Intraocular Lens Outcomes: Comparison of Technologies and Formulas

1. Intraocular Lens Outcomes: Comparison of Technologies and Formulas Helga P. Sandoval, MD, MSCR, Kerry D. Solomon, MD Carolina Eyecare Physicians, LLC Research Assistant Professor of Ophthalmology Storm Eye Institute - Medical University of South Carolina Charleston, South Carolina • Financial Disclosure: HP Sandoval, none; KD Solomon, Alcon , Allergan, AMO , Advanced Vision Research, , Aquesys, Bausch and Lomb, Glaukos, Inspire, LensAR, QLT, Wavetec None of the Authors has any financial interest in any product mentioned herein.

2. Purpose • To compare: • biometry measurements between Lenstar LS 900 and IOL Master • IOL power calculations using Haigis and Holladay 2 formulas.

3. Methods • Retrospective chart review of routine cataract patients who had preoperative measurements taken with both Lenstar LS 900 and IOL Master. • Steep, flat and average keratometry, axial length, anterior chamber depth and white to white were compared. • IOL power obtained using the Haigis and Holladay 2 formulas were compared in patients who underwent uneventful cataract surgery.

4. Methods • The first eye undergoing surgery was selected in patient with bilateral cataracts. • SN60WF IOL power was selected using the Haigis formula from IOL Master in all cases by the same physician (HPS). • All surgeries were performed by the same surgeon (KDS) using the same technique.

5. Results: IOL Master vs. Lenstar • A total of 64 eyes of 64 patients were included for analysis. • Mean age 67.7 ±8.0 years-old. • No differences in mean ±SD flat, steep and average K, ACD, and AL were found between the two machines. Lenstar’s mean white to white was 12.2 ±0.4 compared to 12.0 ±0.4 of the IOL master. • Mean differences were as follows: • Flat K, 0.06 (range -0.53 to 1.02); • Steep K, 0.03 (-1.22 to 1.51); • Average K, 0.04 (-0.63 to 1.27); • ACD, 0.01 (-1.87 to 0.17); • AL, -0.01 (-1.87 to 0.17); • White to white, 1.06 (-1.65 to 1.18).

6. Results: Haigis vs. Holladay 2 • Mean follow-up 30 ±13 days • The calculated IOL power was: • The same with both formulas in 56% of cases • 0.5 D lower with the Holladay 2 in 36% of cases • 0.5 D greater with the Holladay 2 in 8% of cases Eyes with different IOL power were excluded from analysis (28 eyes)

7. Results: Haigis vs. Holladay 2 • Mean target refraction was: • Haigis: -0.18 ±0.13 D • Holladay 2: -0.15 ±0.10 D • Mean arithmetic difference postop MRSE – target refraction was: • Haigis: -0.05 ±0.43 D 0.35 0.23 • Holladay 2: -0.09 ±0.45D • Mean absolute difference postop MRSE – target refraction was: • Haigis: 0.35 ±0.23 D • Holladay 2: 0.37 ±0.26 D

10. Accuracy

11. Conclusions • Slight differences in biometry measurements were found between IOL Master and Lenstar. • These differences may not be clinically significant but further studies are deem necessary to confirm.

12. Conclusions • Slight differences in target refraction were found between the Haigis and Holladay 2 formulas. • These differences were similar when comparing the target refraction to the postoperative MRSE. • Haigis formula constants (a0, a1 and a2) were personalized before this review was made while the Holladay 2 was not. • Further studies comparing the 2 formulas after customization are underway.