Clinical observation of the 6-month safety of the corneal endothelium after trabeculotome tunnelling trabeculoplasty surgery

Purpose To determine the limits of normal interocular symmetry and the repeatability of central corneal thickness (CCT) and endothelial cell morphology and density. Methods Two hundred and seventy-eight subjects (age: 10.9–80.7 years) with healthy eyes were studied. CCT as well as endothelial cell morphology and density were measured by non-contact specular microscopy. Three measurements were obtained per eye per participant. Upper and lower tolerance limits of normal interocular symmetry were defined as the 2.5th and 97.5th percentiles of the interocular differences in CCT, endothelial cell density (CECD), coefficient of variation (CoV), hexagonality, and cell size. Repeatability was determined using the intraclass coefficient correlation (ICC), the coefficient of variation (CV), and the test–retest variability standard deviation (TRTSD). Results The mean interocular differences were −1.05 ± 17.5 µm (p = .32) for CCT and 0.5 ± 90.8 cells/mm2 (p = .76) for CECD. The 2.5th and 97.5th percentiles of the interocular differences were −13.9 and 15.4 µm for CCT and −177.4 cells/mm2 to 182.0 cells/mm2 for CECD. Only interocular difference in CoV correlated weakly with age (r = −0.22, P < .001). ICCs were 0.93 (95% CI: 0.89–0.96, P < .001) for CCT and 0.95 (0.94–0.96, P < .001) for CECD. CV and TRTSD were 1.2% ± 5.3% and 4.4 ± 3.4 µm for CCT and 2.4% ± 3.9% and 17.7 ± 7.7 cells/mm2 for CECD, respectively. Conclusions CCT and CECD showed good repeatability and interocular symmetry in normal Congolese subjects. Absolute interocular differences in CCT and CECD exceeding 15.5 µm and 182 cells/mm2, respectively, should be considered suspicious and investigated. When comparing two intrasession measurements from the same eye, a difference of approximately 4.5 µm in CCT and 18 cells/mm2 or greater may be considered statistically significant.

Purpose: To compare the corneal endothelial cells morphology and central corneal thickness (CCT) before and after phacoemulsification in Sudanese population.&#x0D; Place and Duration of Study: Al-Neelain eye hospital, Khartoum, Sudan, from January 2018 to May 2018.&#x0D; Study Design: Observational longitudinal study.&#x0D; 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.&#x0D; Results: There was significant reduction in mean endothelial cells density after phacoemulsification compared to baseline with p &lt; 0.001. There was also significant post-operative reduction in mean endothelial cells number as compared to baseline (P value &lt; 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.&#x0D; Conclusion: Phacoemulsification causes significant damage to corneal endothelium cells, including decrease in corneal endothelial cell density, hexagonality and cell number.&#x0D; Key Words: Corneal endothelium, Endothelial cell density, Central corneal thickness, Phacoemulsification.

To evaluate corneal endothelial cell density (CD) and morphology in different trimesters of pregnancy. This prospective study included 66 (66 eyes) pregnant women. The patient group was divided into three subgroups comprised of 22 women in the first, second, and third trimesters of pregnancy. An age-matched group of 22 (22 eyes) volunteers served as controls. Corneal measurements were performed using specular microscopy (Noncon Robo SP8000, Konan Medical). Central corneal thickness (CCT) and CD, hexagonal cell ratio (HEX), and coefficient of variation (CV) of the corneal endothelial cell layer of the patients were measured at each trimester. Central corneal thickness did not change significantly during the pregnancy compared to controls (P>0.05). Endothelial CD was decreased in the first trimester and increased in the second and third trimesters, but the difference was not significant (P>0.05). Hexagonal cell ratio was decreased significantly in the first trimester (P<0.05). There was an increase in the second and third trimesters, which was not statistically significant (P>0.05). Coefficient of variation was increased significantly in the first trimester and showed a significant decrease in the second and third trimesters (P<0.05, respectively). Endothelial CD had a significant positive correlation with CV and HEX had a negative correlation with CV in the second trimester (r=0.438, P=0.041 and r=-0.822, P<0.001, respectively). Central corneal thickness and endothelial CD did not change significantly throughout the pregnancy. Hexagonal cell ratio and CV showed a significant but transient increase in the first trimester.

Corneal confocal microscopy (CCM) detects neurodegeneration in mild cognitive impairment (MCI) and dementia and identifiessubjects with MCI who develop dementia. This study assessed whether abnormalities in corneal endothelial cell (CEC) morphology are related to corneal nerve morphology, brain volumetry, cerebral ischemia, and cognitive impairment in MCI and dementia. Participants with no cognitive impairment (NCI), MCI, and dementia underwent CCM to quantify corneal endothelial cell density (CECD) and area (CECA), corneal nerve fiber morphology, magnetic resonance imaging (MRI) brain volumetry, and severity of brain ischemia. Of the 114 participants, 14 had NCI, 77 had MCI, and 23 had dementia. CECD (1971.3 ± 594.6vs 2316.1 ± 499.5 cells/mm2, p < 0.05) was significantly lower in the dementia compared to the NCI group. CECD and CECA were comparable between the MCI and NCI groups (p = 0.13-0.65). Corneal nerve fiber density (CNFD) (31.7 ± 5.6vs 24.5 ± 9.2 and 17.3 ± 5.3 fibers/mm2, p < 0.01), corneal nerve branch density (CNBD) (111.8 ± 58.1vs 50.4 ± 36.4 and 52.7 ± 21.3 branches/mm2, p < 0.0001), and corneal nerve fiber length (CNFL) (24.6 ± 6.6vs 16.5 ± 6.8 and 16.2 ± 5.0mm/mm2, p < 0.0001) were lower in the MCI and dementia groups compared to the NCI group. Lower CECD partially mediated the impact of age and diabetes on CNFL reduction (p < 0.05), whereas CECA lost its significance after adjustment (p = 0.20). CEC morphology does not affect the association between corneal nerve fiber loss and MCI/dementia. CECD and CECA had no significant association with cerebral ischemic lesions (p = 0.21-0.47), dementia (p = 0.11-0.35), or cognitive decline (p = 0.37-0.38). However, lower CECD and higher CECA were associated with decreased cortical gray matter volume (p < 0.05-0.01). CEC loss occurs in patients with dementia, and both endothelial cell loss and hypertrophy are associated with cortical gray matter atrophy. CNF loss occurs in individuals with MCI and dementia. Corneal nerve and endothelial cell abnormalities could act as biomarkers for neurovascular pathology in dementia. Corneal endothelial cell density is significantly reduced in patients with dementia.Corneal nerve fiber density, branch density, and length are lower in subjects with mild cognitive impairment (MCI) and dementia.Corneal endothelial cell loss and hypertrophy are associated with cortical gray matter atrophy.Corneal nerve and endothelial cell abnormalities could act as biomarkers for neurovascular pathology in dementia.Reduced corneal endothelial cell density partially mediates the effects of age and diabetes on corneal nerve fiber loss.

Purpose: To evaluate the changes in central corneal thickness and corneal endothelium in contact lens-wearing diabetic patients.

AIM: To compare the difference in corneal endothelial cell density and morphology after phacoemulsification using ringer lactate (RL) and balanced salt solution (BSS) irrigating solutions. METHODS: The prospective randomized controlled trial study was conducted between February 2017 and April 2017 in Dr. YAP Eye Hospital, Yogyakarta, Indonesia. There were a total of 52 subjects (52 eyes) who were senile cataract patients further grouped into two, 26 patients undergoing the phacoemulsification procedure using RL irrigating solution and the other 26 patients with BSS irrigating solution, both conducted by one operator. On the 1, 7, and 28d post operative, an evaluation was done to measure the density and corneal endothelial cell morphology, as well as the variable of inflammation in the two groups. RESULTS: Fifty-two eyes had undergone phacoemulsification with posterior intraocular lens implantation. Both groups were evaluated for the endothelial cell reduction and corneal endothelial cell morphology change, along with postoperative inflammation. On the 28d postoperative, endothelial cell reduction in the BSS group (173.96 cell/mm2, 8.12%) was lower than the RL group (253.20 cell/mm2, 10.25%), percentage of corneal endothelial cell variation coefficient increase in the BSS group (2.92%, 8.36%) was lower compared to the RL group (3.42%, 9.96%), decrease of hexagonal cells of corneal endothelium cells presentation percentage in the BSS group (4.30%, 8.17%) was lower compared to the RL group (4.84%, 8.97%), and the percentage increase of central corneal thickness in the BSS group (4.69 μm, 0.89%) was almost equal to the RL group (4.53 μm, 0.90%). All of the results regarding difference in density and corneal cell endothelium morphology between the two groups did not reveal any statistically significant difference (P&gt;0.05). Inflammatory variable in the two groups were even. CONCLUSION: BSS and RL were equal in their capability of maintaining endothelial cell loss and endothelial cell morphologic change in senile cataract patients after phacoemulsification.

Background: This is a cross-sectional study to further understand the effects of axial length elongation on the corneal endothelial cell's morphology in myopic children. Abnormal changes in the morphology of corneal endothelium are indicators of corneal stress or instability which could be linked to myopia. Methods: 111 school children comprising of 37 emmetropes, 37 mild myopes and 37 moderate myopes aged 8-9 years old were recruited. Visual acuity was measured using the LogMar chart, cycloplegic refraction was determined using an open-field autorefractor (Grand Seiko WAM-5100, Hiroshima, Japan) and refined using subjective refraction. Morphology of corneal endothelial cells [endothelial cell density, coefficient of variation, hexagonality and central corneal thickness] was evaluated using a non-contact specular microscope (Topcon SP-2000P). Axial length was measured with A-scan ultrasound biometry (PacScan Plus, Sonomed Escalon, NY). The correlation between morphology of corneal endothelial cells and axial length were assessed using Pearson Correlation and Linear regression analysis. Results: There was no significant difference in corneal endothelial cells and axial length between gender (p>0.05). Significant reduction in endothelial cells density and hexagonality and increased coefficient of variation was found in eyes of higher myopic power which had longer axial when compared to emmetropes (p<0.001). Except for central corneal thickness, all corneal endothelial cells parameters correlated significantly with axial length (p<0.05). For every 1mm increase in axial length, endothelial cells density decreased by 73.27cells/mm 2, hexagonality decreased by 2.32% and coefficient of variation increased by 1.75%. Conclusions: There were significant changes in morphology of cornea endothelial cells in young moderate myopic children of Chinese ethnicity at 8-9 years of age. This result provides normative data for Malaysian children of Chinese ethnicity that can be used for comparison and reference for clinical procedures, thereby facilitating decision-making with respect to interventions for myopia control, especially in prescribing contact lens for children.

Background: This is a cross-sectional study to further understand the effects of axial length elongation on the corneal endothelial cell's morphology in myopic children. Abnormal changes in the morphology of corneal endothelium are indicators of corneal stress or instability which could be linked to myopia. Methods: 111 school children comprising of 37 emmetropes, 37 mild myopes and 37 moderate myopes aged 8-9 years old were recruited. Visual acuity was measured using the LogMar chart, cycloplegic refraction was determined using an open-field autorefractor (Grand Seiko WAM-5100, Hiroshima, Japan) and refined using subjective refraction. Morphology of corneal endothelial cells [endothelial cell density, coefficient of variation, hexagonality and central corneal thickness] was evaluated using a non-contact specular microscope (Topcon SP-2000P). Axial length was measured with A-scan ultrasound biometry (PacScan Plus, Sonomed Escalon, NY). The correlation between morphology of corneal endothelial cells and axial length were assessed using Pearson Correlation and Linear regression analysis. Results: There was no significant difference in corneal endothelial cells and axial length between gender (p>0.05). Significant reduction in endothelial cells density and hexagonality and increased coefficient of variation was found in eyes of higher myopic power which had longer axial when compared to emmetropes (p<0.001). Except for central corneal thickness, all corneal endothelial cells parameters correlated significantly with axial length (p<0.05). For every 1mm increase in axial length, endothelial cells density decreased by 73.27cells/mm 2, hexagonality decreased by 2.32% and coefficient of variation increased by 1.75%. Conclusions: There were significant changes in morphology of cornea endothelial cells in young moderate myopic children of Chinese ethnicity at 8-9 years of age. This result provides normative data for Malaysian children of Chinese ethnicity that can be used for comparison and reference for clinical procedures, thereby facilitating decision-making with respect to interventions for myopia control, especially in prescribing contact lens for children.

To evaluate the corneal endothelial cell density and morphology in Chinese patients with pseudoexfoliation syndrome (PEX). Medical records of 16 patients (20 eyes) with PEX who presented to our institution between July 2008 and June 2010 were retrospectively reviewed. Thirteen eyes had combined glaucoma. The information of five apparently normal fellow eyes in these patients was also recorded. Left eyes of 20 patients with bilateral senile cataracts but no other eye disease were included as controls. Specular microscopy was performed in all eyes to analyze for corneal endothelial cell density and morphology. Cell density, coefficient of variation in cell size, and percentage of hexagonal cells in corneal endothelium were evaluated. The mean corneal endothelial cell density in the PEX eyes was 2298±239 cells/mm(2), significantly lower than that in the cataract eyes (2652±18 cells/mm(2), P=0.026), but there were no significant differences in coefficient of variation of cell size and frequency of hexagonality between these two groups. No significant differences in the three parameters were found between the apparently normal fellow eyes and the PEX eyes or the cataract eyes, or between the PEX eyes with and without glaucoma. Corneal endothelial cell density may decrease in Chinese patients with PEX. The development of glaucoma in PEX eyes does not seem to be related with the change in corneal endothelial cell density or morphology.

Background: This is a cross-sectional study to further understand the effects of axial length elongation on the corneal endothelial cell’s morphology in myopic children. Abnormal changes in the morphology of corneal endothelium are indicators of corneal stress or instability which could be linked to myopia.Methods: 111 school children comprising of 37 emmetropes, 37 mild myopes and 37 moderate myopes aged 8-9 years old were recruited. Visual acuity was measured using the LogMar chart, cycloplegic refraction was determined using an open-field autorefractor (Grand Seiko WAM-5100, Hiroshima, Japan) and refined using subjective refraction. Morphology of corneal endothelial cells [endothelial cell density, coefficient of variation, hexagonality and central corneal thickness] was evaluated using a non-contact specular microscope (Topcon SP-2000P). Axial length was measured with A-scan ultrasound biometry (PacScan Plus, Sonomed Escalon, NY). The correlation between morphology of corneal endothelial cells and axial length were assessed using Pearson Correlation and Linear regression analysis.Results: There was no significant difference in corneal endothelial cells and axial length between gender (p>0.05). Significant reduction in endothelial cells density and hexagonality and increased coefficient of variation was found in eyes of higher myopic power which had longer axial when compared to emmetropes (p<0.001). Except for central corneal thickness, all corneal endothelial cells parameters correlated significantly with axial length (p<0.05). For every 1mm increase in axial length, endothelial cells density decreased by 73.27cells/mm2, hexagonality decreased by 2.32% and coefficient of variation increased by 1.75%.Conclusions: There were significant changes in morphology of cornea endothelial cells in young moderate myopic children of Chinese ethnicity at 8-9 years of age. This result provides normative data for Malaysian children of Chinese ethnicity that can be used for comparison and reference for clinical procedures, thereby facilitating decision-making with respect to interventions for myopia control, especially in prescribing contact lens for children.

To evaluate long-term changes in corneal endothelial cell count and morphology after congenital cataract extraction and intraocular lens implantation. Cataract extraction and posterior chamber intraocular lens (IOL) implantation was performed on 54 congenital cataract patients (83 eyes). The corneal endothelial cell density (ECD), coefficient of variation (CV), hexagonality, and central corneal thickness (CCT) were measured for a retrospective analysis of long-term changes in corneal endothelial characteristics. The mean age at the time of IOL implantation was 5.00 (3.62) years [mean (SD)], and the mean follow-up period was 8.83 (1.49) years. In a comparison of the treated and normal eyes of patients who underwent unilateral surgery, the treated eyes showed a significantly greater CCT (p < 0.05), and there was no significant difference in ECD, CV, and hexagonality (p > 0.05). In addition, there was no statistically significant difference in the ECD and CCT between the primary and secondary IOL implantation groups. Our results did not show any significant corneal endothelial cell loss in congenital cataract patients; however, their CCTs were increased.

Purpose. Topical or intracameral administration of H-7 doubles outflow facility and reduces intraocular pressure in cynomolgus monkeys, by relaxing and expanding the trabecular meshwork (TM) and Schlemm’s canal (SC). Since H-7 may have anti-glaucoma potential, we determined its effects on the corneal endothelium and ciliary epithelium for safety considerations. Methods. Following topical H-7, aqueous humor flow (AHF), corneal endothelial transfer coefficient (k a) and anterior chamber (AC) entry of i.v. fluorescein were measured by fluorophotometry; AC aqueous protein concentration ([Protein] AC) was determined by Lowry assay; and corneal thickness and endothelial cell density and morphology were measured by ultrasonic pachymetry and specular microscopy respectively. Following intracameral H-7, specular and/or light and electron microscopy of the corneal endothelium or ciliary epithelium were performed. Results. Following unilateral topical H-7: (1) AHF and k a were essentially unchanged at 0.5–3.0, 3.5–6.0, and 0.5–6.0 hr, with an insignificant increase from 0.5–1.5 hr; (2) [Protein] AC was insignificantly increased at 1–1.5 hr but had returned to baseline by 2.5 hr; (3) entry of i.v. fluorescein into aqueous or cornea was modestly and transiently increased; (4) the central cornea thickened significantly at 1–2.5 hr, gradually returning to baseline 2.5 hr after H-7, while peripheral corneal thickness was less affected; (5) corneal endothelial cell borders became indistinct by 1 hr, but cell morphology was recovering by 3–5 hr and had completely returned to normal by 24 hr; (6) corneal endothelial cell density was unchanged at 5–24 hr. Following intracameral H-7, no significant changes were observed in corneal endothelial cell density or morphology by specular microscopy, nor in corneal endothelial or ciliary epithelial morphology by light and electron microscopy. Conclusions. A facility-effective intracameral dose of H-7 had no discernible structural effect on the corneal endothelium or ciliary epithelium. It is not yet clear whether carefully chosen topical doses of H-7 or analogues can enhance outflow facility without meaningfully affecting the cornea and ciliary processes.

To investigate the corneal endothelial cell density and morphology and central corneal thickness in the Guangxi Maonan and Han adolescent students of China. Noncontact specular microscope (Topcon SP3000P, Tokyo, Japan) was performed in 133 adolescent students of Maonan nationality (M:F 54:79) and 105 adolescent students of Han nationality (M:F 50:55), 5 to 20y of age, who were randomly selected from 3 schools in Huanjiang Maonan Autonomous County of Guangxi Zhuang Autonomous Region of China. Parameters studied included endothelial cell density, mean cell area, coefficient of variation in cell size, percentage hexagonality and central corneal thickness. Endothelial cell density, mean cell area, coefficient of variation in cell size, percentage hexagonality and central corneal thickness in the study population were (2969.50±253.93) cells/mm(2), (339.23±29.44) µm(2), (29.96±4.07) %, (64.58±9.41) % and (523.71±32.82) µm in Maonan and (2998.26±262.65) cells/mm(2), (336.11±30.07) µm(2), (29.89±5.03) %, (64.91±11.64) % and (524.39±33.15) µm in Han, respectively. No significant differences were observed in endothelial cell density, mean cell area, coefficient of variation in cell size, percentage hexagonality and central corneal thickness between Maonan and Han (P=0.615, 0.659, 0.528, 0.551, 0.999). In Maonan and Han, we found age was negatively correlated with endothelial cell density and percentage hexagonality and positively correlated with mean cell area and coefficient of variation in cell size. Negative correlation was also found between central corneal thickness and age in Han, whereas no correlation was found in Maonan. There were no differences between Maonan and Han in corneal endothelial cell density and morphology and central corneal thickness. In these two nationalities, there were statistically significant decrease in endothelial cell density and percentage hexagonality with increasing age and statistically significant increase in cell area and coefficient of variation in cell size with increasing age. Central corneal thinned with increasing age in Han, whereas difference did not attain statistical significance in Maonan.

Introduction: Diabetes Mellitus (DM) has emerged as a significant cause of ocular morbidity. The toxic effects of hyperglycaemia spare no cell in the body and cornea, has also revealed certain changes in diabetic patients. Higher phacoemulsification time and power effect corneal endothelial cells. This can inflict an additional stress on the altered diabetic corneal endothelium. Aim: To compare the Central Corneal Thickness (CCT) thickness and endothelial Cell Density (CD) and morphology in Type 2 Diabetes Mellitus (T2DM) patients undergoing phacoemulsification with age-matched non diabetic controls undergoing phacoemulsification. Materials and Methods: A prospective, hospital-based, interventional study was conducted in the Department of Ophthalmology, Government Medical College, Jammu, Jammu and Kashmir, India. The duration of the study was nine months, from April 2021 to December 2021. The study included 50 patients with T2DM and 50 non diabetic controls. All patients underwent phacoemulsification performed by a single surgeon. The CCT and endothelial cell parameters were measured preoperatively and postoperatively at one week, six weeks and three months using Topcon specular microscope. Postoperative changes in the corneal endothelial cells were compared between the two groups for a period of three months. Statistical analysis was done by using the Statistical Package for Social Sciences (SPSS) version 25.0 (IBM Corp. Released 2017. Armonk, NY, USA). Categorical variables were analysed using Chi-square test and the groups were compared using Student’s t-test. Results: The mean age of the study participants was 63.22±7.52 years in diabetic group and 64.52±7.29 years in non diabetic group. Diabetic patients showed significantly greater corneal thickness than non diabetic controls (p=0.034). This pattern was observed till the last follow-up at three months. The endothelial cell parameters were comparable between diabetic and non diabetic patients. There was a fall in endothelial cell count in all patients postoperatively, but it was significantly higher in the diabetic patients at three months (p=0.048). Postoperatively, Co-efficient of Variation (CV) was significantly higher in diabetic patients (p=0.001) accompanied by a decreased hexagonality (p=0.039) at the end of three months. Conclusion: A diabetic cornea is different than a non diabetic cornea at the cellular level. Diabetics show accelerated corneal endothelial cell loss and greater variation in cell morphology in response to surgical stress. Diabetes mellitus is a risk factor for endothelial cell loss in patients undergoing cataract surgery.

Introduction: Pseudoexfoliation Syndrome (PEX) is characterised by the formation or deposition of abnormal fibrillar material on intraocular structures. Various ocular complications, such as chronic open-angle glaucoma, zonular dehiscence causing lens subluxation/dislocation, poor mydriasis are associated with PEX. In PEX eyes, corneal endothelial changes have been demonstrated along with thinner Central Corneal Thickness (CCT). Aim: To evaluate the CCT, corneal Endothelial Cell Density (ECD) and morphology in patients with pseudoexfoliation and to compare the results with age matched controls. Materials and Methods: A case-control study was done on a total of 147 eyes of 81 patients with pseudoexfoliation with equal number of eyes in age matched controls were evaluated for corneal ECD, coefficient of variation in cell size, percentage of hexagonal cells and CCT using a non-contact specular microsope. The quantitative data was represented as their mean±Standard Deviation (SD). The paired t-test was used for analysing quantitative data. Results: The average ECD in the PEX group was 2301.30±117.37 cells/mm2. It was significantly lower than the average ECD in controls 2632.91±24.04 cells/mm2 (p-value &lt;0.001). The average CCT in the PEX group was 508±19.09 microns and in the age matched controls was 524.22±6.36 microns. The average CCT was low in the PEX group and difference was statistically significant (p≤0.001). The coefficient of variation and percentage of hexagonality were altered but did not show any statistical significance in both the groups. Conclusion: ECD and CCT is significantly decreased in eyes with PEX. Pleomorphism and polymegathism was not found significant in this study.