Deep anterior lamellar keratoplasty using precut anterior lamellar cap for herpes simplex keratitis: a long-term follow-up study

Purpose

To evaluate the feasibility, safety and efficacy of deep anterior lamellar keratoplasty (DALK) using precut anterior lamellar cap (ALC) for patients with herpes simplex keratitis.

Methods

In this single-centre retrospective study, 48 consecutive patients with herpes simplex keratitis and having undergone DALK using either big bubble technique or manual lamellar dissection, between February 2009 and March 2010, were included. Each patient received DALK using either a precut ALC or a full-thickness stroma (FTS), and completed a minimum follow-up time of 36 months.

Results

There were no significant differences in the age, sex, eyes and sizes of trephination between two groups. Postoperative best spectacle-corrected visual acuity of 0.3 logarithm of the minimum angle of resolution or better at the last follow-up visit was achieved in 74.1% of eyes in the FTS group and 71.4% in the ALC group (p=0.84). The mean central corneal thickness and corneal volume were significantly higher in the FTS group (550.7±34.3 µm and 61.21±4.12 mm³) than the ALC group (393±45.7 µm and 54.68±4.55 mm³; p<0.0001). The mean simulated keratometry value was lower in the ALC group as compared with the FTS group (p=0.03; 44.51±2.60 vs 46.06±2.31). There was no difference in biomechanical behaviour of two types of corneal tissues after DALK. Corneal curvature remained stable in the ALC group, and no signs of corneal ectasia were observed during follow-ups.

Conclusions

DALK using precut ALC should be considered as a selective surgical approach. A postoperative subnormal central corneal thickness of about 400 µm would not influence corneal curvature and refractive status.