Analysis of Changes in Anterior, Posterior and Total Corneal Astigmatism after On-Axis Cataract Surgery

PURPOSE: To assess the changes in anterior, posterior, and total corneal astigmatism after cataract surgery with on-axis clear corneal incision cataract surgery. METHODS: This study included 48 eyes (24 eyes with 'with-the-rule [WTR]' and 24 eyes with 'against-the-rule [ATR]') that underwent phacoemulsification and intraocular lens insertion through on-axis clear corneal incision. The ATR group with vertically steep axis of posterior corneal astigmatism was divided into subgroups 1 and 2 for the opposite axis. Autorefraction, uncorrected and best-corrected visual acuities were measured. Corneal astigmatism (anterior, posterior and total) was measured using Pentacam(R) preoperatively and 1 week, 1 month, and 2 months postoperatively. RESULTS: Multivariate linear regression analysis of preoperative data showed positive correlations among anterior, posterior and total astigmatism. Anterior corneal astigmatism showed a significant decrease in both WTR and ATR groups in all measured points (all p 0.05) and significant decrease in the ATR subgroup 1 (p 0.05). According to correlation analysis based on trend line equations, 1.7 diopters of anterior astigmatism could expect 0.3 diopters of posterior astigmatism and 0.5 diopters of total astigmatism for the WTR group and 0.4 diopters of anterior astigmatism could expect 0.2 diopters of posterior astigmatism and 0.4 diopters of total astigmatism for the ATR group. CONCLUSIONS: Considering the majority of cataract patients have vertically steep posterior corneal astigmatism, temporal incision for ATR patients is generally effective. Moreover, for patients with WTR astigmatism of more than 1.7 diopters or ATR astigmatism greater than 0.8 diopters, additional preoperative correction based on posterior astigmatism is needed for more precise prediction of postoperative total corneal astigmatism.

Comparison of Higher Order Aberrations and Astigmatism after On-Axis Small Incision Cataract Surgery

PURPOSE: To assess the changes of corneal astigmatism and higher order aberrations (HOAs) of the anterior and posterior corneal surface after cataract surgery with on-axis clear corneal incision in eyes with-the-rule (WTR) astigmatism and against-the-rule (ATR) astigmatism. METHODS: This study included 50 patients who underwent phacoemulsification and IOL insertion through a 2.8-mm on-axis clear corneal incision. The eyes were divided into two groups: (1) 26 eyes with WTR astigmatism with a superior incision and (2) 24 eyes with ATR astigmatism with a temporal incision. During the follow-up period, visual acuity was measured, and the surgically induced astigmatism (SIA) and HOAs of the anterior and posterior corneal surface were measured with Pentacam(R) (Occlus, Wetzlar, Germany) preoperatively and 1 week, 1 month, and 2 months postoperatively. RESULTS: There were no significant differences in UCVA and BCVA between the two groups. HOAs increased in both groups 1 week after surgery, but no significant differences were found between the groups (p > 0.05). Surgically induced astigmatism was larger in the WTR group than in the ATR group (p < 0.05). At postoperative 2 months, there were significant differences in HOAs between the two groups, and there were statistically significant differences in HOAs, oblique trefoil at front side, and in HOAs, horizontal coma at rear side (p < 0.05). CONCLUSIONS: In conclusion, superior incision in eyes with WTR astigmatism resulted in higher SIA compared to temporal incision in eyes with ATR astigmatism. Moreover, HOAs was significantly decreased in eyes with WTR astigmatism with superior incision. Thus, superior incision could be more effective in reducing corneal astigmatism in eyes with WTR astigmatism.

Induced Astigmatism after Rabbit Cataract Surgery Using Tissue Adhesive

In order to compare the amount of surgically induced astigmatism among sutureless group(Group 1),10-0 nylone suture group(Group 2),and using tissue adhesive group(Group 3),we analysed a series of rabbit cataract surgery cases in these three groups. We performed cataract surgery on 30 eyes of 15 rabbits by Irrigation and aspiration technique. After cataract surgery,10 eyes by sutureless technique,10 eyes were closed by conventional 10-0 nylon suture technique, and 10 eyes by tissue adhesive(Beriplast) technique.We collected keratometric data before and after surgery(At 1,2,4,8 weeks).In postoperative astigmatic change,three groups had the distinct features in the evolution for postoperative astigmatism.The group 1 showed early against-the-rule(ATR)astigmatism,which advanced ATR and showed about 0.5D astigmatic change at 8 weeks.The group 2 showed early with-the-rule(WTR)astigmatism about 1.13D,which advanced toward ATR from 1week.The group 3 showed little ATR about 0.2D,which was minimal change in astigmatism.At 8 weeks after operation,there was no signifi-cant difference in the astigmatic change among the three groups(P>0.05), which were no complications observed. In this study,the tissue adhesive(Beriplast)seem to be a simple,effective and less induced astigmatic changing corneoscleral suture technique than other suture techniques