Outcomes of Microcoaxial Cataract Surgery using 1.8mm versus 2.2mm Corneal Incision

The authors have no financial interest

Jung Hwa Na M.D. Eun Chul Kim M.D.

Department of Ophthalmology and Visual Science, The Catholic University of Korea

Purpose

• To compare the postoperative results of microcoaxial cataract surgery (MCCS) using 1.8mm incision (Stellaris Vision Enhancement

System, Bausch & Lomb Inc., USA) with 2.2mm incision (Infinity Vision System, Alcon

Laboratories, Inc., USA).

Patients and Methods (1)

• Retrospective Comparative study

• Total Forty seven eyes of 30 patients– 1.8mm Group (Stellaris Group) : 21 eyes– 2.2mm Group (Infinity Group) : 26 eyes

• Cataract grade II or III according to the Lens Opacities Classification System III scale

Patients and Methods (2)

Patients and Methods (3)

• Intraoperative parameters– Total phacoemulsification time

– Cumulative Dissipated Energy (CDE)

• Postoperative parameters– Follow-up at 1 week, 1 month, and 2 months– Best Corrected Visual Acuity (BCVA)– Percentage decrease in endothelial cell density (ECD)– Surgical induced astigmatism (SIA)

Statistical Analysis

• Mann-Whitney Test for comparing two independent groups

• Wilcoxon signed ranks test for comparing before and after operation in the same group

• Significance : P-value less than 0.05

Patients demographics1.8mm Group 2.2mm Group P-value

Eyes 21 26

Age 70.0 (61.0~82.5) 68.0 ( 60.0~74.5) 0.500

Preoperative BCVA (LogMAR)

0.52 (0.30~0.76) 0.30 (0.15~0.57) 0.649

Axial Length (mm)

23.15 (22.35~23.74) 23.84 (22.94~24.65) 0.076

ECD (cells/mm²) 2538.0 (2418.0~1865.0)

2620.5 (2460.5~2828.0)

0.535

CV 43.0 (38.5~50.0) 40.5 (37.8~47.3) 0.346

Hexagonality 51.0 (45.5~55.5) 51.5 (46.8~58.0) 0.847

* Median (Interquartile range)

Phacoemulsification time (sec)

Cumulative Dissipated Energy (CDE)

41.72±17.87

50.30±18.21

P=0.095 P=0.915

• Phacoemulsification time : 1.8 mm Group > 2.2 mm Group• CDE : 1.8 mm Group < 2.2 mm Group → No statistically difference

Visual Acuity (LogMAR)

P=0.102

P=0.131 P=0.520 P=0.358

No statistical difference in BCVA.

EndotheliumMean Endothelial Cell Density (cell/ ㎟ )

PreOP 1month 2months P-value*

1.8mm Group 2626.9±340.4 2116.1±716.2

2453.8±551.1

0.060

2.2mm Group 2706.2±402.9 2278.6±341.0

2324.1±299.2

0.016

P-value† 0.535 0.551 0.525

*: Between Preoperative mean ECD and the value of 2 months after operation at each group.†: Between independent two groups at each follow-up period.

ECD decrement (%) at 2 months after operation ; 1.8mmGroup>2.2mmGroup (P=0.151)

Surgical induced astigmatism• At the 2 months after operation• Vector analysis• 1.8mm Group : 0.46 ± 0.43 Diopters• 2.2mm Group : 0.51 ± 0.47 Diopters• No difference in SIA (P=0.984)

74%

13%13%

62.5%25%

12.5%

Conclusion

• Although not statistically significant, phacoemulsification time tends to take longer and the eyes in which SIA more than 0.5D developed less frequently in 1.8mm Group. – Maybe due to the smaller diameter of phaco tip and incision in

1.8mm MCCS

• We could not find any statistically significant difference in phacoemulsification time, CDE, visual outcome, and SIA between 1.8mm and 2.2mm MCCS.

1.8 mm MCCS is effective as 2.2 mm MCCS