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Refractive error is becoming a significant public health issue. Photorefractive Keratectomy (PRK) is a corneal surface surgical technique that removes the corneal epithelium before stromal photoablation by ultraviolet radiation from the Excimer laser. We designed a retrospective study to characterize corneal remodeling after myopic Photorefractive Keratectomy and assess the accuracy of laser-predicted ablation depth (AD). This study took place in 15-20 National Ophthalmology Hospital, Paris, France. 150 eyes with preoperative manifest spherical equivalent between - 10.00D and - 0.25D and cylinder < 3D, treated with the WaveLight® EX500 laser between 01/2019 and 01/2023, were followed for at least three months. The main outcome measurements were postoperative changes in epithelial (ET) and stromal (ST) thicknesses measured with spectral domain optical coherence tomography and mean simulated keratometry (SimK) assessed with corneal topography. The central ET significantly decreased at M1, increased over the preoperative value from M1 to M6, and stabilized after M6. The increase in central ET after M1 was associated with an increase in mean SimK (r = 0.34). The achieved AD was 7.9 ± 8.0 µm greater than the laser-predicted AD. Stromal over-ablation was significantly and independently associated with myopia > 6D preoperative mean SimK > 44D and transepithelial procedures., (© 2024. The Author(s).)

Purpose: The purpose of this study was to report the first remote telesurgery in a case of epithelial basement membrane disease with recurrent corneal erosions., Methods: Topography-guided transepithelial photorefractive combined phototherapeutic keratectomy (PRK-PTK) is a surgical option that treats corneal irregularities and prevents the recurrences of erosions while treating the refractive error., Results: We performed for the first time a remote transepithelial topography-guided combined PRK-PTK using the iRes®2 excimer laser platform (iVIS Technologies, Taranto, Italy), with the surgeon sitting in his own room and controlling the excimer laser in remote with 5G connection through the Remote Control Station and the patient in the operating room. At one-month post-operative, visual acuity was 20/20 and the patient's symptoms subsided., Conclusions: Our surgery opens the era of telesurgery in the corneal panorama., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To evaluate the refractive results of Transepithelial Photorefractive Keratectomy (t-PRK) with the Technolas Teneo2 Excimer laser platform., Methods: In this retrospective comparative interventional case series, a total of 199 patients with myopia ranging from - 1 to - 7 diopters were enrolled and separated into three groups based on their target refraction of zero (group 1), - 0.25 (group 2), and - 0.5 diopters (group 3), respectively. The main outcome measure was post-operative cycloplegic refraction. Trans-PRK was performed using the Technolas Teneo2 Excimer laser. To prevent any remaining epithelium during stromal ablation, we adopted the thickest epithelial point in the 7 mm central map as the reference for Phototherapeutic keratectomy (PTK) depth. Patients were examined three and twelve months after the procedure, and the results were analyzed., Results: At the 12-month follow-up, uncorrected distance visual acuity was 20/20 in all patients. However, there was a significant difference in cycloplegic spherical equivalent refraction between the three groups. The 12-month post-operative spherical equivalent refraction was 0.90 ± 0.33 D, 0.79 ± 0.26 D, and 0.60 ± 0.19 D in groups 1, 2, and 3, respectively (P < 0.001; Kruskal-Wallis test). The rates of spherical equivalent refraction of more than 0.75 D were 58.3%, 39.1%, and 9.1% in the 0 D, - 0.25 D, and -0.50 D groups, respectively (P < 0.001; Chi-squared test)., Conclusions: The t-PRK with Technolas Teneo2 Excimer laser and epithelial thickness map adjustment of PTK induce a significant amount of residual hyperopia (> 0.75 D) in a large proportion of eyes with a target refraction of 0 or - 0.25, which is significantly reduced by using a target refraction of - 0.5., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: To evaluate the characteristic of corrective epithelial thickness after femtosecond laser-assisted lenticule intrastromal keratoplasty (LIKE) to correct moderate-to-high hyperopia., Methods: The prospective case series study of the LIKE procedure was performed to correct moderate-to-high hyperopia. The epithelial thickness map was generated by anterior segment optical coherence tomography (AS-OCT) in the corneal central 9-mm zone. Keratometry and corneal higher order aberrations were analyzed by Pentacam (Oculus Optikgeräte GmbH) preoperatively and postoperatively., Results: In the 26 eyes of 13 participants who underwent the LIKE procedure for moderate-to-high hyperopia, the attempted spherical equivalence (SEQ) was +6.50 ± 1.09 diopters (D). Compared to the preoperative epithelial thickness maps, the postoperative epithelial thickness had become significantly thinner in the central 5-mm zone; the difference was 6 to 7 µm. The paracentral epithelium performed nonuniform remodeling; the thinnest epithelial thickness was located in the inferotemporal section, which has the greatest difference from the superonasal; the difference between these two was approximately 3 µm. Through correlation analysis, it was found that the sections with thinner epithelium were significantly related to corneal curvature and corneal vertical coma., Conclusions: The LIKE procedure can be used to correct moderate-to-high hyperopia. This study further indicated the epithelial remodeling characteristic after the LIKE procedure: the central and paracentral corneal epithelial thickness becomes thinner, and the epithelial thickness distributes non-uniformly, which may be the important factor of the postoperative curvature asymmetric distribution and induction of corneal vertical coma. [ J Refract Surg . 2024;40(5):e321-e327.] .

Purpose: The amniotic membrane (AM), the inner layer of the placenta, is a semitransparent, avascular, and thin tissue that is useful due to its structure. Amniotic membrane transplantation (AMT) avoids the need for keratoplasty to prevent corneal perforating. The purpose of the study was to evaluate the visual (gain of or no change in visual acuity) and corneal outcomes (closure of the ulcer or corneal healing) of AMT in patients with ocular surface diseases., Materials and Methods: This was a retrospective case control study (success or failure of the surgery). It was undertaken at a single academic center. The study cohort consisted of subjects with ocular surface diseases. Patients were treated with AMT for refractory ocular surface diseases. They were divided into five subgroups according to the preoperative diagnosis. The technique of AMT used was the onlay method with two layers of AM. Primary outcome measures included best corrected visual acuity (BCVA), the number of AMTs, and reepithelization of the corneal epithelium at the end of the treatment. Two weeks to six months were given to consider epithelial closure. Treatment success was defined as corneal healing within 6 months., Results: A total of the 66 eyes of 66 patients (39 male/27 female) with a mean age of 44 ± 23 years (range 1-88 years) were included in the study. A single AMT procedure achieved epithelial closure in 74.2% ( n  = 49) of the eyes (53% in <15 days, 19.6% in 15-30 days, and 1.5% in 1-6 months). The fastest reepithelization occurred in neurotrophic keratopathy, 76.9% of which cases occurred within 15 days after the AMT procedure. Treatment failure was observed in five patients (7.5%), four with keratitis and one with neurotrophic keratopathy. The highest closure rates were found in persistent epithelial defects, graft-versus-host disease (GvHD), and bullous keratopathy, although there was no statistically significant difference in BCVA. Pairwise comparisons were made of neurotropic keratoplasty versus bullous keratopathy ( P  = 0.025), neurotrophic keratopathy versus keratitis ( P  = 0.004), GVHD versus keratitis ( P  = 0.003), and lastly, GvHD versus bullous keratopathy ( P  = 0.023)., Conclusions: AMT is a safe, valuable, and fast treatment technique to treat corneal epithelial defects stemming from different etiologies that are refractory to conventional treatment.

Rationale: Ophthalmologists mainly treat epithelial ingrowth by lifting the flap and scraping the ingrowth or using scraping combined with phototherapeutic keratectomy, mitomycin C, and so on. The potential usefulness of nonsteroidal anti-inflammatory drugs in such circumstances has not been reported before., Patient Concerns: A 32-year-old man and a 25-year-old man underwent lifting and scraping of the flap and phototherapeutic keratectomy to remove the epithelial ingrowths. Unfortunately, the ingrowths recurred and continued to develop., Diagnosis: The patients were diagnosed with corneal epithelial ingrowth., Interventions: The administration of bromfenac sodium and fluorometholone eye drops., Outcomes: Epithelial ingrowths in both patients disappeared after 6 and 1 month of treatment, respectively. There were no adverse reactions to the eye drops., Lessons: Nonsteroidal anti-inflammatory drugs may be broadly applied in the treatment of epithelial ingrowth after laser in situ keratomileusis., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: The aim of this study is to compare the healing of corneal epithelial defects or ulcers on the corneal graft in comparison with the patient's own cornea after treatment with 100%, undiluted autologous serum eye drops., Methods: In a retrospective study over 7 years, we analysed 263 treatments with autologous serum eye drops of persistent corneal epithelial defects (erosions [88%] vs. ulcers [12%]). We compared the epithelial healing tendency of patients with defects on their own cornea (51.9%) vs. patients who had previously undergone penetrating keratoplasty (48.1%). Complete epithelial healing during the 28 days of treatment was considered as therapeutic success. In addition, the recurrence rate of the epithelial defects after finishing the therapy was analysed., Results: 88.2% of the epithelial defects healed during 28 days of therapy. The recurrence rate during follow-up was 5.1%. There was no significant difference with respect to success rate between corneal defects on the patient's own cornea (87.8%) and on the graft (88.6%; p = 0.137). There was a significantly lower success rate for corneal ulcers (74.2%) than for erosions (90.3%; p < 0.001). The recurrence rate of erosions was 4.4%, vs. 4.3% in ulcers during follow-up., Conclusion: The results of our study suggest that autologous serum eye drops are a non-invasive and safe alternative treatment for persistent corneal epithelial defects - with no significant difference in patients with a defect on their own cornea vs. defects on the corneal graft. The success rate, but not the recurrence rate, is significantly worse in ulcers than in erosions., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Purpose: To compare the efficacy of an intracanalicular dexamethasone insert with tapered topical steroid over 28 days after corneal cross-linking (CXL)., Setting: Single private practice, outpatient setting., Design: Prospective observational randomized study., Methods: This prospective randomized study investigated the efficacy of a dexamethasone intracanalicular insert on post-CXL pain and inflammation in progressive keratoconus patients. 20 patients (40 eyes) were enrolled; half were randomized to the dexamethasone intracanalicular insert group; half were prescribed a 28-day topical tapering steroid regimen. All patients were evaluated for pain scores, rate of re-epithelialization, ease of the post-CXL regimen, and need for rescue pain medication after standard bilateral epithelium-off CXL on postoperative day (POD) 1, POD3, and POD4 to 7, as well as postoperative week (POW) 1, POW2, POW3, and POW4., Results: 20 patients (40 eyes) underwent standard-of-care epithelium-off bilateral CXL for progressive keratoconus. 10 patients were randomized to receive prednisolone eyedrops on a tapering schedule after CXL; 10 patients received dexamethasone intracanalicular inserts at the time of CXL. Regardless of the postoperative steroid regimen, there was no significant difference in the rate of re-epithelialization or use of rescue pain medication between groups. There was a nominal, however, statistical difference in pain scores between groups, favoring prednisolone eyedrops. Both groups stated no difficulty in following postoperative regimens. There were no adverse events noted in relation to treatment or the CXL procedure., Conclusions: Using a dexamethasone insert to alleviate pain and inflammation can be considered as a safe and efficacious part of a post-CXL regimen., (Copyright © 2023 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

Objective: To compare the visual and topographic outcomes between mechanical epithelial debridement followed by accelerated corneal collagen cross linking (CXL) vs. transepithelial phototherapeutic keratectomy followed by accelerated CXL for treatment of progressive keratoconus., Study Design: Quasi experimental study. Place and Duration of the Study: Armed Forces Institute of Ophthalmology (AFIO), National University of Medical Sciences, Rawalpindi, Pakistan, from December 2020 to December 2021., Methodology: On the basis of surgical technique used, patients were divided into two groups, Group A comprising of twenty eyes that underwent mechanical epithelial removal followed by accelerated CXL, and Group B comprising of twenty-two eyes that underwent transepithelial phototherapeutic keratectomy (t-PTK) followed by accelerated CXL. All variables were recorded preoperatively and 6 and 12 months postoperatively and included uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), MRSE (manifest refraction spherical equivalent), and keratometric indices (flat K, steep K, Kmax , mean K, thinnest pachymetry, KPI, K prob, CLMIaa, and I-S)., Results: Forty-two eyes of twenty-nine patients were included in the study and were divided into two groups; Group A (mechanical epithelial removal followed by accelerated CXL) and Group B (t-PTK followed by accelerated CXL). The visual acuity improved in both the groups at 6 and 12 months, with more significant improvement in Group B in both UCVA (p=0.005) and CDVA (p=0.004) parameters. Keratometric outcomes showed significant differences in median values for flat K (p=0.048) and thinnest pachymetry (p=<0.001) in Group A, while significant difference in Kmax (p=0.024) and thinnest pachymetry (p=<0.001) in Group B. At 6 and 12 months, the CLMIaa, PPK, and I-S values were significantly lower in Group B (p=0.002 for all three indices)., Conclusion: Transepithelial PTK followed by accelerated CXL yielded better outcomes regarding visual acuity and keratomertic indices as compared to mechanical epithelial removal followed by accelerated CXL and did not show any significant decrease in corneal pachymetry., Key Words: Mechanical, Corneal Collagen Crosslinking (CXL), Transepithelial, Phototherapeutic keratectomy, Keratoconus.

Objective: To compare outcomes of phototherapeutic keratectomy (PTK) versus epithelial debridement combined with anterior stromal puncture (ASP) or diamond burr for the treatment of recurrent corneal erosions (RCES) in a large tertiary centre., Methods: Patients with a diagnosis of RCES secondary to trauma or epithelial basement membrane dystrophy who underwent a surgical procedure between 2009 and 2019 were included in the study. The following data were collected: demographics, ocular history, prior medical treatment, ocular surgeries, intervention, complete epithelialization at postoperative week 1, recurrences, and complications. Recurrence was defined as either an objective finding of a corneal epithelial defect or symptoms suggestive of recurrent epithelial erosion on history. Recurrence rate and time to epithelialization were compared between groups., Results: A total of 97 eyes (73 patients) were included in the study. Mean patient age was 51 ± 16.1 years, and mean follow-up was 474 days. RCES was secondary to epithelial basement membrane dystrophy in 80% (n = 78 of 97), trauma (15%, n = 15 of 97), or idiopathic (4%, n = 4 of 97). Epithelial debridement with ASP was performed in 34 eyes (35%), diamond burr in 33 eyes (33%), and PTK in 30 eyes (31%). Compared with epithelial debridement with ASP (recurrence 29.4%), the recurrence rate was significantly lower for both the diamond burr (9.1%, p = 0.031) and PTK groups (10%, p = 0.048). The diamond burr and PTK groups also had a significantly higher rate of complete epithelialization at 1 week (p < 0.05)., Conclusion: Compared with epithelial debridement with ASP, diamond burr and PTK have significantly lower rates of recurrence and time to epithelialization and may be considered first for surgical management of RCES., (Copyright © 2022 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

Purpose: To describe the clinical outcomes of manual scraping of epithelial ingrowth followed by compressed heating air flow after laser in situ keratomileusis (LASIK)., Methods: We underwent a retrospective, noncomparative, and interventional case series. Twenty eyes of 17 patients were included in this study. Each patient with a history of LASIK underwent epithelial removal with mechanical debridement followed by compressed heating air flow. Our primary outcome was the recurrence of epithelial ingrowth after 3 months of follow-up, while our secondary outcomes were uncorrected distance visual acuity, corrected distance visual acuity, and complications after surgery., Results: Ten patients (58.8%) were male, and eight eyes of seven (41.2%) patients underwent primary LASIK surgery, while12 eyes of 10 patients had flap-lift retreatment LASIK; sixteen eyes (80.0%) underwent mechanical microkeratome LASIK and four (20.0%) underwent femtosecond laser-assisted LASIK. Mean age at surgical removal of epithelial ingrowth was 37.0 years ± 9.3 years (range 24 to 55 years). There was recurrence of ingrowth in two eyes (10%) after 3 months of follow-up. The mean corrected distance visual acuity of patients before surgery was 0.07 ± 0.09 logMAR, and after the last follow-up was 0.02 ± 0.04 logMAR (p=0.06). The odds ratio of presenting with epithelial ingrowth after LASIK enhancement compared to primary LASIK was 29.41., Conclusion: Manual scraping followed by compressed heating air flow is a safe and effective treatment of clinically significant epithelial ingrowth after LASIK. At the last follow-up, no eye lost any line in corrected distance visual acuity.

Background: The aim of this study was to assess the effect of different grades of dermatochalasis (DC) and upper eyelid blepharoplasty (UEB) surgery on corneal epithelial thickness (CET), objectively using anterior segment-optical coherence tomography (AS-OCT) measurements., Methods: 90 eyes of patients with DC were divided into three groups according to the severity of the DC. Forty-one eyes of age and sex-matched patients without DC were randomly selected as the control group. The study did not include patients with more than 2 D of spherical refractive error and more than 1.5 D of astigmatism, a history of previous eyelid surgery, ocular surface disease, contact lens use, and ophthalmic eye drop use. CET measurements of all the patients were performed with an AS-OCT (RTVue-XR, Optovue Inc., USA)., Results: There were statistically significant differences in the CET of the superior, superonasal, superotemporal, inferotemporal, and temporal sectors between the DC and control groups (p = 0.001, p = 0.02, p = 0.03, p = 0.02, p = 0.04, respectively). While there were no differences in CET among the sectors of the control group, there was a difference in CET among some sectors of the DC group. When the DC group was subdivided by severity, there was no difference between subgroups for CET across all sectors both preoperatively and postoperatively. In the measurements made 6 months after UEB surgery, the CET in all sectors increased statistically significantly compared to those measured in the preoperative period., Conclusion: This study revealed that DC reshaped the corneal epithelium and UEB surgery restored this remodeling 6 months after surgery., Level of Evidence Iii: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 ., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)

Objective: The aim was to analyze and compare the refractive results of anxious patients treated with transepithelial photorefractive keratectomy (TransPRK) while under general anesthesia (ITN) versus patients treated under local anesthesia (TRO)., Material and Methods: The TransPRK treatment was performed with the AMARIS 1050 RS laser (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany) in a group of patients with ITN and a group of patients, treated as usual with TRO. The method used an aspheric aberration neutral ablation profile, as well as SmartPulse technology and 7D eyetracking. In ITN propofol and rocuronium were injected intravenously. The artificial respiration was via a resuscitation bag after intubation with a laryngeal mask. To achieve pain insensitivity in the group of patients in TRO three drops of Conjucain Edo 0.4% were instilled at intervals of a few minutes. Follow-up examinations were performed after 1 and 4 days and after 1 and 3 months., Results: A total of 35 consecutive TransPRK laser treatments under ITN were retrospectively compared with a group of 699 eyes treated with TransPRK under TRO in the period from February 2017 to December 2021. The preoperative sphere had a range of -5.50 to -1.0 dpt, the average cylinder was 1.19 dpt and cylinders were treated up to 4.75 dpt. The results after 3 months follow-up showed a predictability of 100% eyes within the target correction of less than 0.5 dpt in ITN and in TRO 97%. The astigmatic correction showed 91% of eyes in ITN with less than 0.5 dpt and an angle of error of 83% within ±5°. In TRO 96% of eyes showed astigmatic correction with less than 0.5 dpt and an angle of error of 77% within ±5°. After 3 months 83% of eyes treated in ITN reached a visual acuity of 1.0 or more and 84% of eyes treated in TRO., Conclusion: The TransPRK performed in ITN led to equal refractive results than when treated as usual in TRO. For anxious patients there is the possibility of laser vision correction in ITN. Because of shorter treatment time and accordingly shorter time under general anesthesia, TransPRK is an advantage for LASIK surgery., (© 2022. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Purpose: To analyze the optical consequences of epithelial remodeling in irregular corneas and their impact on the choice of different surface ablation techniques., Methods: Anterior corneal and stromal surface topographies and epithelial thickness maps were analyzed in 24 eyes with irregular corneal optics. On two of the eyes, four different surface ablation techniques were simulated: (1) conventional anterior topography-guided photorefractive keratectomy (PRK), (2) transepithelial phototherapeutic keratectomy (PTK), (3) transepithelial anterior topography-guided PRK, and (4) stromal topography-guided PRK., Results: Stromal surface topographies showed higher keratometric values, astigmatism, asphericity, and corneal higher order aberrations compared to topographies of anterior corneas covered by epithelium. Transepithelial anterior topography-guided PRK and stromal topography-guided PRK both resulted in regularized stromal surface, transepithelial PTK achieved partial regularization corresponding to the smoothing effect of the epithelial remodeling, and conventional anterior topography-guided PRK delivered after epithelial removal resulted in residual stromal surface irregularities., Conclusions: The difference in optical landscapes between the stromal and anterior surfaces in irregular corneas will represent a source of error when anterior topography-guided treatments are delivered on the deepithelialized stroma, as in conventional PRK. In contrast, anterior topography-guided ablations performed as transepithelial PRK and stromal topography-guided PRK delivered after epithelial removal address the full stromal irregularity, whereas transepithelial PTK alone may be used when topography-guided treatments are not possible. The authors conclude topography-guided PRK of irregular corneas should lead to significantly improved regularization only if it includes the effect of epithelial remodeling. [ J Refract Surg . 2022;38(8):529-537.] .

Purpose: The purpose of this study was to describe a case with recurrent corneal erosions who was treated with a Bowman layer (BL) onlay graft., Method: BL onlay transplantation was performed., Results: In a 79-year-old female patient who presented with bilateral map-dot-fingerprint dystrophy and a history of recurrent painful corneal erosions, BL onlay grafting was performed to restore the corneal surface. At 1 month postoperatively, the epithelium was smooth over the graft, and until 1.5 years postoperatively, the patients had no complaints and no recurrence of the epithelial corneal erosion., Conclusions: In the described case, the transplantation of an isolated BL graft as an onlay proved to be an effective treatment for painful chronic recurrent erosions in the context of map-dot-fingerprint dystrophy in a patient who had undergone numerous unsuccessful previous treatments., Competing Interests: G. R. J. Melles is a consultant for DORC International and SurgiCube International. J. S. Parker is a consultant for DORC International and Ziemer Ophthalmic Systems. The remaining authors have no funding or conflicts of interest to disclose., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To investigate the effect of topical insulin on epithelization in persistent epithelial defects (PED) refractory to usual treatment compared to autologous serum., Design: Retrospective, consecutive case-control series., Methods: The charts of 61 consecutive patients with PED treated with topical insulin (case group) and 23 treated with autologous serum (control group) were reviewed. Primary efficacy end points were the percentage of patients in which epithelization was achieved, as well as the rate and time until epithelization. Secondary efficacy point was need for amniotic membrane transplantation (AMT) or other surgeries., Results: Mean time between PED diagnosis and start of topical insulin was 22.7 ± 18.5 days (range 13-115) and the mean area was 14.8 ± 16.2 mm 2 (range 1.1-70.6). In the control group, mean time was 27.9 ± 16.8 days, mean epithelial defect area being 18.6 ± 15.0 mm 2 (range 1.7-52.9). No differences in baseline characteristics were found between groups (p > 0.05). Epithelization was achieved in 51 patients (84%) on insulin and 11 patients (48%) on autologous serum (p = 0.002). In those patients, mean time until reepithelization was 32.6 ± 28.3 days (range 4-124) in the insulin group and 82.6 ± 82.4 days (range 13-231) in the autologous serum group (p = 0.011). The need for AMT was significantly lower in the insulin group (p = 0.005). PED recurrence was higher in patients treated on autologous serum (43%) compared with insulin (11%) (p = 0.002)., Conclusions: Topical insulin is an effective treatment and safely promotes healing of PED. In our series, topical insulin presented better epithelization outcomes than autologous serum and could thus be considered as a first-line treatment., (© 2021 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Purpose: To investigate the efficacy of outpatient clinic-based sutureless amniotic membrane transplantation (AMT) along with therapeutic contact lens (T-lens) application in eyes with persistent epithelial defects (PED)., Methods: Nine eyes of nine patients (mean age, 71.7 ± 5.2 years) diagnosed with PED and treated with in-office sutureless AMT combined with T-lens application were retrospectively reviewed. Demographics, systemic diseases, PED etiology, corneal epithelial defect size, visual acuity, corneal scraping culture results, and clinical course were evaluated., Results: Among nine eyes with PED, three had neurotrophic keratopathy, four had infectious keratitis (three with fungal keratitis and one with bacterial keratitis), one had limbal deficiency, and one had marginal keratitis. The mean epithelial defect size (calculated as an average of the horizontal and vertical diameters) was 3.13 ± 1.42 mm, and the mean duration from AMT to epithelial healing was 30.1 ± 10.5 days (range, 14-51 days) in successful trials. The success rates were 77.8% (7/9) per patient and 66.7% (8/12) per trial. The causes of failure in two patients were AMT displacement and uncontrolled infection., Conclusions: Our results demonstrate that in-office sutureless AMT combined with T-lens application can be used in patients with PED who are refractory to medications. It will be especially helpful for elderly patients because of its easy-to-use method. To achieve successful outcomes with AMT, an appropriate periocular environment as well as infection control need to be considered.

Purpose: To compare the 36-month visual, refractive, and topographic results and the optical quality of the cornea between mechanical and transepithelial phototherapeutic keratectomy (PTK) epithelium removal techniques prior to the accelerated corneal cross-linking (CXL) procedure in patients with progressive keratoconus., Methods: Keratoconic eyes that received either mechanical epithelium removal or transepithelial PTK epithelium removal prior to accelerated CXL with 36 months of follow-up were included. The uncorrected (UDVA) and corrected (CDVA) distance visual acuity, spherical equivalent (SE), manifest astigmatism, flat keratometry (K1), steep keratometry (K2), maximum keratometry (Kmax) readings, thinnest corneal thickness (TCT), topographic astigmatism, point spread function (PSF), and aberrometric parameters including root mean square higher order aberrations (RMS HOAs), vertical coma, and spherical aberration (SA) were assessed preoperatively and 12, 24, and 36 months postoperatively., Results: One hundred ten eyes of 110 patients with keratoconus were included (mechanical epithelium removal group: 69 eyes, transepithelial PTK epithelium removal group: 41 eyes). After the CXL procedure, the mean UDVA, CDVA, manifest astigmatism, RMS HOAs, SA, vertical coma, and PSF improved significantly throughout the follow-up visits in both groups ( P < .05 for all variables). The improvement in the mean UDVA, CDVA, manifest astigmatism, K1, K2, Kmax, RMS HOAs, SA, vertical coma, and PSF were significantly better in eyes that underwent transepithelial PTK epithelium removal when compared to eyes that underwent mechanical epithelium removal during the follow-up period ( P < .05 for all variables)., Conclusions: Transepithelial PTK-assisted accelerated CXL seems to be more efficient in improving the visual acuity and the optical quality while stabilizing the cornea compared to the accelerated CXL with mechanical epithelium removal in patients with progressive keratoconus. [ J Refract Surg . 2022;38(3):191-200.] .

Chemical injury of the conjunctiva and cornea are true ocular emergencies and require immediate intervention. They can produce severe, extensive ocular damage, including limbal stem cell deficiency (LSCD), and lead to irreversible visual loss. LSCD can be treated surgically through autologous limbal stem cell transplantation (LSCT). Autologous LSCT can be performed through cultivated limbal epithelial transplantation (CLET) or by direct grafting of limbal epithelial cells through conjunctival-limbal autografting (CLAU) or simple limbal epithelial transplantation (SLET). In this review we provide an overview of each surgical approach. CLET allows for a implantation of a large graft in the recipient eye while preserving donor cells. Its success rate is higher with an increased number of transplanted stem cells; failures tend to occur within the first year. CLAU is performed by directly transplanting autologous limbal stem cells from the patient's healthy eye, reducing the risk of immune rejection. This constitutes a risk for the donor eye, as the removal of stem cells from the fellow eye may lead to LSCD in the donor eye. SLET consists of direct implantation of donor stem cells on an amniotic membrane, thus avoiding the need for ex-vivo expansion. Combinations of CLAU and SLET within a single procedure have also been successfully utilized. Autologous LCST is an effective technique for surgical management of unilateral LCSD. Depending on the patient history and status of the fellow eye, either CLET, CLAU or SLET (including the combination of mini-CLAU and SLET) can be used to restore long-term function and prevent visual impairment., (Copyright © 2021. Published by Elsevier Masson SAS.)

Background: To assess transepithelial photorefractive keratectomy (tPRK) in terms of corneal epithelial healing rate, postoperative pain, postoperative discomfort, and visual and refraction outcomes compared to mechanical epithelial debridement PRK (mPRK) and alcohol-assisted PRK (aaPRK)., Methods: In this double-masked, randomized clinical trial, thirty-nine patients underwent tPRK in one eye and mPRK in the fellow eye (arm A), and 33 patients underwent tPRK in one eye and aaPRK in the contralateral eye (arm B). All surgical procedures were done using the Schwind Amaris excimer laser. The area of corneal epithelial defect in all eyes was captured and analyzed using ImageJ software., Results: Mean epithelial healing time was respectively 3.74 ± 0.82 and 3.59 ± 0.79 days in tPRK versus mPRK (P = 0.21) in arm A, and 3.67 ± 0.92 and 3.67 ± 0.74 days in tPRK versus aaPRK (P = 1.00) in arm B. Accounting for the initial corneal epithelial defect area, the epithelial healing rate was faster in conventional PRK groups compared to tPRK (both P<0.001) in both arms. However, there was no significant difference in safety, efficacy, spherical equivalent refractive accuracy, or corneal haze development between tPRK and conventional PRK groups (all P > 0.05)., Conclusions: All three methods are effective in terms of visual and refractive outcomes. However, although time to complete re-epithelialization was similar with the three methods, the epithelial healing rate was faster in conventional PRK considering the initial corneal epithelial defect area, and the patients experienced less pain and discomfort in the first postoperative day., Trial Registration: IRCT, IRCT20200317046804N1 . Retrospectively registered 5 May 2020., (© 2022. The Author(s).)

A man aged 26 years presented with complaints of diminution of vision in his right eye for 1 year following a fist injury. He had a history of laser-assisted in situ keratomileusis in both eyes 5 years earlier. On examination, his uncorrected distance visual acuity (UDVA) in the right eye was 1.0 logMAR. Slit-lamp examination of the right eye revealed a superotemporal dislocation of the flap with coexisting epithelial ingrowth encroaching the pupillary area. Due to the presence of long-standing fixed flap folds, a flap amputation was performed along with removal of the epithelial ingrowth using 0.02% mitomycin C as adjunct. Postoperatively, the UDVA was 0.3 logMAR on day 1, which improved to 0.2 logMAR at 1 week. At 1 year, the UDVA was 0.2 logMAR improving to 0.1 logMAR with refraction, with minimal paracentral corneal haze and no signs of corneal ectasia., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To evaluate the clinical outcomes of patients who underwent corneal surgery with debridement of epithelium by localised application of an alcohol-impregnated sponge instead of the usual alcohol reservoir method., Design: This study retrospectively included 52 eyes of 27 patients who underwent LASEK (laser-assisted subepithelial keratectomy) and CXL (cross-linking) surgery after application of this alcohol-assisted debridement method between January 2019 and April 2019., Participants: Twenty-four patients who underwent LASEK and three patients who underwent CXL surgery were included in this study, which comprised a total of 52 eye operations., Methods: Epithelial debridement was performed after placing a 20% ethanol-impregnated sponge on the cornea for 20 seconds., Results: The mean pachymetry value was 509.40 ± 30.37 µm, the mean preoperative spherical equivalent was - 2.14 ± 1.02 dioptres, and the highest myopia and astigmatism values were - 4.25 dioptres and - 2.75 dioptres, respectively. It was seen that the corneal epithelium was completely and easily debrided in a size identical to that of the applied sponge., Conclusions: Complete debridement of the corneal epithelium can be performed quickly, safely, and easily with this specially prepared sponge., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

We describe a modified technique of intraoperative optical coherence tomography (iOCT)-guided removal of post-laser-assisted in situ keratomileusis (LASIK) epithelial ingrowth with interface ethyl alcohol and mitomycin C application to prevent a recurrence. Epithelial ingrowth was visualized as hyperreflective deposits in the interface on iOCT, and the location and extent were noted at the beginning of the procedure. A simple dimple-down maneuver was performed to help identify the circumference of the LASIK flap. iOCT helped to delineate the flap edge and ensure dissection in the correct plane with complete removal of epithelial cell nests. Real-time visualization of the interface helped in on-table decision making regarding the extent of lifting the flap to encompass the entire region of hyperreflective epithelial ingrowth, as well as the need for additional interventions to ensure complete flap apposition at the end of surgery. All patients gained an uncorrected visual acuity of 20/20-20/25 with no recurrence., Competing Interests: None

Purpose: To compare the short-term complaints of postoperative pain, and other ocular discomfort symptoms in patients who underwent photorefractive keratectomy (PRK) with alcohol-assisted epithelial removal in one eye versus mechanical debridement in the other eye., Method: A prospective, interventional, contralateral double blind clinical trial was performed on 164 eyes of 82 candidates of PRK surgery. The patients were divided into two groups. The first group was alcohol-assisted PRK group in which the epithelial removal was performed on their right eye. The second group was mechanical PRK group in which epithelial removal was performed on their left eye. A numerical rating scale was given to the patients to describe the severity of postoperative pain on the first day following PRK. Postoperative discomfort symptoms including the complaints of light sensitivity, tearing, blurring, and foreign body sensation was also provided by the survey form., Results: One day following PRK, the mean pain score of the alcohol-assisted PRK group and the mechanical PRK group was 3.4±3.1 and 4.1±3.3, respectively (P=0.019). The highest scores recorded for alcohol-assisted and mechanical treated groups were burning (5.22) and light sensitivity (5.46), respectively. Sixty-eight (82.9%) of all patients experienced postoperative pain, and in 52 (76.5%) of them, the time of pain onset was less than 2 hrs., Conclusion: We found less pain and discomfort using alcohol-assisted technique compared with mechanical epithelial removal that was provided by a detailed pain and ocular discomfort symptoms assessment one day following PRK surgery., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2021 Contact Lens Association of Ophthalmologists.)

Purpose: To comprehensively compare visual quality between small incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (tPRK)., Methods: Sixty-four eyes in the SMILE group and 42 eyes in the tPRK group were enrolled in this study. In both groups, visual acuity, manifest refraction, higher-order aberrations (HOAs), contrast sensitivity (CS) at four spatial frequencies (3, 6, 12, 18 c/d) under three conditions (photopic, low glare, high glare), the cut-off value of the modulation transfer function (MTFcut-off), the objective scatter index (OSI) and the Strehl ratio (SR) were measured preoperatively and 1, 3 and 6 months postoperatively., Results: At 6 months postoperatively, the SMILE and tPRK groups showed similar safety, efficacy and predictability. Additionally, MTFcut-off, SR and OSI exhibited comparable results. In contrast, the photopic area under the logarithm of the CS function (AULCSF) showed better outcomes in the tPRK group than in the SMILE group (SMILE versus tPRK: 1.21 ± 0.10 versus 1.25 ± 0.09, p = 0.014). Furthermore, the induced coma aberrations were larger in the SMILE group (SMILE versus tPRK: 0.10 ± 0.16 versus 0.06 ± 0.12, 95% CI [0.08, 0.31], p < 0.0001)., Conclusions: Both SMILE and tPRK obtained comparable visual quality at 6 months postoperatively, accompanied by better photopic CS and smaller induced coma aberrations with tPRK. Paying more attention to alignment or developing a centration technique would be beneficial for visual quality when performing SMILE., (© 2021 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Purpose: To investigate the etiology and long-term surgical prognosis of the abnormal epithelium for partial limbal stem cell deficiency (LSCD), following superficial keratectomy DESIGN: Retrospective, interventional case series METHODS: This single-center, retrospective study was conducted to assess the prognosis of consecutive patients who underwent superficial keratectomy, with or without amniotic membrane transplantation (AMT), for the treatment of partial LSCD, from 2010 to 2019. We analyzed the etiologies of partial LSCD, surgical success rate, prognosis for recurrent cases, and the improvement in visual acuity., Results: We included 40 patients (51 eyes) with partial LSCD. All eyes were in clinical stage II without dense fibrovascular tissue. Idiopathy was the most common etiology (39%), followed by multiple surgeries involving the corneoscleral limbus (19%). All eyes attained corneal reepithelialization and transparency. Furthermore, the visual acuity improved or remained unchanged postoperatively. We observed recurrence in 19 eyes (37%) with a mean follow-up period of 26.3 months. Despite no significant difference in the recurrence rates among different etiologies, postoperative delayed epithelialization and extensive limbal involvement were identified as risk factors for recurrence (P < .001 and P = .013, respectively). Repeat surgeries were performed in 16 eyes. The final success rate was 84%., Conclusions: Superficial keratectomy is useful for the treatment of partial LSCD of varied etiologies, with an expected improvement in visual acuity postoperatively. Although the procedure can be repeated and have a high success rate, there have been several cases of recurrence in the long-term postoperative course., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: To study the outcomes of alcohol-assisted photorefractive keratectomy (PRK) when compared with transepithelial PRK (TransPRK) using 2 software programs, with or without SmartPulse Technology (SmartSurfACE), in high myopia., Setting: Vissum Miranza, University Miguel Hernandez, Alicante, Spain., Design: Retrospective, consecutive, case series., Methods: High myopic eyes undergoing surface ablation were included. The main inclusion criteria were preoperative spherical equivalent (SE) above -5.50 diopters (D) and no other ocular surgeries. Mitomycin-C was used in all the surgeries. The outcomes were analyzed using the 6-month follow-up visit data., Results: 135 eyes were included. Alcohol-assisted PRK was performed in 65 eyes, transepithelial PRK (TransPRK1) in 32 eyes, and TransPRK2 in 38 eyes. The mean all groups preoperative sphere, cylinder, and SE were -6.00 ± 0.87 D, -1.13 ± 1.03 D, and -6.57 ± 0.69 D, respectively. The mean efficacy index in the alcohol-assisted PRK group was 0.91 ± 0.18 compared with 0.98 ± 0.1 and 0.98 ± 0.12 in the TransPRK1 and TransPRK2, respectively (P = .027). The mean safety index in alcohol-assisted PRK was 0.99 ± 0.05, whereas it was 1 ± 0.06 in the TransPRK1 and 0.99 ± 0.08 in the TransPRK2 (P = .780). A final SE of ± 0.50 D was achieved in 96.9% of eyes in the TransPRK1 group and in 100% eyes in the TransPRK2 group compared with 73.8% in the alcohol-assisted PRK group (P < .001)., Conclusions: Surface ablation with the Amaris 500 excimer laser with flying spot pattern and mitomycin C use showed adequate refractive outcomes in high myopia correction in the 3 groups. TransPRK with or without SmartPulse Technology achieved statistically significant better outcomes than alcohol-assisted PRK in refractive predictability and efficacy., (Copyright © 2021 Published by Wolters Kluwer on behalf of ASCRS and ESCRS.)

Alcohol (ethanol) has been used in medicine since time immemorial. In ophthalmic practice, besides as an antiseptic, it was given as retrobulbar injections to relieve severe ocular pain. Alcohol can be applied topically to the surface of neoplastic or suspicious lesions to kill cells that might desquamate and seed during surgical excision, to treat epithelial ingrowth that can occur following corneal surgeries, particularly laser in situ keratomileusis (LASIK), and to treat superficial infectious keratitis. In view of its ability to achieve a smooth cleavage plane between the epithelium and the Bowman's layer, alcohol-assisted delamination (ALD) of the corneal epithelium has been used widely and effectively for a variety of diagnostic and therapeutic indications, at times delivering both outcomes. Diagnostically, ALD yields an intact epithelial sheet which can be fixed flat to provide excellent orientation for histopathological evaluation. Therapeutically, it is most commonly used to treat recurrent corneal erosion syndrome, where its efficacy is comparable to that of phototherapeutic keratectomy but with several advantages. It has also been used to treat various forms of epithelial/anterior stromal dystrophies, which can obviate or delay the need for corneal transplantation for several years. In addition, ALD is performed in corneal collagen cross-linking and corneal refractive surgery for relatively atraumatic removal of the epithelium. In this review, we aimed to provide a comprehensive overview of the diagnostic and therapeutic use of topical alcohol in ophthalmology, to describe the surgical and fixation techniques of ALD, and to highlight our experience in ALD over the past decade., (Copyright © 2021 Elsevier Inc. All rights reserved.)

A 59-year-old woman who underwent uneventful laser in situ keratomileusis surgery 16 years ago presented with traumatic flap dislocation complicated by an epithelial ingrowth in the right eye. The epithelial ingrowth was managed with re-lifting the flap, mechanical debridement, soaking with 70.0% alcohol, and irrigation. The flap was repositioned and secured with a two-part glue technique. Serial anterior segment-optical coherence tomography demonstrated a well-attached flap with no gap or haze in the flap-stromal interface. Three weeks postoperatively, the patient returned to emmetropia and the uncorrected distance visual acuity improved to 20/20. Twelve months postoperatively, the patient's visual acuity remained 20/20, and there was no evidence of recurrent epithelial ingrowth., Competing Interests: None

Purpose: To compare the visual and tomographic outcomes of epithelium-on and epithelium-off corneal collagen crosslinking (CXL) in an accelerated protocol in eyes with progressive keratoconus., Methods: Sixty-one patients with progressive keratoconus (female patients, n = 30; male patients, n = 31) aged 17 and 48 years (mean age: 25.8 ± 6.2 yrs) were included in this study. Patients underwent either epithelium-off (n = 27) or epithelium-on (n = 34) CXL using an accelerated protocol. Patients with at least 12 months of follow-up were included in the study. Visual and tomographic data from 3, 6, and 12 months after surgery were analyzed., Results: There were no differences between the visual and tomographic characteristics of the epithelium-on and epithelium-off groups at baseline (P > 0.05). No significant changes in uncorrected and best spectacles-corrected visual acuity were found at any stage during the first 12 months within either group or between the groups (all P > 0.05). There were no changes in thickness and keratometric parameters at any stage during the first 12 months within either group, or between groups (P > 0.05) except for a transient significant thinning of the central cornea in all groups in the first 3 months which recovered by 6 months. There was no significant difference between groups regarding the number of eyes with progression in the 12 months after treatment (P > 0.05)., Conclusions: Epithelium-on and epithelium-off CXL in an accelerated protocol provide comparable visual and tomographic outcomes after 1 year in eyes with progressive keratoconus., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The aim of simple limbal epithelial transplantation (SLET) is the regeneration of the corneal surface in unilateral complete limbal stem cell deficiency (LSCD)., Indications: SLET is indicated for unilateral complete LSCD., Contraindications: Contraindications include bilateral LSCD, severe corneal thinning, pronounced keratoconjunctivitis sicca, chronic inflammatory condition of the ocular surface, malposition of the eyelids and pronounced adhesions of the conjunctiva with trichiasis., Surgical Technique: A 1‑h biopsy is obtained from the superior limbus of the healthy donor eye. A 360° peritomy is performed on the LSCD eye and pannus tissue covering the cornea is removed. An amniotic membrane (AM) is glued to the corneal surface with fibrin. The donor tissue is then divided into 8-10 small pieces, which are placed on the AM sparing the visual axis and fixed by fibrin glue. A contact lens is placed on the eye. A surgical video, which is available online, shows the surgical technique in detail., Follow-Up: Examinations are necessary within the first postoperative week and 1 month after SLET, then every 3 months within the first postoperative year. Antibiotic eye drops should be applied 5 times daily until complete epithelialization. Topical steroids should be applied 6 times daily in the early postoperative period and can be tapered thereafter. Artificial tears can improve epithelial healing. Ideally, all eye drops should be preservative-free. The contact lens can be removed after 7-10 days. The AM dissolves within a few weeks. An epithelialization of the corneal surface can be observed by the second postoperative week., Evidence: A recent systematic review reported a stable epithelialized corneal surface in 78% of SLET cases after 1.5 years. An improvement of visual acuity of at least two lines was found in 69% of SLET cases.

Purpose: To compare single-step transepithelial photorefractive keratectomy (TPRK) to conventional alcohol assisted epithelial removal then photorefractive keratectomy (AAPRK) regarding pain, epithelial healing, visual acuity, corneal haze measured subjectively and objectively, higher order aberrations changes, contrast sensitivity and vector analysis of astigmatic correction with one year follow-up., Methods: A prospective double-blind randomized study of 29 subjects (58 eyes) who underwent myopic aberration-free laser correction by smart pulse technology using Schwind Amaris 1050 Hz with 1-year follow-up. Right eye was randomly treated by AAPRK or TPRK. Postoperative assessment was performed on day 1 and 3, at 1st week, and 1st, 3rd, 6th, and 12th months. Patients were assessed for pain, epithelial healing, visual acuity, corneal haze, astigmatic correction, higher order aberrations and contrast sensitivity., Results: Epithelial healing was complete by the 3rd day in 62.1% of AAPRK eyes and in 89.7% of TPRK eyes. First day postoperative pain was higher in TPRK group (p = 0.0134). The decimal uncorrected visual acuity at 12 months was 1.47 ± 0.39 and 1.57 ± 0.38 in the AAPRK and TPRK groups respectively (p = 0.3719). Post-photorefractive keratectomy haze reached a final level of 0.04 ± 0.14 and 0.02 ± 0.1 in AAPRK and TPRK groups respectively (p = 0.5607). Contrast sensitivity was comparable in low and high frequency cycles per degree. Vector analysis of astigmatic correction showed correction index at one year of 0.99 and 1.05 for AAPRK and TPRK groups respectively., Conclusions: Alcohol assisted and transepithelial photorefractive keratectomy have comparable results regarding safety and efficacy.

Background: Keratoconus is the most common corneal dystrophy. It can cause loss of uncorrected and best-corrected visual acuity through ectasia (thinning) of the central or paracentral cornea, irregular corneal scarring, or corneal perforation. Disease onset usually occurs in the second to fourth decade of life, periods of peak educational attainment or career development. The condition is lifelong and sight-threatening. Corneal collagen crosslinking (CXL) using ultraviolet A (UVA) light applied to the cornea is the only treatment that has been shown to slow progression of disease. The original, more widely known technique involves application of UVA light to de-epithelialized cornea, to which a photosensitizer (riboflavin) is added topically throughout the irradiation process. Transepithelial CXL is a recently advocated alternative to the standard CXL procedure, in that the epithelium is kept intact during CXL. Retention of the epithelium offers the putative advantages of faster healing, less patient discomfort, faster visual rehabilitation, and less risk of corneal haze., Objectives: To assess the short- and long-term effectiveness and safety of transepithelial CXL compared with epithelium-off CXL for progressive keratoconus., Search Methods: To identify potentially eligible studies, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2020, Issue 1); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature database (LILACS); ClinicalTrials.gov; and World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not impose any date or language restrictions. We last searched the electronic databases on 15 January 2020., Selection Criteria: We included randomized controlled trials (RCTs) in which transepithelial CXL had been compared with epithelium-off CXL in participants with progressive keratoconus., Data Collection and Analysis: We used standard Cochrane methodology., Main Results: We included 13 studies with 723 eyes of 578 participants enrolled; 13 to 119 participants were enrolled per study. Seven studies were conducted in Europe, three in the Middle East, and one each in India, Russia, and Turkey. Seven studies were parallel-group RCTs, one study was an RCT with a paired-eyes design, and five studies were RCTs in which both eyes of some or all participants were assigned to the same intervention. Eleven studies compared transepithelial CXL with epithelium-off CXL in participants with progressive keratoconus. There was no evidence of an important difference between intervention groups in maximum keratometry (denoted 'maximum K' or 'Kmax'; also known as steepest keratometry measurement) at 12 months or later (mean difference (MD) 0.99 diopters (D), 95% CI -0.11 to 2.09; 5 studies; 177 eyes; I 2 = 41%; very low certainty evidence). Few studies described other outcomes of interest. The evidence is very uncertain that epithelium-off CXL may have a small (data from two studies were not pooled due to considerable heterogeneity (I 2 = 92%)) or no effect on stabilization of progressive keratoconus compared with transepithelial CXL; comparison of the estimated proportions of eyes with decreases or increases of 2 or more diopters in maximum K at 12 months from one study with 61 eyes was RR 0.32 (95% CI 0.09 to 1.12) and RR (non-event) 0.86 (95% CI 0.74 to 1.00), respectively (very low certainty). We did not estimate an overall effect on corrected-distance visual acuity (CDVA) because substantial heterogeneity was detected (I 2 = 70%). No study evaluated CDVA gain or loss of 10 or more letters on a logarithm of the minimum angle of resolution (logMAR) chart. Transepithelial CXL may result in little to no difference in CDVA at 12 months or beyond. Four studies reported that either no adverse events or no serious adverse events had been observed. Another study noted no change in endothelial cell count after either procedure. Moderate certainty evidence from 4 studies (221 eyes) found that epithelium-off CXL resulted in a slight increase in corneal haze or scarring when compared to transepithelial CXL (RR (non-event) 1.07, 95% CI 1.01 to 1.14). Three studies, one of which had three arms, compared outcomes among participants assigned to transepithelial CXL using iontophoresis versus those assigned to epithelium-off CXL. No conclusive evidence was found for either keratometry or visual acuity outcomes at 12 months or later after surgery. Low certainty evidence suggests that transepithelial CXL using iontophoresis results in no difference in logMAR CDVA (MD 0.00 letter, 95% CI -0.04 to 0.04; 2 studies; 51 eyes). Only one study examined gain or loss of 10 or more logMAR letters. In terms of adverse events, one case of subepithelial infiltrate was reported after transepithelial CXL with iontophoresis, whereas two cases of faint corneal scars and four cases of permanent haze were observed after epithelium-off CXL. Vogt's striae were found in one eye after each intervention. The certainty of the evidence was low or very low for the outcomes in this comparison due to imprecision of estimates for all outcomes and risk of bias in the studies from which data have been reported., Authors' Conclusions: Because of lack of precision, frequent indeterminate risk of bias due to inadequate reporting, and inconsistency in outcomes measured and reported among studies in this systematic review, it remains unknown whether transepithelial CXL, or any other approach, may confer an advantage over epithelium-off CXL for patients with progressive keratoconus with respect to further progression of keratoconus, visual acuity outcomes, and patient-reported outcomes (PROs). Arrest of the progression of keratoconus should be the primary outcome of interest in future trials of CXL, particularly when comparing the effectiveness of different approaches to CXL. Furthermore, methods of assessing and defining progressive keratoconus should be standardized. Trials with longer follow-up are required in order to assure that outcomes are measured after corneal wound-healing and stabilization of keratoconus. In addition, perioperative, intraoperative, and postoperative care should be standardized to permit meaningful comparisons of CXL methods. Methods to increase penetration of riboflavin through intact epithelium as well as delivery of increased dose of UVA may be needed to improve outcomes. PROs should be measured and reported. The visual significance of adverse outcomes, such as corneal haze, should be assessed and correlated with other outcomes, including PROs., (Copyright © 2021 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

Purpose: Anterior stromal puncture is an inexpensive technique for treating recurrent corneal erosions but is often ineffective and cannot be used in the optical axis because of scarring. These studies tested a novel microfabricated imprinting instrument to assess its potential efficacy for the treatment of corneal epithelial disease in the optical axis., Methods: The device is made using glass rods, bundled and drawn through multiple iterative cycles, and then fused under high heat to generate a solid rod comprised of many parallel, aligned, cladded fibers. The rods are sliced into discs and then etched to yield designable spikes based on the borosilicate composition of the glass., Results: Imprinting the cornea yields a regular pattern of imprints. Histologic studies showed both nonpenetrating stable deformations of Bowman layer, with formation of stable epithelial attachments, and full thickness penetration, with superficial ingrowth of the basal epithelium., Conclusions: Microimprinted corneal tissue shows focal subepithelial scarring without evidence of optically evident anterior stromal scarring, and may be an effective way of treating recurrent corneal erosions in the optical axis, which is not currently possible using standard anterior stromal puncture methods.

Purpose: To present management of a patient with bilateral limbal stem cell deficiency (LSCD) by using "simple oral mucosal epithelial transplantation" (SOMET) technique., Methods: Case report., Results: A 65-year-old female diagnosed with bilateral LSCD based on clinical findings. After stabilizing the ocular surface, we performed SOMET in the right eye. At 13 months postoperatively, visual acuity improved from counting fingers to 10/100 and a stable epithelium with regressed corneal vascularization was observed., Conclusions: This report showed that SOMET seems to be an alternative technique in LSCD., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 Contact Lens Association of Ophthalmologists.)

Purpose: The purpose of this study was to evaluate and compare the 5-year efficacy and safety of accelerated transepithelial (A-epi-on) corneal collagen cross-linking (CXL) with standard CXL (epi-off) in children with progressive keratoconus (KC)., Methods: This prospective cohort study included 78 eyes of patients aged 18 years old or younger with progressive KC who underwent CXL at the Oftalmosalud Institute of Eyes, Lima, Peru. A-epi-on CXL was performed in 32 eyes (30' of impregnation/5' of irradiation at 18 mW/cm2) and epi-off CXL was performed in 46 eyes (30'of impregnation/30' minutes of irradiation at 3 mW/cm2). Visual acuity, refraction, and the Scheimpflug imaging parameters were evaluated preoperatively and postoperatively at 1 and 5 years., Results: The best corrected visual acuity improved to 0.06 logarithm of the minimum angle of resolution (SD: 0.19, P = 0.03) and 0.09 logarithm of the minimum angle of resolution (SD: 0.13, P < 0.001) in the A-epi-on and epi-off groups, respectively. The mean flattening in the mean keratometry was 0.09 diopters (D) (SD: 0.68, P = 0.33) and 3.18 D (SD: 5.17, P < 0.001) in the A-epi-on CXL and Epi-off groups at the 5-year follow-up. Significant differences were found in the change at 1 and 5 years between the groups for cylinder reduction, flat and mean K, and pachymetry (all P < 0.05). The KC progression rate was 9.37% (3/32) in the A-epi-on CXL; no progression was found in the epi-off CXL group at the 5-year follow-up., Conclusions: Both procedures halted the progression of KC at the 5-year follow-up; however, epi-off CXL was safer and more effective when compared with A-epi-on CXL.

Purpose: To determine the galectin-3 (Gal3), interleukin-1 (IL-1), interleukin-6 (IL-6), and epidermal growth factor (EGF) levels in corneal epithelium of patients with recurrent corneal erosion (RCE) syndrome and compare them with healthy controls., Methods: In this prospective interventional case control study, 32 eyes of 32 patients with RCE syndrome who had corneal epithelial erosions and 28 eyes of 28 healthy participants scheduled for photorefractive keratectomy (control group) were included. Exclusion criteria included corneal dystrophies, ectasia, dry eye, previous ocular surgery or topical medications, and systemic diseases. Epithelial samples were obtained during epithelial debridement in the study group and mechanical epithelial keratectomy in the control group. Galectin-3 levels were studied by the chemiluminescent microparticle immunoassay method. IL-1, IL-6, and EGF levels were determined using corresponding ELISA kits., Results: The median Gal3 levels were 132.25 ng/mL in the study group and 106.50 ng/mL in the control group. The median IL-1 and IL-6 levels were 6.24 pg/mL and 10.16 pg/mL, respectively, in the study group which were higher than that in the control group. The median EGF level in the study group was lower than that the control group with 1.30 pg/mL versus 2.67 pg/mL. In the control group, there was a significant positive correlation between EGF and IL-6 (r = 0.554; P = 0.040). A similar correlation was not observed in patients with RCE (r = -0.071; P = 0.794)., Conclusions: The lack of increased EGF expression and the imbalance between growth factors, adhesion molecules, and interleukins may be the reason for the impaired wound healing response in RCE syndrome.

We compared the level of transforming growth factor-β1 (TGF-β1) in the tear fluid of 20 patients with high myopia who underwent transepithelial photorefractive keratectomy (T-PRK) in one eye and laser subepithelial keratomileusis (LASEK) in the contralateral eye. Tear fluid samples were collected with scaled microcapillary tubes before (day 0) and on days 1, 3, and 5 after surgery. The release of TGF-β1 was determined by multiplying the concentration of TGF-β1 by capillary tear fluid flow. Corneal haze was also evaluated in 1, 3, and 6 months after surgeries. The median TGF-β1 release after T-PRK and LASEK differed significantly on days 1 and 3 (p<0.005) and on day 5 (p<0.05). The mean corneal haze score after T-PRK and LASEK also significantly differed in 1 month (p<0.005), but no significant differences in this parameter were revealed at later terms. Thus, the level of TGF-β1 in the tear fluid after T-PRK was lower than after LASEK, which can be the cause of less pronounced corneal haze in 1 month after surgery.

To compare the effectiveness of self- retained cryopreserved AM as an adjuvant therapy for infectious corneal ulcers. Retrospective, case-control study of 24 eyes of 24 consecutive patients with central and paracentral corneal infectious ulcers and initial visual acuity worse than 20/200. Among them, 11 eyes of 11 patients received additional placement of self-retained cryopreserved AM. Epithelialization and Best Corrected Snellen Visual Acuity (BCSVA) were compared between the two groups. At baseline, both groups had comparable age, gender, visual acuity (VA), size and location of corneal ulcer. Patients receiving additional placement of cryopreserved AM had significantly faster epithelialization within 3.56 ± 1.78 weeks vs 5.87 ± 2.20 weeks (p = 0.01) and achieved complete epithelialization in significantly more patients (72.7% vs 23.1% p = 0.04) despite overall larger baseline defect size (32.7 ± 19.5 mm 2 vs 21.5 ± 10.7 mm 2 , p = 0.11). Consequently, the AM group had clinically significant BCSVA (> 3 lines) (81.8% vs 38.4%, p = 0.047) and total VA improvement (log MAR 0.7 ± 0.6 vs 1.6 ± 0.9, p = 0.016) compared to the control group at the time of complete epithelialization. In-office sutureless AM may be an effective adjuvant therapy in treating sight-threatening infectious corneal ulcers by promoting faster corneal epithelialization and overall better recovery of the VA.

Purpose: To compare the biomechanical properties of the cornea after epithelial removal in eyes with keratoconus undergoing corneal cross-linking., Methods: Prospective interventional case series at a university hospital tertiary referral center. Corneal biomechanical properties were measured in patients with keratoconus undergoing corneal cross-linking, immediately before and after epithelial debridement by using a dynamic ultrahigh-speed Scheimpflug camera equipped with a noncontact tonometer., Results: The study comprised 45 eyes of 45 patients with a mean age of 19.6 ± 4.9 years (range 14-34). The cornea was found to be 23.7 ± 15.7 μm thinner after epithelial removal (P < 0.01). Corneal stiffness was reduced after epithelial removal as demonstrated by a significant decrease of parameters such as stiffness parameter A1 (12.31, P < 0.01), stiffness parameter-highest concavity (2.25, P < 0.01), A1 length (0.13 mm, P = 0.04), highest concavity radius of curvature (0.26 mm, P = 0.01), highest concavity time (0.22 ms, P = 0.04) and an increase in A1 velocity (-0.01 m/s, P = 0.01), A1 deformation amplitude (-0.03 mm, P ≤ 0.01), A1 deflection length (-0.32 mm, P < 0.01), A2 deformation amplitude (-0.03 mm, P = 0.01), and A2 deflection length (-1.00 mm, P < 0.01). There were no significant differences in biomechanical intraocular pressure (0.15 mm Hg, P = 0.78), deformation amplitude (0.03, P = 0.54), maximum inverse radius (-0.01 mm, P = 0.57), and whole eye movement length (-0.02 mm, P = 0.12)., Conclusions: Dynamic ultrahigh-speed Scheimpflug camera equipped with a noncontact tonometer offers an alternative method for in vivo measurements of the epithelial layer's contribution to corneal biomechanical properties. Our results suggest that corneal epithelium may play a more significant role in corneal biomechanical properties in patients with keratoconus than previously described.

Purpose: To present the results of a modified surgical technique for secure tightening and fixation of multilayer amniotic membranes (AMs) in sterile deep or perforating corneal ulcers., Methods: We retrospectively analyzed the data of patients suffering from corneal ulcers who had been treated between February 2016 and June 2018 with running and resorbable sutures to fixate multilayer AMs. The parameters analyzed were gender, age, etiology of corneal ulcer, ulcer diameter, corneal thickness (CST) before and after the microsurgical procedure as measured with optical coherence tomography, number of inlays, repeat surgical procedures, follow-up duration in months, and rate of success (defined as a stable anterior chamber with improved CST, a negative Seidel test, and no need for any microsurgical keratoplasty during the first 6 months after treatment). The results were statistically evaluated using the Wilcoxon test. A P-value ≤0.05 was considered to show a statistically significant difference., Results: The CST increased significantly after AM transplantation (from 206.26 ± 114.93 μm at baseline to 454.70 ± 244.08 μm at 1-3 months; P < 0.001). Repeat multilayer transplantation was required in 7 of the 23 patients included (30.4%), in 6 of whom the treated eye was stable at month 6. In 2 of the 23 patients, perforating keratoplasty became necessary. One patient also demanded such a procedure to improve his visual acuity. The success rate was 91.3% (n = 21)., Conclusions: Running resorbable suture fixation of multilayer AMs proved to be an efficient means for the treatment of noninfectious deep or small perforating corneal ulcers.

Purpose: This study describes a femtosecond laser (FS) approach to machine corneal epithelial microchannels for enhancing riboflavin (Rf) penetration into the cornea prior to corneal crosslinking (CXL)., Methods: Using a 1030-nm FS laser with 5- to 10-µJ pulse energy, the corneal epithelium of slaughterhouse rabbit eyes was machined to create 2-µm-diameter by 25-µm-long microchannels at a density of 100 or 400 channels/mm 2 . Rf penetration through the microchannels was then determined by applying 1% Rf in phosphate-buffered saline for 30 minutes followed by removal of the cornea and extraction from the central stromal button. Stromal Rf concentrations were then compared to those obtained using standard epithelial debridement or 0.01% benzalkonium chloride (BAK) to disrupt the epithelial barrier., Results: Microchannels formed using a 5-µJ/pulse at a density of 400 channels/mm 2 achieved a stromal Rf concentration that was 50% of that achieved by removal of the corneal epithelium and imbibing with 1% Rf. Stromal Rf levels were also equal to that of debrided corneas soaked with 0.5% Rf, threefold higher than those soaked with 0.1% Rf, and twofold higher than corneas soaked in BAK without epithelial debridement. Organ culture of treated corneas showed a normal corneal epithelium following FS machining while BAK-treated corneas showed extensive epithelial and stromal damage at 24 hours posttreatment., Conclusions: FS corneal epithelial machining can be used to enhance penetration of Rf into the stroma for corneal CXL., Translational Relevance: The creation of epithelial microchannels allows for stromal Rf concentrations high enough to perform true transepithelial crosslinking., Competing Interests: Disclosure: S. Bradford, None; E. Mikula, None; Y. Xie, None; T. Juhasz, None; D.J. Brown, None; J.V. Jester, None, (Copyright 2020 The Authors.)

Purpose: To compare the efficacy, safety and stability of standard epithelium-off cross-linking (SCXL) versus accelerated epithelium-off cross-linking (ACXL) and transepithelial epithelium-on cross-linking (TCXL) in the treatment of progressive keratoconus (KC) in children., Methods: This prospective multicentre controlled trial included 271 eyes (136 children) with grade 1-3 progressive KC who were randomized to undergo SCXL (n = 91, as a control group), ACXL (n = 92) or TCXL (n = 88). Uncorrected and corrected distance visual acuity, subjective refraction, pachymetry, keratometry and corneal topography measurements were recorded preoperatively and 6, 12 and 24 months postoperatively., Results: At 1 year, there was no significant difference in uncorrected distance visual acuity, refractive sphere, cylinder, spherical equivalent or Kmax between the ACXL and SCXL groups; however, during year 2, ACXL regressed while SCXL continued to improve. After 2 years, there were significant differences in all visual, refractive and keratometric components between SCXL and both ACXL and TCXL (p < 0.0001) and between ACXL and TCXL (p < 0.0001). KC progressed in 5.4% of patients who had ACXL and 28.4% of those who had TCXL but in none of those who had SCXL. Vernal keratoconjunctivitis was documented in 43.3% of eyes that progressed postoperatively., Conclusion: SCXL was more effective for paediatric KC and achieved greater stability than either ACXL or TCXL, and ACXL was superior to TCXL. SCXL also achieved marked improvement in both myopia and spherical equivalent; however, these refractive outcomes were unpredictable and uncontrollable. TCXL had a 28.4% failure rate within 2 years. SCXL is preferable for management of paediatric KC., (© 2019 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Purpose: The purpose of this study was to compare postoperative epithelial healing time and ocular discomfort score in patients wearing two types of silicon hydrogel bandage contact lenses (BCLs) following bilateral photorefractive keratectomy (PRK)., Methods: For the study's contralateral eye comparison, 43 patients who underwent bilateral PRK were randomized to be fitted for a senofilcon a lens in one eye and a lotrafilcon B lens in the other. The patients were masked to the specific BCL in each eye. On the first 3 days after PRK, the epithelial defect size was calculated, and patients reported their level of ocular discomfort, including pain, epiphora, and photophobia, on a visual analog scale (0 = no pain or discomfort, 10 = highest level of pain and discomfort)., Results: Epithelial defect size (mm 2 ) did not differ significantly between the BCLs on Day 1 (senofilcon A vs. lotrafilcon B: 14.15 ± 5.59 vs. 14.93 ± 5.72, p = .327), Day 2 (senofilcon A vs. lotrafilcon B: 7.43 ± 4.67 vs. 7.04 ± 3.82, p = .586), or Day 3 (senofilcon A vs. lotrafilcon B: 0.59 ± 1.44 vs. 0.38 ± 1.08, p = .348) postoperation. By Day 3, re-epithelialization was complete in 35 eyes (81.3%) with senofilcon A lenses and 36 eyes (83.7%) with lotrafilcon B lenses. Patients reported less pain in eyes with senofilcon A lenses during the first 3 days postoperation (for all, p < .001) and less epiphora during the first 2 days postoperation (Day 1: p =  .008, Day 2: p <  .001, Day 3: p = .267) than in eyes with lotrafilcon B lenses. No significant difference in photophobia emerged between the BCLs postoperatively (for all, p > .05)., Conclusions: Although duration of corneal re-epithelialization after PRK between the two BCLs did not differ significantly, senofilcon A lenses caused significantly less pain and epiphora after PRK., Competing Interests: Declaration of Competing Interest ZD declares that she has no conflict of interest. ND declares that he has no conflict of interest. DMU declares that she has no conflict of interest., (Copyright © 2019 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)