Comparative study of three methods of evaluation of the corneal endothelium in pseudophakic patients: fluorophotometry, specular microscopy and pachymetry.

BACKGROUND

At present, three techniques, based on different methodological suppositions, are used indiscriminately for the study of the corneal endothelium. These are pachymetry, specular microscopy and fluorophotometry. The purpose of this work was to study the corneal endothelium of pseudophakic patients with the three techniques mentioned. On the basis of the results obtained, we discuss the relations between them and their practical clinical utility.

METHODS

One hundred and fourteen eyes of pseudophakic patients were studied using the three corneal endothelial evaluation techniques, both in the immediate pre-operative period and 1 year after surgery.

RESULTS

Statistically significant relations exist between the number of endothelial cells and the fluorophotometric endothelial permeability coefficient (Kc.ca) 12 months after surgery, between the increase in corneal thickness in the first week after the operation and the Kc.ca 12 months after surgery, and between fluctuations of the corneal thickness greater than 30 microns and both the endothelial cell count and the Kc.ca 12 months after surgery. There are no significant relationships among the pre-operative values obtained with the three methods.

CONCLUSION

The results show how the parameters measured with the functional techniques (fluorophotometry, pachymetry) generally become normal after the surgical trauma, while the endothelial cell count remains irreversibly altered. The results obtained with different techniques are more closely related in more pathological endothelia, while no relation among them are shown in the study of normal endothelia. It is also shown how pachymetry is a good clinical predictor, in the immediate post-operative period, of the long-term status of the corneal endothelium.