1. Nang-Hee Song(MD) 1, Jae-Woong Koh (MD/PhD) 1, Gil-Joong Yoon (MD/PhD) 2 Department of Ophthalmology, Chosun University College of Medicine, Gwangju, Republic of Korea 1 Happy Eye Clinic, Gwangju, Republic of Korea 2 Authors have no financial interest. Refractive correction and the intra-ocular pressure change after cataract surgery in rural South Korea

2. Dr. SongDr. Koh Dr. Yoon

3. Introduction Astigmatism after cataract surgery : Location of the incisied wound, Length of the incised wound, the type of the suture, the sutured method, and tension of the suture Most important factor is Location of the incisied wound, Length of the incised wound Clear corneal incision was reported in 1992, - Simple, Light in hand/Shorter operative time/Less tissue damage/ Easy lens insertion/Less inflammatory response Temporal corneal incision occurred less astigmatism than superior corneal incision. Because - The distance between the visual axis and the corneal limbus is longer - The palpebral blink-related pressure is lower

4. Introduction First, With the rule astigmatism is caused by oppression of the operative wound and suture The development into Against the rule astigmatism is caused by enlargement of the operative wound and dissolution of the suture. WR astigmatism, caused by the operation, is reduced with time and develops into AR astigmatism. due to relaxation of the wounded surface or its glide. Temporal corneal curvature can be gentle and astigmatism can be reduced when the incision is performed in the direction of the axis of the maximum corneal curvature.

5. Purpose/Method Purpose To ascertain how long it would take to stabilize the refractive power after the cataract surgery and how intraocular pressure (IOP) would change after cataract surgery. Method Nonrandomised comparative retrospective study The charts of 163 patients (221 eyes) Sutureless clear corneal incision method Group 1 : Superior incision (86 eyes) Group 2 : Temporal incision (135 eyes) Refractive power and IOP were prospectively analyzed after the operation.

6. Result Baseline characteristics of eyes before cataract surgery CharacteristicsTotal (221)Group 1 (86)Group 2 (135) Age, mean(years)±SD † 66.87±13.3466.65±13.7967.01±13.11 Gender (male : female)86 : 13529 : 5757 : 78 UCVA *, mean±SD0.30±0.220.26±0.220.32±0.22 BCVA Π, mean±SD0.60±0.390.61±0.420.60±0.29 Keratometry, mean(D)±SD44.85±1.0944.06±1.2743.69±1.80 SE §, mean(D)±SD-1.15±1.35-0.90±1.31-1.31±1.42 IOP %, mean(mmHg)±SD15.62±3.9715.21±3.4815.88±4.35

7. Result The change of spherical equivalents after cataract surgery between group 1(superior incision) and group 2 (temporal incision) Statistically significant changes at the 1st day, the 1st week and the 1st month after the operation (p=0.017, p=0.019, p=0.015, p<0.05) But 2 months and 3 months after the operation, statistically significant changes were not observed in SE (p=0.991, p=0.133, p>0.05). There was no statistically significant difference between the two groups during this period (p>0.05).

8. Result Comparison of postoperative change in spherical equivalents between group 1 (superior incision approach) and group 2 (temporal incision approach) Preop POD 1D POD 1WK POD 1MO POD 2MO POD 3MO Group 1 0.90 ± 1.31-0.58 ± 1.17-0.38 ± 1.10-0.57 ± 1.17-0.22 ± 1.37-0.12 ± 0.63 Group 21.31 ± 1.42-0.03 ± 0.99-0.27 ± 0.95-0.07 ± 0.99-0.24 ± 1.03-0.18 ± 1.05

9. Result The change of IOP after cataract surgery between group 1(superior incision) and group 2 (temporal incision ) IOP was somewhat increased 1 day after the operation, but a statistically significant decrease was observed 1 week after the operation. Statistically significant differences were observed 1 day after the operation (p<0.05) in the values that were continuously measured until 3 months (p>0.05) There was no statistically significant difference between the two groups during this period (p>0.05)

10. Discussion Ordinarily astigmatism becomes stable 3 months after the operation Parker, Clorfeine and Richards ( Arch Ophthalmol 1989;107;353-7.) Corneal astigmatism and its axis continuously change for at least 3 yrs Cravy (J Cataract Refract Surg 1991;17:415-23.) Corneal astigmatism was more stable in temporal incision than in superior. Astigmatism was generally reduced and visual acuity recovered early. Joel C. Ax et al. (J Cataract Refract Surg 1993;19:380-6. Preoperative AR astigmatism could be reduced by temporal incision. Nielson et al. (J Cataract Refract Surg 1995;21:43-8.) Postoperative astigmatic effect did not change until the 6th week. Superior incision and temporal incision caused AR astigmatism and WR astigmatism respectively

11. Discussion The study about the pattern of postoperation IOP change Radius et al, in 1984 : The average IOP decreased with as much as 0.6 mmHg 24 months after the operations. Savage et al reported similar results. (Ophthalmology 1985;92:1506-16.) Many studies that postoperative IOP is heightened in the early days but decreases with time.

12. Conclusion Refractive power has been stabilized from 2 months after the cataract surgery. IOP have been stable from 1 week after the cataract surgery. These results recommended the time for refractive correction and IOP stabilizing time after cataract surgery.