1. Authors Waseem Aalam, MD; William May, MD; Sultan Alrashidi, MD; Abdul Elah al Towerki, MD; Rajiv Khandekar, MS, PG Dip; Yassine Daoud, MD The authors have no financial interest to disclose COMPARISON OF WOUND SEALING IN SINGLE PLANAR AND MULTI-PLANAR FEMTOSECOND LASER CORNEAL CATARACT SURGERY INCISIONS

2. PURPOSE : To compare single plane (SP) and multi plane (MP) corneal incisions by Femtosecond laser (FL) in terms of invasion of bacterial size particles in response to a pressure challenge.

3. METHODS: Two corneal incisions (one SP and one MP) were created using femtosecond laser on five human eyeballs. The eye was brought to physiologic pressure by injections of normal saline with a 30-gauge needle. Pressure was checked and found to be between 14mm Hg to 18mm Hg India ink was placed on the wounds and washed away. The wound was photographed with a millimeter ruler.

4. METHODS: The IOP was then reset between 12 to 18 mmHg and the India ink was again placed on the eye. A pressure challenge of 80mm Hg was made with an ophthalmodynamometer (figure 1). The ink was washed away. A second photograph was taken of the same wound in the same manner. Length-wise invasion (LI) and area-wise invasion (AI) of dye was measured by planimetry (figure 2,3). The difference of invasion in SP vs. MP group was compared both with and without pressure challenge.

5. RESULTS: The mean rank of LI difference before and after pressure in five eyes through SP wound was 4.9mm and through MP wound was 6.1mm. The observed variation by type of surgical wound making was not statistically significant (p = 0.53). The mean rank of AI difference before and after pressure in five eyes through SP wound was 3.8mm 2 and through MP wound was 7.2mm 2. The observed variation by type of surgical wound was statistically significant (p = 0.007).

6. FIGURE 1 : OPHTHALMODYNAMOMETER AND RULER

7. FIGURE 2 : SINGLE PLANE WOUND. (A) BEFORE PRESSURE CHALLENGE (B) AFTER PRESSURE CHALLENGE.

8. FIGURE 3 : MULTI PLANE WOUND (A) BEFORE PRESSURE CHALLENGE (B) AFTER PRESSURE CHALLENGE.

9. FIGURE 4:DEFAULT INCISION CONTOUR FOR MULTI PLANE AND SINGLE PLANE FS WOUND.

10. FIGURE 5: SETTINGS FOR SINGLE-PLANE DEFAULT INCISION ON FEMTOSECOND ASSISTED LASER MACHINE (ALCON LENSEX LASER)

11. FIGURE 6: SETTINGS FOR MULTI-PLANE DEFAULT INCISION ON FEMTOSECOND ASSISTED LASER MACHINE (ALCON LENSEX LASER)

12. CONCLUSION: A femtosecond laser created multi-planar wound contour allows significantly more invasion of bacterial sized particles of India Ink in response to a pressure challenge equivalent to a hard squeeze than a single plane FL incision.