Long Term Results of Femtosecond Laser-Assisted Sutureless Anterior Lamellar Keratoplasty “FALK” Mohamed Abou Shousha, MD, Sonia H. Yoo, MD, William Feuer, MS, Carol L. Karp, MD, Terrence P. O'Brien, MD, William W. Culbertson, MD, Eduardo Alfonso, MD Financial Disclosure Sonia H. Yoo with Abbott (L) and Carl Zeiss Meditec (L) and William W. Culbertson with Abbott (L). Other authors have no financial interest in the subject matter of this poster.

Purpose To evaluate the long term results of Femtosecond Laser-Assisted Sutureless Anterior Lamellar Keratoplasty (FALK) for anterior corneal pathologies.

Methods  Retrospective, non-comparative, interventional case series  13 eyes of 13 consecutive patients who underwent FALK for anterior corneal pathologies.  Main Outcome Measures:  Preoperative and postoperative best spectacle-corrected visual acuity (BSCVA)  Manifest refraction  Postoperative complications  Need for adjunctive surgery. Methods

 Follow-up ranged from 12 to 60 months (mean= 29 months).  BSCVA was significantly improved over preoperative values at the 12, 18, 24 and 36 month visits. Results: BSCVA

Methods  % of patients achieved BSCVA > 20/30 :  54% at the 12 month visit.  50% at the 18 month visit.  33% at the 24 month visit.  The BSCVA of the eye that completed the 60 month visit was 20/50.  BSCVA > 20/50 was recorded for all patients at all examination times, except for one eye owing to a preexisting cataract. Results: BSCVA

Methods  Patients achieved a mean gain of 5 lines of BSCVA at the 6, 12, 18 and 24 months visit, 4 lines at the 36 month visit and 6 lines at the 60 month visit.  At a mean of 5 weeks postoperatively, 83.3% of patients achieved BSCVA within 2 lines of that recorded at the 24 month visit. Results: BSCVA

Methods  At the 12 month visit, mean spherical equivalent and refractive astigmatism were -0.4 diopters (D) and 2.2 D, respectively, with no significant shift from preoperative values or values recorded along different follow-up visits. Results: Manifest Refraction PreoperativePostoperative 6m 12 m 18 m 24m 36m60m Number of Eyes Mean spherical equivalent (diopters) -1.4 ±2.3 D-1.2 ±3.2 D-0.4 ±3.4 D-0. 1 ±3 D0.17 ±2.8 D0.2 ±2.8 D-3.8 Mean Cylinder (diopters) 1.8 ± ± ± ± ± ±1.22 Data presented as mean ±SD [range] m: months

Methods 1.Phototherapeutic keratectomy :  2 eyes at the 4 th and 10 th postoperative month 2.Photorefractive Keratectomy:  2 eyes at the 4 th and 16 th postoperative month. 3.Cataract extraction:  1 eye at the 24 th postoperative month 1.Phototherapeutic keratectomy :  2 eyes at the 4 th and 10 th postoperative month 2.Photorefractive Keratectomy:  2 eyes at the 4 th and 16 th postoperative month. 3.Cataract extraction:  1 eye at the 24 th postoperative month Results: Adjunctive Surgeries  Preoperative slit lamp image (a) shows a visually significant central corneal scar.  The depth of the scar that was used to plan the femtosecond lamellar cut was determined from the optical coherence tomography (OCT) image (c).  Postoperative slit lamp image (b) discloses the presence of a residual scar. Thickness of the residual scar was measured from OCT image (d).  PTK to the stromal bed was done 4 months postoperatively and resulted in a gain of 2 BSCVA lines.  Post- PTK OCT image (e) shows a significant reduction of the stromal scar tissue and a thin residual stromal bed of only 171 µm.  The patient shows stability of BSCVA and manifest refraction up till the end of a follow up period of 35 months.

Methods  Residual scar (6 eyes)  Immediate postoperative stromal bed interface haze (3 eyes)  Persistent dry eye (3 eyes)  Anisometropia (2 eyes)  High postoperative astigmatism (>5 D) (2 eyes)  Surface Haze after adjunctive PRK (1 eye)  Suspicious ectasia (1 eye)  Immediate postoperative recurrence of pathology (1 eye)  Epithelial ingrowth (1 eye)  Residual scar (6 eyes)  Immediate postoperative stromal bed interface haze (3 eyes)  Persistent dry eye (3 eyes)  Anisometropia (2 eyes)  High postoperative astigmatism (>5 D) (2 eyes)  Surface Haze after adjunctive PRK (1 eye)  Suspicious ectasia (1 eye)  Immediate postoperative recurrence of pathology (1 eye)  Epithelial ingrowth (1 eye) Results: Complications Epithelial ingrowth in the interface.

Residual Scars Slit lamp image (a) shows a preoperative visually significant central corneal scar. Five months postoperative FALK, the slit lamp image (b) discloses a residual stromal scar that was not considered significant enough to warrant an adjunctive surgery. Sixty months postoperatively slit lamp image (c) shows fading of the residual stromal scar. Residual Corneal scar  Despite the incomplete removal of scar tissue in 6 eyes, those cases gained an average of 6.5 lines of BSCVA (±10.5, -1 to 27) at the 6 month visit compared to preoperative BSCVA.  With the exception of those two cases where PTK was performed, the residual scar was not clinically significant enough to warrant an adjunctive surgery  Despite the incomplete removal of scar tissue in 6 eyes, those cases gained an average of 6.5 lines of BSCVA (±10.5, -1 to 27) at the 6 month visit compared to preoperative BSCVA.  With the exception of those two cases where PTK was performed, the residual scar was not clinically significant enough to warrant an adjunctive surgery

Methods  FALK improves the BSCVA of patients with anterior corneal pathologies with rapid visual rehabilitation and less induced astigmatism. Favorable results of FALK remained stable throughout the follow-up period with no sight threatening complications. Conclusions