Thinning rate over 24 months in ultrathin DSAEK.

AIM: To describe the changes in corneal graft thickness following ultrathin Descemet's Stripping Automated Endothelial Keratoplasty (UT-DSAEK) comparing pre- and postoperative values over a 24-month period. METHODS: In this retrospective single-center case series, patients who received eye bank-prepared tissues for UT-DSAEK surgery were included. Preoperative and postoperative graft thickness measurements were determined in the eye bank and in clinic using anterior segment optical coherence tomography (AS-OCT) images. Graft thickness measurements and their percentage change between preoperative values and values at 1 day, 1 week and 1, 6, 12, 24 months were calculated. RESULTS: In total, 47 eyes of 47 patients with a mean age of 69 ± 11 years (29 males) were included. Twnty-three patients had Fuchs' endothelial dystrophy (49%) and the remaining 24 had pseudophakic bullous keratopathy (51%). In total, 29/47 eyes underwent UT-DSAEK alone (62%) and 18/47 received combined cataract surgery as a triple procedure (38%). Preoperative donor graft thickness was 92 ± 28 µm. Compared to preoperative values, where graft thickness increased to 194 ± 101.3 µm at 1 day, 151.1 ± 71.4 µm at 1 week, and 108.4 ± 52.5 µm at 1 month. Graft thickness continued to gradually decrease over time until 6 months (91.7 ± 33.6 µm), and then plateaued at 12 months (83.9 ± 25.0 µm), showing minimal changes at 2 years (101.4 ± 37.5 µm). CONCLUSION: Preoperative DSAEK graft thickness measurements as reported by the eye bank are a valid approximation of DSAEK graft thickness at 6 months after surgery and these measurements tend to stabilize over time up to 2 years after surgery.

Eye bank versus surgeon prepared DMEK tissues: influence on adhesion and re-bubbling rate.

AIM: To investigate the difference in adhesion and rebubbling rate between eye bank and surgeon prepared Descemet membrane endothelial keratoplasty (DMEK) tissues. METHODS: Laboratory and clinical retrospective comparative interventional case series. Research corneal tissues were obtained for laboratory investigation. The clinical study involved patients with endothelial dysfunction who underwent DMEK surgery and tamponade with air. Tissues were stripped using a standard DMEK stripping technique (SCUBA) and shipped as prestripped or loaded in a 2.2 intra-ocular lens cartridge with endothelium facing inwards (preloaded) before transporting from the eye bank to the surgeon. For surgeon prepared tissues, all the grafts were stripped in the theatre and transplanted or stripped in the laboratory and tested immediately. Adhesion force and elastic modulus were measured in the centre and mid-periphery in a laboratory ex vivo investigation using atomic force microscopy, while rebubbling rates were recorded in the clinical study. RESULTS: There was no difference in endothelial cell viability between surgeon or eye bank prepared tissue. Surgeon-stripped DMEK grafts in the laboratory investigation showed significantly higher elastic modulus and adhesion force compared to prestripped and preloaded tissues (p<0.0001). In the clinical data, rebubbling rates of 48%, 40% and 15% were observed in preloaded, prestripped and surgeon-stripped DMEK grafts, respectively. Rebubbling rates were significantly associated with combined cataract surgery (p=0.009) and with time from harvesting the graft to the surgery (p=0.02). CONCLUSIONS: Decreased adhesion forces and elastic modulus in eye bank prepared tissues may contribute to increased rebubbling rates.

Investigating the Effects of Coenzyme Q10 on Human Corneal Endothelial Cells.

PURPOSE: To investigate the effects of Coenzyme Q10 (CoQ10) treatment on immortalised human corneal endothelial cells (HCEC-12). METHODS: HCEC-12 cells were cultured in different concentrations of CoQ10 (0.1%, 0.2%, 0.5%, and 1.0%) and analysed using live/dead staining assay to determine appropriate concentration for subsequent experiments. Cells were pretreated with CoQ10 before inducing apoptosis by ethanol (EtOH) treatment for 30 seconds which was followed by posttreatment with CoQ10. Viable, apoptotic, and dead cell proportions were analysed using Annexin V-FITC immunofluorescence staining. Mitochondrial intensity and respiratory functions were also investigated using MitoTracker staining and a Seahorse XFe24 analyser, respectively. Results were compared to a positive control for apoptosis. The experiments were carried out in triplicates. Graphpad prism software was used for statistical analysis where p < 0.05 was deemed statistically significant. RESULTS: CoQ10 treatment at 0.5% and 1% showed 92% and 30% viable cells compared with 0.1% and 0.2% that showed 96% and 94% viable cells, respectively (p=0.0562). 0.1% and 0.2% concentrations were, thus, used for subsequent experiments. Annexin V-FITC apoptotic analysis showed 2% at 0.1% and 3% at 0.2% of apoptotic cells (p=0.0824). Mitochondrial respiratory function and mitochondrial intensity increased in apoptotic cells following 0.1% CoQ10 treatment. CONCLUSION: 0.1% CoQ10 was found optimal for reducing apoptosis and increasing metabolic activity on human corneal endothelial cell line. These results support the need for further ex vivo studies to investigate the safety profile of CoQ10 as an antiapoptotic agent for human corneal endothelium.

Rebubbling rate in preloaded versus surgeon prepared DSAEK.

PURPOSE: To compare the clinical outcomes of eye bank preloaded Descemet stripping automated endothelial keratoplasty (DSAEK) grafts and surgeon prepared. METHODS: In this retrospective study, the data were obtained from two groups (a) surgeon cut DSAEK where tissue was prepared by the surgeon immediately before surgery, and (b) preloaded DSAEK tissue shipped to the surgeon after preparation by the eye bank. Standard DSAEK preparations using Moria microkeratome with single pass method were performed. For the tissues prepared by the eye banks, they were preloaded in an iGlide device and shipped in transport media. Standard DSAEK surgery using bimanual pull-through technique was performed for all the grafts. Air was used as a tamponade. Main outcome measures included best corrected visual acuity (BCVA) and rebubbling rate. RESULT: Out of 107 eyes of 101 patients that underwent DSAEK surgery, 33 tissues were prepared by the surgeon (sc-DSAEK), while 74 were prepared by the eye bank (pl-DSAEK). sc-DSAEK showed a rebubbling rate of 9.1%, compared to the 16.2% for the preloaded DSAEK (p = 0.11). There was no statistical difference in postoperative BCVA between the two groups. Logistic regression analysis showed no association between detachment rate and cataract surgery, graft preparation method, graft diameter and reason for graft. CONCLUSION: Preloaded grafts have similar rebubbling rate and visual acuity achieved compared with surgeon prepared grafts.

Clinical outcomes of pre-loaded ultra-thin DSAEK and pre-loaded DMEK.

OBJECTIVE: To compare clinical outcomes and complications between pre-loaded ultra-thin Descemet stripping automated endothelialkeratoplasty (pl-UT-DSAEK) and pre-loaded Descemet membrane endothelial keratoplasty (pl-DMEK). METHODS AND ANALYSIS: Comparative study in patients with endothelial dysfunction associated with Fuchs endothelial corneal dystrophy and pseudophakic bullous keratopathy who underwent pl-UT-DSAEK or pl-DMEK transplants. For both groups, the tissues were pre-loaded at the Fondazione Banca degli Occhi del Veneto (Venice, Italy) and shipped to The Royal Liverpool University Hospital (Liverpool, UK). Best corrected visual acuity (BCVA) and re-bubbling rates were the main outcome measures. RESULTS: 56 eyes of 56 patients were included. 31 received pl-UT-DSAEK and 25 received pl-DMEK. At 12 months, BCVA (LogMAR) was significantly better for pl-DMEK (0.17±0.20 LogMAR) compared with pl-UT-DSAEK (0.37±0.37 LogMAR, p<0.01). The percentage of people that achieved ≥20/30 was significantly higher in the pl-DMEK group. The rate of re-bubbling, however, was significantly higher for pl-DMEK (44.0%) than for Pl-UT-DSAEK (12.9%), p<0.01. CONCLUSION: Pl-DMEK offers better BCVA than pl-UT-DSAEK. The higher re-bubbling rate associated with pre-loaded DMEK is of concern.