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Audit & Research

The numbers, efficacy, predictability and safety of laser refractive surgery procedures are shown in Figures 9.1 to 9.4.

A total of 64,932 laser refractive surgery procedures were performed at SNEC from 1992 to 2014.

Over the past 10 years, nearly 100% of patients achieved an unaided visual acuity of 6/12 or better after laser refractive surgery procedures.

Since 2010, predictability has been consistently greater than 95% at SNEC.

Complication rates versus total number of cases (1992 to 2014)

The complication rates of post-refractive surgery have been consistently low, at <3%, over the audit period (1998 to 2014). Over the last five years of audit, the complication rates decreased further to 0.1 to 0.45%.

Latest audit results

In 2014, LASIK procedures were performed and audited in 1,276 eyes from 645 patients. 99.3% of eye achieved unaided visual acuity of 6/12 or better and 79.7% of eyes achieved that of 6/6 or better. 98.6% of eyes were within +/- 1.0 dioptre of attempted correction.

TABLE 9.1 Laser refractive surgery procedures: comparison of the FDA's 2003 study with SNEC's efficacy and safety rates in 2014.


Post-operative 3-month comparison

FDA (Allegretto laser)

(U.S. Food and Drug Administration, 2003)

N = 290 ≤ -7D


(EX500 laser)


N = 357 ≤ -7D



Efficacy (%)

Eyes with

UAVA 6/12 or better



Eyes with

UAVA 6/6 or better



Predictability (%)

Eyes with

predictability +/- 1.00D



Eyes with

predictability +/- 0.50D



Safety (%)

Eyes with loss of

≥ 2 lines BCVA



Cases with improved or unchanged BCVA



BCVA, best-corrected visual acuity; D, dioptre; FDA, Food and Drug Administration; UAVA, unaided visual acuity.


  1. Liu, Y. C., Pujara, T., & Mehta, J. S. (2014). New instruments for lenticule extraction in small incision lenticule extraction (SMILE). PLoS One, e113774.

  2. Mohamed- Noriega, K., Riau, A. K., Lwin, N. C., Chaurasia, S. S., Tan, D. T., & Mehta, J. S. (2014). Early corneal nerve damage and recovery following small incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK) Investigative Ophthalmology & Visual Science, 55, 1823-1834.

  3. U.S. Food and Drug Administration. (2003). Summary of safety and effectiveness data for a supplemental premarket approval application. Retrieved from here.