Principal Component Analysis of a Real-World Cohort of Descemet Stripping Automated Endothelial Keratoplasty and Descemet Membrane Endothelial Keratoplasty Cases: Demonstration of a Powerful Data-Mining Technique for Identifying Areas of Research.

PURPOSE: Principal component analysis (PCA) is a descriptive exploratory statistical technique that is widely used in complex fields for data mining. However, it is rarely used in ophthalmology. We explored its research potential with a large series of eyes that underwent 3 keratoplasty techniques: Descemet membrane endothelial keratoplasty (DMEK), conventional Descemet stripping automated endothelial keratoplasty (ConDSAEK), or ultrathin-DSAEK (UT-DSAEK). METHODS: All consecutive DMEK/DSAEK cases conducted in 2016 to 2022 that had ≥24 months of follow-up were included. ConDSAEK and UT-DSAEK were defined as preoperative central graft thickness ≥130 and <130 µm, respectively. Seventy-six patient, disease, surgical practice, and temporal outcome variables were subjected to PCA, including preoperative anterior keratometry, the use of sulfur hexafluoride gas (SF6) versus air for primary tamponade, and postoperative best corrected visual acuity and endothelial cell density. Associations of interest that were revealed by PCA were assessed with the Welch t test or Pearson test. RESULTS: A total of 331 eyes were treated with DMEK (n = 165), ConDSAEK (n = 95), or UT-DSAEK (n = 71). PCA showed that ConDSAEK and UT-DSAEK clustered closely, including regarding postoperative best corrected visual acuity, and were clearly distinct from DMEK. PCA and follow-up univariate analyses suggested that in DMEK, 1) flatter preoperative anterior keratometry (average, K1, and K2) associated with more rebubbling (P = 0.004-0.089) and graft detachment (P = 0.007-0.022); 2) graft marking did not affect postoperative ECD; and 3) lower postoperative endothelial cell density associated with SF6 use (all P > 0.001) and longer surgery (P = 0.005-0.091). All associations are currently under additional investigation in our hospital. CONCLUSIONS: PCA is a powerful technique that can rapidly reveal clinically relevant associations in complex ophthalmological datasets.

Narrative review after post-hoc trial analysis of factors that predict corneal endothelial cell loss after phacoemulsification: Tips for improving cataract surgery research.

PURPOSE: Identifying pre/perioperative factors that predict corneal endothelial-cell loss (ECL) after phacoemulsification may reveal ways to reduce ECL. Our literature analysis showed that 37 studies have investigated one or several such factors but all have significant limitations. Therefore, the data of a large randomized controlled trial (PERCEPOLIS) were subjected to post-hoc multivariate analysis determining the ability of nine pre/perioperative variables to predict ECL. METHODS: PERCEPOLIS was conducted in 2015-2016 to compare two phacoemulsification techniques (subluxation and divide-and-conquer) in terms of 3-month ECL. Non-inferiority between the techniques was found. In the present study, post-hoc univariate and multivariate analyses were conducted to determine associations between ECL and age, sex, cataract density, preoperative endothelial-cell density, phacoemulsification technique, effective phaco time (EPT), and 2-hour central-corneal thickness. The data are presented in the context of a narrative review of the literature. RESULTS: Three-month data were available for 275 patients (94% of the randomized cohort; mean age, 74 years; 58% women). Mean LOCSIII cataract grade was 3.2. Mean EPT was 6 seconds. Mean ECL was 13%. Only an older age (beta = 0.2%, p = 0.049) and higher EPT (beta = 1.2%, p = 0.0002) predicted 3-month ECL. Cataract density was significant on univariate (p = 0.04) but not multivariate analysis. The other variables did not associate with ECL. CONCLUSIONS: Older age may amplify ECL due to increased endothelial cell fragility. EPT may promote ECL via cataract density-dependent and -independent mechanisms that should be considered in future phacoemulsification research aiming to reduce ECL. Our literature analysis showed that the average ECL for relatively unselected consecutively-sampled cohorts is 12%.

Five-year clinical outcomes of 107 consecutive DMEK surgeries.

PURPOSE: The long-term clinical outcomes, postoperative complications, and graft survival of Descemet-membrane endothelial keratoplasty (DMEK) remain poorly understood. We retrospectively assessed these variables in all consecutive eyes that underwent DMEK for any indication in 2014-2018. The findings were compared to the long-term DMEK studies of five other groups (3-10-year follow-up). METHODS: Patients underwent ophthalmological tests preoperatively, at 1, 3, 6, and 12 postoperative months, and then annually. Five-year graft survival was determined by Kaplan-Meier estimator. Change in best-corrected visual acuity (BCVA), endothelial-cell density (ECD), and central-corneal thickness (CCT) at each timepoint was determined. RESULTS: 107 eyes (80 patients; 72 years old; 67% female) underwent first-time DMEK for uncomplicated Fuchs endothelial corneal dystrophy (94% of eyes), pseudophakic bullous keratopathy (3%), and regraft after previous keratoplasty (3%). The most common complication was graft detachment requiring rebubbling (18%). Thirteen grafts (12%) failed at ≤15 months. Cumulative 5-year graft-survival probability was 88% (95% confidence intervals = 79-94%). BCVA improved from 0.6 logMAR preoperatively to 0.05 logMAR at 1 year (p<0.0001) and then remained stable. Donor ECD dropped by 47% at 6 postoperative months and then continued to decrease by 4.0%/year. Five-year endothelial-cell loss was 65% (from 2550 to 900 cells/mm2). CCT dropped from 618 to 551 µm at 5 years (p<0.0001). These findings are generally consistent with previous long-term DMEK studies. CONCLUSIONS: DMEK has low complication and high graft-survival rates and excellent clinical outcomes that persist up to 5 years post-surgery. DMEK seems to be a safe and effective treatment in the long term.

Corneal Perforation Repair Using a Novel Lyophilized Amniotic Membrane Graft Technique: Plug and Patch.

BACKGROUND The use of amniotic membranes for corneal perforations using different surgical techniques has been widely described in the literature. This case report is a novel variation in the technique that can be useful for incorporating in clinical practice when the need arises. CASE REPORT A 36-year-old male patient presented to our clinic with a corneal ulcer in his left eye caused by herpetic keratitis, treated with a topical non-steroidal anti-inflammatory (indomethacin 0.1% solution). Examination revealed a paracentral 2-mm wide corneal perforation on the site of the corneal ulcer. The patient was admitted to the hospital. He was treated with intravenous piperacillin-ofloxacine, and an emergency surgical intervention using a lyophilized amniotic membrane was performed using a "plug and patch" technique. Postoperatively, the patient received 48 h of intravenous antibiotics and was discharged on topical antibiotic/corticosteroid eyedrops along with a 10-day course of oral antibiotics (ofloxacin) and antiviral therapy (valaciclovir). Three months after surgery, the anterior chamber was formed, the corneal defect was closed, and visual acuity improved. One year after initial presentation, anterior segment optical coherence tomography showed a large scarred but healed cornea. CONCLUSIONS We report the successful use of combination of a single round-shaped rolled amniotic membrane with a multilayered amniotic membrane transplantation for the treatment of a 2-mm-wide perforated corneal ulcer. This technique allowed for preservation of the globe integrity without the need for a keratoplasty, stopped further tissue loss, and was associated with a rapid visual recovery.

Postoperative, but not preoperative, central corneal thickness correlates with the postoperative visual outcomes of Descemet membrane endothelial keratoplasty.

Descemet membrane endothelial keratoplasty (DMEK) restores visual acuity in patients with progressive corneal endothelial diseases such as Fuchs endothelial corneal dystrophy (FECD). However, patients often prefer to delay the surgery as long as possible, even though outcomes are poorer in advanced FECD. A recent study proposed that preoperative central corneal thickness (CCT) of ≥625 µm associated with worse best spectacle-corrected visual acuity (BSCVA) after DMEK for FECD. Since this threshold could signal to both surgeons and patients when to perform DMEK, we further explored the relationship between CCT and BSCVA with a retrospective cohort study. The cohort consisted of all patients with FECD who underwent DMEK in a tertiary-care hospital in 2015-2020 and were followed for 12 months. Extremely decompensated corneas were not included. Relationships between preoperative CCT and BSCVA on days 8 and 15 and months 1, 3, 6, and 12 were examined with Pearson correlation analyses. Eyes with preoperative CCT <625 or ≥625 µm were also compared in terms of postoperative BSCVA. Relationships between postoperative CCT and final BSCVA were also explored. The cohort consisted of 124 first-operated eyes. Preoperative CCT did not correlate with postoperative BSCVA at any timepoint. Eye subgroups did not differ in postoperative BSCVA. However, postoperative CCT at 1-12 months correlated significantly with 12-month BSCVA (r = 0.29-0.49, p = 0.020-0.001). Thus, postoperative, but not preoperative, CCT correlated with postoperative BSCVA. This phenomenon may reflect factors that distort preoperative CCT measurements but disappear after surgery. This observation and our analysis of the literature suggest that while there is a relationship between CCT and post-DMEK visual acuity, preoperative CCT measurements may not always adequately reflect that relationship and may therefore not be a reliable predictor of DMEK visual outcomes.

Membranoproliferative glomerulonephritis after intravitreal vascular growth factor inhibitor injections: A case report and review of the literature.

Systemic administration of agents that inhibit vascular endothelial growth factor (VEGF) and therefore vascular proliferation is often used to treat various cancers. However, these agents are associated with a number of side effects, including proteinuria and renal injury. Intravitreal injection of anti-VEGF agents has become the cornerstone of macular disease treatment. Since these agents cross the blood-retina barrier and enter the circulation, systemic side effects have been reported. We report the novel case of a 57-year-old patient who presented with macular oedema secondary to central retinal vein occlusion, underwent three monthly loading-dose injections with the anti-VEGF agent ranibizumab, and 2 weeks after the second injection presented with biopsy-verified membranoproliferative glomerulonephritis. Twelve weeks after presenting with renal failure and 10 weeks after his last anti-VEGF injection, the patient demonstrated spontaneous recovery of his kidney function. The patient had a history that promoted renal fragility, including hypertension, liver transplantation 6 years earlier for alcohol-related cirrhosis and new-onset diabetes mellitus after transplant. Our literature review and case suggest that although adverse renal events after intravitreal anti-VEGF injections are very rare, ophthalmologists and nephrologists should be aware of this risk.

Ability of routinely collected clinical factors to predict good visual results after primary Descemet membrane endothelial keratoplasty: a cohort study.

BACKGROUND: A comprehensive analysis of routinely collected pre/perioperative demographic/clinical factors that could predict final visual acuity after primary Descemet membrane endothelial keratoplasty (DMEK) has not been conducted previously. METHODS: A retrospective monocenter cohort study was performed with consecutive patients with Fuchs endothelial corneal dystrophy (FECD) who underwent DMEK or triple-DMEK (DMEK combined with cataract surgery) in 2016-2020 in a French tertiary-care hospital. DMEK-only patients were pseudophakic. Patients were followed for 12 months. Surgery was considered successful when 12-month best-corrected visual acuity (BCVA) was ≤0.1 logMAR (≥0.8). Exploratory multivariate analysis was conducted with the following routinely collected variables to determine their ability to predict 12-month BCVA: patient age and sex; graft donor age; triple DMEK; preoperative values of BCVA, endothelial cell density (ECD), central corneal thickness (CCT), and mean anterior keratometry; and rebubbling. RESULTS: Of 100 eyes (100 patients; mean age, 72 years; 61% female), 81 achieved a 12-month BCVA of ≤0.1 logMAR. Logistic regression analysis showed that older age was a significant prognosticator for 12-month BCVA > 0.1 logMAR (Odds Ratio = 0.914, 95% confidence intervals = 0.846-0.987; p = 0.02). CONCLUSIONS: An older age associated with worse visual acuity outcomes after DMEK. This was confirmed by our analysis of the literature and supports the notion that DMEK should be conducted without delay once symptoms appear. Patient sex, donor age, triple-DMEK, and anterior keratometry also did not predict final BCVA in the literature. Preoperative CCT, ECD, and BCVA, and rebubbling occasionally appear in the literature as BCVA predictors, possibly reflecting an underlying ECD-BCVA axis.

Identification of the preoperative and perioperative factors that predict postoperative endothelial cell density after Descemet membrane endothelial keratoplasty: A retrospective cohort study.

Low postoperative endothelial-cell density (ECD) plays a key role in graft failure after Descemet-membrane endothelial keratoplasty (DMEK). Identifying pre/perioperative factors that predict postoperative ECD could help improve DMEK outcomes. This retrospective study was conducted with consecutive adult patients with Fuchs-endothelial corneal dystrophy who underwent DMEK in 2015-2019 and were followed for 12 months. Patients underwent concomitant cataract surgery (triple-DMEK) or had previously undergone cataract surgery (pseudophakic-DMEK). Multivariate analyses assessed whether: patient age/sex; graft-donor age; preoperative ECD, mean keratometry, or visual acuity; triple DMEK; surgery duration; surgical difficulties; and need for rebubbling predicted 6- or 12-month ECD in the whole cohort or in subgroups with high/low ECD at 6 or 12 months. The subgroups were generated with the clinically relevant threshold of 1000 cells/mm2. Surgeries were defined as difficult if any part was not standard. In total, 103 eyes (95 patients; average age, 71 years; 62% women) were included. Eighteen eyes involved difficult surgery (14 difficult graft preparation or unfolding cases and four others). Regardless of how the study group was defined, the only pre/perioperative variable that associated significantly with 6- and 12-month ECD was difficult surgery (p = 0.01, 0.02, 0.05, and 0.0009). Difficult surgery also associated with longer surgery duration (p = 0.002). Difficult-surgery subgroup analysis showed that difficult graft dissection associated with lower postoperative ECD (p = 0.03). This association may reflect endothelial cell loss due to excessive graft handling and/or an intrinsic unhealthiness of the endothelial cells in the graft that conferred unwanted physical properties onto the graft that complicated its preparation/unfolding.

Corneal Endothelial Cell Loss After Endocapsular and Supracapsular Phacoemulsification: The PERCEPOLIS Randomized Clinical Trial.

PURPOSE: Subluxation techniques are superior to divide-and-conquer in procedure duration, pain, and ultrasound quantity, but their safety in endothelial cell loss (ECL) is unclear. This randomized single-blind noninferiority clinical trial aimed to determine whether subluxation supracapsular phacoemulsification techniques are inferior to a reference endocapsular technique (divide-and-conquer) regarding postoperative corneal ECL. METHODS: Patients (aged18 years or older) with greater than +0.2 logarithm of the minimum angle of resolution best spectacle-corrected visual acuity and normal to severe density cataract were randomized to subluxation or divide-and-conquer phacoemulsification in 2015 to 2016. Follow-up with ophthalmic tests was conducted on day 4 and months 1, 3, and 12. The primary study outcome was ECL at all time points. Secondary study end points were operative variables, including effective phaco time and procedure duration. A clinically relevant noninferiority ECL limit was established on the basis of the literature. RESULTS: In total, 292 patients (mean age, 73 yrs; 59% female) were randomized and underwent subluxation (n = 148) or divide-and-conquer (n = 144). Day 4 and month 1, 3, and 12 data were available for 243, 270, 275, and 198 patients, respectively. The unexpectedly high dropout at 12 months meant that the 12-month ECL data could only be assessed qualitatively. Surgery was successful in all patients. Subluxation was noninferior to divide-and-conquer in ECL. Effective phaco times were similar, but subluxation associated with shorter procedure duration. CONCLUSIONS: The subluxation technique was noninferior to divide-and-conquer regarding postoperative ECL, at least in the first 3 months, and associated with reduced intervention time. Subluxation techniques may be suitable alternatives to endocapsular techniques.Clinical Trial Registration-URL: ClinicalTrials.gov. Unique identifier: NCT02535819.

Efficacy and safety of single-step transepithelial photorefractive keratectomy with the all-surface laser ablation SCHWIND platform without mitomycin-C for high myopia: A retrospective study of 69 eyes.

BACKGROUND: Studies suggest that transepithelial photorefractive keratectomy (TransPRK) with the all-surface laser ablation (ASLA)-SCHWIND platform is effective and safe for both low-moderate myopia and high myopia. In most studies, mitomycin-C is administered immediately after surgery to prevent corneal opacification (haze), which is a significant complication of photorefractive keratectomy in general. However, there is evidence that adjuvant mitomycin-C induces endothelial cytotoxicity. Moreover, a recent study showed that omitting adjuvant mitomycin-C did not increase haze in low-moderate myopia. The present case-series study examined the efficacy, safety, and haze rates of eyes with high myopia that underwent ASLA-SCHWIND TransPRK without adjuvant mitomycin-C. METHODS: All consecutive eyes with high myopia (≤-6 D) that were treated in 2018-2020 with the SCHWIND Amaris 500E® TransPRK excimer laser without adjuvant mitomycin-C in a tertiary-care hospital (France) and were followed up for 6 months were identified. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and spherical equivalent (SE) were recorded before and after surgery. Postoperative haze was graded using the 4-grade Fantes scale. Efficacy rate (frequency of eyes with 6-month UCVA ≤0.1 logMAR), safety rate (frequency of eyes that lost <2 BSCVA lines), predictability (frequency of eyes with 6-month SE equal to target SE±0.5 D), efficacy index (mean UCVA at 6 months/preoperative BSCVA), and safety index (BSCVA at 6 months/preoperative BSCVA) were computed. RESULTS: Sixty-nine eyes (38 patients) were included. Mean preoperative and 6-month SE were -7.44 and -0.05 D, respectively. Mean 6-month UCVA and BSCVA were 0.00 and -0.02 logMAR, respectively. Efficacy rate and index were 95.7% and 1.08, respectively. Safety rate and index were 95.7% and 1.13, respectively. Predictability was 85.5%. Grade 3-4 haze never arose. At 6 months, the haze rate was zero. CONCLUSIONS: ASLA-SCHWIND TransPRK without mitomycin-C appears to be safe as well as effective and accurate for high myopia.

Secondary Corneal Myxoma After DMEK (Descemet Membrane Endothelial Keratoplasty).

BACKGROUND This is a clinical case of secondary corneal myxoma, which developed 18 months after Descemet membrane endothelial keratoplasty (DMEK). The DMEK was performed to treat viral endotheliitis and, postoperatively, a diagnosis of Crohn's disease was made. CASE REPORT A 52-year-old male, with no prior clinical history, presented with an endotheliitis in the left eye. The hypothesis of an undetected herpes infection was favored, and an antiviral treatment was prescribed using valacyclovir (1 g orally, 3 times daily). After 3 months of antiviral treatment, the endotheliitis was successfully controlled and a combined intervention of DMEK endothelial graft and phacoemulsification was performed. A corneal tumor was found 18 months after a successful DMEK procedure and was surgically removed. A pathological examination revealed a secondary corneal myxoma. CONCLUSIONS Corneal myxomas are rare lesions, often secondary to trauma in the Bowman's membrane, which is why it is often called a myxomatous corneal degeneration. In this instance, there is no link with Carney complex. However, myxomas under the eyelid or within the orbit are often associated with cardiac myxomas. Treatment is strictly surgical, either by simple excision or by surgical excision followed by graft. To the best of our knowledge, this is the first time that such an association between DMEK and secondary corneal myxoma has been described in the literature.

Does Preoperative or Postoperative Graft Thickness Influence Postoperative Visual Acuity in Descemet Stripping Automated Endothelial Keratoplasty for Advanced Pseudophakic Bullous Keratopathy?

PURPOSE: To describe the evolution of best spectacle-corrected visual acuity (BSCVA) after Descemet stripping automated endothelial keratoplasty (DSAEK) for very advanced pseudophakic bullous keratopathy (PBK) and to determine whether the thickness of corneal grafts in DSAEK surgery for advanced PBK correlates with BSCVA 6 months postoperatively. METHODS: In a prospective, single-center, observational study, 141 eyes treated with DSAEK surgery were studied, from patients requiring posterior lamellar transplantation for advanced PBK. Graft thickness was measured during the surgery and in vivo 6 months later. The primary end point was BSCVA in LogMAR at 6 months. RESULTS: BSCVA 6 months after surgery was slightly correlated with 6 months graft thickness (r = 0.24, P = 0.01), but not with preoperative graft thickness (r = 0.01, P = 0.93). After adjusting for preoperative BSCVA, a better 6 months BSCVA was best associated with thinner grafts at 6 months (P < 0.01), but not with preoperative graft thickness (P = 0.80). CONCLUSIONS: BSCVA after DSAEK was significantly related to graft thickness measured 6 months after surgery, suggesting that better BSCVA after DSAEK is related to a decrease in graft thickness after surgery and not to the use of a thinner graft during surgery. This decrease may be because of the good health of the endothelium, but this result may be biased because of the intrastromal scars inherent in severe PBK. This study shows that DSAEK is a good option for advanced PBK but has low visual acuity potential recovery because of stromal scarring. Therefore, a penetrating keratoplasty may be indicated to obtain maximal recovery of visual acuity or for monocular patients.

Correlation Between Postoperative Central Corneal Thickness and Endothelial Damage After Cataract Surgery by Phacoemulsification.

PURPOSE: To study the correlation between postoperative corneal edema and endothelial cell loss after cataract surgery by microcoaxial phacoemulsification. METHODS: Eighty-five eyes of 85 consecutive patients with mild cataract (up to C5, N4, and P5: per LOCS III classification) were included in a prospective study from September 2014 to November 2014. Eighty-five eyes were necessary to obtain a precision of 0.15 for computation of the Pearson correlation coefficient. Pachymetry and endothelial cell density measurements were taken preoperatively, 2 hours after surgery, and 4 days, 15 days, and 1 month after surgery using CEM-530 noncontact specular microscopy (Nidek CO Ltd, Japan). Every surgery was performed using the Stellaris device (Bausch & Lomb, Bridgewater, NJ) in a microcoaxial mode with 2.2-mm incisions. RESULTS: Mean age was 73 ± 2.1 years, with 41 women (48%) and 44 men (52%). The mean surgical time was 8 ± 5.5 minutes, and the mean effective phacoemulsification time was 7 ± 3.7 seconds. Mean central corneal thickness augmentation was 46.68 ± 10 µm (8.39%) 2 hours after surgery, 10 ± 18 µm (1.8%) 4 days after surgery, and only 0.76 ± 11.4 µm (0.1%) 15 days after surgery. Mean endothelial cell loss was 3.0 ± 1.5% at 2 hours, 9.0 ± 3.3% at D4, 10 ± 4.6% at D15, and 11 ± 4.7% at 1 month. At D4, significant endothelial loss (>15%) was mostly related to significant immediate corneal edema (>15%), whereas low postoperative edema (<5%) did not lead to significant endothelial loss (loss <5%). At D15 and D30, endothelial cell loss seemed to be closely correlated with immediate postoperative edema (Pearson correlation coefficient between central corneal edema at H2 and endothelial cells loss at 1 month: r = 0.4, P < 0.0001). CONCLUSIONS: Postoperative corneal thickness measurement may therefore become a marker of endothelial damage after phacoemulsification.

Visibility and Depth of the Stromal Demarcation Line After Corneal Collagen Cross-Linking Using Anterior Segment Optical Coherence Tomography: Comparison Between Isoosmolar and Hypoosmolar Riboflavin.

PURPOSE: To evaluate and compare visibility and depth of the stromal demarcation line (DL) created after corneal collagen cross-linking (CXL) using anterior segment optical coherence tomography (AS-OCT) between 2 groups: CXL with isoosmolar and hypoosmolar riboflavin. METHODS: In this retrospective study performed at Metz-Thionville Regional Hospital, consecutive patients with progressive keratoconus underwent CXL using an accelerated protocol (10 min, 9 mW/cm ultraviolet-A). AS-OCT (RS-3000, Nidek) was performed at 1 month after surgery, with stromal DL visibility graded. The corneal demarcation line depth (DLD) was also measured. RESULTS: Seventy-five eyes of 58 patients with a mean age of 25.2 ± 9.1 years were enrolled in the study. Preoperative mean anterior Kmax was 57.4 ± 5.4 D. The mean thinnest pachymetry was 474.3 ± 35.7 µm. The mean depth of the stromal DL on 1-month optical coherence tomography evaluation was 331.2 ± 62.7 µm. A DL was visible (grades 1 and 2) in 54 (72%) treated eyes. A positive correlation was found between patient age and the DLD: deeper lines were found in older patients [r = 0.38, P = 0.005, confidence interval 95% (0.12; 0.58)]. Forty-one patients were included in the isoosmolar group and 34 in the hypoosmolar group: neither visibility nor DLD was significantly different between groups. The mean depth was 334.5 ± 67.5 µm and 328.1 ± 59.0 µm in the isoosmolar and hypoosmolar groups, respectively (P = 0.82). A DL was visible (grades 1 and 2) in 26 eyes (63.4%) and 28 eyes (82.4%) in the isoosmolar and hypoosmolar groups, respectively (P = 0.12). CONCLUSIONS: The use of isoosmolar or hypoosmolar riboflavin does not significantly modify the depth or visibility of the stromal DL 1 month after accelerated CXL on AS-OCT evaluation.