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

2020 ◽  
Author(s):  
Hiroyasu Goukon ◽  
Kazutaka Kamiya ◽  
Masahide Takahashi ◽  
Nobuyuki Shoji

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.

2020 ◽  
Author(s):  
Hiroyasu Goukon ◽  
Kazutaka Kamiya ◽  
Masahide Takahashi ◽  
Nobuyuki Shoji

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).


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hiroyasu Goukon ◽  
Kazutaka Kamiya ◽  
Masahide Takahashi ◽  
Nobuyuki Shoji

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Abd Elaziz Mohamed Elmadina ◽  
Raghda Faisal Abdelfatah ◽  
Saif Hassan Alrasheed ◽  
Mustafa Abdu ◽  
Manzoor Ahmad Qureshi

Purpose:  To compare the corneal endothelial cells morphology and central corneal thickness (CCT) before and after phacoemulsification in Sudanese population. Place and Duration of Study:  Al-Neelain eye hospital, Khartoum, Sudan, from January 2018 to May 2018. Study Design:  Observational longitudinal study. Methods:  One hundred and forty eyes of 140 patients with immature senile cataract were selected by convenient sampling. The age ranged from 40 to 85 years. The patients underwent complete ocular examination including morphology of corneal endothelial cells and CCT using computerized non-contact specular microscope. Inclusion criteria for the study was eyes with normal corneal endothelial cells and cell density more than 1000 cells/mm2. We excluded patients with ocular or systemic diseases, previous history of intraocular surgery, refractive surgery or trauma as well as contact lenses wear. The patients underwent phacoemulsification by a single surgeon. The examination parameters were repeated one month after surgery. Descriptive and comparative statistical analyses were performed using SPSS for Windows Version 21.0. Results:  There was significant reduction in mean endothelial cells density after phacoemulsification compared to baseline with p < 0.001. There was also significant post-operative reduction in mean endothelial cells number as compared to baseline (P value < 0.001). Mean endothelial cells hexagonality was reduced after surgery with P value of 0.003. No significant difference was found between mean coefficient variation of endothelial cells size before and after phacoemulsification (P = 0.55). Central corneal thickness showed significant increase post-operatively, P = 0.003. Conclusion:  Phacoemulsification causes significant damage to corneal endothelium cells, including decrease in corneal endothelial cell density, hexagonality and cell number. Key Words:  Corneal endothelium, Endothelial cell density, Central corneal thickness, Phacoemulsification.


2020 ◽  
Vol 40 (12) ◽  
pp. 3403-3412
Author(s):  
Carlo Cagini ◽  
F. Riccitelli ◽  
M. Messina ◽  
F. Piccinelli ◽  
G. Torroni ◽  
...  

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.


2019 ◽  
Author(s):  
Chung Young Kim ◽  
Mee Kum Kim

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.


2017 ◽  
Vol 102 (2) ◽  
pp. 248-252 ◽  
Author(s):  
Karl Anders Knutsson ◽  
Giorgio Paganoni ◽  
Stanislav Matuska ◽  
Oriella Ambrosio ◽  
Giulio Ferrari ◽  
...  

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.


2018 ◽  
Author(s):  
Chung Young Kim ◽  
MD Mee Kum Kim

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.


2021 ◽  
Vol 62 (8) ◽  
pp. 1135-1140
Author(s):  
Dongyoung Lee ◽  
Gyu Le Han ◽  
Dong Hui Lim ◽  
Tae Young Chung

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.


Sign in / Sign up

Export Citation Format

Share Document