Decrease In Central Corneal Thickness Research Articles

Anisotropy and viscoelasticity of different corneal regions in rabbit corneal ectasia model

The mechanical properties of the cornea in corneal ectasia disease undergo a significant reduction, yet the alterations in mechanical properties within distinct corneal regions remain unclear. In this study, we established a rabbit corneal ectasia model by employing collagenase II to degrade the corneal matrix within a central diameter of 6 mm. Optical coherence tomography was employed for the in vivo assessment of corneal morphology (corneal thickness and corneal curvature) one month after operation. Anisotropy and viscoelastic characteristics of corneal tissue were evaluated through biaxial and uniaxial testing, respectively. The results demonstrated a marked decrease in central corneal thickness, with no significant changes observed in corneal curvature. Under different strains, the elastic modulus of the cornea exhibited no significant differences in the up-down and naso-temporal directions between the control and model groups. However, the cornea in the model group displayed a significantly lower elastic modulus compared to the control group. Specifically, the elastic modulus of the central region cornea in the model group was significantly lower than that of the entire cornea within the same group. Moreover, in comparison to the control group, the cornea in the model group exhibited a significant increase in both creep rate and overall deformation rate. The instantaneous modulus and equilibrium modulus were significantly reduced in the model cornea. No significant differences were observed between the entire cornea and the central cornea concerning these parameters. The results indicate that corneal anisotropy remains unchanged in collagenase-induced ectatic cornea. However, a significant reduction in viscoelastic properties is noticed. This study provides valuable insights for investigating changes in corneal mechanical properties within different regions of ectatic corneal disease.

Outcomes of hemi-Descemet membrane endothelial keratoplasty and phacoemulsification for the treatment of primary Fuchs' endothelial corneal dystrophy combined with cataract

This study evaluates the long-term results of surgical treatment of patients with Fuchs' endothelial corneal dystrophy and cataract. The study included 24 patients (24 eyes) with primary Fuchs' endothelial corneal dystrophy and cataract, who underwent cataract phacoemulsification with IOL implantation and of Descemet's membrane endothelial keratoplasty with a semicircular graft (hemi-DMEK). The effect of treatment was assessed by best corrected visual acuity (BCVA), central corneal thickness (CCT) and endothelial cell density (ECD). In total, surgical treatment involved 14 donor corneas that were divided in half during the preparation and isolation of the Descemet's membrane (DM). By month 12 after the surgery an increase in visual functions and graft transparency were observed in 23 patients (23 eyes) out of 24. Repeated keratoplasty was required in one case due to fibrosis of the posterior layers of recipient's corneal stroma. At 12 months postoperatively, the study group showed an increase in BCVA from 0.16±0.1 to 0.75±20, a decrease in CCT from 650.9±4.5 μm to 519.6±43.9, and a decreased in ECD from 2850.5±84.7 cells/mm2 up to 1285.5±277.2 cells/mm2. Thus, the loss of endothelial cells at one year after surgery amounted to 54.9%. The developed method for transplantation of a semicircular DM fragment provides a tissue-saving approach to endothelial keratoplasty, and considering the high percentage of transparent engraftment of grafts and complete visual rehabilitation, it can be recommended in the treatment of patients with cataract and Fuchs' endothelial corneal dystrophy.

Corneal Optical Densitometry in the Evaluation of 2-Year Graft Function Following Endothelial Keratoplasty

This study aimed to assess clinical application of the Scheimpflug corneal tomography for objective evaluation of corneal optical density in eyes undergoing Descemet's stripping endothelial keratoplasty (DSEK). In this prospective study, 39 pseudophakic eyes with bullous keratopathy were enrolled. All eyes underwent primary DSEK. Ophthalmic examination included best corrected visual acuity (BCVA) measurement, biomicroscopy, Scheimpflug tomography, pachymetry, and endothelial cell count. All measurements were taken preoperatively and within a 2-year follow-up period. Gradual BCVA improvement was observed in all patients. After two years, the mean and median BCVA values were 0.18 logMAR. A decrease in central corneal thickness was noted only during the first 3 months postoperatively and was followed by a gradual increase. Corneal densitometry decreased constantly and most significantly in the first 3 months postoperatively. The consecutive decrease in endothelial cell count of the transplanted cornea was most significant during the first 6 months postoperatively. Six months postoperatively, the strongest correlation (Spearman's r = -0.41) with BCVA was found for densitometry. This tendency was maintained throughout the entire follow-up period. Corneal densitometry is applicable for objective monitoring of early and late outcomes of endothelial keratoplasty, showing a higher correlation with visual acuity than pachymetry and endothelial cell density.

Effect of conventional and orthokeratological hard contact lenses on anatomical and functional characteristics of the cornea

This study evaluated the potential effects of conventional hard contact lenses (HCL) and orthokeratological contact lenses (OKL) on anatomical and functional condition of the cornea in myopia correction. The study included 80 patients (159 eyes) with low, moderate and high myopia. Group 1 consisted of 40 patients (79 eyes) who used conventional HCL; group 2 included 40 patients (80 eyes) who used OKL. All patients underwent topographic keratometry, corneal pachymetry mapping (Pentacam, Oculus, Germany; Visante OCT, Carl Zeiss, Germany), high-order aberrometry (OPD Scan, Nidek, Japan), confocal microscopy (Confoscan 4, Nidek, Japan), evaluation of corneal biomechanical properties (ORA, Reichert Technologies, USA) and corneal light scattering (Pentacam, Oculus, Germany). Examinations were taken before the treatment started and after 8-12 months of contact lens wear. Group 1 showed corneal thickness increase in all zones (by 0.9-1.1%), no significant changes in corneal refraction, and increase in corneal hysteresis and corneal resistance factor. OKL wear led to a significant flattening of anterior surface of the cornea and steepening of its paracentral area, decrease in central corneal thickness (by 2.8%) and increase in mid-peripheral thickness (by 2.2%). No significant changes in posterior corneal surface were observed in the study patients. More significant increase in higher-order aberrations and the degree of light scattering was observed in group 2, while changes in subepithelial nerve plexus and stromal structure were more significant in group 1. Long-term OKL wear shows more significant morphological and functional corneal changes compared to RGP lens.

Effect of Topical Prostaglandin Analogue Therapy on Central Corneal Thickness: A Systematic Review.

To investigate whether prostaglandin analogue (PGA) eyedrops have a significant effect on central corneal thickness (CCT), we conducted a systematic search of literature published from 2000 to 2021. Among the studies conducted on topical PGA therapy in open-angle glaucoma or ocular hypertension patients over 18 years old, prospective studies with CCT change as an outcome were included. A single-arm meta-analysis was conducted to assess the overall effect on CCT, and subgroup analysis according to exposure time of PGA eyedrops was also performed. We counted the number of articles that reported on severe events (CCT reduction of 25 μm or more) and obtained their proportion. The methodological quality was assessed by the McHarm tool. Twenty-two reports of prospective studies were selected. The results of the single-arm meta-analysis showed very high heterogeneity. Still, in subgroup analysis, when PGA was used for more than 6 months, heterogeneity was low, and a significant decrease in CCT was observed. Severe events were reported in two reports and occurred in 3.8% to 14.8% of participants. PGA eyedrop use may cause a clinically significant CCT decrease, requiring CCT follow-up.

The need of rebubbling in case of small graft detachments after Descemet Membrane Endothelial Keratoplasty (DMEK).

To investigate the need of rebubbling for small graft detachments after Descemet Membrane Endothelial Keratoplasty (DMEK). In this retrospective study we evaluated 111 eyes from 111 patients that showed graft detachment after DMEK surgery and have achieved graft adherence by injection of air or 20% sulfur hexafluoride (SF6) to the anterior chamber (rebubbling group; n = 57) or by spontaneous adherence without intervention (control group; n = 54) at final examination. Subgroups in terms of the maximum height and in terms of the detachment area in relation to graft area were formed. Outcome measures were the increase in best-corrected visual acuity (BCVA) and the decrease in central corneal thickness (CCT) from the measurement before DMEK to six months after surgery and postoperative endothelial cell density. BCVA increased in the rebubbling group and the control group, the difference being 0.22 logMAR, p = 0.048. For eyes with a maximum height less than 500 µm, the increase of BCVA was 0.39 ± 0,36 logMAR in the control group and 0.62 ± 0,53 logMAR in the rebubbling group, p = 0.045. There was no difference of statistical significance of BCVA between both groups regarding the detachment area of less than 20% in relation to graft area. The mean decrease in CCT and postoperative endothelial cell density showed no significant difference between the rebubbling group and the control group. Compared to spontaneous graft adherence, a rebubbling shows no beneficial effect on the clinical outcome for small detached DMEK grafts. Rebubbling does not decrease postoperative endothelial cell density.

Monitoring of central corneal thickness after phacoemulsification-comparison of statical and rotating Scheimpflug pachymetry, and spectral-domain OCT.

To explore the possibility of deploying three contactless devices (static and rotating Scheimpflug technology, spectral domain optical coherence tomography) for measuring central corneal thickness (CCT) in preoperative and postoperative examinations of cataract patients. Totally 72 patients who had undergone surgery without complications were selected. The CCT was measured prior to the operation, as well as on the first, 5th-7th and 28th day following the operation using the Nidek NT 530-P, Sirius®, and Topcon OCT-2000 devices. A significant postoperative increase and subsequent decrease in CCT was identified with all three devices. The correlations were highly significant and thus reflect a very good degree of comparability at all times with the exception of the rotating Scheimpflug camera. The postoperative results from the latter differed significantly from the other devices. The correlations were Sirius/Topcon (P=0.010) and Sirius/Nidek (P<0.0005). No statistically significant difference could be identified in the comparison between Topcon and Nidek (P=0.056). All three devices are suitable for postoperative monitoring of CCT. The measurement results are only comparable to a limited extent and not interchangeable in the course of treating a single patient. This is due to the different imaging technology used in the devices and the resulting modalities for conducting the measurements.

Evaluation of central corneal thickness in patients with dry eye disease in a tertiary eye hospital in Kancheepuram

Background: Dry eye disorder is a disease mainly due to the tear insufficiency which results in eye discomfort and disturbances in vision. Dry eye also affects the ocular dimensions, especially corneal thickness. Central corneal thickness (CCT) assessment plays an important role in refractive surgeries and in the pre-operative assessment of other ocular surgeries. Aims and Objectives: This study aims to assess the effect of dry eye disease (DED) on CCT with age- and gender-matched controls. Materials and Methods: One hundred and four subjects (52 cases and 52 controls) who attended SRM Medical College and Hospital ophthalmology outpatient department were included in the study. DED was diagnosed with DEQS questionnaire, slit-lamp examination, TFBUT, and Schirmer’s test. Pachymetry was used for measuring the CCT of all subjects. Student “t”-test was used to determine the significance of difference between two means. P&lt;0.05 was considered statistically significant. Results: In our study, there were 60 female patients and 44 male patients. The ratio of male-to-female was 1:1.3. The CCT among cases was very low (533.19 μm±30.05) compared to controls (569.27 μm±45.56) and this difference was statistically significant (P&lt;0.05). When subgrouped under gender, the difference in CCT among males between the two groups was statistically significant and it was highly significant among females. When the reduction in CCT among the cases was studied under different age groups, the subjects in the 41–60 years age group had a statistically highly significant difference in CCT between the two groups while it was also significant in other age groups. Conclusion: There is a significant decrease in CCT due to DED. Pachymetry for central corneal estimation shall be included in the routine management of dry eye patients so that corneal thinning could be identified earlier and treated with artificial tears or other substitutes.

Validation of the multi-metric D-index change in the assessment of keratoconus progression

To validate the effectiveness of the multi-metric D-index by Pentacam in detecting keratoconus (KC) progression. This was a retrospective study of KC patients at the Rabin Medical Center, Petah Tikva, Israel, during 2016-2018 with at least two corneal tomography examinations six months apart. Agreement between clinical diagnosis of progression (1.5D increase in mean keratometric value, 1D increase in Kmax, a 5% decrease in central corneal thickness (CCT), worsening of visual acuity by more than one line, or deterioration of manifest corneal astigmatism > 1.5D) and the D-index was evaluated. Receiver operating characteristic (ROC) analysis was used to find the D-index's optimal cutoff value to show progression. We included KC eyes in the stable group (N = 7) and the progression group (N = 54). Patient demographics and tomographic parameters at baseline were similar between the groups. The D-index change was significantly higher in the progression group than in the stable group (median + 1 and 0.0, respectively, p = 0.024). Based on the ROC analysis, the optimal D-index cutoff change within at least six months was 0.32 (59.3% sensitivity and 100% specificity (area under the curve [AUC] = 0.771, Youden = 0.592). Subjects with a D-index change above this value had a 21.1-fold increase in odds for corneal ectasia progression requiring CXL (OR: 21.1, 95%CI 1.17-398.8, p = 0.038). The multi-metric D-index can serve as a clinically feasible parameter to detect KC progression and guide patients' referral for further interventions.

A cross sectional study on evaluating the corneal endothelial cell density and central corneal thickness in eyes with primary glaucoma.

This study aims at evaluating glaucoma-induced damage to the corneal endothelium and the effect of central corneal thickness (CCT) on the intra-ocular pressure (IOP) measurement in patients newly diagnosed with primary glaucoma. It is a hospital-based cross-sectional study involving 60 newly diagnosed primary glaucoma patients >18 years. They underwent fundus examination, four-mirror gonioscopy, and perimetry for confirming the diagnosis. Evaluation and analysis of corneal endothelial cell density and CCT were performed. Chi square test was performed to find out the association between glaucoma, corneal endothelial cell density, and CCT. Evaluation of 60 patients revealed that by age distribution, the corneal endothelial cell density was lower in the 51-65 year age group and an age-related decrease in corneal endothelial cell density and CCT was found in newly diagnosed primary glaucoma patients. The mean CCT was 525 micrometers in patients with IOP between 20 to 40 mm Hg and 528 micrometers in patients with IOP between 41 to 60 mm Hg. The mean corneal endothelial cell density was 2361 cells/mm2 in primary open-angle glaucoma (POAG) and 2284 cells/mm2 in primary angle-closure glaucoma (PACG). The mean CCT was 525 micrometers in POAG and 528 micrometers in PACG. The corneal endothelial cell density was lower in patients with PACG when compared with POAG, and the average CCT showed no significant difference in POAG and PACG patients. However, CCT was increased in patients with a higher intra-ocular pressure. The corneal endothelial cell density was lower in patients with a high intra-ocular pressure.

Biometric changes after vitrectomy with silicone oil tamponade

Background: The Lenstar LS 900 (Haag-Streit AG, Koeniz, Switzerland) is an optical biometer, and its measurements are highly repeatable and precise in cataractous eyes. This study investigated changes in biometric parameters, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), vitreous cavity depth (VD), and central corneal thickness (CCT) before and after three-port 23-Gauge pars plana vitrectomy with silicone oil tamponade.&#x0D; Methods: This was a prospective follow-up study. Patients who were scheduled for surgery underwent a detailed slit-lamp examination and objective cycloplegic refraction preoperatively. In eligible cases, the Lenstar LS 900 was used to measure biometric parameters. At the 1-month postoperative follow-up, we repeated the same assessments for the silicone oil (SO)-filled eyes. Data were analyzed to assess the significance of changes and to test the possible correlation of values between the two time points.&#x0D; Results: Twenty-three patients with a mean ± SD age of 60 ± 12 years completed the study. Postoperatively, we found a significant increase in AL and a decrease in ACD and CCT (all P &lt; 0.05), with no significant changes in LT and VD. A significant correlation was found for ACD, CCT, and cylinder values between the two time points (all P &lt; 0.05). Postoperatively, the spherical and cylindrical components of refraction demonstrated a hyperopic shift, but did not change statistically significantly.&#x0D; Conclusions: The Lenstar LS 900 underestimated the ACD and overestimated the AL in SO-filled eyes when comparing pre- and postoperative values, in phakic as well as pseudophakic eyes. In planning for cataract surgery in this group of patients, it is more reasonable to calculate IOL power based on the biometric data of the fellow eye, although this may not eliminate possible errors. Further studies with a larger sample size, longer follow-up, and robust study design are necessary to confirm our preliminary results.

Resident Perspectives 56–3

Resident Perspectives 56–3

Temporal evolution of the biological response to laser-induced refractive index change (LIRIC) in rabbit corneas

Laser-induced refractive index change (LIRIC) is a new, non-incisional, non-ablative, femtosecond photo-modification technique being developed for vision correction in humans. Prior, exvivo studies showed intra-tissue refractive index change to induce minimal cell death, restricted to the laser focal zone in the corneal stroma, and with no observable damage to the epithelium or endothelium. Here, we used live rabbits to ascertain longer-term consequences of LIRIC in vivo. Specifically, we assessed cell death, fibrosis, corneal nerve distribution, endothelial cell density, and corneal structure for up to 3 months after LIRIC. A +2.5 D gradient-index LIRIC Fresnel lens was inscribed inside 20 applanated corneas of Dutch Belted rabbits, over a circular region of the mid-stroma measuring 4.5 mm in diameter. Twelve additional rabbit eyes were used as applanation-only controls to differentiate the effects of laser treatment and suction applanation on biological and structural parameters. In vivo optical measurements were performed pre-operatively, then immediately, 2, 4, and 12 weeks after the procedure, to measure endothelial cell density and changes in corneal structure. Groups of four rabbits were sacrificed at 4 hours, 2, 4, and 12 weeks after LIRIC for histological determinations; the TUNEL assay was used to evaluate cell death, H&E staining was used to assess inflammatory infiltration, and immunostaining for α-smooth muscle actin (α-SMA) and βIII tubulin (Tuj-1) was performed to assess myofibroblast differentiation and corneal nerve distribution, respectively. Consistent with prior ex vivo data, only minimal cell death was observed in the laser focal zone, with TUNEL-positive cells restricted to the stromal region of refractive index change 4 h after LIRIC. No TUNEL-positive cells were evident anywhere in the cornea 2, 4, or 12 weeks after LIRIC. Applanation-only corneas were completely TUNEL-negative. Neither LIRIC-treated nor applanation-only eyes exhibited α-SMA-positive staining or altered corneal nerve distributions at any of the time points examined. In vivo confocal imaging revealed normal endothelial cell densities in all eyes (whether LIRIC-treated or applanation-only) at all time points. Optical coherence tomography showed suction applanation to cause a temporary decrease in central corneal thickness, which returned to normal within 4 h. Corneas into which LIRIC Fresnel lenses were written while applanated did not undergo major structural or shape changes beyond the temporary thinning already described for suction applanation. The present findings suggest that LIRIC patterns, which generated a clinically-relevant refractive correction in the mid-stromal region of live rabbit corneas, induced little-to-no disruption to corneal structure and biology for 3 months after the procedure. This affirms the relative safety of LIRIC and predicts that compared to traditional laser vision correction surgeries, common post-operative complications such as dry eye, haze, or patient discomfort may be entirely avoided.

Hyperosmolar Eye Drops for Diurnal Corneal Edema in Fuchs’ Endothelial Dystrophy: A Double-Masked, Randomized Controlled Trial

The Eye Drops for Early Morning-Associated Swelling (EDEMAS) trial assessed the efficacy of hyperosmolar eye drops on corneal edema resolution. Double-masked, randomized controlled trial of hyperosmolar eye drops. Participants with Fuchs' dystrophy scheduled for Descemet membrane endothelial keratoplasty. One eye was randomized to hyperosmolar eye drops (treatment); the fellow eye was randomized to artificial tears (placebo). After baseline examination in the afternoon, corneas were examined using Scheimpflug tomography after eye opening in the morning. Participants received eye drops twice. Imaging was repeated every 30 minutes up to 4 hours. Decrease in central corneal thickness 1 hour after eye opening (primary end point), corneal thickness, subjective visual function, glare, visual acuity, and adverse events (AEs) (secondary end points). A total of 68 participants received the allocated intervention (59 eyes received treatment; 55 eyes received placebo). All eyes had stromal edema; none had epithelial edema. Corneal thickness was 626 μm in the treatment arm and 622 μm in the placebo arm after eye opening, indicating an early morning edema compared with baseline of+21 μm and+24 μm, respectively. Decrease in corneal thickness after 1 hour was-10.5 μm in the treatment arm (95% confidence interval [CI],-12.8 to-8.2) and-11.2 μm (95% CI,-13.6 to-8.9) in the placebo arm (between-arm difference, 0.7 μm, 95% CI,-2.0 to 3.5; P= 0.59), indicating no clinically relevant effect of hyperosmolar eye drops on early morning corneal edema. Results were not compatible with a relevant treatment effect on corneal thickness, visual acuity, and glare over the entire course of the study. Increase in subjective visual function was less rapid in the treatment arm than in the placebo arm. Adverse events, most commonly burning after eye drop application, were more common with treatment (30 eyes) than placebo (1 eye; risk difference, 49 percentage points; 95% CI, 36-62). In this double-masked, randomized controlled trial, resolution of early morning stromal edema was not accelerated by hyperosmolar eye drops, which more frequently caused AEs. These results are not compatible with a clinically relevant effect of hyperosmolar eye drops and do not support their routine use.

Evaluation of central corneal thickness with meibomian gland dysfunction in postmenopausal women

Background: Meibomian gland dysfunction is a common chronic disease of eyelid wherein there is reduction in the quantity as well as changes in the composition of meibomian gland secretions, resulting in instability and thinning of the tear film which ultimately interferes with the ocular surface. It has also been observed that postmenopausal women may present with decrease in central corneal thickness due to hormonal changes. Studies have been done regarding the role of meibomian gland dysfunction in central corneal thickness changes.Objectives: To assess and compare the central corneal thickness and estimate estradiol levels in postmenopausal women with and without MGD, as well as and to correlate estradiol levels with severity of MGD in postmenopausal women with MGD.Design: Duration based, comparative two-group study.Participants: 80 participants with 160 eyes among which 40 were postmenopausal women with MGD and 40 were postmenopausal women without MGD.Methods: All female subjects satisfying the inclusion and exclusion criteria in the age group of 52 – 65 years who visited VIMS and RC, Bangalore between January 2018 to February 2020 were included. They underwent full ophthalmological examination – visual acuity assessment, retinoscopy, refraction, slit lamp examination, fundus examination, horizontal and vertical corneal curvature assessment, specular microscopy, tear break up time and Schirmer I test along with estimation of estrogen, progesterone and FSH levels. Results: This study concluded that mean central corneal thickness was reduced in case of postmenopausal women with MGD when compared to postmenopausal women without MGD with statistically significant results.Conclusion: Central corneal thickness was considerably less in postmenopausal women with MGD when compared to postmenopausal women without MGD, CCT assessment must be considered in every woman, especially in elderly patients.

Comparison of the Success Rate of Two Different Marking Techniques (F-Mark and Asymmetric Triangular Mark) to Orient the Donor Graft During Descemet Membrane Endothelial Keratoplasty.

We evaluated the effects of various graft-marking techniques on surgical results in patients undergoing Descemet membrane endothelial keratoplasty. In this single-center retrospective study, 65 eyes from 55 patients that had received various types of marking or no marking and that had been used for Descemet membrane endothelial keratoplasty endothelial graft preparation were included. Patients were divided into 3 groups according to the marking technique used: group I (F-marked graft; 17 eyes), group II (asymmetric triangle-marked graft; 12 eyes), and group III (unmarked graft; 36 eyes). The main outcome measurements were best-corrected visual acuity, endothelial cell density, central corneal thickness, postoperative complications, rebubbling, and secondary keratoplasty rates. In groups I, II, and III, rates of patients with 6-month best-corrected visual acuity ≥ 20/32 were 35.7%, 77.8%, and 71.9%, respectively (P = .04). The mean 6-month endothelial cell density decrease for each group was 43.3%, 48.8%, and 46.4%, respectively (P = .589), whereas the mean 6-month central corneal thickness decrease for each group was 7.7%, 15.8%, and 34.0%, respectively (P = .001). Rates of primary graft failure for groups I, II, and III were 35.3%, 8.3%, and 13.9%, respectively. Rebubbling was performed in 21.5% of eyes, and secondary keratoplasty was required in 29.2% of eyes. Although graft-marking techniques for Descemet membrane endothelial keratoplasty greatly facilitate graft positioning during surgery, both the potential toxic effects of alcohol on the endothelium when marking with gentian violet dye and the risk of graft detachment with asymmetric marking must be considered.

A pilot study of genipin cross-linking effects on bullous keratopathy in rabbits

AIM: To evaluate the effects of genipin cross-linking on bullous keratopathy in rabbits. METHODS: Nine female New Zealand white rabbits with bullous keratopathy were used as an experimental model. They were randomized into three groups. Corneas in Group A (treatment group, n=3) were immersed in 0.25% genipin at 24℃ for 40min; those in Group B (control group, n=3) were immersed in 0.9% sodium chloride solution at 24℃ for 40min; and those in Group C (blank control group, n=3) received no treatment. Follow-up examinations were performed within 2wk after treatment, including slit-lamp microscopy, central corneal thickness (CCT), evaluations of body weight and stress responses, histopathological analyses, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) for detecting stromal cell apoptosis. RESULTS: Compared to Groups B and C, remission of corneal edema, corneal healing, disappearance of epithelial bullae, a significant decrease in CCT (P&lt;0.05), and a significant increase in body weight (P&lt;0.05) were found in Group A. Animals in Group A became more active and showed less aggression and violent resistance behavior. More regular and dense arrangement of collagen fibers in the corneal stroma and formation of blue strips of cross-linking products were observed in Group A. Cell apoptosis occasionally occurred in the corneal stroma of Group A, while no cell apoptosis was observed in Groups B and C. CONCLUSION: Genipin cross-linking treatment for bullous keratopathy in rabbits results in remission of corneal edema and relief of pain. We hypothesize that genipin cross-linking strengthens collagen fibers in corneal stroma to avoid the formation of corneal edema and bullae.

Effects of Netarsudil and Latanoprost Alone and in Fixed Combination on Corneal Endothelium and Corneal Thickness: Post-Hoc Analysis of MERCURY-2.

IntroductionTo describe the changes in endothelial cell density (ECD), the coefficient of variation (CV), the percentage of hexagonal cells (%HEX), and central corneal thickness (CCT) following 3 months of therapy with netarsudil 0.02%/latanoprost 0.005% fixed combination, and to compare these changes with those seen with netarsudil 0.02% or latanoprost 0.005% in eyes with ocular hypertension or open-angle glaucoma.MethodsA subset of subjects enrolled in a Phase 3 evaluation of the intraocular pressure-lowering efficacy and safety of netarsudil 0.02%/latanoprost 0.005% fixed combination once daily (QD) versus each of its individual components underwent corneal endothelial cell imaging by specular microscopy and ultrasound pachymetry at baseline and following 3 months of therapy. Images were evaluated in masked fashion at an independent reading center. Changes from baseline to 3 months in ECD, CV, %HEX, and CCT were compared between treatment groups.ResultsData from 415 subjects obtained at both baseline and Month 3 were included in this post hoc analysis. Changes from baseline to Month 3 in ECD, CV, and %HEX were clinically insignificant in all three groups, and the changes in the netarsudil/latanoprost fixed combination group demonstrated no statistical difference from those seen in the netarsudil and latanoprost groups. Mean CCT decreased more in the fixed combination group (− 6.4 µm) than in either the netarsudil group (− 3.3 µm, p = 0.0248) or the latanoprost group (− 1.2 µm, p < 0.0001).ConclusionsNetarsudil 0.2%/latanoprost 0.005% fixed combination QD for 3 months in eyes with ocular hypertension or open-angle glaucoma had no clinically significant effects on endothelial cell density or morphology. The significant decrease in CCT in the fixed combination group compared to the two individual component groups may indicate that the potential effects of each drug on CCT are additive, although the magnitude of the observed effects is likely of negligible clinical significance.Clinicaltrials.gov IdentifierNCT02674854.

Yaşla Beraber Ön Segment Parametrelerindeki Değişimin Dual Scheimpflug Topografi ile Değerlendirilmesi

Objective: The aim of this study was to investigate the changes according to age in anterior segment parameters measured by Galilei Dual Scheimpflug Analyzer. Material and Methods: Healthy subjects were recruited and classified into seven groups according to age. Group 1 consisted of subjects whose ages ranged between 5 and 10 years. Group 2, 3, 4, 5, 6, 7 consisted of subjects who were in their second, third, forth, fifth, sixth and seventh decades, respectively. After a detailed examination, anterior segment parameters were assessed by using Galilei Dual Scheimpflug Analyzer. The following parameters were obtained from topographic and pachymetric maps for analysis: anterior chamber angle (ACA), anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), pupil diameter (PD) and corneal horizontal diameter (CHD). Statistical analysis was performed by using SPSS for Windows version 23.0. Results: The age of subjects ranged between 5 and 67 years. Of 229 subjects, 152 (66.4%) were female and 77 (33.6%) were male. The decrease in CCT, CHD, PD, ACD and ACA with age was statistically significant and a negative correlation was present (p=0.000). Except Group 1, the decline in ACV by increasing age was statistically significant and a negative correlation was present [r (458) =-0.34. p=0.000]. Conclusion: All anterior segment parameters except mean ACV measured by Galilei Dual Scheimpflug Analyzer were found to decline with age and mean ACD achieved to adult size till the beginning of the second decade.

Comparison of anterior segment changes after femtosecond laser LASIK and SMILE using a dual rotating Scheimpflug analyzer

BackgroundTo compare the changes in the anterior segment after femtosecond laser in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) using a dual rotating Scheimpflug (DRS) analyzer (Galilei®; Ziemer Ophthalmology, Port, Switzerland).MethodsA total of 218 eyes of 109 patients who underwent FS-LASIK or SMILE for myopic correction were retrospectively studied. Ninety-eight eyes of 49 patients who underwent FS-LASIK were compared to 120 eyes of 60 patients treated with SMILE. A DRS analyzer was used for preoperative and 6-month postoperative anterior segment analyses. Measured variables included the central corneal thickness (CCT), anterior chamber depth (ACD), anterior and posterior keratometry (K), anterior and posterior best-fit sphere radius, and maximum posterior elevation (MPE).ResultsAfter the procedure, the amount of CCT decrease was higher in the SMILE group than in the FS-LASIK group, but it was not statistically significant. The MPE was significantly increased after both procedures (p < 0.001 and p = 0.001 in the FS-LASIK and SMILE groups, respectively), with the amount of elevation being higher after FS-LASIK than after SMILE even though it was not statistically significant. And there was a significant change in the steep and average posterior K in the FS-LASIK group (p = 0.006 and 0.001, respectively), but not in the SMILE group.ConclusionsRegarding changes in the MPE and posterior K, changes in the posterior corneal surface were greater after FS-LASIK than after SMILE.Trial registrationThe trial registration number: KCT0003628. Date of registration: 15 March 2019.