Corneal Thickness Research Articles

Ocular Shape of Cataract with Retinitis Pigmentosa: A Case-Control Study

Purpose: To investigate the anterior segment morphology in cataracts with Retinitis Pigmentosa (RP). Setting: XXXX (anonymized for review) University Hospital. Design: A retrospective matched case-control study. Methods: The analysis included 28 eyes of 28 patients with cataracts and RP and 28 eyes of 28 patients with cataracts but without RP, matched for age and sex. Lens thickness, anterior lens curvature (Front R), posterior lens curvature, anterior chamber depth (ACD), anterior chamber width, central corneal thickness (CCT), white-to-white distance (WTW), corneal curvature, and axial length (AL) were compared between the groups. Data were obtained from preoperative evaluations conducted before cataract surgery. The same set of comparisons was also conducted for 18 eyes of 18 patients with cataracts and RP and 18 eyes of 18 patients with cataracts but without RP, matched for age, sex, and AL. Cases including missing data, categorized as Emery–Little classification grade 4 or above, or those with a history of acute angle closure were excluded. Results: In the age- and sex-matched analysis, cataracts with RP showed significantly a thicker lens, steeper Front R, shallower ACD, thinner CCT, and shorter AL. In the analysis matched by age, sex, and AL, cataracts with RP had a thicker lens, steeper Front R, and larger WTW. Conclusions: Cataracts with RP demonstrated centripetal swelling of the lens, centrifugal corneal thinning, and AL shortening. A decrease in tension between the lens and eyeball wall due to zonular weakness in the RP may lead to swelling of the lens and horizontal flattening of the eyeball.

Efficacy of Sutureless Scleral Fixation of One-Piece T-Shaped Haptic Intraocular Lens in Maintaining Anterior Chamber Stability During Descemet Membrane Endothelial Keratoplasty in Vitrectomized Eyes: Leak Test and Iris Diaphragm Reconstruction

Objectives: This study aimed to describe the outcomes of a staged procedure combining Descemet membrane endothelial keratoplasty (DMEK) and sutureless scleral fixation (SSF) of a one-piece intraocular lens (IOL) in a case series. Co-performing endothelial keratoplasty (EK) and SSF is associated with intraoperative and postoperative complications such as graft deployment difficulties, air migration, graft detachment, and IOL opacification or tilt, all of which are evaluated in this study. Methods: This is a retrospective observational case series. Clinical data were collected from eight eyes of eight patients who underwent DMEK for endothelial failure and had previously received an SSF with one-piece IOL following complete vitrectomy. During DMEK surgery, an air leak test was conducted to check for air migration into the posterior chamber. If instability was detected, pupilloplasty was performed. Intraoperative and postoperative data, including DMEK graft unfolding time, were collected. Corrected Distance Visual Acuity (CDVA), refraction, endothelial cell density (ECD), central corneal thickness (CCT), intraocular pressure (IOP), and complications were recorded over a 12-month follow-up period. Results: We performed pupilloplasty in four patients (50%). The median CDVA improved from preoperative 0.85 logMAR (range: 0.60 to 1.00) at baseline to 0.18 logMAR (range: 0.10 to 0.70, p = 0.012) at 12 months. The median refraction value changed significantly from −1.00 to −0.50 at 12 months. The median percentage reduction in ECD after 12 months was 33.4% (range 30 to 40). The median baseline CCT was 689 μm (range: 651 to 701) at baseline visit and 541.5 μm (range: 525 to 591, p = 0.008) at 12 months. The median IOP was reduced significantly during follow-up. The median graft unfolding time was 6 min (5 to 9). One patient required rebubbling for partial detachment on postoperative day one. No complications occurred within 12 months. Conclusions: The effective compartmentalization of the anterior and posterior chambers in vitrectomized eyes with an SSF one-piece IOL and pupilloplasty can facilitate critical steps of DMEK surgery in complex eyes. Additionally, the air leak test could prove useful in identifying the need for iris-lens diaphragm reconstruction.

Deep learning based highly accurate transplanted bioengineered corneal equivalent thickness measurement using optical coherence tomography

Corneal transplantation is the primary treatment for irreversible corneal diseases, but due to limited donor availability, bioengineered corneal equivalents are being developed as a solution, with biocompatibility, structural integrity, and physical function considered key factors. Since conventional evaluation methods may not fully capture the complex properties of the cornea, there is a need for advanced imaging and assessment techniques. In this study, we proposed a deep learning-based automatic segmentation method for transplanted bioengineered corneal equivalents using optical coherence tomography to achieve a highly accurate evaluation of graft integrity and biocompatibility. Our method provides quantitative individual thickness values, detailed maps, and volume measurements of the bioengineered corneal equivalents, and has been validated through 14 days of monitoring. Based on the results, it is expected to have high clinical utility as a quantitative assessment method for human keratoplasties, including automatic opacity area segmentation and implanted graft part extraction, beyond animal studies.

A Novel Artificial Endothelial Replacement Membrane for the Treatment of Chronic Corneal Edema.

The purpose of this study was to report the safety and efficacy results of an artificial lamellar implant for the treatment of chronic corneal edema. The EndoArt (EyeYon Medical, Ness Ziona, Israel), an artificial endothelial replacement membrane designed to treat corneal edema, was implanted in 24 eyes of 24 patients with low-to-normal visual potential. We present the safety and efficacy results from a prospective, open-label, single-arm, multicenter study conducted over a 12-month period. Twenty-four patients were enrolled, with no device-related serious adverse events reported. Seventeen patients completed 12-month follow-up, showing a reduction in average central corneal thickness from 759 ± 116 μm to 613 ± 135 μm. Best-corrected distance visual acuity improved from 1.88 ± 0.79 logarithmic minimum angle of resolution (logMAR) to 1.34 ± 0.57 logMAR. Sixty percent gained at least 3 early treatment diabetic retinopathy study (ETDRS) lines. The EndoArt was removed in 5 cases due to incomplete attachment and replaced by corneal transplants; 1 patient was lost to follow-up, and 1 had a procedure failure. No device-related long-term complications, infections, or inflammations were reported. The implants remained transparent throughout the study. The first-in-human results of EndoArt implantation demonstrated the device's potential to treat patients suffering from corneal edema with a favorable safety profile and effective edema reduction in most subjects, with no device-related serious adverse event. The EndoArt may offer a viable solution in regions facing a shortage of donor corneas, as well as for patients who have poor prognosis with human tissue.

What intrinsic factors affect the central corneal thickness?

The cornea is one of the tissues responsible for covering and protecting the inner structures of the eye. Central corneal thickness (CCT) is defined as the distance between the anterior epithelial surface and the posterior surface of the endothelial layer. This parameter plays a very important role regarding intraocular pressure (IOP) measurement, evaluation of corneal uniformity, selection of a suitable technique for corneal refractive surgery and the planning of surgical procedures to overcome corneal disease. This comprehensive review elucidates the multifaceted factors influencing the central corneal thickness. Recognising the impact of these factors not only enhances our understanding of corneal dynamics but also contributes significantly to the refinement of diagnostic and therapeutic strategies in ophthalmology.

Determining the Relationship Between Corneal Stiffening and Tissue Dehydration After Corneal Cross-Linking.

To quantify corneal cross-linking (CXL)-induced stiffening via mechanical testing to estimate the impact of changes in hydration levels (H) and evaluate depth-dependent tissue hydration after CXL. Eighty-three porcine corneal buttons were divided into three groups: Standard protocol CXL (S-CXL), accelerated CXL (A-CXL), and untreated (nonirradiated riboflavin-only) controls. Samples were hydrated or dehydrated to modulate H and dynamic mechanical analyzer compression tests were performed to measure Young's modulus (E). To extract the solid tissue network modulus, the cornea was modeled as a biphasic material after measuring E at different H. Corneal hydration was correlated with depth-dependent tissue thickness characterized by confocal reflection microscopy (CRM). Young's modulus increased fourfold after S-CXL (0.72 ± 0.1 MPa) and threefold after A-CXL E (0.53 ± 0.12 MPa) versus controls (0.17 ± 0.045 MPa). However, H decreased from 4.07 ± 0.35 in controls to 2.06 ± 0.2 after S-CXL and 2.79 ± 0.12 after A-CXL. After H modulation and biphasic mechanical modeling, Young's modulus for corneal solid tissue network showed only a 1.8-fold increase after S-CXL (2.25 MPa) and 1.5-fold increase after A-CXL (1.85 MPa) versus controls (1.22 MPa). With CRM, the overall thickness of the corneal tissue was found to linearly correlate to hydration H as expected. No appreciable depth dependence of hydration-induced thickness changes throughout the corneal buttons were observed. Corneal tissue hydration changes significantly impact measured corneal stiffness after CXL using mechanical testing. Not considering H leads to major overestimation of the stiffening effect of the CXL procedure. Depth-dependence of corneal thickness because of changing hydration is strongly dependent on the integrity of the tissue.

Association between myopia and sleep duration among primary school students in minority regions of Southwest China: a school-based cross-sectional research.

To investigate the relationship between sleep duration and myopia among primary school students in minority regions of Southwest China. The school-based, cross-sectional study was conducted from October 2020 to January 2021. All participants underwent a comprehensive ocular examination and completed a questionnaire on demographic characteristics, ophthalmological history and major environmental factors for myopia. Spherical equivalent (SE) and ocular biometric parameters were measured after cycloplegia, with myopia being defined as SE ≤-0.5 D (Diopter). Multivariate regression models were used to examine the association of sleep duration with myopia, SE and axial length (AL). A total of 857 students from grades 2 to 4 were included in the analysis, of which 63.6% were myopic and 62.0% belonged to ethnic minorities. Boys had a slightly higher prevalence of myopia compared with girls (66.7% vs 60.6%, p=0.06). Myopic students had longer AL, deeper anterior chamber depth and thinner central corneal thickness compared with non-myopic students (all p<0.05). There was no significant association between sleep duration and myopia in both boys and girls (p=0.319 and 0.186, respectively). Moreover, girls with a sleep duration of 8-9 hour/day had higher SE and shorter AL compared with those with less than 8 hour/day of sleep (β=0.41 and -0.32, respectively, all p<0.05). This cross-sectional study did not find a significant association between sleep duration and myopia. However, it suggests that 8-9 hours of sleep per day may have a protective effect on SE progression and AL elongation in girls. Future studies with objectively measured sleep duration are needed to validate the findings.

Effect of Belin-Ambrósio deviation index on 2-year refractive outcomes of PRK.

To assess the effect of preoperative Belin-Ambrósio deviation (BAD-D) index on 2-year visual, refractive, and tomographic outcomes, as well as the efficacy and safety of photorefractive keratectomy (PRK) surgery. Eye clinic, Mashhad, Iran. Prospective cohort study. This study included 66 patients (66 eyes) who underwent PRK surgery, with a minimum follow-up period of 2 years. Participants were divided into 2 groups: preoperative BAD-D ≥1.60 (high BAD-D) and preoperative BAD-D <1.60 (low BAD-D). Preoperative and postoperative visual, refractive, and tomographic parameters were evaluated, and the efficacy and safety of the procedure were compared between groups. 66 patients with a mean age of 35.50 ± 8.21 years (range 22 to 55 years) were included. Postoperatively, the mean spherical equivalent (SE) of refractive error was +0.32 ± 0.65 diopters (D) in the high BAD-D group and +0.18 ± 0.66 D in the low BAD-D group ( P = .40). In addition, at 2 years of follow-up, the mean uncorrected distance visual acuity was 0.98 ± 0.07 in the high BAD-D group and 0.97 ± 0.08 in the low BAD-D group ( P = .905). Among the postoperative tomographic parameters, front elevation thickness, maximum Ambrósio relational thickness, astigmatism, and central corneal thickness were significantly different between the 2 groups (all, P < .05). At the 2-year follow-up, the mean Safety Index was 1.02 ± 0.04, and 1.01 ± 0.04 in high and low BAD-D groups, respectively ( P = .37), and the mean Efficacy Index was 0.99 ± 0.07 and 0.98 ± 0.06 in high and low BAD-D groups, respectively ( P = .40). The preoperative BAD-D index does not predict postoperative visual, refractive, and tomographic outcomes in patients with low-to-moderate myopia. However, in patients with normal preoperative BAD-D values, higher agreement was expected between the attempted and achieved SE.

Intrastromal Corneal Ring Segments and Keratoconus Progression: A Case Series Study.

To assess keratoconus (KC) progression following the implant of intrastromal corneal ring segments (ICRSs) in young patients. Retrospective, longitudinal, observational, controlled nonrandomized case series study. Keratoconus patients aged 25 years or younger who underwent uneventful ICRS surgery and completed at least 3 years of follow-up were enrolled. Controls were of similar age and treatment-naive patients with KC. The following Pentacam imaging (Oculus, Wetzlar, Germany) data were analyzed: keratometric (maximum, in-flattest meridian, in-steepest meridian, and mean), aberrometric (higher-order aberrations and coma), pachymetric (thinnest corneal thickness), and elevation (maximum posterior elevation). The main outcome measure was KC progression. The study sample comprised 20 eyes of 18 cases (age 20.20 ± 3.70 years, nine right eyes, 14 male patients) and 30 eyes of 24 controls (age 20.80 ± 3.20 years, 15 right eyes, 21 male patients). The mean follow-up duration was 4.90 ± 1.70 years (range 3-8 years) for cases and 4.50 ± 1.40 years (range 3-8 years) for controls. Four cases and two controls met criteria for KC progression. Intrastromal corneal ring segments did not have significant impact on KC progression in the cohort.

A Comparative Study of the Hand-held IC200 and Slit Lamp-mounted ST500 rebound tonometers with Goldmann Applanation Tonometry

To compare the agreement and repeatability of intraocular pressure (IOP) measured with the slit lamp-mounted ST500 rebound tonometer (iCare Finland Oy, Helsinki, Finland), the hand-held IC200 rebound tonometer (iCare Finland Oy) and Goldmann applanation tonometry (GAT). Cross-sectional study. Glaucoma patients and staff of the Eye Care Centre, Nova Scotia Health, Halifax, Canada. IOP was measured twice each with the IC200, ST500, and GAT. Bland-Altman analysis was used to compare each pair of tonometers and whether the difference between tonometers depended on mean IOP. Intra-class correlation coefficients were also computed. Repeatability of the measurements with each tonometer was assessed by calculating the mean and variance of the difference between the first and second measurement. The relationship between IOP and central corneal thickness was also evaluated. Agreement and repeatability of IOP measurements with the IC200, ST500 and GAT. One eye of 157 participants (64 men and 93 women) with a median (Interquartile range) age and CCT of 62 (45 - 72) years and 553 (533 - 572) μm, respectively, were enrolled. Median IOP with the IC500, ST500 and GAT was 17.1 (14.3 - 21.0), 16.5 (14.0 - 20.8) and 17.0 (14.0 - 20.5) mm Hg, respectively, while the range of IOP (measured with GAT) was 8.5 to 53.0 mm Hg. Measurements with the three tonometers were not statistically different from each other and in neither of the three paired comparisons was the difference in IOP between two tonometers dependent on mean IOP. The ICC values (0.97-0.98) showed excellent agreement between the tonometers. The variance of the difference between the first and second measurements of the ST500 was significantly lower than that of GAT (P = 0.04) and IC200 (P < 0.01). ICCs for intra-tonometer repeatability were also excellent (0.97-0.99). The ST500 shows good agreement with GAT over a large range of IOP, and significantly higher repeatability compared to the IC200 and GAT, suggesting it may be advantageous in clinical settings where topical anesthesia or skilled staff are unavailable.

Validating and updating the OHTS-EGPS model predicting 5-year glaucoma risk among ocular hypertension patients using electronic records

ObjectiveTo validate and update the OHTS-EGPS model predicting risk of conversion from OHT to glaucoma using electronic medical records (EMR). DesignEvaluation and update of a risk prediction algorithm using EMRs and linked visual field (VF) tests. ParticipantsNewly diagnosed OHT patients attending hospital glaucoma services in England. Inclusion criteria: IOP 22-32 mmHg (either eye); normal baseline VF test, defined as Glaucoma Hemifield Test (GHT) ‘within normal range’ in a reliable VF test; at least two VF tests in total; no significant ocular co-morbidities. MethodsRisk factors: age, ethnicity, sex, IOP, vertical cup-to-disc ratio, central corneal thickness, VF pattern standard deviation, family history of glaucoma, systemic hypertension, diabetes mellitus, glaucoma treatment. Glaucoma conversion was defined as two consecutive and reliable VF tests with GHT ‘outside normal limits’ and/or need for glaucoma surgery. For validation, the OHTS-EGPS model was applied to predict a patient’s risk of developing glaucoma in 5 years. In the updating stage, the OHTS-model was re-fitted by re-estimating the baseline hazard and regression coefficients. The updated model was cross-validated and several variants were explored. Main Outcome MeasuresMeasures of discriminative ability (c-index) and calibration (calibration slope) were calculated and pooled across hospitals using random effects meta-analysis. ResultsFrom a total of 138,461 patients from ten hospital glaucoma services in England 9030 patients with OHT fitted the inclusion criteria. A total of 1530 (16.9%) patients converted to glaucoma during this follow-up period. The OHTS-EGPS model provided a pooled c-index of 0.61 (95% confidence interval: 0.60, 0.63), ranging from 0.55 to 0.67 between hospitals. The pooled calibration slope was 0.45 (0.38, 0.51), ranging from 0.25 to 0.64 among hospitals. The overall re-fitted model performed better than the OHTS-EGPS model, with a pooled c-index of 0.67 (0.65, 0.69), ranging from 0.65 to 0.75 between hospitals. ConclusionsWe performed an external validation of the OHTS-EGPS model in a large English population. Re-fitting the model achieved modest improvements in performance. Given the poor performance of the OHTS-EGPS model in our population, one should use caution in its application to populations that differ from those in the OHTS and EGPS.

Relationship between corneal hysteresis and the site of damage to peripapillary retinal nerve fibre layer thickness in open-angle glaucoma

Corneal hysteresis (CH) is associated with glaucomatous structural changes. We retrospectively investigated the association between CH and the regional circumpapillary retinal nerve fibre layer thickness (cpRNFLT) in 419 eyes of 419 patients with normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG). CH was used as the explanatory variable, and cpRNFLT (total and quadrant) was used as the dependent variable. Standardized β coefficients were compared both overall and between the NTG and POAG groups. Multiple regression analysis with CH as the explanatory variable and cpRNFLT parameters as the dependent variables suggested that even after adjusting for age, sex, intraocular pressure (IOP), axial length, and central corneal thickness, all areas of the cpRNFLT were significantly associated with CH, except for the nasal quadrant. In the stratified analysis by glaucoma type, a positive relationship between CH and regional cpRNFLT tended to be maintained in the NTG group but not in the POAG group (P = 0.060 for interaction). Additionally, in the NTG group, the CH-inferior cpRNFLT relationship was particularly strong in the less-IOP fluctuation group. These results suggest that CH may be a potential predictor of anatomical vulnerability around the optic nerve, particularly enhancing the inferior regions of NTG.

Comparative Analysis of Central Corneal Thickness in Ocular Hypertension and Healthy Individuals.

This study aimed to compare the central corneal thickness (CCT) between patients with ocular hypertension (OHT) and healthy individuals, and to investigate the relationship between CCT and intraocular pressure (IOP), diopter, and corneal endothelium cell count (CECC). The CCT of 30 healthy subjects and 38 patients with OHT was measured using a non-contact specular microscope. IOP, diopter, and CECC were also assessed for all participants. Comparative analysis of CCT between the two groups was performed, along with correlation analysis between CCT and each parameter. The average CCT for all participants was 527.57 ± 35.84 µm. The average CCT was 516.07 ± 34.76 µm for healthy subjects and 536.66 ± 34.46 µm for patients with ocular hypertension, showing a significant difference between the two groups (P ≤ 0.05). CCT was not correlated with age (Pearson r = -0.098, P = 0.426), diopter (spherical equivalent refraction) (Pearson r = -0.158, P = 0.197), or corneal endothelium cell count (Pearson r = 0.065, P = 0.598). However, a positive correlation was found between ocular hypertension and central corneal thickness (Pearson r = 0.278, P = 0.022). Patients with ocular hypertension of members of the Chinese Han population exhibited greater CCT compared to healthy subjects in this study. CCT showed no association with age, diopter, or corneal endothelium cell count; however, a positive correlation was observed between intraocular pressure and CCT. With CCT as the abscissa and IOP as the ordinate, the linear regression equation is Y=0.05+0.021X (F = 5.508, P = 0.022). The use of non-contact tonometers for measuring CCT may impact the accuracy of diagnosing and treating glaucoma and ocular hypertension.

Corneal Artificial Endothelial Layer (EndoArt): Literature Review and Our Experience

Background/Objectives: The objective of this study was to examine the morphological corneal changes and outcomes following the implantation of an artificial endothelial layer (EndoArt) in patients with chronic corneal oedema. Methods: A systematic review of the literature was conducted alongside a detailed analysis of two clinical cases with chronic corneal oedema that were treated using EndoArt. Our experience with these two cases is included to provide practical insights and real-world outcomes. Results: Across the 24 cases reported (including the two presented here), an analysis was possible in 23 cases. Notably, 82% of patients had undergone at least one previous corneal transplant, with 39% having undergone three or more transplants. Additionally, 78% of cases had ocular comorbidities, with glaucoma surgery being the most prevalent (83%), which could have impacted visual outcomes. The follow-up period ranged from 3 to 17 months with a median of 3 months. After EndoArt implantation, the average reduction in the central corneal thickness (CCT) was 29%, and the rebubbling rate was 47.8%, with some cases requiring no rebubbling, while others required it up to 100% of the time. Visual acuity significantly improved from a mean best-corrected visual acuity (BCVA) value of 1.61 ± 0.5 logMAR to 1.07 ± 0.59 logMAR (p &lt; 0.001). The CCT decreased from 771 ± 146 µm to 580 ± 134 µm (p &lt; 0.001). These findings are consistent with our experience. Conclusions: EndoArt shows promise as an alternative treatment for chronic corneal oedema in complex cases where conventional corneal transplantation has failed or carries a high risk of failure. The morphological changes observed using anterior segment optical coherence tomography (OCT) and in vivo confocal microscopy (IVCM) were similar to those reported after endothelial keratoplasty, with the notable exception of the absence of the hyper-reflective donor–host interface.

Scleral lens fitting after paediatric limbal dermoid removal

Purpose. This case report describes the management of refractive error and amblyopia using a scleral lens fitted to the eye of a young child with an irregular cornea resulting from limbal dermoid removal and corneal transplant in infancy. Material and Methods. A young infant was initially fitted with spectacles and occlusion therapy following the surgical excision of a limbal dermoid and full thickness corneal transplant. The vision did not improve in spite of patching so the child was referred for contact lens fitting. Various iterations of scleral lens fitting were carried out. Results. Scleral lens fitting was attempted from the age of 2 years but transplant rejections, the COVID-19 pandemic and variable cooperation meant that adequate lens wear could not be achieved in the early stages. In addition, the corneal shape changed during the course of the fitting. During these periods, spectacle wear and occlusion therapy were maintained until a good lens fit could be achieved following several modifications. Treatment is ongoing but at the age of 5 years, the visual acuity is 0.24 logMAR letters. Conclusion. Scleral lenses can be used to habilitate the vision in an eye with an irregular cornea but when scleral lens wear is not possible, it is important to persevere with spectacle correction and patching therapy. Several iterations of scleral lenses may be needed as the eye changes and the child grows.

Corneal Endothelial Keratoprosthesis EndoArt in Patients with Glaucoma at High Risk of Graft Failure After Keratoplasty.

The novel endothelial keratoprosthesis EndoArt improves corneal edema by reducing the inflow of aqueous humor into the cornea. We assessed the early outcome after EndoArt implantation in patients at a high risk of graft failure after keratoplasty. This retrospective study included 14 patients with high-risk eyes owing to at least one of the following risk factors for graft failure after keratoplasty: multiple previous surgeries (glaucoma surgery, keratoplasty) and recurrent intraocular inflammation because of uveitis, aniridia, or anterior synechia. After descemetorhexis, the EndoArt keratoprosthesis was placed on the posterior stroma, secured with a gas bubble and 1 to 3 transcorneal holding sutures. Best spectacle-corrected visual acuity and central corneal thickness were calculated preoperatively and postoperatively. In addition, detachment of the keratoprosthesis and the need for additional gas injections (rebubbling) were analyzed. Octafluoropropane (C3F8) 12% in 11 patients and sulfur hexafluoride 20% in 3 patients were used to attach EndoArt. Detachments requiring at least 1 rebubbling occurred in 8 eyes. Preoperative best spectacle-corrected visual acuity was 1.6 (±0.6) logarithm of the minimal angle of resolution and improved to 1.3 (±0.6) after 12 weeks. Preoperative central corneal thickness (771.8 μm ± 157) significantly decreased postoperatively in all patients (622.1 μm ± 184.7 [P = 0.025] and 562.8 μm ± 183.6 [P = 0.012] after 6 and 12 weeks, respectively). EndoArt improved visual acuity and significantly reduced corneal thickness within 3 months postoperatively, subjectively, but not statistically significantly. The rebubbling rates in this cohort with an altered anterior segment anatomy were relatively high. Patients at a high risk of graft failure may benefit from this novel endothelial keratoprosthesis.

Ten-Year Follow-Up After Descemet Membrane Endothelial Keratoplasty.

To examine clinical results up to 10 years after Descemet Membrane Endothelial Keratoplasty (DMEK) and Triple-DMEK. Prospective study including 201 eyes, of which 54 eyes [38 DMEKs and 16 Triple-DMEKs; Fuchs endothelial dystrophy (n = 45), pseudophakic bullous keratopathy (n = 9)] reached the minimum follow-up of 5 years and were followed up for up to 10 years. We evaluated best-corrected visual acuity (BCVA, logarithm of the minimum angle of resolution [logMAR]), endothelial cell density (ECD, cells/mm2), minimal central corneal thickness (CCT, μm), central retinal thickness (μm), rebubbling, graft survival and re-DMEK rate, chamber angle alterations, and incidence of glaucoma. Fifty-four eyes had a 5-year and 37 eyes an 8- to 10-year follow-up. Mean follow-up was 94.4 ± 12.1 months. Best-corrected visual acuity increased from 0.6 ± 0.3 logMAR to 0.1 ± 0.2 logMAR at 6 months (P ≤ 0.001) and was 539 ± 54 μm at long term. Endothelial cell density decreased from 2488 ± 320.9 (donor) to 980.1 ± 437 cells/mm2 with an average ECD loss/year of 4% and did not correlate with BCVA. Central corneal thickness decreased from 596.9 ± 82.2 μm to 498.6 ± 24.3 μm at 12 months (P ≤ 0.001) and remained stable (P = 1.000). Mean rebubbling rate was 0.3 ± 0.5/eye and did not correlate with BCVA. Eight eyes (14.8%) received at least 1 rebubbling. Primary graft failure/rejection rate was 1.5%/0% within the first postoperative year, and secondary graft failure rate was 12.4% at 7 years. Eight eyes (preoperative n = 3, de novo n = 5) had open-angle glaucoma without chamber angle changes (14.8%, P ≤ 0.001). Although ECD decreases continuously in the long-term follow-up, excellent visual acuity can be preserved 10 years after DMEK and Triple-DMEK. The final outcome can be estimated 6 months after surgery.

Off-Centered DMEK Grafts: Impact and Resolution.

The aim of this study was to assess the outcomes of off-centered Descemet membrane endothelial keratoplasty (DMEK) grafts compared to descemetorhexis. This is a retrospective case series of DMEK procedures conducted between June 2022 and July 2023 with postoperative graft decentration, characterized by a gap between the graft and descemetorhexis edge. Eight eyes of 8 patients met the inclusion criteria. The average gap between the descemetorhexis edge and DMEK graft was 911.2 μm (range 306-1468). The resulting focal peripheral edema overlying the gap resolved in all cases, with a median time of 3 months. Best-corrected visual acuity improved from 0.49 (±0.26) logarithm of the minimum angle of resolution to 0.01 (±0.02) logarithm of the minimum angle of resolution at 12 months (P = 0.003). Central corneal thickness decreased from 646.5 (±177.8) μm to 473.7 (±29.6) μm at 12 months (P = 0.05). One eye, in the overlapped area of host-donor Descemet membranes, had small peripheral partial graft detachment less than one-third of graft surface area. No eyes required graft rebubbling. A larger descemetorhexis to DMEK gap showed a trend toward longer resolution times (P = 0.06). Focal edema in the inferonasal periphery took longer to recover compared with the nasal position (P = 0.01). Larger descemetorhexis to DMEK gaps did not significantly influence the longitudinal visual acuity trend (P = 0.75). Decentered DMEK, characterized by a gap between the graft and descemetorhexis edge, leads to focal stromal edema that diminishes over time, with no impact on final visual acuity.

Observations on relative peripheral refraction in Chinese adults with myopia based on a novel application of multispectral refraction topography

In this population-based observational cross-sectional study, we investigated retinal peripheral refraction in Chinese adults with myopia. We categorized 1511 Chinese adults with myopia (18 − 55 years) into low (LM), moderate (MM), and high myopia (HM) groups. Axial length, central corneal thickness, steep keratometry, flat keratometry, and intraocular pressure were measured. Refractive difference values (RDVs) for different eccentricities (RDV0–53) and the superior (RDV-S), inferior (RDV-I), temporal (RDV-T), and nasal (RDV-N) retinal regions were measured using multispectral refractive topography. The hyperopic defocus was higher for the MM group than for the LM group in RDV20–53, RDV-S, and RDV-T and HM group in RDV20–53, RDV-S, RDV-T and RDV-N. The hyperopic defocus was higher for the HM group than for the LM group in RDV20-53, RDV-S and RDV-T but lower for the LM group in RDV-N. RDV-N decreased with age (R2 = 0.0191, slope = − 0.01, p < 0.0001), whereas RDV-S (R2 = 0.0112, slope = 0.01,p < 0.0001) and RDV-T increased (R2 = 0.0038, slope = 0.01, p = 0.0160). RDV correlated with central spherical equivalent and axial length. Flat keratometry explained the most RDV variation (RDV20–30: β = 0.0714, p < 0.0001; RDV-N: β = 0.1801, p < 0.0001; RDV-S: β = 0.1426, p < 0.0001; RDV-T: β = 0.1239, p < 0.0001). Reference values for peripheral retinal defocus are provided for Chinese adults with different myopia ranges.

Biomimetic Curcumin-Loaded Liposomes for the Treatment of Dry Eyes and Meibomian Gland Dysfunction: An In Vivo Study

Background/Objectives: Meibomian gland dysfunction (MGD) and dry eye syndrome (DES) are common eye diseases characterized by altered tear film stability and inflammation of the ocular surface, causing significant discomfort and possible visual impairment. This study aimed to investigate the efficacy of curcumin-loaded liposomes (Lipo@Cur) compared to cyclosporine A-loaded liposomes (Lipo@CycA) in experimental rabbit models of MGD and DES, with a focus on their ability to improve tear film stability and reduce ocular surface inflammation. Methods: MGD and DES were induced using complete Freund’s adjuvant (CFA) and treated to evaluate the effect of liposomal formulations on tear break-up time (TBUT), clinical signs of inflammation (telangiectasia, conjunctival hyperemia, meibomian foramen occlusion), and corneal as well as conjunctival histological cells. Results: Lipo@Cur increased TBUT and reduced the signs of ocular surface inflammation, potentially approaching the effectiveness of clinically approved cyclosporine A encapsulated in liposomes (Lipo@CycA). Histological analysis suggested improvements in corneal epithelial thickness and goblet cell density in the treated groups, which may indicate a reversal of DES-induced damage to the ocular surface. Conclusions: Plant-originated curcumin encapsulated in liposomes offers a promising therapeutic strategy for the management of MGD and DES that may improve patient outcomes by addressing the underlying inflammatory mechanisms of these conditions.