epithelium and anterior stroma, delivered on the visual axis with cyclotorsion correction, treating up to 50% of refractive astigmatism. After the epithelial photorefractive keratectomy, all patients underwent corneal cross-linking. The mean keratometry (K) and maximal K both decreased [from 43.37 ± 2.23 to 41.84 ± 2.01 ( P = 0.03) and from 44.95 ± 3.08 to 42.78 ± 2.19 ( P = 0.03), respectively]. Astigmatism was significantly reduced (from 3.53 ± 2.36 to 0.88 ± 0.89 diopter; P = 0.02). Uncorrected visual acuity improved significantly in all patients from a mean of 0.56 ± 0.32 to 0.15 ± 0.14 logMAR ( P = 0.01). Best-corrected visual acuity improved from 0.22 ± 0.24 to 0.06 ± 0.06 logMAR ( P = 0.07; 1-tail P = 0.04). All patients maintained visual acuity during the follow-up period, up to 25 months, mean = 329 days. The Tel-Aviv Protocol was found to be safe [mean safety index: 1.63 ± 1.03 (range: 1.00-4)] and effective [mean efficacy index: 1.29 ± 0.66 (range: 0.71-2.1)]. The Tel-Aviv Protocol, developed initially for keratoconus treatment, is a safe and promising procedure to stop postrefractive surgery ectasia progression while significantly improving vision, thereby avoiding keratoplasty.

Light adjustable intraocular lenses in cataract surgery: considerations.

Light adjustable intraocular lens (LAL) is a promising concept in cataract surgery. This review explores considerations for the use of LALs. Through updates, the safety of LALs and light delivery devices have been enhanced, enabling more efficient treatment with lower ultraviolet (UV) energy. Preoperative topography and aberration are essential for understanding indications for LALs. Furthermore, when determining intraocular lens power, it is crucial to factor in potential postoperative myopia or hyperopic adjustments. This is achieved by establishing a proper postimplantation refractive target and considering potential wavefront changes. Postoperative adjustments for defocus and astigmatism have demonstrated excellent outcomes. Monovision strategy by adjustable blended vision of LALs revealed distance vision of 20/20 along with near vision of J2 in 96% of patients. However, the results of clinical studies on postrefractive cataract surgery showed contrasting outcomes at distance, indicating the need for further research results regarding its effectiveness. A new postoperative workflow needs to be designed to enable a systematic follow-up process. LALs are safe and demonstrate promising refractive outcomes. To achieve appropriate results, understanding the changes in optical characteristics associated with adjustment and constructing a new postoperative workflow are necessary.

Fuchs endothelial corneal dystrophy masking an underlying postrefractive surgery ectasia

Introduction: This article describes a case presenting Fuchs endothelial corneal dystrophy (FECD) masking an underlying postrefractive surgery ectasia. Patient and Clinical Findings: A 69-year-old woman presented in January 2022 with blurriness, halos, and glare in the left eye. Ocular history included a photorefractive keratectomy performed twice in her left eye in 2007 for hyperopic astigmatism. A diagnosis of asymptomatic Fuchs dystrophy was noted in 2010. She had acute decompensation of the cornea in the left eye because of FECD, and the first Descemet-stripping automated endothelial keratoplasty (DSAEK) with cataract surgery was performed in 2018. Diagnosis, Intervention, and Clinical Findings: The patient had a failed DSAEK graft in the left eye. A repeat DSAEK was performed in 2022, and 6 months postoperatively, the patient started showing signs of ectasia in the left eye. The authors believe the ectasia was preexisting but masked by the failed DSAEK graft and FECD and started showing after corneal deturgescence postoperatively. Conclusions: The presence of FECD and corneal ectasia can complicate diagnosis because of overlapping clinical and topographic features. This case highlights the importance of preoperative topography with epithelial/stromal thickness mapping in patients with a history of multiple refractive corneal procedures to consider the possibility of ectasia and prevent unforeseen outcomes and complications. Further research is necessary to determine standardized imaging techniques, particularly in cases of concurrent diseases.

Assessment of the specificity of corvis biomechanical index-laser vision correction (CBI-LVC) in stable corneas after phototherapeutic keratectomy.

The Corvis Biomechanical Index-Laser Vision Correction (CBI-LVC) is a biomechanical index to detect ectasia in post-refractive surgery patients (PRK, LASIK, SMILE). This study aims to evaluate the distribution of the CBI-LVC in stable patients who underwent Phototherapeutic Keratectomy (PTK) compared to PRK patients. Patients who underwent PRK and PTK performed between 2000 and 2018 in Humanitas Research Hospital, Rozzano, Milan, Italy and remained stable for at least four years post-surgery were included. All eyes were examined with the Corvis ST (Oculus, Germany), whose output allows the calculation of the CBI-LVC. The distribution and specificity of the CBI-LVC in the two populations were estimated using a Wilcoxon Mann-Whitney test and compared. 175 eyes of 148 patients were included (85 eyes of 50 PTK patients and 90 eyes of 90 PRK patients). The distribution of CBI-LVC in the two groups showed a minor difference, with a median value in PRK patients of 0.000 (95% CI 0.000; 0.002) and 0.008 (95% CI 0.000; 0.037) in PTK patients (Mann-Whitney U test p = 0.023). The statistical analysis showed that the CBI-LVC provided a specificity of 92.22% in the PRK group, while in the PTK group it was 82.35%. Nevertheless, this difference was not statistically significant (Chi-squared test with Yates, p = 0.080). CBI-LVC provided similar specificity in stable PTK patients compared to those who underwent PRK. These results suggest that the CBI-LVC could be a useful tool to aid corneal surgeons in managing PTK patients.

Comparison of intraocular lens power prediction accuracy of formulas in American Society of Cataract and Refractive Surgery post-refractive surgery calculator in eyes with prior radial keratotomy.

To evaluate the accuracy of intraocular lens (IOL) power prediction of the formulas available on the American Society of Cataract and Refractive Surgery (ASCRS) post-refractive calculator in eyes with prior radial keratotomy (RK) for myopia. This retrospective study included 25 eyes of 18 patients whose status was post-RK for treatment of myopia, which had undergone cataract extraction with IOL implantation. Prediction error was calculated as the difference between implanted IOL power and predicted power by various formulae available on ASCRS post-refractive calculator. The formulas compared were Humphrey Atlas method, IOLMaster/Lenstar method, Barrett True-K no-history formula, ASCRS Average power, and ASCRS Maximum power on ASCRS post-refractive calculator. Median absolute errors were the least for Barrett True-K and ASCRS Maximum power, that is, 0.56 (0.25, 1.04) and 0.56 (0.25, 1.06) D, respectively, and that of Atlas method was 1.60 (0.85, 2.28) D. Median arithmetic errors were positive for Atlas, Barrett True-K, ASCRS Average (0.86 [-0.17, 1.61], 0.14 [-0.22 to 0.54], and 0.23 [-0.054, 0.76] D, respectively) and negative for IOLMaster/Lenstar method and ASCRS Maximum power (-0.02 [-0.46 to 0.38] and - 0.48 [-1.06 to - 0.22] D, respectively). Multiple comparison analysis of Friedman's test revealed that Atlas formula was significantly different from IOLMaster/Lenstar, Barrett True-K, and ASCRS Maximum power; ASCRS Maximum power was significantly different from all others (P < 0.00001). In post-RK eyes, Barrett True-K no-history formula and ASCRS Maximum power given by the ASCRS calculator were more accurate than other available formulas, with ASCRS Maximum leading to more myopic outcomes when compared to others.

Refractive surgery and dry eye.

Refractive surgery is one of the most common elective surgeries performed worldwide. The incidence of dry eye disease (DED) after corneal refractive surgery varies among different studies. Pre-existing untreated DED has been identified as a risk factor for postsurgical dry eye symptoms. On the basis of both evidence and clinical experience, some recommendations for ocular surface and DED management pre- and post-refractive surgery are described. In aqueous deficiency Dry Eye Disease, preservative-free lubricating drops should be preferred, in addition to ointment and gel forms. Topical anti-inflammatory agents (Cyclosporine 0.1%, hydrocortisone phosphate, fluorometholone) should be used for 3-6 months in cases of ocular surface damage. The therapy of evaporative DED includes lifestyle modifications, lid hygiene (either performed by the patient or offered as professional lid hygiene by the physician), use of lubricating eye drops with lipid components, topical and/or systemic antibiotic treatment with anti-inflammatory properties and Intense Pulsed Light (IPL-) Treatment for meibomian gland dysfunction.

The use of orthokine therapy for the treatment of post refractive surgery corneal ulcer, a case report

Post refractive corneal ulcers is a disastrous complication, can affect healthy individuals, is cumbersome to treat, and sometimes has a poor prognosis with corneal scarring. Accurate diagnosis and prompt treatment of corneal infection is very important; however, until now, there has been no specific protocol for the management of this common eye disease and severe cases may require a corneal transplant.The patient is a 42-year-old male who suffered a corneal ulcer after photo refractive keratectomy (PRK) surgery in which the cornea was completely destroyed. None of the routine treatments were effective and, due to the progression of corneal melting, the patient became a candidate for tectonic corneal transplant. As a last option, topical orthokine treatment was prescribed for this patient which had a dramatic improvement in the clinical course with the control of inflammation.In this study, a new method of orthokine therapy was performed for a severe corneal ulcer and recovery was clearly evident in the patient follow-up. This is the first case report of treatment of a corneal wound infection with this method of orthokine therapy. It is suggested for consideration as a new treatment for such infectious disease.

Keratometry Agreement Between Two Swept-Source OCT Devices in Healthy and Post-refractive Surgery Eyes

To evaluate the keratometry agreement between two swept-source devices for healthy and post-refractive surgery eyes and compare them. One hundred volunteers between 20 and 55 years of age were recruited for this study including both healthy and post-refractive surgery eyes. Three consecutive measurements of simulated keratometry (Sim K), posterior keratometry (PK), and total keratometry (TK) were obtained with the IOLMaster 700 and Anterion. The agreement was assessed through the Bland-Altman method. Limits of agreement (LoA) were calculated as mean difference ±1.96·SD and it represents the 95% of the differences between devices. For both groups, Sim K measurements exhibited a mean difference close to 0 and within a range of ±0.30 and ±0.36 diopters (D) for the control and post-refractive surgery groups, respectively. Meanwhile, the IOLMaster 700 provided flatter PK values (0.30 D on average) for both groups. In general, the post-refractive surgery group exhibited slightly greater mean differences and wider 95% LoA than the control group for Sim K and PK. Steeper TK values were obtained by the IOLMaster in both groups (control = 0.50 D and post-refractive surgery = 0.75 D). TK differences between devices were significantly greater in the post-refractive surgery group (ranging from 0.38 to 1.14 D) compared to the control group (ranging from 0.15 to 0.85 D). The IOLMaster 700 and Anterion are not interchangeable for TK measurements and eyes that had corneal refractive surgery even decreased the agreement between devices. Differences between devices for Sim K and PK measurements should be clinically judged, particularly in eyes with previous corneal surgery. [J Refract Surg. 2023;39(5):347-353.].