Posters

Predictability of visual acuity after Descemet's stripping endothelial keratoplasty

Poster Details

First Author: M. Tsatsos UNITED KINGDOM

Co Author(s):    C. MacGregor   A. Turnbull   P. Hossain   D. Anderson           

Abstract Details

Purpose:

To assess the predictability of visual outcome after Descemet stripping endothelial keratoplasty.

Setting:

Dorchester County Hospital NHS Foundation Trust/Southampton University Hospital

Methods:

34 Consecutive patients undergoing manually-dissected DSEK for Fuchs’ endothelial dystrophy or bullous keratopathy were prospectively studied. Patients with vision-limiting ocular comorbidities were excluded. Central graft and total corneal thicknesses were measured using anterior segment optical coherence tomography at 1 day, 1 week, 1 month, 3 months, 6months and 12 months postoperatively. BCVA logMAR visual acuity was also recorded at each time-point. Correlations between graft thickness, total corneal thickness and visual acuity were calculated, and trends were analysed to determine the extent to which the postoperative course could be predicted.

Results:

Graft thickness reduced significantly between 1 day and 1 month postoperatively (p<0.05). After the first month, graft thickness continued to reduce but at a much slower rate. Statistically significant (p<0.01) positive (r 0.619) relationships between BCVA and GT were seen. Graft thickness alone explains 46.5% of the variability of logMar. The addition of time evolution increases the predictive ability to 54.4%. Diagnosis shows a significant effect until day 90 with Fuchs having better BCVA compared to Bullous keratopathy (p=0.039) but shows no significant difference after that. The overall inclusion of the diagnosis (FED or PBK) and type of operation (primary, combined or redo) variables invokes a highly non-significant improvement in the model's performance (p=0.524)

Conclusions:

As graft thickness increases, visual acuity worsens in a predictable fashion. The standardized coefficients demonstrate the relative importance of graft thickness, with graft thickness accounting for 46.5% of the total variability in visual acuity. A secondary finding is while patients at 365 days postoperatively have significantly better visual acuity than at 90 days postoperatively, there was no significant difference in acuity between 90 and 180 days. This confirms that for many patients, visual rehabilitation continues well beyond the first few postoperative months. Fuchs patients have better VA compared to Bullous until 3 months postoperatively but show no difference after that.

Financial Disclosure:

NONE