Abstract
Purpose: :
How to evaluate a new model of penetrating keratoplasty assisted by femtosecond laser: a decagonal shaped cut in a prospective study with patients undergoing full-thickness corneal transplant surgery in department of Ophthalmology of Mediterranean University II, Marseille, France
Methods: :
16 eyes from 16 patients were included (age average: 71.4 years): Mainly 9 Fuchs’ dystrophy, 4 pseudophakic bullous keratoplasty. Others were keratoconus, corneal amylosis and corneal scar. A Femtec laser (20/10 PerfectVision; GmbH, Heidelberg, Germany) realised a decagonal shape penetrating trephination for donor and recipient. 4 patients also benefited cataract surgery or intraocular lens change. All patients were controlled after surgery, after one week, 1, 3, 6 and 9 months and one year. Were then performed: a clinical exam with visual outcome, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD) and pachymetry, corneal topography using an OPD Scan and an anterior optical coherence tomography (OCT) to study the quality of wound and suture. Scanning electron microscopy was performed on patient’s cornea after surgery. All patients reviewed and signed an informed consent for surgery form.
Results: :
The post-operative follow-up ranged from 3 months to one year with an average of 6.75 months ± 3.5. All patients benefited a high quality of cutting without tissular bridges’ problem. No wound leakage. At the last postoperative examination, mean UCVA was 20/54 [20/100; 20/32] and mean BSCVA was 20/33 [20/50; 20/25] with a mean spherical manifest refraction of -0.68 D ± 1.8 and mean cylinder of 2 D ± 1.4. Difference between preoperative and postoperative visual acuity is statistically significant for UCVA p=0.0019 and BSCVA p=0.001. Mean corneal astigmatism obtained from topographic "sim K" measurements (dK with OPD scan, Nidek, Japan) was 3.02 ± 1.35. Irregular astigmatism values were high with a mean SRI 1.39 and SAI 1.33. Potential visual acuity (OPD scan) was 20/37. Pachymetry average was 513 µm and mean ECD was 1560 cells/mm² with 31% cell loss density after surgery. OCT images showed a high quality of wound configuration with minor gap between donor and recipient.
Conclusions: :
Femtosecond laser allows a new surgical decagonal shape with a safe and predicable cutting. First results look quite promising with quicker visual recovery and good BSCVA. Additional studies are necessary to precisely quantify the irregular astigmatism and optical aberrations induced.
Keywords: cornea: clinical science • laser • astigmatism