Factors affecting post-operative astigmatism in superior and temporal approaches in Manual Small Incision Cataract Surgery

Background: Cataract surgery and intraocular lens implantation restores near normal visual acuity in otherwise healthy eyes, safe surgery, postoperative emmetropia and early resuming of normal activities are three major considerations of present day cataract surgery. Aim: To evaluate and compare surgically induced altered refractive status following superior versus temporal incision in small incision cataract surgery. Materials and methods: 100 cases of cataract surgery were selected for study of post-operative refractive status in superior versus temporal incision in cataract surgery. A complete ocular examination including anterior and posterior segment examination and general physical examination was performed in all cases. Results: Majority (75%) of patients of the present study who underwent cataract extraction belonged to age group of above 50 years with maximum preponderance in the age group of between 61-70 years. The minimum amount of astigmatism one week after surgery in Group – 2 was 0.5D and the maximum amount was 6.0D. The average amount of astigmatism one week after surgery in Group – 2 was 2.75D. The minimum amount of astigmatism 6 weeks after surgery in Group – I was 0.25D and maximum amount was 4.0D. The minimum amount of astigmatism 6 weeks after surgery in Group – Giridhar Bellamkonda, Sri Kavya. Factors affecting post-operative astigmatism in superior and temporal approaches in Manual Small Incision Cataract Surgery. IAIM, 2018; 5(3): 44-54. Page 45 2 was 0.25D and maximum amount was 2.0D. The complications were seen in early postoperative period more in superior incision group than in temporal group. Astigmatism was cleared in temporal group when compared to superior incision group. After 6 weeks of postoperative follow-up, visual acuity of every patient was recorded after giving proper pseudophasic correction. Temporal Incision had 92% 6/6 -6/9 and 6/12-6/18 visual acuity. Conclusions: Amount of astigmatism was less in temporal incision SICS than superior incision SICS. The postoperative refractive status, is also good in temporal incision SICS than superior incision SICS.

Comparison of changes in astigmatism after cataract surgery in temporal versus superior incisions.

Introduction- Patients undergoing cataract surgery develop astigmatism based on location of incision. This retrospective study investigated the “Pre & post operative astigmatism after cataract surgery based on incision”. Purpose of this study was to compare astigmatismobtained in temporal & superior incision. Material and Methods- Out of 50 cataract patients collected, 25 patients were in the temporal incision PHACO group and 25 were in the superior incision PHACO group. Corneal astigmatism and corrected visual acuity were assessed 30 and 90 days after cataract surgery. Results- against the rule astigmatism is more common after superior incision cataract surgery and with the rule astigmatism is more common after temporal incision cataract surgery. Conclusion: The study reveals temporal incision, increase with the rule & superior incision increase against the rule and also concluded astigmatism is least in temporal incision.

Comparative study of surgically induced astigmatism in superior versus temporal incision in small incision cataract surgery cases.

Background: Location of incision has a significant impact on surgical outcome. It has been reported that temporal incisions induce less astigmatism than superior incisions indicating the importance of incision location. The objective of the present study was to study the effect of surgical induced astigmatism in superior versus temporal incision in small incision cataract surgery cases. Methods: 100 patients of cataract attending to Sarojini Devi eye hospital with the rule and against the rule astigmatism were included in the study. The astigmatic profile and the effect of surgical incision on astigmatism were studied. A prospective study was done in which patients were divided into two groups. MSICS was performed with superiorly located incision in group I and temporally located incision in group II. Results: Out of the total 100 patients undergoing MSICS, 59 patients had ATR, 36 patients had WTR and 5 patients had no astigmatism. Thus the pre-operative astigmatic profile shows that ATR is more common type of astigmatism in this group. Among 50 patients in superior incision group, 18 had pre-operative WTR, 29 had ATR and 3 did not have astigmatism. Postoperatively the no. of patients with WTR decreased to 10, the no. of patients with ATR increased to 35 showing that superior incision flattens vertical meridian and steepens the horizontal meridian causing ATR shift. Among 50 patients in temporal incision group, 18 had pre-operative WTR, 30 had ATR and 2 did not have astigmatism. Post operatively the no of patients with WTR increased to 25, the no of patients with ATR decreased to 20. Conclusions: Placement of incision on steep axis reduces pre-existing astigmatism. Thus in ATR astigmatism it is placed temporally and in WTR astigmatism it is placed superiorly. Thus a simple modification in incision placement can minimize surgically induced astigmatism and reduce pre-existing astigmatism.

Comparison of Astigmatism According to Incision Location in 3.2mm Scleral Tunnel Incision Cataract Surgery

To evaluate surgically induced astigmatism for 6 months following 3.2mm scleral tunnel incision cataract surgery according to incision site we divided 115 patients(124 eyes) into superior incision group 1 (58 eyes) and superotemporal incision group 2 (66 eyes). Each group was classified into 3 cases according to preoperative astigmatism. Postoperative astigmatic changes by vector method were 0.40 diopter(D) against-the-rule astigmatism(ATR) in group 1, 0.25 D ART in group 2 at 6 months and there was no difference between two groups(P>0.05). In the preoperative with-the-rule astigmatic cases, postoperative astigmatic changes were 0.56 D ART in group 1, 0.38 D ATR in group 2, in the preoperative against-the-rule astigmatic cases, postoperative astigmatic changes were 0.25 D ART in group 1, 0.12 D ART in group 2, in the preoperative no astigmatic cases, postoperative astigmatism changes were 0.53 D ATR in group 1, 0.25D ART in group 2 at 6 months. There was no significant difference between two groups in postoperative astigmatic changes(P>0.05) and corneal astigmatisms were stabilized after 2 months postoperatively in both groups(P<0.05).

The Effect of Astigmatic Control after Cataract Extraction with Temporal Incision

A group of 25 preoperative against-the-rule(AR) eyes had undergone phacoemulsification and posterior chamber lens implantation, 15 of them prepared with lateral(temporal) scleral pocket incision and 10 with superior scleral incision. Temporal incision group showed early AR astigmatism increment by about 1 diopter(D), which decayed slowly over the next 2 months. Superior incision group showed early with-the-rule (WR) astigmatism by about 2.5D, which shifted toward AR astigmatism at postoperative 10 day and the AR astigmatism increased substantially by the next 2 months. The early postoperative complications were hyphema(2 eyes, 13.3%) and corneal edema(1 eye, 6.7%) in the temporal incision group, which cleared spontaneously within 1 week pctoperative. There were no hyphema and corneal edema in the superior incision group. In summary, the temporal incision effectively achived rapid post-operative astigmatic recovery with strong axial stability in a manner that surgically induced astigmatism favorably reduces pre-existing AR astigmatism.