Sutureless Tectonic Mini-Descemet's Stripping Automated Endothelial Keratoplasty (“mini-DSAEK”) for the management of corneal perforations

Purpose To report the outcomes of a new technique, pull-through sutureless ‘mini-DSAEK’, to manage corneal perforations secondary to different aetiologies including trauma, neurotrophic ulcer following penetrating keratoplasty (PK), herpes simplex keratitis and microbial keratitis. Methods In this retrospective case series, we report the clinical outcomes of five cases of sutureless tectonic mini-DSAEK performed in patients presenting with large corneal perforations to Southend University Hospital between November 2019 and October 2020. One corneal perforation was sufficiently peripheral for the tectonic mini-DSAEK graft to be successfully positioned outside of the central visual axis. Four corneal perforations were central or paracentral for which the tectonic grafts involved the visual axis. Results Anterior chambers remained deep and formed with no evidence of leak in all subsequent follow ups in all patients representing 100% tectonic success. All tectonic grafts remained attached except one partially detached graft. One patient underwent uneventful phacoemulsification with intraocular lens implant 8 months after the primary intervention with excellent visual outcome. Two patients underwent two-piece mushroom PK and one patient underwent triple procedure (cataract extraction + intraocular lens + PK) for visual rehabilitation 2–6 months after the primary intervention with good visual outcome. Conclusion Sutureless tectonic pull-through mini-DSAEK is a useful technique in the management of corneal perforations, with a number of advantages compared with conventional techniques.

OCT Application for Sterile Corneal Graft Screening in the Eye Bank

Background and Objective Sterile donor tomography enables the detection of corneal tissues with refractive anomalies. The aim of this study was to determine the curvature and thickness of donor corneas to support proper selection in the eye bank. Methods 704 donor corneas (Klaus Faber Center, LIONS Eye Bank Saar-Lor-Lux, Trier/Westpfalz, in Homburg/Saar) were measured using the anterior segment optical coherence tomograph (AS-OCT) CASIA 2 (Tomey Corp., Nagoya, Japan). The corneoscleral discs were measured in their cell culture flask, which was positioned in a holder on the chin rest of the AS-OCT, after conversion to medium II (with 6% dextran T-500). The measured raw data were analysed and processed in MATLAB (MathWorks Inc., Natick, Massachusetts, USA), after which the refractive power of the steep and flat meridian at the anterior and posterior surface and the central corneal thickness (CCT) of the donor corneas were determined. Results values are expressed as mean x̅ ± standard deviation SD. Results The mean refractive power of the steep/flat meridian at the anterior surface was 45.4 ± 1.8 D/44.0 ± 1.3 D, the corresponding values for the posterior surface were − 6.2 ± 0.3 D/− 5.9 ± 0.2 D, and the mean CCT was 616.3 ± 85.1 µm. Of the 704 (100%) measured donor tissues, 590 (83.8%)/670 (95.2%) donor corneas showed no anomaly beyond respectively x̅ ± 2 SD/x̅ ± 3 SD among the 5 examined parameters. 72 (10.3%)/23 (3.3%) donor corneas had only 1 anomaly, 26 (3.7%)/10 (1.4%) had 2 anomalies, 10 (1.4%)/1 (0.1%), 3 anomalies, 5 (0.7%)/0 (0.0%), 4 anomalies, and 1 (0.1%)/0 (0.0%), 5 anomalies. Conclusions AS-OCT provides an objective and sterile screening method to identify corneal tissues with curvature anomalies in order to further optimise donor selection in the eye bank. To avoid postoperative refractive surprises, donor corneas with a total refractive power that deviates > ± 3 SD from the mean should not be used for penetrating or anterior lamellar keratoplasty, but may be suitable for posterior lamellar keratoplasty (DMEK or DSAEK). In the future, sterile donor tomography could enable: (1) the harmonisation of donor and recipient tomography, which may minimise residual astigmatism for a particular donor-recipient pair; and (2) the improvement of IOL power calculation in a classical triple procedure by means of regression analysis between pre- and postoperative total refractive power of corneal grafts.

Impact of Pre- and Intraoperative Factors on Endothelial Cell Density in the Early and Late Stage after Penetrating Keratoplasty

Aim This retrospective investigated the impact of donor age, recipient age, donor endothelial cell density, vis-à-tergo, and additional intraoperative lens exchange (triple-procedure) on overall early and late phase postoperative endothelial cell density (ECD) following penetrating keratoplasty (PKP) in various diagnosis groups. Patients and Methods In 590 cases with diagnosed keratoconus (KC), Fuchs dystrophy (FD) and herpes simplex virus infection (HSV) who underwent PKP or triple surgery, the ECD in cells/mm2 was analysed, both preoperatively, with all-sutures-in (early postoperative stage), and after last suture removal. The factors were tested by Mann-Whitney U-test, correlation analysis and linear regression analysis. Outcome Correlation analysis demonstrated a weak negative correlation between the patientʼs ECD and donor age (early postoperative stage: r = − 0.25, p < 0.001; after last suture removal: r = − 0.16; p = 0.003). Regression analysis revealed that donor age did not impact postoperative patient ECD. There was a weak negative correlation between postoperative ECD and recipient age (early postoperative stage: r = − 0.31, p < 0.001; after last suture removal: r = − 0.34, p < 0.001). Regression analysis confirmed the negative impact of recipient age on patient ECD (early postoperative stage: β = − 13.2, p = 0.001; after last suture removal: β = − 4.6, p < 0.001). Correlation analysis determined a weak positive correlation between postoperative ECD and donor endothelial cell density (early postoperative stage: r = 0.37, p < 0.001; after last suture removal: r = 0.32, p < 0.001). Regression analysis also determined that donor endothelial cell density had a positive impact on postoperative ECD following last suture removal (β = 0.4, p < 0.001). Vis-à-tergo and additional lens exchange (triple procedure) had no significant effect on postoperative ECD (p > 0.05). This was also confirmed by the results of the regression analysis after last suture removal. Conclusion Recipient age and donor endothelial cell density have a significant impact on postoperative ECD following PKP. Not all of the statistical tests proved donor age to be a significant influencing factor. Vis-à-tergo and additional lens exchange (triple procedure) had no significant effect on postoperative ECD following PKP.

A STUDY ON ENDOTHELIAL CELL LOSS AFTER OPTICAL KERATOPLASTY- A RETROSPECTIVE STUDY IN A TERTIARY EYE CARE CENTRE IN CHENNA

Aim: a study of endothelial cell loss after optical keratoplasty in 50 patients in a tertiary care centre in Chennai. Materials and Methods: A retrospective study was carried out on 50 patients who underwent optical keratoplasty in a tertiary care centre in Chennai. 50 patients in the age group 11-80 were included in this study. Postoperatively they were periodically followed up regarding graft clarity, presence of vascularisation, vision and endothelial cell count. During follow up presence of any complications were assessed and recorded. At the end of 6 months, there was an average of 37.5% loss of endothelial ce Observation And Results: lls in PKP and 44.5% in LKPs and 38.6% in Triple procedure. At the end of one month, patients who had repeat Keratoplasty for failed graft had more loss (20.1%) whereas at the end of 6 months, Pseudophakic Bullous Keratopathy patients showed more loss (49.4%). These indicate migration of endothelial cells along a density gradient after keratoplasty. Overall there is continuous loss of endothel Conclusion: ial cells in all cases of Keratoplasty regardless of the indication for keratoplasty and the type of keratoplasty. Even in cases of clear grafts, there is a continuous loss of endothelial cells. It has been reported that chronic subclinical rejection, chronic low-level inammation or continued interaction between the donor endothelium and a healthy recipient endothelium could explain the greater cell loss

Vergleich der sterilen Spendertomographie in der Hornhautbank mit der Tomographie des Transplantates nach perforierender Keratoplastik

Zusammenfassung Hintergrund Seit 2018 verwenden wir die sterile Spendertomographie in der Hornhautbank routinemäßig, um refraktive Überraschungen nach Keratoplastik zu vermeiden. Ziel dieser Studie war es, Spendertomographieparameter mit Tomographieparametern des Transplantates nach perforierender Keratoplastik (PKP) zu vergleichen. Methoden Diese Studie umfasste 193 Spendergewebe der Hornhautbank, die für eine PKP verwendet wurden (Transplantatdurchmesser 8,2 ± 0,7 mm). Messungen wurden mit dem optischen Kohärenztomographen des vorderen Augenabschnittes (VAA-OCT) Casia 2 (Tomey Corp., Nagoya, Japan) präoperativ sowie postoperativ nach 5 ± 4 Monaten bei liegenden Fäden und nach 22 ± 4 Monaten ohne Fäden durchgeführt. Post- und präoperative Werte wurden mithilfe des Wilcoxon-Rangsummentests verglichen. Ergebnisse Postoperativ, bei liegenden (bzw. ohne) Fäden, war die Brechkraft (P) der Hornhautvorderfläche (v) im steilen Meridian (S) (PvS) unverändert (−0,2 dpt; p = 0,78) (um 2,7 dpt größer [p < 0,01]) und im flachen Meridian (F) (PvF) um 4,5 dpt (2,8 dpt) niedriger (p < 0,01) im Vergleich zu den Spendertomographiewerten. Der Astigmatismus (v) war um 4,3 dpt (5,4 dpt) größer (p < 0,01). An der Rückfläche (r) war PrS um 0,9 dpt (0,9 dpt) und PrF um 0,3 dpt (p < 0,01) (0,1 dpt [p = 0,42]) kleiner, während der Astigmatismus (r) um 0,7 dpt (0,9 dpt) größer war (p < 0,01). Die zentrale Hornhautdicke war um 55,7 μm (p < 0,01) (27,5 µm [p = 0,01]) kleiner. Die Gesamtbrechkraft ohne Fäden änderte sich nicht signifikant im Vergleich zur Hornhautbankmessung. Schlussfolgerung Zentrale Hornhautdicke, Brechkraft (P) und Astigmatismus veränderten sich postoperativ im Vergleich zu den Spendertomographiewerten, mit Ausnahme von P im steilen Meridian der Vorderfläche bei liegenden Fäden sowie von P im flachen Meridian der Rückfläche nach Entfernung aller Fäden. Die Gesamtbrechkraft ohne Fäden ändert sich allerdings nicht signifikant. Diese Informationen könnten für eine Verbesserung der Kunstlinsenberechnung bei klassischer „Triple-Procedure“ von Bedeutung sein.