Binocular vision parameters and visual performance in bilateral keratoconus corrected with spectacles versus rigid gas-permeable contact lenses / Parámetros de visión binocular y rendimiento visual en queratocono bilateral corregido con gafas versus lentes de contacto rígidos permeables al gas

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)

Citation network analysis on keratoconus

Objective: The high incidence of keratoconus has caused its management, etiology, and pathogenesis to be controversial topics in the ophthalmology field. This study aims to analyze the relationship between the different publications and authors through citation networks, as well as to identify the research areas and determine the most cited article. Methods: The search for publications was carried out through the Web of Science database, using the term “Keratoconus” between 1900 and December 2022. The Citation Network Explorer and CiteSpace software were used for the publication analysis. Results: 9,655 publications were found, with 124,379 citations generated on the network. The year with the highest number of publications was 2021. The most cited publication was “Keratoconus” by Rabinowitz, published in 1998. Cluster function gave five groups of research areas about keratoconus: corneal signs and parameters, cross-linking efficiency and effects, clinical factors, keratoplasty, and treatment. Conclusions: The citation network offers an objective and comprehensive analysis of the papers on keratoconus. (AU)

[Ophthalmic disqualification from the military services: Multicentric cross-sectional study]. / Inaptitude ophtalmologique dans les armées : étude épidémiologique multicentrique.

PURPOSE: This article aims to describe the causes of ophthalmological disqualification from the military services detected during specialist consultations conducted at Army Training Hospitals. METHODS: This observational, cross-sectional, multicenter study retrospectively included individuals deemed as "unfit for military service" due to eye diseases identified during the specialist consultation conducted at 3 ATHs between January 2020 and December 2021. The data collected included age, medical and surgical history, reasons for ophthalmological disqualification, uncorrected distance visual acuity, best corrected distance visual acuity and cycloplegic refraction. RESULTS: Over this period, 133 subjects (98 men and 35 women) were included. Thirty-eight candidates (28.6%) were declared unfit due to a refractive error beyond the required limits, including 30 myopic subjects in excess of -10 diopters (D) and 8 hypermetropic subjects over +8 D. Twenty-five candidates (18.8%) were unfit under the age of 21 years due to corneal refractive surgery performed before the required age. Four subjects (3.0%) were unfit due to phakic intraocular lenses. Degenerative conditions were observed in 23 subjects (17.3%), including 21 patients with severe keratoconus. Other causes of incapacity were linked to oculo-orbital trauma in 11 subjects (8.3%), moderate or severe amblyopia in 7 patients (5.3%), congenital causes in 7 subjects (5.3%), inflammatory or infectious diseases in 7 candidates (5.3%), hereditary causes in 6 subjects (4.5%) and undetermined visual dysfunctions in 4 subjects (3.0%). CONCLUSION: The three main causes of ophthalmological disqualification were high ametropia, refractive surgery performed before the required age and keratoconus.

Main issues in deep anterior lamellar keratoplasty: A systematic narrative review.

Deep anterior lamellar keratoplasty (DALK) has emerged as a transformative approach in managing corneal pathologies, notably keratoconus (KC), providing a viable alternative to penetrating keratoplasty (PK). This systematic review explores the intricacies of DALK, comparing its preoperative, intraoperative, and postoperative considerations with PK. Extensive literature searches revealed a wealth of data regarding DALK's advantages and challenges, with an emphasis on graft survival, visual outcomes, and complications. In the preoperative phase, DALK showcases its versatility, catering to a wide spectrum of patients, including those with KC and ocular surface disorders. Intraoperatively, it offers innovative techniques to address emphysema, bubble formation, and Descemet's membrane perforation, all while maintaining a strong focus on patient-centered outcomes. Postoperatively, DALK's lower rejection rates and decreased complications underscore its potential superiority over PK, although unique challenges such as graft failure from nonimmunologic factors demand vigilant management. This comprehensive review not only serves as a valuable resource for ophthalmic surgeons but also sheds light on the evolving landscape of corneal transplantation, highlighting DALK's role as a transformative force in the field.

Biomechanical changes in keratoconus after customized stromal augmentation.

PURPOSE: To verify corneal biomechanical changes, poststromal augmentation using myopic small-incision lenticule extraction's (SMILEs) lenticules in advanced keratoconus (KCN) through Corvis ST (Oculus, Wetzlar, Germany). MATERIALS AND METHODS: A clinical trial enrolled 22 advanced KCN patients. We implanted lenticules exceeding 100 µ according to a nomogram and evaluated biomechanical factors through Corvis ST at 3-, 6-, and 24-month postimplantation. We examined parameters during the first applanation (A1), second applanation (A2), highest concavity (HC)/max concavity events, and Vinciguerra screening parameters, as recently established criteria derived from the ideal blend of diverse biomechanical and ocular factors and formulated through the application of logistic regression. Regression analyses explored relationships with age, mean keratometry value, thickness, sphere, cylinder, and best-corrected visual acuity. RESULTS: Patients were well matched for age, intraocular pressure, and central corneal thickness (CCT). The mean spherical equivalent decreased from -13.48 ± 2.86 Diopters (D) to -8.59 ± 2.17 D (P < 0.007), and mean keratometry decreased from 54.68 ± 2.77 D to 51.95 ± 2.21 D (P < 0.006). Significant increases were observed in HC time (HCT), Radius-central curvature radius at the HC state-, peak distance (PD) during HC state, CCT, first applanation time, and stiffness parameter (A1T and SP-A1), whereas HC deformation amplitude, maximum deformation amplitude ratio at 2 mm, Corvis Biomechanical Index (CBI), integrated radius (IR), second applanation deformation amplitude (A2DA), first applanation velocity and deflection amplitude (A1V and A1DeflA) significantly decreased postlenticule implantation. Multivariable regression revealed age positively correlated with SP-A1 (P = 0.003) and negatively with HC delta Arc length (P = 0.007). Mean K positively correlated with CCT (P = 0.05) and negatively with CBI (P = 0.032). Best-corrected visual acuity positively correlated with HCT (P = 0.044), and the cylinder positively correlated with PD (P = 0.05) and CCT (P = 0.05) whereas negatively with IR (P = 0.025). CONCLUSIONS: Stromal augmentation using myopic SMILE lenticules induces significant corneal biomechanical changes in KCN.

Outcomes of 320-degree intrastromal corneal ring segment implantation for advanced keratoconus.

PURPOSE: The purpose of this study is to investigate visual and tomographic outcomes and complications of long-arc length intrastromal corneal ring segment (ICRS) implantation for the treatment of advanced keratoconus. MATERIALS AND METHODS: This retrospective study enrolled 10 eyes of 9 subjects. All patients received 320-degree ICRS (320-ICRS) implantation with femtosecond laser-assisted technique based on their advanced grading with preoperative high keratometry (K) value, asphericity (Q), and astigmatism. Medical records and corneal tomography changes of consecutive patients were reviewed at baseline, 1, and 3 months after treatment. RESULTS: There are 6 female and 3 male patients with a mean age of 29.6 ± 7.8 years in this study. Mean K (Km) reduced from 59.01 ± 5.81 D preoperatively to 50.7 ± 5.3 and 50.2 ± 3.66 postoperatively (after 1 month and 3 months respectively, P < 0.001). The changes in mean K, K1, K2, and maximum K (Kmax) reading were all statistically significant (all P < 0.001). Mean uncorrected distance visual acuity (UCVA) improved from 20/400 to 20/200. Mean best-corrected distance visual acuity (BCVA) improved from 20/100 to 20/60. Both UCVA and BCVA showed a trend of improvement at postoperative month 3, though insignificant in BCVA (P = 0.114). Mean Q improved from -1.59 ± 0.62 preoperatively to -0.48 ± 1.08 and -0.11 ± 1.04 postoperatively (after 1 month and 3 months respectively, P = 0.016, 0.002). No intraoperative or postoperative complications were observed. CONCLUSIONS: The present results suggest that implanting a 320-ICRS is a safe and effective procedure for treating patients with advanced keratoconus. Preoperative corneal measurements and the selection of types and thickness of ICRS are important to prevent unpredictable results.

A comprehensive review on corneal crosslinking.

Corneal crosslinking (CXL) represents a paradigm shift in the management of corneal ectatic disorders. Before CXL was introduced, patients would need specialty contact lenses and possible corneal transplantation. CXL involves a biochemical reaction in which ultraviolet A light is used in conjunction with Riboflavin to form crosslinks in between corneal stromal collagen. This leads to strengthening and stabilizing of the collagen lamellae, resulting in mechanical stiffening of the cornea. Multiple protocols have been proposed including epithelium on versus off and varying light intensity and duration of treatment. All protocols appear to be safe and effective with few reported complications including infection, stromal haze, scarring, and endothelial toxicity. Overall, CXL has demonstrated to halt the progression of the disease clinically and in keratometry readings and improve the quality of life for patients. It is a minimally invasive, cost-effective procedure that can be performed in an outpatient setting with a fast recovery time and long-lasting results.

An unusual coexistence of iris mammillations and optic disc pit with keratoconus: A case report and literature review.

Iris mammillations are distinctive uniform nipple-like elevations that cover the anterior surface of the iris partially or totally. It is a rare finding and may coexist with other ocular and extraocular manifestations. Optic nerve pit (ONP), also known as optic disc pit (ODP) or optic hole, is a congenital defect resulting from the failure of fetal fissure closure during the embryonic development. It belongs to the congenital cavitary anomalies spectrum. This case presents a 19-year-old female patient who complained of a gradual decrease in visual acuity in both eyes for 4 years. Slit-lamp and fundus examinations revealed iris mammillations and ODP in the left eye. Corneal topography revealed bilateral keratoconus, which was managed with cross-linking. Iris mammillations and ODP are poorly understood ocular anomalies that are not reported frequently and have never been reported previously both combined with keratoconus. Thus, ophthalmologists should be aware of these conditions, their differential diagnosis, and their possible association with other disorders. This is the first reported case of the combined coexistence of iris mammillations and ODP with keratoconus.

Pre-Descemet's endothelial keratoplasty with glued intraocular lens implantation with pinhole pupilloplasty in a case of ocular comorbidity in achromatopsia.

Ocular comorbidities can happen as congenital defective gene associations. We present a 37-year-old female patient who was mentally challenged and had coexisting achromatopsia gene abnormality on genetic analysis. She was operated in childhood for congenital cataract, and posterior chamber intraocular lens (IOL) was implanted at 10 years of age elsewhere. The patient presented 27 years later with luxated IOL with endothelial decompensation. There was a coexisting steep and thin cornea noted on corneal topography. She was managed with pre-Descemet's endothelial keratoplasty with transpositioning of posterior chamber IOL to glued IOL with single-pass four-throw pupilloplasty. Postoperatively, the cornea was clear with centered glued IOL. The lesser postanesthetic challenges and faster rehabilitation are obtained in combination procedures with reduced complications in such rare scenarios.

Identification and Verification of Ferroptosis-Related Genes in Keratoconus Using Bioinformatics Analysis.

Objective: Keratoconus is a commonly progressive and blinding corneal disorder. Iron metabolism and oxidative stress play crucial roles in both keratoconus and ferroptosis. However, the association between keratoconus and ferroptosis is currently unclear. This study aimed to analyze and verify the role of ferroptosis-related genes (FRGs) in the pathogenesis of keratoconus through bioinformatics. Methods: We first obtained keratoconus-related datasets and FRGs. Then, the differentially expressed FRGs (DE-FRGs) associated with keratoconus were screened through analysis, followed by analysis of their biological functions. Subsequently, the LASSO and SVM-RFE algorithms were used to screen for diagnostic biomarkers. GSEA was performed to explore the potential functions of the marker genes. Finally, the associations between these biomarkers and immune cells were analyzed. qRT‒PCR was used to detect the expression of these biomarkers in corneal tissues. Results: A total of 39 DE-FRGs were screened, and functional enrichment analysis revealed that the DE-FRGs were closely related to apoptosis, oxidative stress, and the immune response. Then, using multiple algorithms, 6 diagnostic biomarkers were selected, and the ROC curve was used to verify their risk prediction ability. In addition, based on CIBERSORT analysis, alterations in the immune microenvironment of keratoconus patients might be associated with H19, GCH1, CHAC1, and CDKN1A. Finally, qRT‒PCR confirmed that the expression of H19 and CHAC1 was elevated in the keratoconus group. Conclusion: This study identified 6 DE-FRGs, 4 of which were associated with immune infiltrating cells, and established a diagnostic model with predictive value for keratoconus.

Correlation Between the Cost and Safety of Corneal Graft Types.

Background Corneal diseases are the fourth most common cause of blindness worldwide. In the majority of these diseases, vision reduction is reversible and can be restored to a large extent by replacing the cornea through specific surgery and, in particular, transplantation. In Greece, due to a lack of organized eye banks as well as donors, the grafts intended for corneal transplantation usually come from eye banks abroad. This study focuses on the dynamics of cost versus value in the decision-making process for the procurement of corneal grafts, ultimately investigating the safety that the procured grafts provide to patients. Methodology A total of 267 patients with severe vision problems who underwent 301 corneal and amniotic membrane transplants from years 2020 to 2023 at the Transplant Unit of the Athens General Hospital "Georgios Gennimatas" were included in this study. All patients who were deemed appropriate to undergo corneal transplant operations, the diagnosis that led to the specific surgery, and other relevant data were recorded and evaluated. Results There was no significant difference in the ratio between males and females (51.3% male and 48.7% female). The mean age of the patients was 66.5 years (SD = 13.7 years). Graft problems were faced by 13.9% of the patients, with the amniotic membrane by 1.5% (in the total number of surgical operations) and both eyes by 4.5% of patients. The majority of the patients had undergone only one surgery (88.8%). Reoperation was needed in 14% of the cases, and 7.6% of the cases were surgeries that occurred due to graft rejection or non-functioning grafts from surgeries performed at another hospital or clinic. In the majority of surgeries (60.8%), a Descemet's stripping automated endothelial keratoplasty graft was used. The mean cost was 3,167 euro (SD = 960.3 euro). Furthermore, in 35.8% of the surgeries, the graft was preserved with amphotericin. Conclusions The present study draws useful conclusions about the effectiveness of surgical interventions through the correlation of cost and safety of the grafts that are approved and finally used in corneal transplants, as well as the submission of proposals to improve the procedures and lead to patient benefits.

Descemet Membrane Detachment Triggered by Contrast-Enhanced Computed Tomography in a Patient with a History of Penetrating Keratoplasty for Keratoconus Treatment.

Introduction: We report a case of late-onset Descemet membrane detachment triggered by contrast-enhanced computed tomography more than 30 years after penetrating keratoplasty for keratoconus and describe its successful treatment with air tamponade. Case Presentation: A 53-year-old woman with a history of uneventful penetrating keratoplasty more than 30 years ago for keratoconus presented with acute vision loss caused by corneal edema 2 days after undergoing contrast-enhanced computed tomography. Anterior-segment optical coherence tomography (AS-OCT) revealed corneal stromal edema in the graft and Descemet's fold and partial Descemet membrane detachment without a tear. The patient received 0.1% betamethasone eye drops once every hour, along with sub-Tenon's triamcinolone acetonide injection. Anti-inflammatory treatment improved corneal edema; however, the detachment area widened. Air tamponade facilitated complete Descemet membrane reattachment and improved corneal thickness with complete restoration of visual acuity. Conclusion: An immune response may have been involved in the progression of Descemet membrane detachment in this patient. Anti-inflammatory treatment may have facilitated Descemet membrane reattachment prior to air or gas tamponade. AS-OCT is an excellent imaging modality to detect Descemet membrane detachment in eyes with presumed late penetrating graft rejection or failure.

Evaluation of the results of contact lens assisted corneal cross-linking treatment in keratoconus patients with thin corneas.

PURPOSE: We aimed to compare the efficacy and safety of accelerated contact lens-assisted cross-linking (CA-CXL) with Lotrafilcon B and Comfilcon A lenses in keratoconus (KC) patients with thin corneas. STUDY DESIGN: Retrospective, single-center study. MATERIALS AND METHODS: We retrospectively included 51 eyes of 39 KC patients with corneal thickness <400µm after epithelial scraping (Epi-off), who underwent accelerated CA-CXL treatment with Lotrafilcon B (n=20) and Comfilcon A (n=31). Uncorrected and corrected distance visual acuity (UDVA and CDVA), manifest refraction values, corneal topographic data and endothelial cell density were recorded at preoperative and postoperative 1st, 3rd and 6th month controls. RESULTS: CDVA in the Comfilcon A group was higher than CDVA before surgery at 6 months postoperatively (p<0.001). When the two lenses were compared, CDVA was found to be significantly higher in the Lotrafilcon B group in the preoperative, postoperative 1st month and 3rd month values, but there was no significant difference between the postoperative 6th month values (p=0.028, p=0.018, p=0.044, p=0.181, respectively). The maximum keratometry (Kmax) value at the 6th month after surgery in the Comfilcon A group was significantly lower than in the Lotrafilcon B group (p=0,009). There was no significant difference between the endothelial cell density values between the groups (p=0.623, p=0.609, p=0.794, p=0.458, respectively). There was no significant difference between the progression, regression, and stability rates of the two groups (p=0.714). CONCLUSIONS: Accelerated CA-CXL with Lotrafilcon B and Comfilcon A silicone hydrogel lenses is a safe and effective method to stop progression in patients with thin corneas.

[Effect of keratoplasty on the quality of life of keratoconus patients]. / Effet de la kératoplastie sur la qualité de vie des patients atteints de kératocône.

Corneal deformations caused by keratoconus produce high levels of optical aberration (OA). Despite appropriate optical correction, these alter the quality of vision and diminish the patient's quality of life, especially since the affected population is predominantly young and of working age. When thinning is too severe or corneal transparency too impaired, a corneal transplant may be considered. In this study, we compare the quality of life of patients with keratoconus in the early (stages 1 and 2) or advanced (stages 3 and 4) stages of the Krumeich classification, as well as patients who have had keratoconus treated by keratoplasty. Quality of life was assessed using the NEI-VFQ 25 questionnaire, the most widely used for keratoconus. An aberrometric examination (OQAS®; HD Analyser, Visiometrics, Terrassa, Spain) was also performed to assess patients' quality of vision. Our results show that keratoplasty provides an improvement in quality of life compared with advanced-stage keratoconus in the areas of distance (p=0.0083) and near vision (p=0.029) activities. This improvement also applies to Best-Corrected Visual Acuity (BCVA) (p=0.032) and transparency (OSI) (p=0.049). Our study shows that keratoplasty improves corneal transparency, and it is interesting to note that it improves patients' quality of life over the long term.

SMAD4-Dependent Signaling Pathway Involves in the Pathogenesis of TGFBR2-Related CE-like Phenotype.

(1) Background: Our previous data indicated that disturbance of the Transforming Growth Factor beta (TGFB) signaling pathway via its Type-2 Receptor (TGFBR2) can cause a Corneal Ectasia (CE)-like phenotype. The purpose of this study is to elucidate whether the SMAD4-dependent signaling pathway is involved in the TGFBR2-related CE-like pathogenesis. (2) Methods: Smad4 was designed to be conditionally knocked out from keratocytes. Novel triple transgenic mice, KerartTA; Tet-O-Cre; Smad4flox/flox (Smad4kera-cko), were administered with doxycycline (Dox). Optical Coherence Tomography (OCT) was performed to examine Central Corneal Thickness (CCT), Corneal Radius, Anterior Chamber and CE-like phenotype and compared to the littermate Control group (Smad4Ctrl). (3) Results: The OCT revealed normal cornea in the Smad4Ctrl and a CE-like phenotype in the Smad4kera-cko cornea, in which the overall CCT in Smad4kera-cko was thinner than that of Smad4Ctrl at P42 (n = 6, p < 0.0001) and showed no significant difference when compared to that in Tgfbr2kera-cko. Furthermore, the measurements of the Anterior Chamber and Corneal Radius indicated a substantial ectatic cornea in the Smad4kera-cko compared to Smad4Ctrl. The H&E staining of Smad4kera-cko mimics the finding in the Tgfbr2kera-cko. The positive immunostaining of cornea-specific marker K12 indicating the cell fate of cornea epithelium remained unchanged in Smad4kera-cko and the Proliferating Cell Nuclear Antigen (PCNA) immunostaining further indicated an enhanced proliferation in the Smad4kera-cko. Both immunostainings recapitulated the finding in Tgfbr2kera-cko. The Masson's Trichrome staining revealed decreased collagen formation in the corneal stroma from both Smad4kera-cko and Tgfbr2kera-cko. The collagen type 1 (Col1a1) immunostaining further confirmed the reduction in collagen type 1 formation in Smad4kera-cko. (4) Conclusions: The aforementioned phenotypes in the Smad4kera-cko strain indicated that the SMAD4-dependent signaling pathway is involved in the pathogenesis of the CE-like phenotype observed in Tgfbr2kera-cko.

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

PURPOSE: To 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. SETTING: a private ophthalmology clinic. DESIGN: Prospective interventional case series. METHODS: This 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. RESULTS: The 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. CONCLUSIONS: Despite 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.

Keratometric Outcomes after Simultaneous versus Sequential Intracorneal Ring Segment Implantation with Femtosecond Laser and Corneal Collagen Crosslinking in Egyptian Patients with Keratoconus and Ectasia.

Background: Keratoconus (KC) is degenerative corneal disorder, with central and paracentral thinning and corneal ectasia. For KC progressive cases, primary treatment included corneal collagen cross linking (CXL) to stabilize coning and intracorneal rings segment (ICRS) to correct visual acuity. Aim: The aim of the study is to assess efficacy and safety of ICRS and CXL on one session (Simultaneous) or two sessions (sequential) with maximum of 1 month apart. Patients and Methods: This Prospective Intervention Comparative research made at Armed forces hospital, Cairo, Egypt from January 2017 to December 2019. Forty patients (60 eyes) with mild to moderate KC were enrolled. Patients sorted into Simultaneous group includes 21 patients (30 eyes) undergo two procedures (ICRS then CXL) at the same session and Sequential group included 19 patients (30 eyes) undergo ICRS then CXL on two sessions with month apart. Patients followed up at end of 1st, 3rd, and 6th months. Assessment included changes in corrected corneal surface irregularities as minimum keratometric 1 (K1), maximum keratometric readings (K2), and mean keratometric (Km) readings. Results: Improvement of K1, K2, and Km in Simulations and Sequential groups achieved at end of 1st-, 3rd-, and 6th-month postoperative versus preoperative. Maximum improvement in Simulations and Sequential groups in K1 achieved at end of 6th and 1st months, in K2 at end of 3rd and 6th months and in Km at end of 1st and 3rd months. Conclusions: Combined ICRS and CXL act safely in one or two sessions and there are no statistically significant variations between results on both methods in keratometric readings.

Higher order aberrations in keratoconus .

INTRODUCTION: Keratoconus is a progressive disorder of the cornea that causes thinning (Sedaghat et al. in Sci Rep 11(1):11971, 2021), ectasia, and irregular astigmatism, resulting in poor visual acuity that cannot be corrected with standard sphero-cylindrical spectacle lenses. One feature distinguishing keratoconic corneas is ocular aberrations, manifesting up to five or six times the amount of higher-order aberrations than a normal, healthy eye. These aberrations can cause visual disturbances even at the very early stages of the disease. METHODS: In the past, a diagnosis was derived from clinical symptoms, but technological advances have revealed multiple pre-clinical features, allowing for the differentiation between keratoconic and normal eyes at a much earlier stage. These include anterior and posterior corneal surface elevations, the corneal pachymetry profile, corneal epithelial patterns, wavefront aberration metrics, and corneal biomechanics (Sedaghat et al. in Sci Rep 11(1):11971, 2021).This review discusses the aberrations associated with keratoconus, how to measure them, and treatment methods to minimize their negative influence. CONCLUSIONS: Early diagnosis can lead to early treatment and may allow for arresting progression, thereby improving the long-term prognosis. With the acceleration of refractive surgery, it is important to identify patients with keratoconus, as they are usually contraindicated for refractive surgery.

Prevalence of Keratoconus in the Young Eastern Population of Saudi Arabia.

BACKGROUND: Keratoconus (KCN) is a progressive corneal ectasia that manifests at a young age and significantly impacts vision and quality of life. Early diagnosis allows for effective treatment with corneal collagen crosslinking, yet there is a lack of screening methods. This research aims to screen adolescents and young adults for this sight-threatening disease using quick corneal tomography mapping. METHODS: This prospective cross-sectional study is being conducted at Johns Hopkins Aramco Healthcare in Saudi Arabia, focusing on subjects aged 13-23. We are presenting the data from our study as internal pilot study data. Bilateral corneal imaging with Pentacam HR (Oculus, Wetzlar, Germany), utilizing Scheimpflug corneal tomography, was performed. Historical data on allergies, eye rubbing, KCN, family history, previous eye surgery, and contact lens use were collected. The Belin Ambrosio Enhanced Ectasia Display total D value served as an objective criterion for suspect KCN (SKCN) diagnosis. RESULTS: In this study with 110 participants, KCN was identified in 2.75% of participants and SKCN in 11.93%. Systemic allergies or eczema were reported by 2.80%, with no cases in the KCN or SKCN groups. Eye rubbing behavior was observed in 5.50%, with the highest prevalence (33.30%) in the KCN group. A family history of KCN was found in 21.10%, with SKCN having the highest prevalence (30.80%). CONCLUSION: This restricted population study reveals a significant KCN rate of 2.75%. The condition, easily detected and treatable with corneal collagen crosslinking, highlights the need for larger population studies to determine the disease's true prevalence. Efficient screening programs tailored to regional data are essential for early detection and intervention.

RiTe conjugate mediated corneal collagen crosslinking, a novel therapeutic intervention for keratoconus - in vitro and in vivo study.

Corneal collagen crosslinking (CXL) is an effective method to halt the disease progression of keratoconus, a progressive corneal dystrophy leading to cone shaped cornea. Despite the efficacy of standard protocol, the concerning step of this procedure is epithelial debridement performed to facilitate the entry of riboflavin drug. Riboflavin, a key molecule in CXL protocol, is a sparsely permeable hydrophilic drug in corneal tissues. The present study has employed cell penetrating peptide (CPP), Tat2, to enhance the penetration of riboflavin molecule, and thereby improve currently followed CXL protocol. This study demonstrates approximately two-fold enhanced uptake of CPP riboflavin conjugate, Tat2riboflavin-5'Phosphate (RiTe conjugate), both in vitro and in vivo. Two different CXL protocols (Epi ON and Epi OFF) have been introduced and implemented in rabbit corneas using RiTe conjugate in the present study. The standard and RiTe conjugate mediated CXL procedures exhibited an equivalent extent of crosslinking in both the methods. Reduced keratocyte loss and no endothelial damage in RiTe conjugate mediated CXL further ascertains the safety of the proposed CXL protocols. Therefore, RiTe conjugate mediated CXL protocols present as potential alternatives to the standard keratoconus treatment in providing equally effective, less invasive and patient compliant treatment modality.