Comparison of Corneal Densitometry Between Penetrating Keratoplasty and Deep Anterior Lamellar Keratoplasty in Keratoconus Patients.

OBJECTIVES

Our aim was to compare corneal densitometry values in keratoconic eyes undergoing deep anterior lamellar keratoplasty with the "big bubble" and manual lamellar dissection techniques, as well as penetrating keratoplasty.

MATERIALS AND METHODS

This retrospective study evaluated the postoperative outcomes of 31 eyes treated with big bubble-deep anterior lamellar keratoplasty, 23 eyes with manual lamellar dissectiondeep anterior lamellar keratoplasty, and 37 eyes with penetrating keratoplasty. Corneal densitometry, best corrected visual acuity, and other corneal tomographic parameters were recorded at 1, 6, 12, and 24 months postoperatively. The groups were compared with respect to the outcomes.

RESULTS

There were no significant differences between the groups with respect to the anterior, central, and total corneal densitometry values at 0 to 2 mm and 2 to 6 mm. At 1 month postoperatively, the densitometric value in the posterior corneal layer of the 0- to 2-mm and 2- and 6-mm corneal zones was higher in the manual lamellar dissection-deep anterior lamellar keratoplasty group than in the big bubble-deep anterior lamellar keratoplasty and penetrating keratoplasty groups (P = .001). At 6, 12, and 24 months, the manual lamellar dissectiondeep anterior lamellar keratoplasty and penetrating keratoplasty groups had similar values in both zones in the posterior layer. The difference between manual lamellar dissection-deep anterior lamellar keratoplasty and big bubble-deep anterior lamellar keratoplasty in both zones in the posterior layer was statistically significant at 6, 12, and 24 months postoperatively (P < .05). The best corrected visual acuity of big bubble-deep anterior lamellar kerat oplasty and penetrating keratoplasty groups was better than that of the manual lamellar dissection-deep anterior lamellar keratoplasty group (P = .047).

CONCLUSIONS

Corneal densitometry values may vary depending on the type of keratoplasty used in keratoconus patients. Higher densitometry values may affect visual quality in keratoplasty patients by decreasing or filtering the light that reaches the retina.