Outcomes of rebubbling for graft detachment after Descemet's stripping endothelial keratoplasty or Descemet's stripping automated endothelial keratoplasty

Purpose

To study the outcomes of rebubbling for graft detachment after Descemet's stripping endothelial keratoplasty (DSEK) or Descemet's stripping automated endothelial keratoplasty (DSAEK).

Methods

From 2260 eyes that underwent DSEK or DSAEK from July 2008 to June 2015, 80 eyes of 80 patients developed graft detachment and were retrospectively reviewed. Host-related, surgery-related and donor-related factors that have a bearing on graft adhesion were looked at retrospectively, and eventual outcomes after rebubbling procedure were studied.

Results

Successful attachment was observed in 77 (96.25%) eyes and clear grafts were achieved in 55 (68.75%) eyes, while 25 (31.25%) eyes had graft failure. The uncorrected and best-corrected distance visual acuities significantly improved from 1 month to 3 months post-operatively and remained stable till 12 months of follow-up. Three lenticules that failed to attach with the first rebubbling procedure underwent a second rebubbling, two underwent a repeat DSEK with good outcomes and four underwent penetrating keratoplasty. On evaluating possible risk factors for graft failure, lower donor endothelial cell density was found to be a significant factor (P = 0.03). The median graft survival following rebubbling was 30 months.

Conclusion

Rebubbling procedure in detached grafts after DSEK or DSAEK can reattach the lenticule in 96% of eyes in immediate post-operative period and the majority of the grafts remained clear on long-term follow-up with a median graft survival period of 2.5 years.

Effect of Angle Opening Parameters on Corneal Endothelial Cell Density and Intraocular Pressure after Posterior Chamber Phakic Intraocular Lens Implantation

This study aimed to investigate the time courses of angle opening parameters and the relationships of these with the corneal endothelial cell density (ECD) and the intraocular pressure (IOP) after posterior chamber phakic intraocular lens (Visian ICL^TM, STAAR Surgical) implantation. We evaluated 116 eyes of 59 consecutive patients (mean age ± standard deviation, 34.0 ± 8.8 years) who underwent V5 implantable collamer lens (ICL) implantation. Preoperatively and 1 day, 1 week, and 1, 3, and 18 months postoperatively, we quantitatively measured the angle opening distance at 500 µm (AOD500), the trabecular-iris space area (TISA500), and the trabecular iris angle (TIA500), using anterior segment optical coherence tomography (CASIA 2, Tomey), and assessed the relationships of these measurements with ECD and IOP in ICL-implanted eyes. All angle parameters (AOD500, TISA500, and TIA500) significantly decreased 1 day postoperatively but remained stable thereafter. At 18 months postoperatively, we found no significant correlations of the angle parameters with ECD (Pearson correlation coefficient r = −0.108, p = 0.249 for AOD500; r = −0.162, p = 0.083 for TISA500; r = −0.022, p = 0.815 for TIA500) or between the angle parameters and IOP (r = −0.106, p = 0.256 for AOD500; r = −0.021, p = 0.826 for TISA500; r = −0.018, p = 0.850 for TIA500). The angle opening metrics significantly decreased immediately after ICL implantation but remained stable thereafter. Narrowing of the angle did not significantly affect ECD or IOP in ICL-implanted eyes during the 18-month postoperative period.

Safety and visual outcomes following Iris-claw phakic intraocular lens bilensectomy

PURPOSE

To evaluate the visual outcomes, safety, efficacy, and causes of bilensectomy for iris fixated phakic intraocular lenses (pIOLs).

METHODS

This was a two center consecutive retrospective study that included 43 eyes that underwent iris-claw pIOL bilensectomy. Patients with follow up less than 4 months were excluded from the study. Uncorrected, corrected visual acuity (UCVA, CDVA), refractive outcomes, efficacy, safety (number of eyes in which the postoperative CDVA was worse than the preoperative CDVA), endothelial cell density (ECD), causes of bilensectomy, the time between the implantation of the pIOL and bilensectomy, intra and postoperative complications were analyzed.

RESULTS

There was a statistically significant improvement in UCVA and CDVA after surgery (p = 0.001). The efficacy index was 0.7, four eyes had a postoperative CDVA worse than the preoperative CDVA. The mean spherical equivalent 1 year after bilensectomy was -0.78 ± 1.70 D. There was a statistically significant endothelial cell loss after iris claw lens bilensectomy (p = .003). Cataract development and endothelial cell loss were the only reasons for bilensectomy. The mean time between pIOL implantation and bilensectomy was 12.2 ± 5.5 years. One patient had corneal edema 8 months after surgery and one had a retinal detachment 11 months after surgery.

CONCLUSION

Bilensectomy was successful in improving UCVA and CDVA with an acceptable refractive outcome. Significant loss of ECD was found after surgery. The results recommend a larger ACD as selection criteria when choosing to implant an Artisan lens, and a close postoperative monitoring of the endothelial cell count.

Corneal endothelial cell loss following cataract surgery in patients with pseudoexfoliation syndrome: a 2-year prospective comparative study

PURPOSE

To compare the corneal endothelial cell density (ECD) before and after cataract surgery in patients with and without pseudoexfoliation syndrome (PEX).

METHODS

In this prospective study, we compared the ECD in 62 PEX patients with 62 patients without PEX (controls). The mean age was 78.3 ± 6.2 years and 77.2 ± 5.9 years, respectively. Patients were examined before and at 6 months, 1 year and 2 years after cataract surgery. The corneal endothelium was examined with confocal microscopy, and the ECD was counted both automatically and semi-manually. Nine patients in the PEX group (15%) and 11 patients in the control group (18%) were lost to follow-up in the 2-year period. Within the PEX and the control groups, we also compared the ECD between patients with and without glaucoma.

RESULTS

Before surgery, the ECD (semi-manual counting) was 2258 ± 342 cells/mm² in the PEX group and 2322 ± 321 cells/mm² in the control group (p = 0.29). There were no significant differences in postoperative ECD between these groups at any visit. After 2 years, the ECD had changed by -679 ± 337 cells/mm² and -704 ± 484 cells/mm² , respectively (p = 0.78). The preoperative ECD was lower in eyes with glaucoma compared to eyes without glaucoma, both within the PEX group (p = 0.05) and the control group (p = 0.03). After surgery, there were no differences between eyes with or without glaucoma.

CONCLUSION

The ECD was not significantly different in PEX eyes compared with control eyes, neither before nor after cataract surgery. However, there seemed to be a lower ECD in eyes with glaucoma before surgery.

Combined specular microscopy and Scheimpflug imaging to improve detection of an upcoming allograft rejection after DMEK

PURPOSE

To assess whether combined analysis of specular microscopy and Scheimpflug imaging improves detection of an upcoming allograft rejection following Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Retrospective analysis of 22 eyes that had developed a clinical proven allograft rejection 28 (±22) months (range: 4-84 months) after DMEK. Specular microscopy and Scheimpflug images routinely made after DMEK were retrospectively analysed for changes in endothelial cell morphology (e.g. nuclear activation), cell density (>10%) and pachymetry (>7%), and/or the presence of subclinical keratic precipitates. The same parameters were evaluated for 22 control eyes matched for age, gender and surgery indication.

RESULTS

A total of 20/22 eyes (91%) showed detectable changes 0.25-75 months before allograft rejection became clinically manifest: 13/22 (59%) showed both specular microscopy and Scheimpflug imaging changes; 5/22 (23%) only had changes on Scheimpflug imaging; and 2/22 (9%) only had specular microscopy changes. In 18/22 (82%) and 14/22 (64%) eyes, subclinical keratic precipitates and endothelial cell morphology changes could be detected, respectively. A total of 11/22 (50%) eyes concurrently showed a >10% drop in endothelial cell density and 4/22 (18%) a >7% pachymetry increase. Of the control eyes, 7/22 (32%) showed changes with specular microscopy but not with Scheimpflug imaging.

CONCLUSIONS

Combined analysis of specular microscopy and Scheimpflug imaging may allow recognizing an upcoming allograft rejection in over 90% of eyes and up to 6 years before rejection becomes clinically manifest. Early recognition of eyes at risk may allow for targeted intensified steroid treatment to prevent endothelial cell damage associated with rejection.

Effect of glaucoma drainage implant surgery on corneal topography: a prospective study

PURPOSE

To study the effect of glaucoma drainage implant (GDI) surgery on corneal topography during the first postoperative year.

METHODS

Twenty-one adult glaucoma patients were implanted with a Molteno3 or a Baerveldt 250 GDI. Corneal topography measurements were taken preoperatively and at 6 and 12 months after surgery. Untreated opposite eyes served as controls.

RESULTS

In the surgical group, the mean ± SD simulated average keratometry values were 44.36 ± 1.69 D, 44.08 ± 1.29 D (p = 0.266) and 44.15 ± 1.32 D (p = 0.554) before and 6 and 12 months after surgery, respectively. The corresponding simulated keratometry astigmatism values were 1.11 ± 1.11 D, 1.20 ± 1.01 D (p = 0.687) and 1.16 ± 0.71 D (p = 0.177). Posterior astigmatism and posterior average keratometry remained unchanged after GDI surgery as well. The mean ± SD central corneal thickness (CCT) was 530 ± 46 μm, 535 ± 56 μm (p = 0.049) and 536 ± 45 μm (p = 0.080) at 0, 6 and 12 months, respectively. A trend towards increased corneal thickness (CT) in response to GDI surgery was also seen in both the average peripheral and the tube-quadrant peripheral CT values. At 12 months postoperatively, the mean endothelial cell density (ECD) had decreased by 8% centrally and by 9% peripherally. Corneal topography parameters, CT and ECD did not significantly change in the control group during follow-up.

CONCLUSION

Glaucoma drainage implant (GDI) surgery did not significantly alter corneal keratometry parameters and thus seems to be an astigmatically neutral procedure. However a slight, although seemingly transient, increase in CCT was observed after GDI implantation.

Improved Interchangeability with Different Corneal Specular Microscopes for Quantitative Endothelial Cell Analysis

Introduction

During our clinical practice and research, we encountered an interchangeability problem when using the SP-2000P and SP-3000P TopCon corneal specular microscopes (CSMs) (TopCon Medical Systems, Tokyo, Japan) regarding the endothelial cell count (ECC). We describe a method to improve interchangeability between these CSMs.

Methods

Five consecutive good-quality endothelial cell photographs were obtained in 22 eyes of 11 subjects. An ECC comparison between the two CSMs was performed after (I) gauging and calibration by the manufacturer, (II) adjustment of the magnification, (III) correction after external horizontal and vertical calibration.

Results

There was a statistically significant difference between the ECC of the SP-2000P and SP-3000P at the start. The SP-2000P counted an average of 500 cells/mm² more than the SP-3000P (p=0.00). After correction for magnification and determining a correction factor based on external calibration, the difference between the ECC of the SP-2000P and the SP-3000P was then found to be 0.4 cells/mm² and was not statistically significant (p=0.98).

Discussion

We propose a method for improving interchangeability, which involves checking magnification settings, re-checking magnification calibration with external calibration devices, and then calculating correction factors. This method can be applied to various specular or confocal microscopes and their associated endothelial cell analysis software packages to be able to keep performing precise endothelial cell counts and to enable comparison of ECCs when a CSM needs to be replaced or when results from different microscopes need to be compared.

Corneal thickness and endothelial cell density in children with type 1 diabetes mellitus

BACKGROUND:

The aim of this study was to detect the effect of diabetes on the corneal endothelium in patients of Type 1 diabetes in the pediatric age group and to compare them with age-matched controls. Further, it was proposed to establish any correlation between these changes and risk factors of diabetes, viz., age, duration of diabetes, and hemoglobin A1c (HbA1c) values.

MATERIALS AND METHODS:

This was a prospective cross-sectional study. Fifty children with Type 1 diabetes, between the ages of 7 and 17 years (average, 12.16 ± 2.63 years), and fifty healthy age-matched controls (average 12.28- ±3.00 years) were examined. The central corneal thickness (CCT) and endothelial cell density (CD) were assessed by the Topcon SP-1P specular microscope. The duration of diabetes (average, 3.91 ± 1.65 years) and the HbA1c values (average, 10.92 ± 2.28) were also noted.

RESULTS:

The average CCT in the diabetics was 525.16 ± 33.14 μ and in the controls 513.44 ± 29.46 μ. This was significantly higher (P = 0.015). The average endothelial CD in the diabetics was 3039.64 ± 292.84 cells/mm² and in the nondiabetics 3360.41 ± 268.04 cells/mm². This was significantly lower (P < 0.001). A significant correlation was found between the endothelial CD and age of the diabetic patients (P = 0.008). However, there was no significant correlation between the endothelial CD and the CCT with either duration of diabetes or HbA1c.

CONCLUSIONS:

A significant decrease in the endothelial CD and increase in the CCT occurs in children and adolescents with Type 1 diabetes. With the age of the diabetic patients, the endothelial CD significantly reduces. However, duration of diabetes and HbA1c do not affect these values.

Significant differences between specular microscopy and corneal bank endothelial cell counts - a pilot study

BACKGROUND

It was shown recently that endothelial cell count performed by cornea banks overestimates the real number of endothelial cells. The aim of this study was to investigate the internal quality of preclinical ECD in human donor corneas using two widely used methods for endothelial cell counting, transmitted light microscopy used in organ culture tissue bank and clinically used specular microscopy.

METHODS

Twenty human donor corneas that could not be transplanted were included in this analysis. Differences in evaluating endothelial cell density (ECD) and hexagonal endothelial cell ratio (HEX) between clinical specular microscopy (CSM) and corneal bank transmitted light microscope (CBLM) were evaluated as well as differences between automated and manual cell counts.

RESULTS

Automated CBLM showed a higher ECD of 31.85% compared to automated CSM, while manual CBLM counting is 10.51% higher compared to manual CSM (p < 0.01). Further, higher average ECD values result in a higher difference between CSM and CBLM measurements. The manual CBLM ECDs were significantly higher compared to automated derived ECD from CSM (p < 0.01). However, no systematic bias can be detected when comparing the differences of the measurements with the average ECD measurements of both methods.

CONCLUSION

This preclinical pilot study confirmed a significant higher ECD using transmitted light microscopy in organ culture compared to clinical specular microscopy. This indicates that the early rapid decrease of EC universally observed after surgery might be partly artefactual.

Phakic Intraocular Lens Implantation After Deep Anterior Lamellar Keratoplasty: Retrospective Case Series Analysis With Long-Term Follow-Up

Purpose

To report outcomes of phakic intraocular lens (IOL) implantation after deep anterior lamellar keratoplasty (DALK) to correct high ametropia.

Setting

Centro Hospitalar Universitário do Porto, Portugal.

Methods

Retrospective case series with 11 eyes submitted to phakic IOL implantation after DALK. Main outcomes measured were uncorrected and corrected distance visual acuity (UDVA and CDVA), refractive error components, tomographic parameters and endothelial cell density (ECD). The minimum follow-up was 3 years for all cases.

Results

Mean ECD loss was 8.7±6.7% at 1 year, 13.1±8.6% at 3 years (n=11; p=0.016, p=0.007, respectively) and 14.0±20.4% at 5 years (n=5, p=0.212). Mean logMAR UDVA increased from 1.27±0.90logMAR preoperatively to 0.16±0.15logMAR postoperatively (p≤0.001) and no statistically significant differences were registered during follow-up. All patients gained at least 5 lines of UDVA. 54.5% of the eyes gained 1 line in CDVA postoperative and only one eye lost one CDVA line through follow-up. Efficacy and safety indexes at 1 and 3 years were 1.01–0.97 and 1.24–1.21, respectively. Mean spherical equivalent was reduced from −7.84±4.63 D preoperatively to −1.05±1.07 D postoperatively (p=0.001). Mean percentage of reduction in refractive cylinder and spherical error was 83.8±15.8% and 73.1±31.5%, respectively, p≤0.001 for both. In one eye there was a significantly gradual ECD loss over 5 years follow-up and the patient will be submitted to IOL explant.

Conclusion

Phakic IOLs were effective for correction high ametropia after DALK, showing high efficacy and safety indexes with stability over time. However, it was registered a continuing endothelial cell loss postoperatively, which assumed to be higher than those reported in eyes without DALK.

Comparison of automated vs manual analysis of corneal endothelial cell density and morphology in normal and corneal endothelial dystrophy-affected dogs

OBJECTIVE

To determine the efficacy of automated imaging software of the Nidek ConfoScan 4 confocal biomicroscope at analyzing canine corneal endothelial cell density and morphology in health and disease, by comparing to a manual analysis method.

ANIMAL STUDIED

Nineteen eyes of 10 dogs were evaluated and include three Beagles, three Jack Russell Terriers, and four miscellaneous breeds. Twelve clinically normal and seven eyes affected with corneal endothelial dystrophy (CED) were scanned and analyzed.

PROCEDURES

Endothelial cell density (ECD), mean and standard deviation (SD) of cell area, percent polymegathism, mean and SD of the number of cell sides, and percent pleomorphism were calculated using automated and manual methods for each scan.

RESULTS

The automated analysis showed significantly greater ECD in comparison with the manual frame method due to misidentification of cell domains in CED-affected dogs. No significant differences in ECD were observed between normal and CED-affected dogs in automated analysis, while CED-affected dogs showed significantly lower ECD in manual frame method and planimetry. Using both automated and manual methods, CED-affected dogs showed greater variability of cell area or the number of cell sides than normal dogs.

CONCLUSION

The automated imaging software is unable to accurately identify cell borders in CED-affected dogs resulting in inaccurate estimates of ECD. Thus, manual analysis is recommended for use in clinical trials assessing adverse events associated with novel medical treatments and/or surgical procedures.

Comparison of changes in corneal endothelial cell density and central corneal thickness between conventional and femtosecond laser-assisted cataract surgery: a randomised, controlled clinical trial

BACKGROUND/AIM

To identify changes in endothelial cell density (ECD) and central corneal thickness (CCT) in eyes undergoing femtosecond laser-assisted cataract surgery (FLACS) compared with conventional phacoemulsification surgery (CPS).

METHODS

This is an intraindividual randomised, controlled clinical trial. One eye was randomised to receive FLACS, while the contralateral eye of the same patient received CPS. The femtosecond laser pretreatment included creating main and side-port corneal incisions, capsulotomy and lens fragmentation. Non-contact endothelial cell microscopy and pachymetry were performed preoperatively and at postoperative day 1, week 1, month 1 and month 3.

RESULTS

A total of 134 paired eyes from 67 patients were included in the analysis. ECD was not significantly different between the two groups at either postoperative month 1 (2370±580 cells/mm² and 2467±564 cells/mm² in FLACS and CPS groups, respectively; p=0.18) or at postoperative month 3 (2374±527 cells/mm² and 2433±526 cells/mm² in FLACS and CPS groups, respectively; p=0.19). No significant difference was observed in the mean CCT values between the two groups over the follow-up period (p>0.05).

CONCLUSION

Postoperative corneal ECD and CCT were comparable between FLACS and CPS during the 3 months' follow-up period.

Comparison of endothelial/Descemet's membrane complex thickness with endothelial cell density for the diagnosis of corneal transplant rejection

Purpose:

This study compared the effectiveness of endothelial/Descemet’s membrane complex thickness obtained using high-definition anterior segment optical coherence tomography with endothelial cell density obtained using confocal microscopy as diagnostic tools in predicting corneal transplant rejection.

Methods:

This observational, prospective, cross-sectional study evaluated penetrating keratoplasty grafts. Slit lamp examination organized the grafts into healthy or rejecting grafts. Grafts were scanned using both high-definition anterior segment optical coherence tomography and confocal microscopy. Central corneal thickness, endothelial/Descemet’s membrane complex thickness, endothelial cell density, and coefficient of variation were each compared with the clinical status. Descemet’s rejection index, defined by endothelial/Descemet’s membrane complex thickness divided by central corneal thickness multiplied by 33, further compared endothelial/Descemet’s membrane complex thickness with central corneal thickness.

Results:

Endothelial/Descemet’s membrane complex thickness, central corneal thickness, and Descemet’s rejection index were all able to differentiate between clear and rejected corneal grafts (p < 0.0001, p = 0.001, and p = 0.012, respectively). Endothelial cell density and coefficient of variation did not correlate with the clinical status (p = 0.054 and p = 0.102, respectively). Endothelial/Descemet’s membrane complex thickness had the largest area under the curve using receiver operating characteristic curves (p < 0.0001). Endothelial/Descemet’s membrane complex thickness had a sensitivity of 86% and specificity of 81% with a cutoff value of >16.0 µm (p < 0.0001). The sensitivity and specificity of endothelial cell density were both 71% with a cutoff value of ⩽897 cells/mm² (p = 0.053). There was a high correlation between endothelial/Descemet’s membrane complex thickness and both Descemet’s rejection index and central corneal thickness (p < 0.0001).

Conclusion:

Endothelial/Descemet’s membrane complex thickness measured by high-definition anterior segment optical coherence tomography is a useful parameter for the diagnosis of corneal graft rejection. The diagnostic performance of endothelial/Descemet’s membrane complex thickness was significantly better than that of endothelial cell density and central corneal thickness. Endothelial cell density and the coefficient of variation were unable to diagnose corneal graft rejection in our cross-sectional study.

Wasp sting of the cornea

Purpose

Many treatments, such as conservative management or penetrating keratoplasty, exist for corneal wasp sting. Here, we report a case of paper wasp sting of the cornea treated by anterior chamber wash immediately following admission, which soon resolved the inflammation.

Case

A healthy 9-year-old boy who had been stung by a paper wasp on his left eye 2 days prior to presentation at Dokkyo Medical University Saitama Medical Center was found to have corneal opacity accompanied by ciliary injection. The boy had difficulty opening his left eye due to pain. His left corneal endothelial cell density was 2,789 cells/mm², which was relatively lesser than that in the right eye. We diagnosed a paper wasp sting of the cornea based on both the patient’s clinical findings and sting history. The anterior chamber was promptly irrigated using a balanced salt solution; the inflammation resolved in a few hours, and the patient could open his left eye easily the following day. One day after the operation, the visual acuity improved to 1.2, and only slight corneal opacity remained at the original wasp sting site.

Conclusion

The positive outcome of the current case suggested that anterior chamber irrigation leads to rapid resolution of the inflammation.

Predictive Factors for Clinical Outcomes after Primary Descemet's Membrane Endothelial Keratoplasty for Fuchs' Endothelial Dystrophy

PURPOSE

The purpose of this study is to identify predictors for the best-corrected visual acuity (BCVA), central corneal thickness (CCT), and the endothelial cell density (ECD) after primary Descemet's membrane endothelial keratoplasty (DMEK).

METHODS

In a prospective observational study, 108 eyes with Fuchs' endothelial dystrophy underwent a primary DMEK. Preoperative data, histologic parameters from host's Descemet's membrane, and follow-up data of the first eye were analyzed in regard to BCVA, CCT, and ECD, 12 months after surgery.

RESULTS

Overall, 12 months postoperative, the BCVA improved to 0.11 ± 0.11 logMAR, the CCT declined to 529 ± 42 µm, and the ECD measured 1675 ± 418 cells/mm². A significant influence of the preoperative CCT on postoperative BCVAs and CCTs was observed (r = 0.299, p = 0.014 and r = 0.507, p < 0.001, respectively). Especially eyes with a CCT <625 µm demonstrated a better BCVA (0.05 ± 0.07 logMAR) than eyes with a CCT ≥625 µm (0.13 ± 0.11 logMAR, p = 0.002). Furthermore, the identification of eyes with an early visual restitution was possible by considering follow-up data of the first eye. A preoperative CCT ≥625 µm was also sensitive to identify eyes with a persistent corneal swelling. The anterior banded layer thickness, which was obtained histologically, correlated to the preoperative CCT and the frequency of graft detachments (r = 0.601, p = 0.023 and r = 0.652, p = 0.041, respectively). Furthermore, a graft's baseline ECD ≤2100 cells/mm² was found to be a risk factor for an ECD deterioration under 1000 cells/mm² (1.8% vs. 15.8%, p = 0.020).

CONCLUSIONS

Simple clinical parameters, such as the preoperative CCT, the course of visual restitution of the first eye, and the graft's baseline ECD, are efficient predictors for relevant outcome parameters after DMEK and therefore may be used for stratification. Furthermore, our findings indicate that a DMEK should be performed in eyes with Fuchs' endothelial corneal dystrophy, if possible, before the CCT exceeds 625 µm to maintain good clinical results.

Corneal integrity and thickness of central fovea after phacoemulsification surgery in diabetic and nondiabetic cataract patients

INTRODUCTION

Here we intended to investigate the changes in corneal endothelial cells and foveal thickness after phacoemulsification surgery on the eyes of diabetic and non-diabetic cataract patients.

MATERIAL AND METHODS

A total of 120 cataract patients who were scheduled for phacoemulsification surgery and intraocular lens implantation were recruited and divided into 2 categories according to the diagnosis of diabetes mellitus. Changes in integrity, endothelial cell density (ECD), coefficient of variation (CV), percentage of hexagonal cells (PHC), central corneal thickness (CCT), and central foveal thickness (CFT) were all recorded at preoperative day 1 and postoperative day 3, 1 week, 1 month, 3 months and 6 months.

RESULTS

None of the recorded variables showed any difference between the nondiabetic and diabetic groups before surgery (p > 0.05). During the postoperative 6 months, ECD and PHC decreased and CV increased in both groups (all p_time < 0.05), whereas CCT and CFT fluctuated in both groups significantly (both p_time < 0.05), with their individual peaks at postoperative 1 week in the diabetic group. The groups differed significantly in ECD, PHC, and CV at each time point postoperatively (all p_group < 0.05). Furthermore, the diabetic group had improved CFT during the postoperative 1 month and higher CCT during the 6 months postoperatively than the nondiabetic group (all p_group < 0.05). The time and group interactions were significant for ECD, CV, PHC, CCT and CFT (all p_{group × time} < 0.05).

CONCLUSIONS

The diabetic group had more changes in corneal endothelial cells and foveal thickness than the nondiabetic group postoperatively.

[Objective assessment of donor material for penetrating corneal transplantation]

Reliable suitability evaluation of donor material is the crucial issue of penetrating corneal transplantation. The main parameter to be considered is endothelial cell density (ECD). However, when it comes to practice, one has to admit significant variation in ECD readings of cadaver corneas obtained by different methods.

AIM

to investigate discrepancies in ECD measurements and to define objective criteria for the evaluation of a donor cornea before full-thickness grafting.

MATERIAL AND METHODS

In a hundred cadaver eyes, discrepancies in ECD measurements by different methods (specular microscopy, confocal microscopy, and keratoanalyzer) were studied and objective evaluation criteria developed along with an optimal algorithm of pretransplantation assessment. Digital fluorescence microscopy was chosen as the reference method.

RESULTS

It has been established that a triple measurement average obtained with any of the tested methods is informative enough as to the state of the donor cornea.

CONCLUSION

The highest ECD values were obtained with specular microscopy, the lowest - with confocal microscopy. For reliable evaluation of donor corneas, we recommend that the average of a triple ECD measurement be taken using one of the mentioned methods.

Endothelial Wound Repair of the Organ-Cultured Porcine Corneas

PURPOSE

To assess whether injured porcine endothelium of small and large corneoscleral disc differ in its reparative/regenerative capacity under various conditions of organ culture storage.

MATERIAL AND METHODS

166 paired porcine corneas were trephined to obtain tissues with diameter 12.0 mm and 17.5 mm (with area neighboring endothelial periphery). In tested discs, central endothelium was mechanically wounded. Density of live endothelial cells (LECD), percentage of dead cells (%DC), coefficient of variation and cell hexagonality were assessed in central and paracentral endothelium following 5- or 9-day incubation in medium with 2% or 10% fetal bovine serum. The parameters were assessed also in fresh and intact cultured discs. Dead endothelial cells (EC) were visualized by trypan blue, cell borders by Alizarin Red S dye. Endothelial imprints were immunoassayed for the proliferation marker Ki-67 and the nucleolar marker fibrillarin.

RESULTS

In fresh corneas, the LECD/mm² (mean ± standard deviation) were 3998.0 ± 215.4 (central area) and 3888.2 ± 363.1 (paracentral area). Only the length of storage had significant effect on wound repair. Lesion was repaired partially after 5-day and fully after 9-day cultivation. After 9-day storage in medium with 10% serum, the mean LECD detected in small discs were 2409.4 ± 881.8 (central area) and 3949.5 ± 275.5 (paracentral area) and in large discs the mean LECD were 2555.0 ± 347.0 (central area) and 4007.5 ± 261.2 (paracentral area). Ki-67 showed cell proliferation associated with healing of EC of both large and small corneas.

CONCLUSIONS

The lesions were completely repaired within 9 days of storage. Presence of the area, where stem cells appear to be located, contributes to stimulation of endothelial reparation less than serum concentration and time of culture. Both cell migration and proliferation contribute to the wound repair.

Investigation of importance of the structural parameters of the eyeball and of the technical parameters of cataract surgery on corneal endothelial changes

The aim of the here presented study was to look into the importance of the structural parameters of the eyeball, in relationship with the technical parameters of cataract surgery regarding the corneal endothelial changes made by it. Material and method: The paper refers at a prospective study in which we included eighty-eight consecutive eyes from eighty-six different patients having age-related cataract and a visual acuity of a values less than 0.8 considering best possible correction with it. The patients didn't have other obvious causes for the decreased visual acuity. The patients included in the present study were admitted at the Ophthalmology Department from Bucharest University Emergency Hospital between the month of April 2015 and February 2016 (ten months). Results: When we compared lots A, B with C, in regarding to the decrease of EDC, the results were relatively very similar. We had only one comparison for which we obtained a statistical significance, and that was for cataracts classified as group IV of hardness; here, between the first and the third lot, at seven days postoperatively we obtain p = 0.0472812. Conclusions: The conclusion for the present research was that in regarding cataract phaco-emulsification surgery we obtained a statistical significance when it comes to the destruction of epithelial cells. The results were observed, giving the depth of the anterior chamber, in cataracts classified in subgroup IV of hardness, only between patients who had a small depth of chamber comparing with those who had a large depth of the anterior chamber of the eye. When it comes to patients who had severe cataracts and small ACD, we need to attract more attention when the surgeon performs the maneuver and to keep an eye on the use of the adhesives which has viscoelastic in order to obtain additional corneal protection. Abbreviations: ACD = anterior chamber depth; ECD = endothelial cell density, EPT = effective time of phacoemulsification.

Posterior chamber phakic intraocular lens implantation: comparative, multicentre study in 351 eyes with low-to-moderate or high myopia

AIM

To compare the clinical outcomes of posterior chamber phakic intraocular lens implantation with a central hole (Hole Implantable Collamer Lens (ICL), STAAR Surgical) for low-to-moderate myopia and for high myopia.

METHODS

This multicentre retrospective case series comprised 351 eyes of 351 consecutive patients undergoing ICL implantation. Eyes were divided into groups based on preoperative degree of myopia: group 1; 57 eyes, manifest spherical equivalent less than -6 dioptres (D), and group 2; 294 eyes, -6 D or more. Safety, efficacy, predictability, stability and adverse events were compared preoperatively; and at 1 day, 1 week and 1, 3, 6 and 12 months postoperatively, RESULTS: Uncorrected and corrected visual acuities were -0.17±0.14 and -0.21±0.10 logMAR in group 1, and -0.16±0.09 and -0.21±0.08 logMAR in group 2, 1 year postoperatively. In groups 1 and 2, 98% and 99% of eyes were within 1.0 D of the targeted correction. Manifest refraction changes of -0.12±0.34 D (group 1) and -0.18±0.43 D (group 2) occurred from 1 day to 1 year. ICL exchanges were necessary in two eyes (0.7%) in group 2. No vision-threatening complications occurred at any time.

CONCLUSIONS

The ICL performed well for the correction of both low-to-moderate myopia and high myopia throughout the 1-year observation period. The clinical outcomes of ICL implantation for low-to-moderate myopia are essentially equivalent to those for high myopia.

Corneal endothelium and central corneal thickness changes in type 2 diabetes mellitus

PURPOSE

This study was conducted to compare the corneal endothelial cell density (ECD), morphological features, and central corneal thickness (CCT) in type 2 diabetes mellitus (DM) with age-matched, nondiabetic control subjects using EM-3000 Specular Microscope.

STUDY DESIGN

This was a prospective, hospital-based, nonrandomized, case-control, observational, and quantitative study.

SUBJECTS AND METHODS

The study included 57 patients (57 eyes) with type 2 DM and 45 control (nondiabetic) subjects (45 eyes). The corneal endothelial structure and CCT were examined in all eyes by noncontact specular microscopy using EM-3000 Specular Microscope. The endothelial structure was studied for ECD, coefficient of variation of cell area (CV), and percentage of hexagonal cells.

RESULTS

The study included 36 eyes without diabetic retinopathy (DR), 14 eyes with nonproliferative DR, and 7 eyes with proliferative DR. There were 26 eyes with a duration of ≤10 years and 31 eyes with a duration of >10 years. Also, there were 24 eyes with HbA_1c ≤7.5% and 33 eyes with HbA_1c >7.5%. ECD was significantly lower in the diabetic cornea than in control group (P=0.014). CV was higher in diabetic cornea (P=0.008). The diabetic cornea group had lower percentage of hexagonal cells than the control group, but the difference was not statistically significant (P=0.603). Also, diabetic cornea was thicker than control group, but not statistically significant (P=0.301).

CONCLUSION

This study documented that type 2 DM causes a significant reduction of ECD and increased CV (polymegathism). Also, diabetic cornea has increased CCT and lower percentage of hexagonal cells than normal subjects, but without statistical significance.

Endothelial cell loss in penetrating keratoplasty, endothelial keratoplasty, and deep anterior lamellar keratoplasty

PURPOSE:

To compare endothelial cell density (ECD) loss rates in penetrating keratoplasty (PKP), Descemet's stripping automated endothelial keratoplasty (DSAEK), and deep anterior lamellar keratoplasty (DALK).

DESIGN:

Single-center, multiple-surgeon, retrospective cohort study.

MATERIALS AND METHODS:

Patients who received PKP, DSAEK, or DALK from 2009 to 2014 were analyzed (68 vs. 38 vs. 11 patients, respectively). We excluded patients with therapeutic PKP or regraft, infection, endothelial rejection, or uncontrolled glaucoma. Only clear grafts and initial ECD more than 1000 cell/mm² were included in the study. The main outcome was ECD loss rate. The follow-up time period was divided into five subgroups: 0–1.5 months, 1.5–6 months, 6–12 months, 12–24 months, and longer than 24 months.

RESULTS:

Average ECD loss rate (cell/mm²/month) declined in all three groups (PKP group: −561.5, −113.2, −36.6, −31.4, and −53.7; DSAEK group: −686.4, −68.3, −21.8, −14.4, and −5.1; DALK group: −576.5, −68, −23.7, 5.9, and 18.3). Although DSAEK group showed faster ECD loss rate in the early postoperative period, it became slower compared to the PKP group within the postoperative 6^th month and demonstrated significant difference within 2 years. No ECD loss developed in the DALK group after the 1^st postoperative year; this was significantly different from the PKP group.

CONCLUSIONS:

Although ECD loss rate in the DSAEK group was initially larger than that in the PKP group, the DSAEK group possessed better long-term endothelial cell survival rate. The DALK group had a lower ECD loss rate than that of the other groups and maintained a stable ECD at 1 year after surgery.

Trabeculectomy with or without Anterior Chamber Maintainer: A Study on Intraocular Pressure, Endothelial Cells, and Central Corneal Thickness

PURPOSE

To compare the impact of trabeculectomy and trabeculectomy with an anterior chamber (AC) maintainer on intraocular pressure (IOP), endothelial cell density (ECD), and central corneal thickness (CCT) in patients with primary open angle glaucoma (POAG).

METHODS

The two groups consisted of 36 (trabeculectomy, Group A) and 42 (trabeculectomy with AC maintainer, Group B) patients with POAG. IOP, CCT, and ECD were measured one day prior to surgery, one month, six months, and 12 months postoperatively.

RESULTS

No complications were observed. The mean decrease of mean IOP from baseline to 12 months was statistically significant for both groups (all p < 0.0001), but more significant in Group B (p = 0.01). ECD decrease was significant in both Groups (all p < 0.01), but more significant in Group A (p < 0.0001). CCT decrease was also greater in Group A (p < 0.0001). The surgical procedure's duration was significantly longer in Group B than in Group A (p < 0.0001).

CONCLUSIONS

Both techniques seem to be effective and safe options for patients with POAG. Using an AC maintainer might add some safety for the ECD and a bit greater IOP reduction; however, the classic technique, which is of less complexity and less time-consuming, has comparable results.

Normal corneal endothelial cell density in Nigerians

Aim

The aim of the study was to describe the corneal endothelial cell density of adults at the MeCure Eye Center and to determine the relationship between age, sex, and corneal endothelial cell density.

Methods

This study was a retrospective study looking at those records of individuals who had undergone specular microscopy or corneal endothelial cell count measurement at the MeCure Eye Center.

Results

The endothelial cell characteristics of 359 healthy eyes of 201 volunteers were studied. The mean corneal endothelial cell density (MCD) was 2,610.26±371.87 cells/mm² (range, 1,484–3,571 cells/mm²). The MCD decreased from 2,860.70 cells/mm² in the 20–30-year age group to 2,493.06 cells/mm² in the >70-year age group, and there was a statistically significant relationship between age and MCD with a P-value of <0.001. There was no statistically significant correlation between sex and corneal endothelial cell density (P=0.45).

Conclusion

This study shows that endothelial cell density in Nigerian eyes is less than that reported in the Japanese, American, and Chinese eyes, and is comparable to that seen in Indian and Malaysian eyes.

Changes in corneal endothelium cell characteristics after cataract surgery with and without use of viscoelastic substances during intraocular lens implantation

PURPOSE

To evaluate whether the use of balanced salt solution (BSS) or an ophthalmic viscoelastic device (OVD) during hydrophilic acrylic intraocular lens (IOL) implantation variously impacts corneal endothelial cell characteristics in eyes undergoing uneventful phacoemulsifications.

METHODS

Prospective nonrandomized observational clinical trial. Patients were assigned either to the BSS plus(®) or to the OVD Z-Celcoat™ group depending on the substance used during IOL implantation. Corneal endothelium cell characteristics were obtained before, 1 week, and 6 weeks after surgery. Intraoperative parameters (eg, surgery time, phacoemulsification energy) were recorded.

RESULTS

Ninety-seven eyes were assigned to the BSS plus and 86 eyes to the Z-Celcoat group. Preoperative corneal endothelium cell density (ECD) and endothelium cell size were 2,506±310 cells/mm(2)/2,433±261 cells/mm(2) and 406±47 µm(2)/416±50 µm(2) (P=0.107/P=0.09). After 1 and 6 weeks, ECD decreased and endothelium cell size increased significantly in both groups (each P<0.001) without significant differences between both groups (each P>0.05). Irrigation-aspiration suction time (30.3±16.6 versus 36.3±14.5 seconds) and overall surgical time (7.2±1.2 versus 8.0±1.4 minutes) were significantly longer in the OVD Z-Celcoat group (each P<0.001). No complications or serious side effects occurred.

CONCLUSION

Implantation of a hydrophilic acrylic IOL under BSS infusion seems to be a useful and faster alternative in experienced hands without generating higher ECD loss rates.