Treatment Of Progressive Keratoconus Research Articles

Early findings in a randomised controlled trial on crosslinking protocols using isoosmolar and hypoosmolar riboflavin for the treatment of progressive keratoconus.

To present baseline characteristics and to present the perioperative corneal thickness during corneal crosslinking (CXL) treatment for progressive keratoconus and to describe how the addition of sterile water (SW) efficaciously can maintain the corneal thickness. The treatment efficacy will be evaluated when the 1-year follow-up is complete. A randomised clinical study using epithelium-off CXL with continuous UVA irradiation (9 mW/cm2) and two kinds of riboflavin solutions: (i) isoosmolar dextran-based riboflavin (n = 27) and (ii) hypoosmolar dextran-free riboflavin (n = 27). progressive keratoconus with an increase in maximum keratometry value (Kmax) of 1.0 dioptre (12 months) or 0.5 dioptres (6 months). Corneae thinner than 400 μm were also included. Perioperative corneal thickness and the effect of adding SW. Seventy-four per cent of the patients in the isoosmolar group and 15% in the hypoosmolar group required the addition of SW, which effectively maintained a corneal thickness of 400 μm in all cases during CXL. The addition of SW was primarily needed during the irradiation procedure and not the preoperative soaking period. Especially during the CXL irradiation phase, isoosmolar riboflavin causes a significant dehydrating effect leading to corneal thinning during CXL. The customised addition of SW is efficacious in maintaining the corneal thickness during CXL and could increase the safety of the procedure.

Progressive high-fluence epithelium-on accelerated corneal crosslinking: a novel corneal photodynamic therapy for early progressive keratoconus.

To assess the preliminary clinical results of a new, progressively higher fluence-pulsed light Epi-On accelerated crosslinking nomogram (PFPL M Epi-On ACXL) in the treatment of progressive keratoconus (KC). Siena Crosslinking Center, Siena, Italy. A prospective pilot open, non-randomized interventional study, including 32 eyes of 32 young-adult patients over 26 years old with Stages I-III progressive KC undergoing PFPL M Epi-On ACXL, was conducted. Riboflavin loading was performed by using Paracel I 0.25% for 4 min and Paracel II 0.22% for 6 min. The Avedro KXL System (Glaukos-Avedro, Burlington, USA) was used for pulsed-light accelerated crosslinking (ACXL) at air room 21% oxygenation and 13 min of UV-A irradiation. The treatment fluence was set at 7.2 J/cm2, 8.6 J/cm2, and 10.0 J/cm2 in corneas with baseline pachymetry <420 μm (group 1: 8 eyes), ≥ 420 μm <460 μm (group 2, 11 eyes), and ≥ 460 μm (group 3, 13 eyes), respectively. Uncorrected distance visual acuity (UDVA), best-spectacle corrected visual acuity (BSCVA), Scheimpflug corneal tomography, and anterior segment OCT (AS-OCT) data were collected at baseline and postoperatively at 1, 3, and 6 months. UDVA and BSCVA improved in all groups (P ≤ 0.05). Maximum keratometry values (K max) showed a significant decrease in the 10.0 J/cm2 group (Δ -1.68 D). The coma (HOAs) value improved significantly by the sixth month in all groups. OCT average demarcation lines were 211 ± 19 μm in group 1, 245 ± 23 μm in group 2, and 267 ± 21 μm in group 3. The preliminary results show that pachymetry-based PFPL M Epi-On ACXL nomogram stabilizes ectasia progression. Higher fluence Epi-On ACXL increases CXL penetration, with better functional outcomes in the absence of complications.

CUSTOMIZED CORNEAL CROSSLINKING WITH EXCIMER LASER ASSISTED EPITHELIUM REMOVAL FOR PROGRESSIVE KERATOCONUS - ONE YEAR RESULTS.

To evaluate the one year visual and tomographic results of customized cross-linking using excimer laser assisted epithelium removal and topography-guided irradiation in the treatment of progressive keratoconus. Coimbra Ophthalmology Unit. Private practice. Coimbra, Portugal. Prospective non-randomized clinical trial. Eyes with documented progressive keratoconus were enrolled. Following de-epithelization with PTK, customized UV irradiation was performed, designed as 3 concentric circular areas centered on the thinnest point (Mosaic System, Avedro, USA). Energy exposure was 5.4J/cm2 in the outer circle and then increased centripetally to 7.2 J/cm2 and 10 J/cm2 . Corrected distance visual acuity (CDVA), refractive outcomes, and Scheimpflug tomographies (Allegro Oculyzer (WaveLight, Germany) were assessed at baseline, and 6 and 12 months postoperatively. This prospective study enrolled 37 eyes of 32 patients. Mean diameter for treated areas was 6.17 ± 0.80, 4.45 ± 0.47, and 2.58 ± 0.14 mm for the outer, medium, and inner circle, respectively. At the 1 year follow-up, mean CDVA improved significantly from 0.38 ± 0.19 to 0.20 ± 0.16 logMAR (p<0.01), with 34 of the 37 eyes (91.89%) retaining or improving CDVA. Mean pre-operative minimum pachimetry decreased from 449.26 ± 41.62 μm to 443.26 ± 41.06 μm (p=0.02). The maximal curvature (Kmax) decreased significantly from 58.50 ± 7.84 D to 57.05 ± 7.27 D (p<0.01). After 1 year, 34 eyes (91.89%) showed no signs of progression. One year after surgery, patients showed a significant improvement in visual acuity while achieving stabilization of disease progression.

Tear film mediators after corneal cross‐linking

AbstractBackground and Purpose: Currently, the gold‐standard treatment of progressive keratoconus (KC) is corneal collagen cross‐linking (CXL), in which riboflavin and ultraviolet‐A radiation increase the corneal biomechanical rigidity, arresting progression. However, post‐operatory results vary significantly among patients. Although it has been suggested that corneal thickness, cone location and patient's age are important factors, their contribution is controversial. The reason for this variability remains obscure. This project aims to find biomarkers that could explain the variability within surgical results after corneal CXL by investigating the correlation between the local corneal inflammatory environment and these results. We hypothesize that better post‐operatory results are related to a reduction in the inflammatory cytokine levels in the patients' tear film. Ultimately, we aim to optimize the patients' surgical outcomes according to their corneal inflammatory environment.Materials and Methods: The research protocol was established after testing different sample collection methods. Patients are interviewed to assess their medical history and relevant habits. Their corneal tomographic and best corrected visual acuity data are registered before and 6 months after surgery. The patient's tear film is sampled twice 6 months apart using Schirmer strips, as the volume yield is larger compared with direct methods (microcapillary tubes or micropipettes), which are more difficult to perform and require stimulation or the instillation of saline into the cul‐de‐sac, originating reflex tearing. The samples are analysed for their total protein content (BCA Protein Assay Kit) and cytokine concentration using Multiplex technology (Th1/Th2/Th9/Th17 Cytokine 18‐Plex Human ProcartaPlex™ Panel) and not ELISA, as we tried before. Statistical analysis to assess sample differences and the correlation between cytokine concentration and tomographic indexes and visual acuity values for each group and subgroup is performed at 6 months.Preliminary results and Discussion: Thirty‐five patients and fifteen control subjects have been enrolled in the study and the first collection of tears has been carried out, as well as some second collections. CXL surgeries for the twenty patients is being performed since October 2020. Two samples were lost due to excessively length of dry Schirmer strip, which we improved by cutting the dry portion. Additionally, the tear fluid from the first eight samples from patients and from control participants was successfully processed for their total protein content.Conclusion: Tear film analysis poses several challenges concerning the small amount of material available without reflex production. This fact precludes the use of conventional ELISA, requiring multiplex modified technology. When dealing with tears it is also important to avoid contamination by using sterilized material, to avoid dilution and to establish an efficient flow of samples from the clinic to the laboratory. This pilot study enabled to identify several methodological frailties and to establish a solid research protocol that can be replicated by other researchers. Understanding the correlation between inflammatory cytokines and surgical outcomes of CXL may allow for the optimization and personalization of CXL. In addition, the results of this research protocol are expected to establish prognostic factors for CXL‐related surgical outcomes, ultimately improving the quality of life of KC patients.

Динамика кератотопографических и биомеханических параметров роговицы после проведения акселерированного ультрафиолетового кросслинкинга с использованием защитного лоскута донорской роговицы в лечении прогрессирующего кератоконуса при «тонкой роговице»

Purpose. To analyze changes in the biomechanical and topographic parameters of the patient's cornea using the Corvis st (OCULUS, Germany) and Pentacam (OCULUS, Germany) device before and after accelerated ultraviolet crosslinking of the cornea using a donor cornea protective flap in the treatment of progressive keratoconus with "thin cornea" and compare the obtained data with the results after classical accelerated crosslinking. Material and methods. According to the proposed technology, 26 patients (26 eyes) were operated on with a diagnosis of progressive keratoconus 2nd stage with corneal pachymetry less than 400 µm, mean value 390 ± 40 µm. Comparison group – patients diagnosed with progressive keratoconus 2nd stage with corneal pachymetry over 400 µm, mean value 450 ± 40 µm, comparable in age and gender, being operated on using the technology of classical accelerated crosslinking. In addition to standard research methods, before and after surgery, patients underwent an assessment of the biomechanical and topographic parameters of the patient's cornea using the Corvis st (OCULUS, Germany) and Pentacam (OCULUS, Germany) devices. Results. The results obtained in both groups were comparable in all parameters: there was a decrease in keratometric parameters in the first months after the operation, with their further stabilization during the entire period of observation. The pachymetry value remained stable, no significant changes in UCVA and Correctable Visual Acuity were detected. Evaluation of specific keratotopographic indices (ISV, IVA, KI, CKI, IHD) showed their decrease both in the main and control groups, and Rmin tended to increase. The value of the inscribed radius tended to decrease, which indicates an increase in the stiffness of the cornea after classical accelerated crosslinking and crosslinking of the proposed technology. Conclusion. Application of the technology of accelerated ultraviolet crosslinking using a protective flap of the donor cornea in the treatment of progressive keratoconus with "thin cornea" leads to an increase in the rigidity of the cornea and stabilization of the ectatic process of the cornea in the postoperative period, just as with the classical technology of accelerated crosslinking. Keywords: progressive keratoconus, "thin cornea", accelerated ultraviolet crosslinking using a donor cornea protective flap, keratopotographic parameters of the cornea, biomechanical parameters of the cornea.

Transepithelial Enhanced Fluence Pulsed Light M Accelerated Crosslinking for Early Progressive Keratoconus with Chemically Enhanced Riboflavin Solutions and Air Room Oxygen.

Purpose: To assess the 3-year clinical results of the 18 mW 7 J/cm2 transepithelial enhanced fluence pulsed light M accelerated crosslinking in the treatment of progressive keratoconus (KC) with chemically enhanced hyper-concentrated riboflavin solutions without iontophoresis and with air-room oxygenation. Setting: Siena Crosslinking Center, Siena, Italy. Methods: Prospective pilot, open non-randomized interventional study including 40 eyes of 30 young adult patients over 21 years old (10 simultaneous bilateral) with early (Stage I and II) progressive KC undergoing TE-EFPL 18 mW/7 J/cm2 ACXL (EFPL M TECXL). The 12 min and 58 s pulsed light (1 s on/1 s off) UV-A exposure treatments were performed with a biphasic corneal soaking using Paracel I 0.25% for 4 min and Paracel II 0.22% for 6 min riboflavin solutions and New KXL I UV-A emitter (Glaukos-Avedro, Waltham, USA) at an air room of 21% oxygenation. All patients completed the 3-year follow-up. Results: CDVA showed a statistically significant improvement in the third postoperative month (Δ + 0.17 d. e.) with a final gain of +0.22 d. eq. AK showed a statistically significant decrease in the sixth postoperative month (Δ − 1.15 diopters). K itmax showed a statistically significant decrease at 1-year follow-up (Δ − 1.3 diopters). The coma value improved significantly by the sixth month (Δ − 0.54 µm). MCT remained stable during the entire follow-up. No adverse events were recorded. Corneal OCT revealed a mean demarcation line depth at 282.6 ± 23.6 μm. Conclusions: Transepithelial enhanced fluence pulsed light M accelerated crosslinking with chemically enhanced riboflavin solution halted KC progression in young adult patients without iontophoresis and no intraoperative oxygen supplementation addressing the importance of increased fluence.

Comparison of accelerated corneal cross-linking for progressive keratoconus in pediatric and adult age groups: One-year results

To compare one-year results of accelerated cross-linking (ACXL) treatment for progressive keratoconus in pediatric and adult age groups. The records of patients who had undergone the ACXL procedure (9mV/cm2, 10min) for progressive keratoconus were evaluated retrospectively. The patients were divided into 2 groups, with the pediatric group aged 17years or less and the adult group aged 18years or more, for the statistical analysis. Pre- and 12-month post- ACXL best-corrected visual acuity (BCVA), maximum keratometry (Kmax), sim K1, sim K2, corneal thickness at the thinnest point (thCT), and corneal astigmatism (CA) values of the patient groups were recorded. Thirty-two right eyes of 32 patients were included in the pediatric group, and 32 right eyes of 32 patients were included in the adult group. A significant improvement in BCVA and a significant decrease in thCT values were present in both groups 12months after the surgery compared to the preoperative period. The decrease in Kmax, sim K1 and sim K2 values compared to the preoperative period was significant in the adult group. When the two groups were compared after 12months, only the simK1 value was significantly lower in the adult group, and there was no significant difference between the other measurements. There is a slight tendency toward more flattening in the adult group 12months after ACXL treatment, but this is not statistically significant.

Evaluation of the efficacy of high-fluence corneal collagen cross-linking in fusarium corneal ulcer in rabbits

Background Accelerated photoactivated chromophore for keratitis–corneal collagen cross-linking (PACK-CXL) was investigated to be effective in the treatment of fungal keratitis in many studies. High-fluence CXL was used effectively in the treatment of progressive keratoconus but not tested in PACK-CXL for fungal infection. Aim To evaluate the antifungal efficacy of high-fluence CXL in the treatment of induced fusarium corneal ulcer in rabbits. Design This is an experimental interventional study. Patients and methods This is an experimental interventional study conducted on 16 eyes of eight rabbits for which fusarium corneal infection was induced by intrastromal corneal injection. The rabbits were divided into two groups: group A received no treatment and was left as a control group. Group B received a single high-fluence PACK-CXL session. All rabbits were followed up for 6 days and then the eyes were enucleated. Culture was performed for seven corneas and histopathology for the remaining cornea. Results There was statistically significant deterioration in group A (P=0.003), while a statistically significant clinical improvement was seen in group B (P&lt;0.001). The median colony-forming units was more in group A (4×104) than in group B (2×102). Histopathological examination also revealed less inflammatory signs in high-fluence PACK-CXL-treated group. Conclusions High-fluence PACK-CXL total ultraviolet A fluence of 7.2 J/cm2 is effective in the treatment of mycotic keratitis.

Ultraviolet crosslinking of corneal collagen in patients with thin cornea. Literature review

For the treatment of progressive keratoconus in the early stages, corneal collagen crosslinking is currently actively used. This technique is based on the stabilization of the pathological process by increasing the biomechanical properties of the own cornea. The thickness of the cornea less than 400 microns significantly limits the possibility of a standard cross-linking procedure performing.The article analyzes the literature data on the use of various methods of corneal crosslinking with a corneal thickness of less than 400 microns, which signifi cantly limits the possibilities of the standard procedure.It is known, that during crosslinking, at the initial stage, de-epithelialization of the cornea is performed, which, in the postoperative period, leads to a pronounced corneal syndrome. This determined the direction of the fi rst modifi cations of the technique associated with the use of partial de-epithelialization or its complete absence. Later, during cross-linking of “thin” corneas, techniques with the use of additional covering materials were actively used in order to replenish the missing corneal tissue of the patient during the UV irradiation procedure. Among them are the use of a soft contact lens without an ultraviolet fi lter, the use of a corneal lenticule obtained after SMILE surgery, the use of a protective fl ap of the donor cornea obtained using a femtosecond laser from the residual stroma of the corneal disc after descemet membrane transplantation or posterior lamellar keratoplasty. The variety of the proposed modifications and the ongoing search for better options indicate the demand for this technology and the need for further research, taking into account the individual characteristics of the patient’s ectasia.

Comparative Results Between “Epi-Off” Accelerated and “Epi-Off” Standard Corneal Collagen Crosslinking-UVA in Progressive Keratoconus – 7 Years of Follow-Up

PurposeThe purpose of the present study was to assess the long-term efficiency and safety of the “epi-off” accelerated CXL (9 mW/cm2 for 10 minutes) in comparison to the standard “epi-off” CXL (3 mW/cm2 for 30 minutes) in terms of topographical and keratometric parameters, refractive data and visual outcomes at 7 years of follow-up, in progressive keratoconus.Material and MethodA retrospective and comparative study was performed. A total of 183 eyes from 183 patients with documented progressive keratoconus were included in the study. The patients were divided in two groups: 93 eyes from 93 patients underwent “epi-off” standard cross-linking technique (3 mW/cm2 for 30 minutes) (S-CXL group) and 90 eyes from 90 patients underwent accelerated “epi-off” corneal CXL technique (9 mW/cm2 for 10 minutes) (A-CXL group).ResultsImprovements in uncorrected distance visual acuity (UDVA) were statistically significant compared to baseline values in both groups at each time-point visit (p=0.0421 at 1 year, p=0.0411 at 7 years for A-CXL and p=0.0375 at 1 year, p=0.0389 at 7 years for S-CXL). At 7 years there was a statistically significant increase in CDVA (p=0.039 in the A-CXL group and p=0.0343 in the S-CXL group at 7 years). Statistically significant reduction was noticed in Ksteep (p=0.0411 in A-CXL group and p=0.0224 in S-CXL group), Kflat (p=0.0198 in A-CXL group and p=0.008 in S-CXL group), K mean (p=0.0106 in A-CXL group and p=0.0193 in S-CXL group) and Kmax (p=0.0413 in A-CXL group and p=0.054 in S-CXL group) at 7 years, compared to baseline values, in both groups, but without any statistically difference between the two procedures, at all time-point visits (p>0.05).ConclusionThe long-term outcomes of “epi-off” accelerated corneal collagen crosslinking-UVA (9 mW/cm2 for 10 minutes) are similar to standard “epi-off” corneal collagen crosslinking procedure in the treatment of progressive keratoconus.

Accelerated versus Standard Corneal Cross-linking for Progressive Keratoconus in Syria.

PurposeTo compare the outcomes of accelerated versus standard corneal cross-linking for the treatment of progressive keratoconus.Methods In this retrospective comparative study, 63 eyes of 40 patients with progressive keratoconus were divided into two groups; 27 eyes in group one were treated with an accelerated protocol (10 mW/cm, 9 min) and 36 eyes in group two were treated with the standard method (3 mW/cm, 30 min). Visual acuity, refraction, corneal topography, corneal tomography, and anterior and posterior corneal higher-order aberrations (HOAs) were assessed preoperatively and 18–30 months postoperatively.ResultsThe LogMAR uncorrected and corrected distance visual acuity values were improved in both groups postoperatively. However, the improvement was significantly higher in group one (P 0.05, all). The flattening in the anterior keratometry readings, flat K, steep K, and average K were significantly higher in group two (P 0.001, all). The maximum anterior keratometry (AKf) values significantly decreased in both groups, whereas the maximum posterior keratometry (AKb) values increased. The reduction in the minimum corneal thickness (ThKmin) was significantly greater (36.49um) in group two, compared to 10.85um in group one. There was a significant increase in the posterior average keratometry, and a significant decrease in the posterior astigmatism, along 3 mm meridian in S-CXL (P = 0.03, P = 0.008, respectively), while the corresponding values showed no statistical significance in group one (P 0.05). The anterior corneal trefoil was significantly reduced in group one (P = 0.002), whereas anterior total HOAs and coma were significantly improved in group two (P 0.0014, all). The posterior corneal spherical aberration decreased significantly in group one (P = 0.02), while group two revealed significant reduction in the posterior trefoil values (P = 0.011). The change in the anterior maximum keratometry was significantly and positively correlated to the preoperative maximum keratometry in group two (P = 0.53, P = 0.003).ConclusionAn accelerated cross-linking protocol using 10 mW/cm for 9 min showed more visual improvement and less pachymetric reduction when compared to the standard protocol, however, anterior corneal flattening, posterior corneal steepening, and the change in the posterior astigmatism were significantly higher in the standard protocol; while corneal HOAs were improved in both protocols.

Методика акселерированного кросслинкинга с использованием защитного донорского лоскута роговицы в лечении прогрессирующего кератоконуса на «тонких» роговицах

Purpose. To develop a method of accelerated ultraviolet crosslinking with an initial corneal thickness equal to or less than 400 microns using a protective donor corneal flap. Definition of safety and effectiveness of this method in the treatment of progressive keratoconus. Material and methods. 20 patients (20 eyes) with a diagnosis of progressive keratoconus 2–3 stages were included in the study. The accelerated crosslinking was carried out with an IROC-VX-2000 device (Switzerland). A protective donor corneal flap was cut out by using a Femto LDV Z8 femtosecond laser (Ziemer, Switzerland). The thickness of the protective flap of the donor cornea was determined as the difference between 450 μm and the obtained value of the patient's pachymetry in 30 minutes of saturation with Dextralink in μm. Results. Indicators of uncorrected visual acuity and corrected visual acuity returned to the level of preoperative values and did not tend to decrease until the end of the observation period for 6 months. The average keratometry indices gradually decreased: after 3 months – 50.3 ± 1.5 μm, after 6 months – 48.9 ± 1.8 μm, by 12 months – 46.7 ± 2.1 μm. A decrease in elevation indicators of the anterior and posterior surfaces was marked on elevation maps throughout the observation period. Conclusion. The proposed ultraviolet crosslinking technique using a protective donor corneal flap in patients with corneal thickness 400 μm or less is reproducible. This technique proves its effectiveness and safety and allows to stabilize the condition in patients with progressive keratoconus with adequate visual function. This makes this technique necessary, taking into account the lack of adequate cross-linking technology with a thin cornea. Keywords: progressive keratoconus, thin cornea, ultraviolet crosslinking, protective donor corneal flap.

Efficacy and Safety of Corneal Collagen Crosslinking in Treatment of Progressive Keratoconus with Consideration to the Long-Term Results

Efficacy and Safety of Corneal Collagen Crosslinking in Treatment of Progressive Keratoconus with Consideration to the Long-Term Results

Long term results of accelerated 9\u2009mW corneal crosslinking for early progressive keratoconus: the Siena Eye-Cross Study 2

PurposeTo assess clinical results of the 9 mW/5.4 J/cm2 accelerated crosslinking (ACXL) in the treatment of progressive keratoconus (KC) over a span of 5 years.MethodsThe prospective open non-randomized interventional study (Siena Eye-Cross Study 2) included 156 eyes of 112 patients with early progressive KC undergoing the Epi-Off 9 mW/5.4 J/cm2 ACXL at the Siena Crosslinking Centre, Italy. The mean age was 18.05 ± 5.6 years. The 20-min treatments were performed using the New KXL I (Avedro, Waltham, USA), 10 min of 0.1% HPMC Riboflavin soaking (VibeX Rapid, Avedro, Waltham, USA) and 10 min of continuous-light UV-A irradiation. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), Kmax, coma, minimum corneal thickness (MCT), surface asymmetry index (SAI), endothelial cell count (ECC) were measured, and corneal OCT performed.ResultsUDVA and CDVA improved significantly at the 3rd (P = 0.028), Δ + 0.17 Snellen lines and 6th postoperative month, respectively (P < 0.001), Δ + 0.23 Snellen lines. Kmax improved at the 6th postoperative month (P = 0.03), Δ − 1.49 diopters from the baseline value. Also, coma aberration value improved significantly (P = 0.004). A mild temporary haze was recorded in 14.77% of patients without affecting visual acuity and without persistent complications. Corneal OCT revealed a mean demarcation line depth at 332.6 ± 33.6 μm.ConclusionThe 5-year results of Epi-Off 9 mW/5.4 J/cm2 ACXL demonstrated statistically significant improvements in UCVA and CDVA, corneal curvature and corneal higher-order aberrations which confers a long-term stability for progressive ectasia. Based on the results of the Siena Eye-Cross Study 2, the 9 mW/5.4 J/cm2 ACXL is a candidate to be the natural evolution of Epi-Off CXL treatment for the management of early progressive corneal ectasia, and thus optimize clinic workflow.

MyoRing Implantation with and without Corneal Collagen Crosslinking for the Management of Keratoconus

Purpose To evaluate the safety and efficacy of femtosecond laser-assisted MyoRing implantation with concurrent corneal collagen crosslinking (CXL) compared to MyoRing alone for the treatment of progressive keratoconus.MethodsA total of 60 patients were enrolled in this randomized controlled trial. The patients were randomly allocated into two groups. In the first group, MyoRing was implanted, while in the second, it was inserted in the corneal stroma using the same technique, along with simultaneous CXL. Visual, refractive, topographic, and abberometric outcomes were measured preoperatively and at every postoperative visit.ResultsData of 47 patients were available at the end of the study; 28 in the MyoRing group and 19 in the MyoRing + CXL group. The mean uncorrected distance visual acuity (UDVA) improved from 0.79 0.39 logMAR to 0.52 0.31 logMAR (P 0.05) in the MyoRing + CXL group and from 0.65 0.38 logMAR to 0.62 0.23 logMAR (P = 0.70) in the MyoRing group. CDVA changed from 0.33 0.19 logMAR to 0.25 0.16 logMAR (P = 0.10) in the MyoRing + CXL group and 0.32 0.22 logMAR to 0.33 0.17 logMAR (P 0.50) in the MyoRing group. The mean keratometry (Km) decreased from 47.5 2.7 D to 43.8 3.2 D (P 0.001) in the MyoRing group and 49.3 3.4 D to 45.1 3.0 D (P 0.001) in the MyoRing + CXL group. Besides, horizontal coma was significantly lower in the MyoRing + CXL group (P = 0.022).ConclusionMyoRing insertion combined with CXL is a safe and effective method for the treatment of keratoconus. The visual and topographic outcomes were comparable to that for MyoRing insertion after 10 months; however, horizontal coma was significantly lower in the MyoRing + CXL group.

Transepithelial Accelerated Corneal Collagen Cross-Linking: Two-Year Results.

PurposeTo report 2-year outcomes of trans-epithelial accelerated corneal collagen crosslinking (TE-ACXL) procedure in the treatment of progressive keratoconus patients.Patients and MethodsTwenty-four eyes from 24 patients who underwent TE-ACXL (6mW/cm2 for 15 minutes) were included in this retrospective interventional study. Best-corrected visual acuity (BCVA), keratometry values, thinnest corneal thickness (PachyMin) and topometric indexes were analysed preoperatively and at 6-month, 12-month, 18-month and 24-month postoperative. Progression was assessed by increase ≥1.00D in maximum keratometry (Kmax); increase ≥1.00D in corneal astigmatism; decrease ≥2% in PachyMin; increase ≥0.42 in D-index.ResultsThere were no complications during or after TE-ACXL. No significant differences (Δ) were observed between baseline and 12-month or 24-month postoperative: ∆BCVA (−0.08 ± 0.25, p=0.190; −0.04 ± 0.17, p=0.588), ∆Kmax (−0.08 ± 1.32, p=0.792; −1.04 ± 1.89, p=0.135), ∆Astigmatism (−0.15 ± 0.89, p=0.485; −0.24 ± 1.38, p=0.609), ∆PachyMin (−0.56 ± 15.70, p=0.882; 0.56 ± 18.74, p=0.931), ∆Index Surface Variation (∆ISV) (−2.11 ± 10.27, p=0.395; −4.67 ± 17.32, p=0.442), ∆Index Vertical Asymmetry (∆IVA) (−0.05 ± 0.17, p=0.208; −0.08 ± 0.26, p=0.397), ∆Index Height Decentration (∆IHD) (0.00 ± 0.02, p=0.368; −0.01 ± 0.04, p=0.484), ∆KI (0.00 ± 0.05, p=0.851; 0.01 ± 0.06, p=0.877) and ∆D-index (0.15 ± 1.14, p=0.572; 0.06 ± 1.36, p=0.892). Eleven to 33% of patients had disease progression at 24-month postoperative according to the parameters used to determine progression.ConclusionAlthough some patients maintain disease progression, TE-ACXL seems to be a safe and effective treatment for keratoconus over the 2-year follow-up period. Studies with longer follow-up periods and larger patient cohorts are recommended.

Safety, Efficacy, and Predictive Factors of Conventional Epithelium-Off Corneal Crosslinking in the Treatment of Progressive Keratoconus.

Purpose To report predictive factors of outcome of conventional epithelium-off corneal crosslinking (CXL) in the treatment of progressive keratoconus. Methods This is a monocentric observational retrospective study conducted at Eye and Ear International Hospital, Lebanon. All patients with progressive keratoconus who underwent CXL between January 2008 and January 2016, with minimal 3-years follow-up were included. Primary treatment outcomes were maximum keratometry (K max), best-corrected distance visual acuity (CDVA), and failure. Failure was defined as an increase of 1.00 diopters (D) or more in K max and/or an increase of 0.1 logMAR or more in CDVA and conversion to corneal transplantation. Statistical analysis was done to identify predictors of treatment success. Univariate and multivariate analyses were performed to determine the correlations between baseline parameters and outcomes, and an equation for predicting K max and CDVA was created. Results 156 eyes of 102 patients were enrolled. The mean age was 23.85 ± 6.52 years. Failure occurred in 31 eyes (19.87%). Gender and thinnest pachymetry did not have any impact on postoperative outcomes. Concerning the CDVA outcome, multivariate analysis showed that a better preoperative CDVA was associated with higher improvement in CDVA, and higher baseline K max and higher posterior mean K were associated with a worse outcome CDVA. Regarding postoperative K max, a higher baseline K max, a worse baseline CDVA, and a younger age were associated with less flattening postoperatively. Conclusion CXL is a safe and effective method in treating progressive keratoconus. However, the clinical benefits can differ among patients, and in our series, a nonnegligible number of cases show a continued progression of their ectasia. Further studies to identify predictors of postoperative progression prior to the procedure could help sort out good responders to treatment.

Comparison of High Intensity Accelerated Corneal Cross Linking Protocols in Treatment of Progressive Keratoconus;

Purpose: To compare the safety and efficacy of Accelerated Corneal Cross Linking (AXL) protocols ,9mW/cm2 for 10 min with 18mW/cm2 for 5 min in terms of refractive and topographic keratometric indices in patients with progressive keratoconus over 3, 6, 12 and 18 months follow-up.&#x0D; Study Design: Quasi experimental study.&#x0D; Place and Duration of Study: Armed Forces Institute of Ophthalmology Rawalpindi Pakistan, from Nov 2016 to Jun 2018.&#x0D; Material and Methods: Sixty eyes, 30 in each group, of 55 consecutive patients diagnosed with progressive keratoconus were enrolled through convenience sampling and were subjected to AXL with irradiance protocols of 18 watt/cm2 for 5 minutes in group 1 and 9mwatt/cm2 for 10 minutes in group 2. All patients underwent a comprehensive ophthalmic examination at baseline and postoperative follow up visits at 3, 6, 12 and 18 months. Primary outcome parameter was disease stability defined as increase in maximum keratometry over baseline K max of no more than 1 diopter at 1 year after AXL. Statistical analysis of data was performed with IBM SPSS software (version 20.0 SPSS). P value of &lt; 0.05 was considered as statistically significant.&#x0D; Results: Disease stability was 96 % in each group. At the final time point of 18 months, group 2 (AXL 9mmwatt/cm2 for 10 min) was superior as compared to group 1 (AXL 18mmwatt/cm2 for 5 min) in terms of flattening of steep and sim K (p = 0.007, 0.023 respectively).&#x0D; Conclusion: The two AXL protocols are safe and appear to show comparable efficacy in disease stability. They can be used alternatively in the treatment of progressive keratoconus.

Comparative Results Between "Epi-Off" Conventional and Accelerated Corneal Collagen Crosslinking for Progressive Keratoconus in Pediatric Patients.

PurposeThe aim of our study was to evaluate the efficacy and safety of epi-off conventional and accelerated corneal collagen cross-linking in the treatment of progressive keratoconus in pediatric patients up to 4 years after treatment.Patients and methodsConventional (standard) CXL epi-off technique was performed in 37 eyes (S-CXL group) and accelerated CXL in 27 eyes (A-CXL group). Refraction, keratometry, cylindrical equivalent, spherical equivalent, slit lamp examination, pachymetry, corneal tomography, anterior segment ocular coherence tomography and visual acuity were performed up to 4 years.ResultsIn the S-CXL group: the flat K values decreased from 47.41±3.39 D to 45.36±3.62 D at 4 years (p=0.004); steep K decreased from 51.98±4.11 to 50.21±4.81 D at 4 years (p=0.0078); mean K decreased with 1.99 D at 4 years (p=0.009). In the A-CXL group: the flat K values decreased from 46.97±4.17 D to 44.97±4.24 D at 4 years (p=0.048); steep K decreased from 50.55±4.10 D to 48.75±4.17 D at 4 years (p=0.0287); mean K decreased from 48.79±3.86 D to 46.86±4.11 D at 4 years (p=0.0356). The preoperative mean UCVA in the S-CXL group was 0.8 ±0.23 logMar and improved during the follow-up reaching 0.65 ±0.24 logMar at 4 years (p=0.072). The baseline mean UCVA in A-CXL group was 0.77±0.25 logMar and increased during the follow-up to 0.63 ±0.25 logMar at 4 years (p=0.0039). A similar improvement of BCVA was observed during the follow-up.ConclusionEpi-off conventional and accelerated CXL are efficient procedures for progressive keratoconus in pediatric patients. Accelerated and conventional CXL were comparable at all time points and both represent viable options for the therapy of KC in these patients.

Efficacy of pulsed-light accelerated crosslinking in the treatment of progressive keratoconus: Two-year results.

The aim of this study was to evaluate the 2-year results of epithelium-off pulsed-light accelerated corneal collagen crosslinking treatment in progressive keratoconus using 30 mW/cm2 ultraviolet A light for 6 min with a total dose of 5.4 J/cm2. A total of 30 eyes of 22 patients with documented progressive keratoconus and treated with epithelium-off pulsed-light accelerated corneal collagen crosslinking using the KXL® crosslinking device (Avedro Inc, Waltham, MA, USA) were included in this retrospective study. Corneal tomographic measurements and best spectacle-corrected visual acuity were compared using analysis of variance with repeated measurements between the baseline visit (before the corneal collagen crosslinking treatment), and the sixth month, first, and second year visits. Flat keratometry (K1), steep keratometry (K2), and mean keratometry (Km) decreased significantly at sixth month, first, and second years (p < 0.001, p = 0.001, and p < 0.001, respectively). Maximum keratometry (Kmax) decreased from 55.40 ± 4.90 D at baseline to 54.82 ± 4.68 D, 54.80 ± 5.12 D, and 54.65 ± 5.36 D at sixth month, first year, and second year, respectively (p = 0.007). The best spectacle-corrected visual acuity improved from 0.34 ± 0.24 logMAR at baseline to 0.25 ± 0.16 logMAR, 0.22 ± 0.15 logMAR, and 0.17 ± 0.13 logMAR at sixth month, first year, and second year, respectively (p < 0.001). At the second year visit, best spectacle-corrected visual acuity remained stable (no lines lost) with respect to the baseline in 8 eyes and increased 1 or more lines in 22 eyes. Pulsed-light accelerated corneal collagen crosslinking using 30 mW/cm2 ultraviolet A light for 6 min with a total dose of 5.4 J/cm2 is an effective treatment modality in cases with progressive keratoconus-it stops progression at 2 years also regresses some of the cases.