Effect of corneal cross-linking on endothelial cell density and morphology in the peripheral cornea

Abstract BACKGROUND: To compare the endothelial cell density and morphology in the peripheral cornea before and after corneal cross-linking (CXL).METHODS: This study evaluated twenty eyes of 20 patients who were treated with standard CXL for progressive keratoconus. Preoperatively and 3 months postoperatively, we compared the corneal endothelial cell density (ECD), the coefficient of variation in cell size (CV), and the percentage of hexagonal cells (HEX), in the peripheral regions of the cornea, using a non-contact specular microscope (EM-3000, Tomey). RESULTS: All keratoconic eyes in this series were measurable in the peripheral regions. No significant differences were found in the peripheral ECD preoperatively and 3 months postoperatively at each point (Wilcoxon signed-rank test, superior, p=0.14, nasal superior, p=0.16, temporal superior, p= 0.35, inferior, p=0.27, nasal inferior, p=0.24, temporal inferior, p=0.10). The mean percentage of the ECD loss was 2.3%, 1.6%, 1.5%, 2.4%, 1.1%, and 2.2%, respectively. No significant differences in the peripheral CV or HEX were found preoperatively and 3 months postoperatively at each point.CONCLUSIONS: Standard CXL does not cause significant changes in endothelial cell density, polymegethism, or polymorphism, in the peripheral regions of the cornea. It is suggested that CXL is a less invasive surgical approach for progressive keratoconus, even in terms of peripheral endothelial cells.TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trial Registry (000031162).

Download Full-text

Effect of Corneal Cross-linking on Endothelial Cell Density and Morphology in the Peripheral Cornea.

10.21203/rs.2.23100/v2 ◽

2020 ◽

Author(s):

Hiroyasu Goukon ◽

Kazutaka Kamiya ◽

Masahide Takahashi ◽

Nobuyuki Shoji

Keyword(s):

Endothelial Cell ◽

Cell Density ◽

Endothelial Cell Density ◽

Rank Test ◽

Cross Linking ◽

Minimally Invasive Surgical ◽

Before And After ◽

Signed Rank Test ◽

Peripheral Cornea ◽

Peripheral Regions

Abstract BACKGROUND: To compare the endothelial cell density and morphology in the peripheral cornea before and after corneal cross-linking (CXL).METHODS: This study evaluated thirty-one eyes of 31 patients who were treated with standard CXL for progressive keratoconus. Preoperatively and 6 months postoperatively, we compared the corneal endothelial cell density (ECD), the coefficient of variation in cell size (CV), and the percentage of hexagonal cells (HEX), in the peripheral regions of the cornea, using a non-contact specular microscope (EM-3000, Tomey).RESULTS: All keratoconic eyes in this series were measurable in the peripheral regions. No significant differences were found in the peripheral ECD preoperatively and 6 months postoperatively at each point (Wilcoxon signed-rank test, superior, p=0.16, nasal superior, p=0.12, temporal superior, p= 0.17, inferior, p=0.37, nasal inferior, p=0.28, temporal inferior, p=0.17). The mean percentage of the ECD loss was 1.3%, 1.3%, 1.0%, 1.4%, 0.7%, and 1.4%, respectively. No significant differences in the peripheral CV or HEX were found preoperatively and 6 months postoperatively at each point.CONCLUSIONS: Standard CXL does not cause significant changes in endothelial cell density, polymegethism, or polymorphism, in the peripheral regions of the cornea. It is suggested that CXL is a minimally invasive surgical approach for progressive keratoconus, even in terms of peripheral endothelial cells.

Download Full-text

Epi-off-lenticule-on corneal collagen cross-linking in thin keratoconic corneas

International Ophthalmology ◽

10.1007/s10792-020-01526-x ◽

2020 ◽

Vol 40 (12) ◽

pp. 3403-3412

Author(s):

Carlo Cagini ◽

F. Riccitelli ◽

M. Messina ◽

F. Piccinelli ◽

G. Torroni ◽

...

Keyword(s):

Visual Acuity ◽

Endothelial Cell ◽

Cell Density ◽

Corneal Thickness ◽

Endothelial Cell Density ◽

Cross Linking ◽

Corneal Transplant ◽

Collagen Cross Linking ◽

Corneal Collagen

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

Download Full-text

Effect of the retention ring-assisted continuous application of riboflavin in pulsed-light accelerated corneal collagen cross-linking on the progression of keratoconus

10.21203/rs.2.72/v2 ◽

2019 ◽

Author(s):

Chung Young Kim ◽

Mee Kum Kim

Keyword(s):

Visual Acuity ◽

Endothelial Cell ◽

Cell Density ◽

Corneal Thickness ◽

Endothelial Cell Density ◽

Cross Linking ◽

Pulsed Light ◽

Continuous Application ◽

Collagen Cross Linking ◽

Corneal Collagen

Abstract Background: To investigate the efficacy and safety of the retention ring-assisted continuous application of 0.1% riboflavin in pulsed-light accelerated corneal collagen cross-linking on the progression of keratoconus. Methods: The medical records of 20 eyes of 18 patients with progressive keratoconus who received collagen cross-linking at Seoul National University Hospital were retrospectively reviewed. Isotonic 0.1% riboflavin was continuously applied for 10 minutes using an 8.0-mm retention ring before the irradiation and accelerated cross-linking was applied with 30-mW pulsed-ultraviolet light at a wavelength 365 nm for eight minutes (1 second on/1 second off; 30 mW/cm2, cumulative dose of 7.2J/cm2) without further intermittent application of riboflavin. Visual acuity, refractive error, topographic index, corneal thickness, and endothelial cell density were evaluated before the operation and at 1, 3, 6, and 12 months. Results: The best corrected visual acuity in logMAR improved from preoperative 0.43 to 0.17 in 12 months (p = 0.050). Maximum keratometry decreased from 51.8 D to 50.4 D at six months (p = 0.015) and 50.1 D at 12 months (p = 0.0003). Astigmatism decreased from preoperative 5.5 D to 4.1 D at 12 months (p < 0.0001). Thinnest corneal thickness decreased at three and six months but recovered in 12 months (p > 0.05). Endothelial cell density decreased at postoperative one month (p = 0.02) but gradually recovered in 12 months (p > 0.05). Conclusions: Retention ring-assisted continuous application of riboflavin for ten minutes in pulsed-light accelerated cross-linking is a comparably safe and effective treatment for halting the progression of keratoconus in 12 months when compared to outcomes of the standard Dresden protocol shown in previous reports.

Download Full-text

Corneal collagen cross-linking in paediatric patients affected by keratoconus

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2016-310108 ◽

2017 ◽

Vol 102 (2) ◽

pp. 248-252 ◽

Cited By ~ 4

Author(s):

Karl Anders Knutsson ◽

Giorgio Paganoni ◽

Stanislav Matuska ◽

Oriella Ambrosio ◽

Giulio Ferrari ◽

...

Keyword(s):

Visual Acuity ◽

Endothelial Cell ◽

Cell Density ◽

Conventional Technique ◽

Endothelial Cell Density ◽

Cross Linking ◽

Demarcation Line ◽

Paediatric Patients ◽

Collagen Cross Linking ◽

Corneal Collagen

Background/aimsTo evaluate the effectiveness of corneal collagen cross-linking (CXL) in paediatric patients.MethodsFifty-two eyes of 43 paediatric patients with progressive keratoconus were enrolled in a prospective cohort study. Corneal CXL was performed using a conventional technique with instillation of 0.1% riboflavin solution containing dextran 20% for 30 min during the soaking phase and during the 30 min ultraviolet A irradiation (3 mW/cm2). Visual outcomes, topographic keratometry, maximum keratometry (K-max), refractive astigmatism, demarcation line and endothelial cell density were measured postoperatively.ResultsA significant decrease of K-max from 59.30±7.08 to 57.07±6.46 (p<0.001) was observed 2 years after treatment. Uncorrected visual acuity improved from 0.59±0.41 LogMAR (logarithm of the minimum angle resolution) to 0.46±0.33 LogMAR (p=0.06) 2 years after the procedure, while best spectacle corrected visual acuity improved from 0.17±0.11 LogMAR to 0.15±0.12 LogMAR (p=0.17). Twenty-five eyes had K-max values of 60 dioptres (D) or greater. In this subgroup, K-max significantly decreased from 64.94±4.99 D to 62.25±4.42 D at 2 years (p<0.001). The demarcation line of the CXL treatment had a mean value of 249±74 µm and did not show a significant correlation with K-max flattening (Spearman r=0.019, p=0.899). Endothelial cell density remained stable 2 years after the procedure, changing from 2800±363 to 2736±659 cells/mm2 (p=0.90).ConclusionCXL is an effective treatment for avoiding keratoconus progression in paediatric patients. The procedure is safe and successful in stabilising keratoconus in eyes with more advanced forms of the disease, characterised by topographic K-max values greater than 60 D.

Download Full-text

Effect of the Retention Ring-Assisted Continuous Application of Riboflavin in Pulsed-Light Accelerated Corneal Collagen Cross-Linking on the Progression of Keratoconus

10.21203/rs.2.72/v1 ◽

2018 ◽

Author(s):

Chung Young Kim ◽

MD Mee Kum Kim

Keyword(s):

Visual Acuity ◽

Endothelial Cell ◽

Cell Density ◽

Corneal Thickness ◽

Endothelial Cell Density ◽

Cross Linking ◽

Pulsed Light ◽

Continuous Application ◽

Collagen Cross Linking ◽

Corneal Collagen

Abstract Purpose: To investigate the efficacy and safety of the retention ring-assisted continuous application of 0.1% riboflavin in pulsed-light accelerated corneal collagen cross-linking on the progression of keratoconus. Methods: The medical records of 20 eyes of 18 patients with progressive keratoconus who received collagen cross-linking at Seoul National University Hospital were retrospectively reviewed. Isotonic 0.1% riboflavin was continuously applied for 10 minutes using an 8.0-mm retention ring before the irradiation and accelerated cross-linking was applied with 30-mW pulsed-ultraviolet light at a wavelength 365 nm for eight minutes (1 second on/1 second off; 30 mW/cm2, cumulative dose of 7.2J/cm2) without further intermittent application of riboflavin. Visual acuity, refractive error, topographic index, corneal thickness, and endothelial cell density were evaluated before the operation and at 1, 3, 6, and 12 months. Results: The best corrected visual acuity in logMAR improved from preoperative 0.43 to 0.18 in 12 months. Maximum keratometry decreased from 51.8 D to 50.4 D at six months (p = 0.015) and 50.3 D at 12 months (p < 0.0001). Astigmatism decreased from preoperative 5.5 D to 4.2 D at 12 months (p < 0.0001). Thinnest corneal thickness decreased at three and six months but recovered in 12 months (p > 0.05). Endothelial cell density decreased at one month (p = 0.02) but gradually recovered in 12 months (p > 0.05). Conclusions: Continuous application of riboflavin using a retention ring for 10 minutes in an accelerated pulsed-light collagen cross-linking seems to be safe and effective for halting the progression of the keratoconus.

Download Full-text

Case Report of Brown McLean Syndrome

Journal of the Korean Ophthalmological Society ◽

10.3341/jkos.2021.62.8.1135 ◽

2021 ◽

Vol 62 (8) ◽

pp. 1135-1140

Author(s):

Dongyoung Lee ◽

Gyu Le Han ◽

Dong Hui Lim ◽

Tae Young Chung

Keyword(s):

Endothelial Cell ◽

Cataract Surgery ◽

Cell Density ◽

Corneal Edema ◽

Endothelial Cell Density ◽

Specular Microscopy ◽

Artificial Tears ◽

Central Cornea ◽

Elevated Lesion ◽

Peripheral Cornea

Purpose: To report two rare cases of Brown McLean syndrome after cataract surgery in a patient with aphakia.Case summary: (Case 1) A 54-year-old woman with Marfan’s syndrome who had aphakia and peripheral corneal edema after left eye cataract surgery 4 years ago. The patient had an elevated lesion in the peripheral cornea without involving the central cornea, and had symptoms of pain, irritation and tearing. Specular microscopy showed normal endothelial cell density and morphology in the edematous cornea. The peripheral corneal edema improved after use of antibiotics, autoserum eyedrops and 5% NaCl eyedrops. (Case 2) A 61-year-old woman with aphakia in her left eye after bilateral cataract surgery 11 years ago, underwent surgery for a macular hole in both eyes. The patient developed peripheral corneal erosions and edema in the left eye 2 months after the surgery. Specular microscopy showed normal endothelial cell density and morphology. The peripheral corneal edema was static over the years while using 5% NaCl eyedrops and artificial tears, and did not progress to involve the central cornea.Conclusions: Brown McLean syndrome is a rare disease but the possibility should be considered if a patient with aphakia after cataract surgery has peripheral corneal edema for several years.

Download Full-text

Effect of the retention ring-assisted continuous application of riboflavin in pulsed-light accelerated corneal collagen cross-linking on the progression of keratoconus

10.21203/rs.2.72/v3 ◽

2019 ◽

Author(s):

Chung Young Kim ◽

Mee Kum Kim

Keyword(s):

Visual Acuity ◽

Endothelial Cell ◽

Cell Density ◽

Corneal Thickness ◽

Endothelial Cell Density ◽

Cross Linking ◽

Pulsed Light ◽

Continuous Application ◽

Collagen Cross Linking ◽

Corneal Collagen

Abstract Background: To investigate the efficacy and safety of the retention ring-assisted continuous application of 0.1% riboflavin in pulsed-light accelerated corneal collagen cross-linking on the progression of keratoconus. Methods: The medical records of 20 eyes of 18 patients with progressive keratoconus who received collagen cross-linking at Seoul National University Hospital were retrospectively reviewed. Isotonic 0.1% riboflavin was continuously applied for 10 minutes using an 8.0-mm retention ring before the irradiation and accelerated cross-linking was applied with 30-mW pulsed-ultraviolet light at a wavelength 365 nm for eight minutes (1 second on/1 second off; 30 mW/cm2, cumulative dose of 7.2J/cm2) without further intermittent application of riboflavin. Visual acuity, refractive error, topographic index, corneal thickness, and endothelial cell density were evaluated before the operation and at 1, 3, 6, and 12 months. Results: The best corrected visual acuity in logMAR improved from preoperative 0.43 to 0.17 in 12 months (p = 0.050). Maximum keratometry decreased from 51.8 D to 50.4 D at six months (p = 0.015) and 50.1 D at 12 months (p = 0.0003). Astigmatism decreased from preoperative 5.5 D to 4.1 D at 12 months (p < 0.0001). Thinnest corneal thickness decreased at three and six months but recovered in 12 months (p > 0.05). Endothelial cell density decreased at postoperative one month (p = 0.02) but gradually recovered in 12 months (p > 0.05). Conclusions: Retention ring-assisted continuous application of riboflavin for ten minutes in pulsed-light accelerated cross-linking is a comparably safe and effective treatment for halting the progression of keratoconus in 12 months when compared to outcomes of the standard Dresden protocol shown in previous reports.

Download Full-text

Myopia, corneal endothelial cell density and morphology in a Japanese population-based cross-sectional study: the JPHC-NEXT Eye Study

Scientific Reports ◽

10.1038/s41598-021-85617-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Naohiko Aketa ◽

Miki Uchino ◽

Motoko Kawashima ◽

Yuichi Uchino ◽

Kenya Yuki ◽

...

Keyword(s):

Endothelial Cell ◽

Cell Density ◽

Contact Lenses ◽

Population Based ◽

Cross Sectional Study ◽

Corneal Endothelial Cell ◽

Endothelial Cell Density ◽

Sectional Study ◽

Cross Sectional ◽

Corneal Endothelial Cell Density

AbstractThis population-based cross-sectional study was performed to determine the mean corneal endothelial cell density (ECD), coefficient of variation (CV), and hexagonality (HEX), and their associations with myopia in Japanese adults living in Chikusei city. Of 7109 participants with available data, 5713 (2331 male and 3382 female) participants were eligible for analysis. After assessing the relationship between participant characteristics and spherical equivalent refraction (SER), the association of SER with the abnormal value of ECD (< 2000 cells/mm), CV (≥ 0.40), and HEX (≤ 50%) were determined using the logistic regression models adjusting for potential confounders (age, intraocular pressure, keratometric power, height, and antihypertensive drug use). In male participants, there was no statistically significant relationships between SER and endothelial parameters. In female participants, compared to emmetropia, SER ≤ − 6 D had significantly higher odds ratio (OR) of having the abnormal value of CV (OR = 2.07, 95% confidence interval [CI] 1.39–3.10) and HEX (OR = 2.04, 95% CI 1.29–3.23), adjusted for potential confounders, indicating that the high myopia was associated with the abnormal values of CV and HEX. Further adjustment for contact lenses wear partly attenuated these associations. Association between the SER and ECD was not detected.

Download Full-text

Endothelial Cell Density and Central Corneal Thickness following Penetrating Keratoplasty of Acanthamoeba Keratitis Patients – A Retrospective Cross-Sectional Observational Study

Klinische Monatsblätter für Augenheilkunde ◽

10.1055/a-1353-5171 ◽

2021 ◽

Author(s):

Lei Shi ◽

Fabian Norbert Fries ◽

Kassandra Xanthopoulou ◽

Tanja Stachon ◽

Loay Daas ◽

...

Keyword(s):

Endothelial Cell ◽

Observational Study ◽

Cell Density ◽

Central Corneal Thickness ◽

Penetrating Keratoplasty ◽

Corneal Thickness ◽

Acanthamoeba Keratitis ◽

Endothelial Cell Density ◽

Cross Sectional ◽

Time Point

Abstract Purpose To analyze endothelial cell density (ECD) and central corneal thickness (CCT) following penetrating keratoplasty (PKP) in Acanthamoeba keratitis (AK) patients. Patients and Methods In this retrospective, clinical, single-center, cross-sectional, observational study, patients were enrolled who underwent PKP at the Department of Ophthalmology of Saarland University Medical Center, Homburg/Saar, Germany between May 2008 and December 2016 with the diagnosis of AK. In all, 33 eyes of 33 patients (14 males, 42%) were enrolled; their mean age at the time of surgery was 39.5 ± 14.3 years. Postoperatively, AK patients received topical polyhexamethylene biguanide, propamidine isethionate, neomycin sulphate/gramicidin/polymixin B sulfate, and prednisolone acetate eye drops (5 ×/day each), and the topical treatment was tapered sequentially with 1 drop every 6 weeks over 6 months. CCT was recorded using Pentacam HR Scheimpflug tomography and ECD with the EM-3000 specular microscope before surgery and 3 and 6 months after surgery as well as after the first and second (complete) suture removal. Results ECD tended to decrease significantly from the time point before surgery (2232 ± 296 cells/mm2) to the time point 3 months after surgery (1914 ± 164 cells/mm2; p = 0.080) and to the time point after the first suture removal (1886 ± 557 cells/mm2; p = 0.066) and decrease significantly to the time point after the second suture removal (1650 ± 446 cells/mm2; p = 0.028). CCT did not change significantly over the analyzed time period (p ≥ 0.475). Conclusion In AK, endothelial cell loss does not seem to be accelerated following PKP, despite the postoperative use of diamidine and biguanide. A subsequent prospective comparative study should confirm our retrospective longitudinal analysis.

Download Full-text