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

Abstract Purpose To 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. Methods The 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. Results UDVA 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. Conclusion The 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.

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Long term results of accelerated corneal collagen cross-linking in pediatric keratoconus

European Journal of Ophthalmology ◽

10.1177/11206721211018362 ◽

2021 ◽

pp. 112067212110183

Author(s):

Yasin Cinar ◽

Cagla Cilem Han ◽

Alparslan Sahin ◽

Zeba A Syed

Keyword(s):

Visual Acuity ◽

Corneal Thickness ◽

University Hospital ◽

Long Term Results ◽

Cross Linking ◽

Distance Visual Acuity ◽

The Mean ◽

Collagen Cross Linking ◽

Corneal Collagen

Purpose: To evaluate the long term visual, refractive, and corneal tomographic outcomes of epithelium-off accelerated corneal collagen cross-linking (ACXL) in the management of pediatric keratoconus (KC). Methods: This retrospective study included patients under 18 years old with progressive KC who underwent ACXL between 2012 and 2019 at Dicle University Hospital. Complete ophthalmic examination was performed including uncorrected distance visual acuity (UDVA), best spectacle-corrected distance visual acuity (CDVA), manifest refraction, and corneal tomography. Evaluations were performed preoperatively and at 6 months intervals postoperatively. Results: Forty-nine eyes of 49 patients were included in the study. The mean age of patients at the time of ACXL was 14.2 ± 1.8 (range: 9.5–17.3) years. Mean follow up was 4.61 ± 1.90 (range: 2.0–8.1) years. The mean LogMAR UDVA improved from 0.94 ± 0.41 to 0.81 ± 0.43, 0.69 ± 0.41, and 0.67 ± 0.33 after 1, 3, and 5 years respectively ( p = 0.001). The mean LogMAR CDVA improved from 0.58 ± 0.36 to 0.46 ± 0.31, 0.34 ± 0.23, and 0.39 ± 0.27 after 1, 3, and 5 years respectively ( p = 0.015). The mean refractive cylinder improved significantly from 6.01 ± 2.07 diopters (D) to 5.46 ± 1.87, 5.38 ± 2.18, and 5.02 ± 2.31 D after 1, 3, and 5 years respectively ( p = 0.005). As compared to preoperative values, steep keratometry and maximum keratometry were not significantly different ( p = 0.805 and 0.448, respectively) following ACXL, while flat keratometry significantly improved after ACXL ( p = 0.012). Although central corneal thicknesses decreased significantly ( p = 0.029), the decrease in thinnest corneal thickness was not statistically significant ( p = 0.205). Conclusion: Epithelium-off ACXL seems to be effective for halting KC progression with long term clinical benefits in pediatric patients.

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Long-term Stability of Ectasia in a Young Patient with Asymmetric Keratoconus

International Journal of Keratoconus and Ectatic Corneal Diseases ◽

10.5005/jp-journals-10025-1102 ◽

2015 ◽

Vol 4 (2) ◽

pp. 66-68

Author(s):

Rosane de Oliveira Corrêa ◽

Ana Laura Caiado Canedo ◽

Rozalia Beildeck ◽

Marcella Quaresma Salomão ◽

Penelope Burle de Politis

Keyword(s):

Visual Acuity ◽

Young Patient ◽

Distance Visual Acuity ◽

Long Term Stability ◽

Uncorrected Distance Visual Acuity ◽

Manifest Refraction ◽

Corrected Distance Visual Acuity ◽

Ring Segment ◽

Intracorneal Ring Segment ◽

The Right

ABSTRACT Purpose To report the clinical course of a typical young patient presenting with asymmetric keratoconus (KC), that demonstrates that stabilization of the ectatic process is possible without cross-linking (CXL) procedure. Methods Case report and review of the literature. Results A 17-year-old male patient was referred due to the diagnosis of keratoconus. Patient complained of loss of vision in the left eye (OS). Uncorrected distance visual acuity (UDVA) was 20/25+ in the right eye (OD) and 20/80 in the left eye; wavefront-assisted manifest refraction gave best corrected distance visual acuity (CDVA) of 20/20 in OD and 20/40 in OS. The diagnosis of keratoconus was confirmed with Placido disk-based topography (Oculus Keratograph 4), and Pentacam HR corneal tomography (Oculus Optikgeräte GmbH, Wetzlar, Germany). Femtosecond laser-assisted intracorneal ring segment (ICRS) implantation was performed in the left eye and treatment for allergy was prescribed for both eyes, along with patient education and advice not to rub the eyes. After 3 months, significant improvement was observed on UDVA (20/30) and CDVA (20/20) in the left eye. Topometric and tomographic stability of ectasia was observed in the right eye in a 4-year follow-up. Conclusion Intracorneal ring segment caused significant regularization of the corneal shape and improvement on visual acuity. Ectasia stability was achieved with no need for CXL, despite the patient's young age. This case raises the point that the indication of CXL for every keratoconic patient should be reconsidered. How to cite this article de Oliveira Corrêa R, Canedo ALC, Beildeck R, Salomão MQ, de Politis PB, Ambrósio R Jr. Longterm Stability of Ectasia in a Young Patient with Asymmetric Keratoconus. Int J Kerat Ect Cor Dis 2015;4(2):66-68.

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Refractive, Topographic, and Aberrometric Results at 2-Year Follow-Up for Accelerated Corneal Cross-Link for Progressive Keratoconus

Journal of Ophthalmology ◽

10.1155/2017/5714372 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 7

Author(s):

Ercüment Bozkurt ◽

Engin Bilge Ozgurhan ◽

Betul Ilkay Sezgin Akcay ◽

Tugba Kurt ◽

Yusuf Yildirim ◽

...

Keyword(s):

Visual Acuity ◽

Spherical Aberration ◽

Corneal Thickness ◽

Corneal Topography ◽

Wavefront Aberration ◽

Distance Visual Acuity ◽

Uncorrected Distance Visual Acuity ◽

Wavefront Error ◽

The Mean

Purpose. To report the visual, refractive, and corneal topography and wavefront aberration results of accelerated corneal cross-linking (CXL) during a 24-month follow-up.Methods. Forty-seven eyes underwent riboflavin-ultraviolet A-induced accelerated CXL treatment (30 mW/cm2with a total dose of 7.2 joules/cm2). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical and cylindrical values, keratometry (K) measurements (Ksteep,Kflat,Kavg, andKapex), central corneal thickness, and anterior corneal aberrometric analyses including total wavefront error (WFE), total high order aberration (HOA), astigmatism, trefoil, coma, quadrafoil, secondary astigmatism, and spherical aberration were evaluated.Results. The mean UDVA and CDVA were significantly improved at 1 (p=0.003andp=0.004, resp.) and 2 years after treatment (p=0.001andp=0.001, resp.). The meanKsteep,Kflat,Kaverage, andKapexvalues were significantly lower than baseline at 12 months (p=0.008,p=0.024,p=0.001, andp=0.014, resp.) and 24 months (p=0.014,p=0.017,p=0.001, andp=0.012, resp.). Corneal thickness showed a significant decrease at 1 month. Total HOA and coma decreased significantly at the 12-month (p=0.001andp=0.009, resp.) and 24-month visits (p=0.001andp=0.007, resp.).Conclusion. Accelerated CXL (30 mW/cm2) was found to be effective in improving UDVA, CDVA, corneal topography readings, total HOA, and coma aberrations during the 24-month follow-up.

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Comparison of Standard and Transepithelial Corneal Cross-Linking for the Treatment of Keratoconus: A Meta-analysis

Journal of Ophthalmology ◽

10.1155/2021/6679770 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Yu Di ◽

Jingyi Wang ◽

Ying Li ◽

Yang Jiang

Keyword(s):

Visual Acuity ◽

Weighted Mean Difference ◽

Meta Analysis ◽

Corneal Thickness ◽

Clinical Results ◽

Cross Linking ◽

Cochrane Central Register ◽

Distance Visual Acuity ◽

Central Register

Purpose. To compare the clinical results of standard corneal cross-linking (SCXL) with transepithelial corneal cross-linking (TECXL) in progressive keratoconus using a meta-analysis. Methods. PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were searched up to June 2020 to identify relevant studies. The PRISMA guidelines were followed. Primary outcomes were change in uncorrected distance visual acuity and maximum keratometry (Kmax) after CXL. Secondary outcomes were change in corrected distance visual acuity, mean refractive spherical equivalent (MRSE), spherical and cylindrical error, endothelial cells density (ECD), and central corneal thickness (CCT). Results. Sixteen studies with a total of 690 eyes (SCXL: 332 eyes; TECXL: 358 eyes) were included. At the last follow-up, SCXL provided a greater decrease in maximum keratometry (Kmax) than TECXL (weighted mean difference (WMD) −1.12; 95% confidence interval (CI) −1.96, −0.29). For the other outcomes, there were no statistically significant differences. Conclusions. Except for a greater decrease in Kmax with SCXL group, both groups have a comparable effect on visual, pachymetric, and endothelial parameters at 24 months after surgery. Larger studies with a longer follow-up time are necessary to determine whether these techniques are comparable in the long term.

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Two-Year Accelerated Corneal Cross-Linking Outcome in Patients with Progressive Keratoconus

BioMed Research International ◽

10.1155/2015/325157 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 24

Author(s):

Arleta Waszczykowska ◽

Piotr Jurowski

Keyword(s):

Visual Acuity ◽

Corneal Thickness ◽

Long Term Results ◽

Cross Linking ◽

Mean Values ◽

Significant Difference ◽

Uncorrected Visual Acuity ◽

The Mean

Purpose. To evaluate the long-term results of accelerated corneal cross-linking (CXL) in patients with progressive keratoconus.Methods. Sixteen patients underwent accelerated CXL at 6 mW/cm2for 15 minutes in one eye. The follow-up visits were scheduled on 7 days, 14 days, and 3, 12, and 24 months after the treatment.Results. There were no significant differences (P>0.05) between preoperative and 2-year postoperative mean values, respectively, in terms of uncorrected visual acuity, best spectacle-corrected visual acuity, maximum keratometryKmax⁡, minimum keratometryKmin⁡, corneal astigmatism, and corneal eccentricity index. We noted a significant flattening of the cornea in 18.7% of patients with a higher preoperativeKmax⁡value (>50 D) and its steepening in patients with a lowerKmax⁡value (<50 D) (6.25%). There was no significant difference in the central corneal thickness and the apical corneal thickness preoperatively and 2 years postoperatively. The mean demarcation line depth was282±11 μm. Persistent corneal haze was noted in 25% of patients.Conclusions. Accelerated CXL appears to be a relatively effective procedure for the treatment of keratoconus in 2-year follow-up.

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3 Years Clinical Outcomes of Aspheric Micro-monovision LASIK for Correction of Presbyopia and Myopic Astigmatism

10.21203/rs.2.15661/v1 ◽

2019 ◽

Author(s):

Fang Liu ◽

Ting Zhang ◽

Quan Liu

Keyword(s):

Visual Acuity ◽

Subjective Rating ◽

Spherical Equivalent ◽

Distance Visual Acuity ◽

Uncorrected Distance Visual Acuity ◽

High Satisfaction ◽

Manifest Refraction ◽

Corrected Distance Visual Acuity ◽

Near Visual Acuity

Abstract Background: To investigate long term safety and efficacy of aspheric micro-monovision LASIK for correction of presbyopia and myop ic astigmatism. Methods: One hundred and fourteen eyes of 57 patients with a mean age 48 ± 4.05 years (range: 43 to 62 years) undergoing aspheric micro-monovision LASIK treatment using the MEL 80 excimer laser (Carl Zeiss Meditec AG, Jena, Germany) were enrolled. Visual acuity, manifest refraction, amplitude of accommodation and patients’ subjective rating was evaluated from 1 day to 3 years postoperatively. Results: There were no eyes in which spherical equivalent changed by over 0.75D between 1 day and 3 years. Ninety five percent of eyes were within ±0.50 D of target correction of spherical equivalent. The percentage of monocular uncorrected distance visual acuity ≧20/20 was 95%,and all eyes achieved 20/25 or better. The percentage of binocular uncorrected near visual acuity ≧J2 was 93%,and all patients achieved J4 or better. Ninety one percent of the patients could see uncorrected both 20/20 and J2 or better binocularly. Six percent (6/108) eyes lost 1 line and no eyes lost 2 lines of corrected distance visual acuity. The overall satisfaction score for surgery was 93±6. Conclusions: The aspheric micro-monovision LASIK using the Carl Zeiss Meditec MEL 80 Platform was an efficacious option for older myopia patients with presbyopia. Three years postoperative outcomes in Chinese population indicated improvements in uncorrected binocular vision at far and near distances with high satisfaction.

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Corneal Collagen Cross-Linking in Pellucid Marginal Degeneration: 2 Patients, 4 Eyes

Case Reports in Ophthalmological Medicine ◽

10.1155/2015/840687 ◽

2015 ◽

Vol 2015 ◽

pp. 1-4 ◽

Cited By ~ 3

Author(s):

Serife Bayraktar ◽

Zafer Cebeci ◽

Merih Oray ◽

Nilufer Alparslan

Keyword(s):

Visual Acuity ◽

Long Term Results ◽

Cross Linking ◽

Specular Microscopy ◽

Distance Visual Acuity ◽

Uncorrected Distance Visual Acuity ◽

Ring Segment ◽

The Right ◽

Collagen Cross Linking ◽

Corneal Collagen

Purpose. To report the long-term results of corneal collagen cross-linking (CXL) with riboflavin and ultraviolet-A irradiation in 4 eyes of 2 patients affected by pellucid marginal degeneration (PMD).Methods. This study involved the retrospective analysis of 4 eyes of 2 patients with PMD that underwent CXL treatment. Of the eyes, three had only CXL treatment and one had CXL treatment after an intrastromal corneal ring segment implantation. We have pre- and postoperatively evaluated uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (BCDVA), corneal topography (Pentacam), specular microscopy, and pachymetry.Results. Patient 1 was a woman, aged 35, and Patient 2 was a man, aged 33. The right eye of Patient 1 showed an improvement in her BCDVA, from 16/40 to 18/20 in 15 months, and her left eye improved from 12/20 to 18/20 in 20 months. Patient 2’s right eye showed an improvement in his BCDVA, from 18/20 to 20/20 in 43 months, and his left eye improved from 16/20 to 18/20 in 22 months. No complications were recorded during or after the treatment.Conclusion. CXL is a safe tool for the management of PMD, and it can help to stop the progression of this disease.

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Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus

International Journal of Keratoconus and Ectatic Corneal Diseases ◽

10.5005/jp-journals-10025-1146 ◽

2017 ◽

Vol 6 (2) ◽

pp. 73-77

Author(s):

Guillermo Rocha ◽

Victor Penner ◽

Kylee Lewis

Keyword(s):

Visual Acuity ◽

Spherical Aberration ◽

Corneal Thickness ◽

Case Series ◽

High Order ◽

Photorefractive Keratectomy ◽

Cross Linking ◽

Distance Visual Acuity ◽

Uncorrected Distance Visual Acuity ◽

High Order Aberrations

ABSTRACT Purpose To demonstrate clinical outcomes of epithelium-off corneal cross-linking (CXL) in combination with wavefront-guided photorefractive keratectomy (PRK) for the treatment of keratoconuns. Materials and methods Total, 28 keratoconic eyes of 21 patients were included. The Sirius Wavefront Analyzer (SCHWIND eye-tech-solutions GmbH and Co. KG) was used to evaluate the high-order aberrations (HOAs). The coupled Amaris 750S excimer laser then performed a PRK of no more than 40 μm using the measured HOA. The CXL was then carried out respecting the standard of 400 μm of corneal thickness. Results The average age was 32 (15—48) years. Uncorrected distance visual acuity (UDVA) improved from 0.58 to 0.31 logMAR (p < 0.001), with best corrected distance visual acuity (CDVA) improving from 0.03 to 0.02 logMAR (p = 0.7). On manifest refraction, the average spherical component decreased from –1.87 to –1.40 D (0.47 ± 2.12, p = 0.4). Cylinder decreased from 2.18 to 0.87 D (1.31 ± 1.14 D, p < 0.001). All HOAs decreased: total HO 0.94 to 0.58 (0.36 ± 0.42, p = 0.05); spherical aberration: 0.142 to –0.018 (0.160 ± 0.160, p < 0.001); secondary astigmatism: 0.21 to 0.11 (0.10 ± 0.11, p = 0.02); coma: 0.80 to 0.42 (0.38 ± 0.47, p = 0.03); trefoil: 0.33 to 0.29 (0.04 ± 0.17, p = 0.7). Conclusion Utilizing HOA to guide the laser treatment in combination with CXL resulted in a significant decrease of HOA at 6 months postprocedure. This is a small case series, but demonstrates a promising trend of improved HOA. Considering that keratoconic eyes have very irregular surfaces with significant HOA, reducing these aberrations should improve best corrected quality of vision. Having longer follow-up and greater numbers may demonstrate a clearer improvement. How to cite this article Penner V, Lewis K, Rocha G. Reduced High-order Aberrations using Wavefront-guided Partial Photorefractive Keratectomy and Accelerated Epithelium-off Corneal Cross-linking for Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):73-77.

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Clinical Evaluation of LASEK for High Myopia Correction between the Triple-A Profile and the Zyoptix Tissue Saving Profile

Journal of Ophthalmology ◽

10.1155/2019/6936042 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7

Author(s):

Min Li ◽

Yuehui Shi ◽

Lina Sun ◽

Lin Liu ◽

Chen Qu ◽

...

Keyword(s):

Visual Acuity ◽

Pulse Rate ◽

High Myopia ◽

Corneal Thickness ◽

Group Versus ◽

Distance Visual Acuity ◽

Uncorrected Distance Visual Acuity ◽

Manifest Refraction ◽

Corrected Distance Visual Acuity ◽

Safety Indices

Purpose. To compare the effects of correcting high myopia using the MEL®90 Triple-A profile LASEK at a 500 Hz pulse rate (Triple-A group) versus the Zyoptix tissue-saving ablations of Technolas 217z laser platform at 100 Hz (TS group). Methods. This retrospective study included 50 eyes in the Triple-A group and 42 eyes in the TS group with manifest refraction spherical equivalent (MRSE) of −6 diopters (D) to −10 D. We compared uncorrected distance visual acuity, MRSE, corrected distance visual acuity, and postoperative complications at 1 month, 3 months, and 6 months. Results. At 6 months after refractive surgery, the efficacy index of Triple-A group was significantly higher than that of the TS group (1.03 ± 0.12 vs 1.00 ± 0.11, P=0.04). The MRSE postoperatively in the Triple-A group was significantly lower than that in the TS group (0.25 ± 0.18 vs 0.38 ± 0.23, P<0.01). The safety indices in the two groups were almost the same after 6 months of surgery (1.03 ± 0.07 vs 1.04 ± 0.11, P=0.63). The proportion of eyes which achieved ±0.13 D was significantly higher in the Triple-A group than that in the TS group at 1 month (80% vs 59.5%, P=0.03), 3 months (82% vs 61.9%, P=0.03) and 6 months (84% vs 64.3%, P=0.03). The changes in refraction 6 months after surgery comparing with 1 month after surgery were 0.12 ± 0.10 D in the Triple-A group and 0.13 ± 0.08 D in the TS group (P=0.56). All (100%) of the patients in the Triple-A group and 50% of the patients in the TS group had a UDVA of 20/16 at 6 months after surgery (P<0.01). The induced spherical aberrations and total HOAs in the Triple-A group were significantly lower than those in the TS group (0.17 ± 0.02 μm vs 0.23 ± 0.02 μm, P<0.01; 0.20 ± 0.04 μm vs 0.39 ± 0.03 μm, P<0.01) at 6 months after surgery. The mean reduced corneal thickness was 113.06 ± 10.5 μm in the Triple-A profile group and 121.43 ± 23.46 μm in the TS group (P=0.02). No patient in either group had haze and high intraocular pressure 6 months after surgery. Conclusion. For treatment of high-myopia patients, the Triple-A profile was more effective, predictable, and accurate than the Zyoptix tissue-saving profile. Meanwhile, the Triple-A profile had less induced spherical aberrations, total HOAs, and cornea ablation depth than the Zyoptix tissue-saving profile. Patients in the Triple-A group with 500 Hz pulse rate treatment achieved superior results. The two surgical procedures were equivalent in terms of safety and stability.

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Long-Term Visual, Refractive and Topographic Outcomes of KeraRings Combined with Accelerated Transepithelial Crosslinking for Management of Different Grades of Progressive Keratoconus: A Retrospective Cohort Study

The Open Ophthalmology Journal ◽

10.2174/1874364102115010054 ◽

2021 ◽

Vol 15 (1) ◽

pp. 54-69

Author(s):

Mohammed Iqbal ◽

Amr Mounir ◽

Khaled Abd-Elaziz ◽

Omar M. Said

Keyword(s):

Visual Acuity ◽

Cohort Study ◽

Retrospective Cohort Study ◽

Retrospective Cohort ◽

Distance Visual Acuity ◽

Uncorrected Distance Visual Acuity ◽

Corrected Distance Visual Acuity ◽

Group A ◽

Group B

Purpose: To evaluate long-term visual, refractive, and topographic outcomes of KeraRings intrastromal implantation combined with accelerated transepithelial cross-linking for management of different stages of progressive keratoconus. Materials and Methods: This retrospective cohort study included 70 eyes of 70 patients with Amsler-Krumeich grades 1 to 4 keratoconus. They were divided into two groups: group-A included 37 eyes with grades 1-2 keratoconus, and group-B included 33 eyes with grades 3-4 keratoconus. Both groups underwent combined Keraring implantation with TCXL treatment. The main outcome measures included the preoperative and postoperative visual acuity, refraction, keratometry readings, and pachymetry. Results: At postoperative month 60, group-B exhibited significantly higher values of all mean uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), sphere/cylinder/spherical equivalent/defocus equivalent (DEQ), and K1/K2/Kaverages/Kmax parameters compared to that of group A. However, group-A exhibited better stability of postoperative improvements. Keratoconus progression (KCP) was greater in group-B (45.5%) than group-A (10.8%). Two eyes revealed segments' migration while one eye showed tunnel vascularization and opacification with segments' migration. Conclusion: The diagnostic criteria of preoperative-KCP are not adequate for the diagnosis of postoperative-KCP following ICRS implantation. UDVA and K average posterior seemed to be more sensitive parameters than K max in documenting early postoperative-KCP. We suggest that deterioration of UDVA≥0.10 log MAR and/or K average posterior ≥0.25 D are highly suspicious of post-ring implantation keratoconus progression (PR-KCP). The occurrence of two of the following parameters: Kmax≥0.50 D, Kaverageanterior≥0.50 D, K average posterior ≥0.25 D, or pachymetry≥1.5% thinning, is diagnostic of PR-KCP. The occurrence of two or more of the following parameters: Kmax≥0.50 D, Kaverageanterior≥0.50 D, Kaverageposterior ≥0.25 D, pachymetry≥ 1.5% thinning or UDVA≥0.10 logMAR, is diagnostic of PR-KCP. We also suggest that Kmax≥0.75 D alone is diagnostic of PR-KCP.

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