Progressive keratoconus in patients older than 48years.

A 6-month evaluation of the topographic and biomechanical changes induced by corneal collagen cross-linking (CXL) in keratoconic eyes using Pentacam and Corvis ST. Longitudinal prospective case series. In this study, 67 eyes of 67 patients with progressive keratoconus (KCN) treated with "Epithelium-off" CXL were evaluated. Patients with stages 1 or 2 of KCN and a corneal thickness of at least 400 μm at the thinnest point were included. Standard ophthalmologic examinations were carried out for all patients. The topographic and biomechanical measurements of the cornea were obtained by Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) and Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) preoperatively and 6-month postoperatively. The mean age of the participants was 21.68 ± 4.23 years. There was significant difference in mean spherical equivalent (SE) before and 6 months after CXL. Uncorrected and best corrected visual acuity improved postoperatively, although not statistically significant. The mean and maximum keratometry showed a significant decrease 6 months after CXL (0.93 ± 0.38 D and 1.43 ± 0.62 D, respectively p < 0.001). Among Corvis ST parameters, first applanation length and velocity (AL1 and AV1) showed statistically significant changes. The radius at highest concavity changed significantly (0.13 ± 0.37 mm mean increase after CXL; p < 0.001). A significant increase was observed in stiffness parameter A1 (SP-A1; p < 0.001) and significant decreases were noted in integrated radius (IR) and deformation amplitude ratio (DAR; p < 0.001). Analyzing biomechanical changes after corneal cross-linking can provide basis for efficient KCN treatment. Corvis ST parameters demonstrated changes in corneal biomechanical characteristics indicative of stiffing after CXL.

Keratoconus (KC) is a noninflammatory cornea disease leading to progressive thinning, causing it to change from its normal dome shape to a cone shape. One of the novel treatments of KC is corneal collagen cross-linking (CXL). Due to its importance, many studies have been conducted to compare corneal cross-linking protocols; this review article aims to discuss corneal cross-linking and compare its different treatment options, including Dresden, accelerated, and customized protocols in patients with progressive KC and their respective long-term outcomes. A search was performed in PubMed and Google Scholar with no language, dates, or study type restriction. Most of the results showed almost no difference between protocols over traditional cross-linking. However, published data are limited, long-term outcomes of novel age groups remain unclear, and further studies are needed.

Clinical relevance Early detection of keratoconus (KC) progression and timing for retreatment. Background Q value (coefficient of corneal asphericity) reflects the shape of the cornea, its refractive power, and spherical aberration. In this study, we aimed to analyze the correlation between changes in Q value and progression of KC in children. Patients and methods In this retrospective cross-sectional study, clinical data of 18 eyes of nine children that were diagnosed as bilateral progressive KC (four boys, five girls: mean age of 11.3±1.6 years) were extracted from a Scheimpflug camera (Pentacam) for analysis before (baseline) and annually after bilateral transepithelial corneal collagen cross-linking (TE-CXL) up to 5 years of follow-up. Results At all follow-up visits up to 5 years, Kmax improved significantly (mean change at 5 years was 1.6 D) (P&lt;0.001); uncorrected visual acuity and best-corrected visual acuity showed significant changes at all follow-up visits (P&lt;0.001). In seven (38.8%) eyes, KC had progressed by more than 1.0 D by the last follow-up visit, despite corneal cross-linking. In the last visit, there was a significant negative correlation between mean Q value and Kmax in both 6 and 8 mm anterior corneal zones (Pearson correlation coefficient, r=−0.847, P&lt;0.001, r=−0.605, P&lt;0.001, respectively). Conclusion There is significant negative correlations between changes in corneal asphericity and progression of KC in children, which could be considered with other parameters in early detection of disease progression and timing for retreatment after transepithelial corneal collagen cross-linking.

To evaluate correlation between Placido-disc and rotating Scheimpflug keratometric findings in children with progressive keratoconus (KC) before and after corneal crosslinking (CXL) and investigate whether these limits of agreement varied according to disease severity. Department of Ophthalmology of São Paulo Hospital, São Paulo, Brazil. Prospective nonrandomized open study. Data obtained using rotating Scheimpflug-based tomography and Placido-disc-based topography devices were collected from preoperative and last follow-up postoperative children with KC operated on using standard CXL protocol. Correlation and agreement analyses were performed between the 2 devices before and after CXL to obtain keratometric (K) findings. 44 eyes from 44 patients aged 8 to 16 years were analyzed at all timepoints. All parameters were found to be strongly correlated before ( r = 0.84 to 0.99, P < .001) and after ( r = 0.93 to 0.99, P < .001) CXL. The mean Scheimpflug measurements of flat K, steep K, Kmax, mean K, and corneal astigmatism were higher than Placido-disc measurements in a preoperative period. This mean difference decreased in postoperative, but, with exception of Kmax and corneal astigmatism, Scheimpflug measurements remained higher. The mean parameter measurements from both devices decreased after CXL; 95% limits of agreement between instruments were wide for all parameters and decreased in postoperative and in mild KC. Keratometry measurements obtained using rotating Scheimpflug and Placido-disc technology were found to be closely correlated but not interchangeable before and after CXL in pediatric patients. Agreement between devices was better after CXL and in mild KC than in advanced KC.

Tear fluid small molecular antioxidants profiling shows lowered glutathione in keratoconus

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. 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. In this study with 110 participants, KCN was identified in 2.75% of participants and SKCNin 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%). 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.

PurposeWe evaluate the long-term visual, refractive, and keratometric outcomes after corneal crosslinking (CXL) in patients with progressive keratoconus (KC) and the incidence of an extreme corneal flattening effect.SettingsOftalmosalud Institute of Eyes, Lima, Perú.DesignRetrospective cohort study.MethodsForty-five eyes that underwent CXL with epithelial removal between June 2006 and September 2011. Data analysis was performed at preoperative evaluation, 1 year postoperatively, and at least 10 years or more postoperatively. Outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and Scheimpflug (Pentacam) analysis. Progression was defined by an increase in steep keratometry (Ks) of 1.5D or greater between 2 examinations. Extreme flattening effect was defined as a decrease in K values equal to or greater than 5 diopters (D).ResultsMean follow-up time was 11 ± 1.07 years (range 10–13 years). There was a significant improvement in Ks, UCVA, CDVA, and spherical equivalent at the last visit. The overall rate of progression was 2.22% (1/45). Extreme flattening was observed in 15.5% (7/45) of the eyes, and this was associated with a loss of CDVA in 4.44% (2/45) of the eyes. One eye with corneal flattening of 11.5 D lost 7 lines of CDVA and required corneal transplantation.ConclusionCXL is a safe and effective procedure to stop the progression of KC with a good overall long-term success rate. Extreme corneal flattening may be more common than commonly recognized, and severe corneal flattening associated with a decrease in CDVA may occur.

Long-term Safety and Efficacy of Corneal Collagen Crosslinking in a Pediatric Group With Progressive Keratoconus: A 7-year Follow-up

One year results of corneal collagen crosslinking on progressive keratoconus

To report refractive, topographic, and visual outcomes 12 months after same-day treatment with corneal cross-linking (CXL) and Ferrara intracorneal ring segments (ICRS) in eyes with progressive keratoconus (KC) and contact lens intolerance. This was a case series of 7 eyes (7 patients) with progressive mild to moderate keratoconus and contact lens intolerance undergoing implantation of Ferrara ICRS immediately followed by corneal cross-linking. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refractive error, pachymetry, and keratometry were evaluated at 3, 6, and 12 months of follow-up. Mean follow-up was 11.7 ± 3.6 months (range, 5-17 months). Mean preoperative UCVA and BSCVA were 0.10 ± 0.07 (range, 0.05-0.2) and 0.56 ± 0.08 (range, 0.5-0.7), respectively. One year after the treatment, mean UCVA and BSCVA measured 0.60 ± 0.24 (range, 0.32-0.9) and 0.82 ± 0.25 (range, 0.5-1.2), respectively. The mean spherical equivalent decreased significantly (P < 0.05) with 3.5 diopters (D). Mean K values (average keratometry of the cornea) decreased from 46.81 ± 2.13 D (range, 44-51 D) to 43.97 ± 2.22 D (range, 42-47.5 D) 1 year after the treatment. The average preoperative thinnest pachymetry measured 462 ± 46 μm (range, 410 ± 546 μm) and did not change significantly after the treatment. In patient 1, the inferior ICRS was removed 5 months postoperatively because of implant migration. The combined treatment of corneal cross-linking and Ferrara ICRS is a safe procedure that may be considered in patients with progressive mild to moderate KC and contact lens intolerance.

Purpose To present and clinically validate a novel software tool that automatically compares tomographic parameters and evaluates keratoconus progression based on prespecified criteria. Materials and Methods Two graders (one cornea specialist and one general ophthalmologist) evaluated two tomographic scans (Pentacam; Oculus Optikgerate GmbH, Wetzlar, Germany) of keratoconus patients separated by more than 4 months and subjectively classified each image pair in 0 – no progression, 1 – doubtful progression, 2 – clear progression. The agreement between the automated software and each grader was evaluated: percentage of agreement and Cohen’s kappa coefficient (k): 0 to 0.2 (poor); 0.2 to 0.4 (fair); 0.4 to 0.6 (moderate); 0.6 to 0.8 (substantial) and 0.8 to 1.0 (almost perfect). Results We included 43 eyes from 26 keratoconus patients (age 27.9±6.9 years) that underwent consecutive tomographic evaluation (7.5±2.6 months between exams). The agreement between the software and a cornea specialist was very high, 92.3% [95% CI 0.88-0.97, p<0.001], with a Cohen’s K of 0.80 [95% CI 0.67-0.93, p<0.001], representing almost perfect agreement. The agreement with a general ophthalmologist was lower, 88.4% [95% CI 0.83-0.93, p<0.001], with a Cohen’s K of 0.66 [95% CI 0.51-0.83, p<0.001], representing substantial agreement. Conclusions The proposed software tool demonstrates excellent agreement with an expert grader in keratoconus progression. This tool may be useful in quickly comparing critical tomographical parameters in serial exams of keratoconus patients, thus potentially improving clinical workflows. Furthermore, it may be a useful adjunct to the general ophthalmologist who may not be familiar with either tomographic examinations and/or evaluation of keratoconus progression.

(English) Due to advanced diagnostic instruments for detection of early-stage keratoconus (KC), and procedures that halt its progression such as corneal collagen cross-linking (CXL), optometry clinics are now seeing less severe cases of irregular corneas. As a result, optometrists are treating earlier stages of KC, and contact lens (CL) solutions for earlier stages of the disease are warranted. This thesis comprehensively evaluated the utility of two specialty soft lenses for KC of varying diameters and thicknesses in 40 eyes (N=20, mean age: 39±10, range: 23-55 yrs.) with KC grade 1 or 2 (based on Amsler-Krumeich) using a randomized, crossover, prospective longitudinal (up to one year follow-up) clinical design. The visual quality, contrast sensitivity, higher order aberrations (HOA), subjective satisfaction and wearer preference were compared between SoftK2 and Semi-scleral SoftK lenses. Objective visual outcomes were also compared with those obtained with gold-standard RGP lenses. Both soft lens designs significantly improved high contrast visual acuity (SoftK2 0.05±0.07, Semi-scleral SoftK 0.10±0.09LogMAR) compared with the habitual state (0.23±0.27 LogMAR). SoftK2 lenses provided low contrast VA 0.29±0.15 LogMAR), high contrast VA (0.04±0.06 LogMAR), contrast sensitivity (1.55±0.12 Log units), and HOA similar to GP lenses (low contrast visual acuity 0.27±0.17 Log MAR, high contrast visual acuity 0.07±0.07 LogMAR and contrast sensitivity 1.55±0.10 LogCS units). With low contrast, Semi- scleral SoftK did not show statistical significance compered to SoftK2 and from habitual state (0.40±0.2 Semi-scleral SoftK 0.52±0.3 habitual). No adverse events, limbal or conjunctival redness, papillary reaction, unusual appearances, or patient complaints requiring clinical action were noted at any of the follow-up visits with either lens type. The SoftK2 lens was preferred by 75% of the participants and had fewer participants with reported adverse events of dryness sensation after two weeks of wear. More participants continued its use over a period of 12-month with SoftK2 (7 participants were still using SoftK2 after 12 months, while no one was with Semi- scleral SoftK). SoftK2, Semi-scleral SoftK, and scleral GP lenses showed significant improvements of coma, trefoil, and tetrafoil HOAs compared to the uncorrected state, without significant differences between the lenses. SoftK2 and Semi-scleral SoftK lenses induced corneal swelling with clinically significant values in the periphery (7%-9% higher than the habitual state), which implies careful monitoring of eventual physiological adaptation changes to sustained hypoxia induced by the lens over time. The soft lenses were expected to only partially correct the refractive error of the KC participants leaving a small residual astigmatism. Since no clinical test currently exists to detect alterations in visual perception due to residual uncorrected astigmatism, an early part of the dissertation, was devoted to examining the utility of a novel test developed by Prof. Arnold Wilkins (UK), the Wilkins Egg and Ball Test (WEBT) to address this question. The results of the WEBT were compared between three cohorts: 32 normal participants (mean age: 24±5) under baseline and induced cylinder ,22 keratoconic eyes (N=13, mean age: 36±12) and 23 astigmatic participants (mean age: 36±12). The WEBT was found to be sensitive to overall blur and not to residual astigmatic blur. Its measurements with Soft K2 compared with Semi-scleral SoftK lenses were not significantly different. We conclude that specialty soft lens designs for keratoconus are a viable alternative for KC patients with Stage 1 or 2 in terms of visual quality and tolerance. However, more research is needed to evaluate the long term eventual physiological implications of induced corneal swelling. (Català) A causa dels instruments diagnòstics avançats per a la detecció del queratocon (QC) en fases primerenques, i de procediments que n’aturen la progressió com el cross-linking (CXL), a les consultes d'optometria ara s’estan atenent casos menys avançats de còrnies irregulars. Com a resultat, els optometristes tracten fases més primerenques del QC, i les solucions de lents de contacte (LC) per a aquestes etapes inicials són necessàries. Aquesta tesi va avaluar exhaustivament la utilitat de dues lents toves especialitzades per al QC, amb diferents diàmetres i gruixos, en 40 ulls (N=20, edat mitjana: 39±10, rang: 23-55 anys) amb QC grau 1 o 2 (segons Amsler-Krumeich) utilitzant un disseny clínic aleatoritzat, creuat, prospectiu i longitudinal (amb seguiment de fins a un any). Es van comparar la qualitat visual, la sensibilitat al contrast, les aberracions d'alt ordre (HOA), la satisfacció subjectiva i la preferència dels usuaris entre les lents toves SoftK2 i les Semi-esclerals SoftK. També es van comparar els resultats visuals amb els obtinguts amb les lents RGP, que són el patró de referència. Ambdós dissenys de lents toves van millorar significativament l'agudesa visual en alt contrast (SoftK2 0,05±0,07, Semi-escleral SoftK 0,10±0,09 LogMAR) en comparació amb l'estat habitual (0,23±0,27 LogMAR). Les lents SoftK2 van proporcionar agudesa visual en baix contrast (0,29±0,15 LogMAR), agudesa visual en alt contrast (0,04±0,06 LogMAR), sensibilitat al contrast (1,55±0,12 unitats Log) i HOA similars a les lents RGP (agudesa visual en baix contrast 0,27±0,17 LogMAR, agudesa visual en alt contrast 0,07±0,07 LogMAR i sensibilitat al contrast 1,55±0,10 unitats LogMAR). Pel que fa al baix contrast, les lents Semi-esclerals SoftK no van mostrar una diferencia estadísticament significativa en comparació amb les SoftK2 ni amb l'estat habitual (0,40±0,2 Semi-escleral SoftK 0,52±0,3 habitual). No es van observar raccions adverses, ni enrogiment limbal o conjuntival, ni reacció papil·lar, ni aparences inusuals, ni queixes dels pacients que requerissin acció clínica en cap de les visites de seguiment amb cap dels dos tipus de lents. El 75% dels participants van preferir les lents SoftK2 i hi va haver menys participants que reportessin esdeveniments adversos de sensació de sequedat després de dues setmanes d’ús. Més participants van continuar utilitzant LC durant un període de 12 mesos amb SoftK2 (7 participants encara utilitzaven SoftK2 després de 12 mesos, mentre que ningú ho feia amb les Semi-esclerals SoftK). Les lents SoftK2, Semi-escleral SoftK i esclerals GP van mostrar millores significatives en coma, trèvol i tetrafoil de les HOA en comparació amb l'estat sense correcció, sense diferències significatives entre les lents. Les lents SoftK2 i Semi-escleral SoftK van induir edema corneal amb valors clínicament significatius a la perifèria (un 7%-9% més que l'estat habitual), cosa que implica la necessitat de controlar amb cura els possibles canvis d'adaptació fisiològica a causa de la hipòxia sostinguda induïda per la lent amb el temps. S'esperava que les lents toves només corregissin parcialment l'error refractiu dels participants amb QC, deixant un petit astigmatisme residual. Com que actualment no hi ha cap prova clínica per detectar alteracions en la percepció visual causades per l’astigmatisme residual no corregit, una part inicial de la tesi es va dedicar a examinar la utilitat d’una prova innovadora desenvolupada pel professor Arnold Wilkins (Regne Unit), el test de l'Ou i la Pilota de Wilkins (WEBT), per abordar aquesta qüestió. Els resultats del WEBT es van comparar entre tres cohorts: 32 participants normals (edat mitjana: 24±5) en condicions de base i cilindre induït, 22 ulls queratocònics (N=13, edat mitjana: 36±12) i 23 participants amb astigmatisme (edat mitjana: 36±12). Es va trobar que el WEBT era sensible al desenfocament general, però no al desenfocament astigmàtic residual. Les seves mesures amb SoftK2 en comparació amb les lents Semi-esclerals SoftK no van mostrar diferències significatives. Concloem que els dissenys de lents toves especialitzades per a queratocon són una alternativa viable per a pacients amb QC en Estadis 1 o 2 pel que fa a la qualitat visual i la tolerància. No obstant això, es necessiten més investigacions per avaluar les possibles implicacions fisiològiques a llarg termini de l’edema corneal induït. (Español) Gracias a los instrumentos de diagnóstico avanzados para la detección del queratocono (KC) en etapas tempranas, y a los procedimientos que detienen su progresión, como el cross-linking (CXL), las clínicas de optometría ahora están viendo casos menos severos de córneas irregulares. Como resultado, los optometristas están tratando etapas más tempranas del KC, y las soluciones de lentes de contacto (CL) para estas etapas iniciales de la enfermedad son necesarias. Esta tesis evaluó de manera integral la utilidad de dos lentes blandas especializadas para KC de diferentes diámetros y grosores en 40 ojos (N=20, edad media: 39±10, rango: 23-55 años) con KC grado 1 o 2 (basado en Amsler-Krumeich) utilizando un diseño clínico prospectivo longitudinal aleatorizado y cruzado (seguimiento de hasta un año). Se compararon la calidad visual, la sensibilidad al contraste, las aberraciones de alto orden (HOA), la satisfacción subjetiva y la preferencia de los usuarios entre los lentes SoftK2 y SoftK Semiescleral. También se compararon los resultados visuales objetivos con los obtenidos con lentes RGP, que son el estándar de referencia. Ambos diseños de lentes blandas mejoraron significativamente la agudeza visual de alto contraste (SoftK2 0.05±0.07, SoftK Semiescleral 0.10±0.09LogMAR) en comparación con el estado habitual (0.23±0.27 LogMAR). Los lentes SoftK2 proporcionaron agudeza visual de bajo contraste (0.29±0.15 LogMAR), agudeza visual de alto contraste (0.04±0.06 LogMAR), sensibilidad al contraste (1.55±0.12 unidades Log) y HOA similares a los lentes GP (agudeza visual de bajo contraste 0.27±0.17 Log MAR, agudeza visual de alto contraste 0.07±0.07 LogMAR y sensibilidad al contraste 1.55±0.10 unidades LogCS). En bajo contraste, los SoftK Semiesclerales no mostraron una diferencia estadísticamente significativa en comparación con los SoftK2 y con el estado habitual (0.40±0.2 SoftK Semiescleral, 0.52±0.3 habitual). No se observaron eventos adversos, enrojecimiento limbal o conjuntival, reacción papilar, apariencias inusuales o quejas de los pacientes que requirieran acción clínica en ninguna de las visitas de seguimiento con ninguno de los tipos de lentes. La lente SoftK2 fue preferida por el 75% de los participantes y tuvo menos eventos adversos reportados, como la sensación de sequedad después de dos semanas de uso. Más participantes continuaron su uso durante un período de 12 meses con SoftK2 (7 participantes aún usaban SoftK2 después de 12 meses, mientras que ninguno continuaba con SoftK Semiescleral). Las lentes SoftK2, SoftK Semiescleral y GP esclerales mostraron mejoras significativas en las aberraciones HOA de coma, trébol y tetrafoil en comparación con el estado no corregido, sin diferencias significativas entre las lentes. Los lentes SoftK2 y SoftK Semiescleral indujeron edema corneal con valores clínicamente significativos en la periferia (7%-9% más altos que el estado habitual), lo que implica la necesidad de un seguimiento cuidadoso de los cambios de adaptación fisiológica eventual por la hipoxia sostenida inducida por la lente con el tiempo. Se esperaba que las lentes blandas solo corrigieran parcialmente el error refractivo de los participantes con KC, dejando un pequeño astigmatismo residual. Dado que actualmente no existe una prueba clínica para detectar alteraciones en la percepción visual debido al astigmatismo residual no corregido, una parte temprana de la disertación se dedicó a examinar la utilidad de una prueba innovadora desarrollada por el Prof. Arnold Wilkins (Reino Unido), la prueba del Huevo y la Pelota de Wilkins (WEBT), para abordar esta cuestión. Los resultados del WEBT se compararon entre tres cohortes: 32 participantes normales (edad media: 24±5) bajo cilindro basal e inducido, 22 ojos con queratocono (N=13, edad media: 36±12) y 23 participantes astigmáticos (edad media: 36±12). Se encontró que el WEBT es sensible al desenfoque general, pero no al desenfoque astigmático residual. Sus mediciones con SoftK2, en comparación con las lentes SoftK Semiescleral, no fueron significativamente diferentes. Concluimos que los diseños de lentes blandas especializadas para queratocono son una alternativa viable para pacientes con KC en etapas 1 o 2 en términos de calidad visual y tolerancia. Sin embargo, se necesita más investigación para evaluar las posibles implicaciones fisiológicas a largo plazo del edema corneal inducido.

PurposeTo evaluate the safety and efficacy of corneal collagen cross-linking (CXL) performed on overlaying a corneal lenticule to thin recipient corneas of progressive keratoconus (KC) patients.MethodsIn this study were enrolled eyes of patients affected by progressive KC with a minimum corneal thickness less than 400 µm, after overlaying a lenticule of human corneal stroma prepared with the femtosecond laser. The lenticules used were 100 µm thick and of 8.5 mm diameter in all the cases. Both the host cornea and the lenticules were subjected to epithelial debridement. CXL was carried out according to the standard protocol. Visual acuity, refraction, slit-lamp examination, endothelial cell density, pachymetry and keratometry, anterior segment tomography (AS-OCT) and confocal microscopy were evaluated preoperatively and at 1, 3, 6 and 12 months postoperatively.ResultsCXL was performed in 10 eyes of 8 patients (main age 23), corneal thickness range 379–414 µm, mean 387.6 µm. One patient was lost at follow-up. In all other cases, visual acuity and the endothelial cell density remained stable over a 12-month follow-up. Preoperative mean K1 and mean K2 were 46.91 ± 1.9 and 50.75 ± 2.93, respectively, and at 12 months mean K1 was 47.36 ± 2.66 and mean K2 50.53 ± 3.35. The AS-OCT clearly showed a demarcation line in all patients at 1, 3 (mean depth 283 µm and 267 µm, respectively) and in some cases at 6 months. Reduced keratocyte density and stromal oedema were observed immediately up to 1 month after treatment, while a slight subepithelial haze was present at 1-month and completely disappeared by 6 months.ConclusionThis new technique seems to offer a therapeutic opportunity for young patients suffering from progressive KC with very thin corneas, in which the standard treatment is not indicate, and delay or avoid the need for a corneal transplant.

Background Keratoconus (KC) is a progressive corneal ectasia traditionally viewed as noninflammatory. However, emerging evidence suggests an inflammatory component involving cytokines such as interleukin-6 (IL-6). Objectives To evaluate serum IL-6 levels in cases with KC and determine its diagnostic and predictive value. Patients and methods This comparative cross-sectional study included 25 KC cases and 25 age-matched and sex-matched healthy controls. All participants underwent a full ophthalmologic assessment, including Sirius topography. Serum IL-6 levels were measured using enzyme-linked immunosorbent assay. Results KC cases showed significantly lower intraocular pressure (13±3 vs. 15±3 mmHg, P =0.019), steeper keratometric readings (K1: 46.5±6.71 vs. 42.28±1.77 D, P =0.005; K2 and K-max: both 50.2±7.1 vs. 43.8±1.96 D, P &lt;0.001), and thinner corneas (450±59 vs. 537±36 μm, P &lt;0.001). Serum IL-6 levels were substantially elevated in KC cases (99±33 vs. 58±10 ng/l, P &lt;0.001). Receiver operating characteristic analysis revealed IL-6 could predict KC with an area under the curve of 0.899; a cutoff of more than 73 ng/l yielded 84% sensitivity and 96% specificity. For high-grade KC, IL-6 had moderate predictive ability (area under the curve=0.745; cutoff &gt;110 ng/l). Logistic regression showed each 1 ng/l increase in IL-6 increased KC risk by 9.9% (odds ratio=1.099; 95% confidence interval: 1.032–1.169; P =0.003). Conclusion Serum IL-6 is elevated in KC cases and is considered a valuable biomarker for diagnosis and assessment of disease severity.

Keratoconus (KC) is a progressive corneal ectasia leading to visual impairment if untreated. Corneal collagen cross-linking (CXL) is an effective treatment to halt KC progression by strengthening corneal biomechanics. However, current CXL treatments lack customization based on regional corneal stiffness, which is crucial for optimal outcomes. This study introduces a novel approach using Stress-Strain Index (SSI) maps to evaluate localized CXL effects on corneal biomechanics. Numerical modelling based on the finite element method was used to carry out inverse analysis of the human eye to simulate KC and CXL treatments, incorporating regional stiffness variations based on collagen fibril density. SSI maps were generated pre- and post-CXL to assess stiffness changes in treated regions. Results demonstrated that CXL increased corneal stiffness within the treated area, but the extent of stiffness recovery varied with CXL diameter and alignment with the KC cone. Smaller CXL diameters led to higher localized stiffness increases, while misalignment between CXL and KC areas resulted in suboptimal biomechanical restoration. The study highlights the potential of SSI mapping for personalized CXL treatments, enabling precise targeting of biomechanically weakened regions to restore corneal health. This approach contributes to the development of biomechanics-based customization of CXL therapies.