Aug 2026· Journal of the College of Physicians and Surgeons--Pakistan : JCPSP· Vol 36 8, pp.
1023-1027
· 0 citations
Medicine
TL;DR
A 2.75-mm on-axis limbal incision during phacoemulsification produces low and predictable SIA, a statistically significant reduction in corneal astigmatism and substantial improvement in visual acuity, which provides a practical, cost-neutral option for astigmatism management in cataract surgery.
Abstract
Objective
To estimate surgically induced astigmatism (SIA) and the flattening effect produced by an on-axis incision in patients undergoing phacoemulsification cataract surgery.
STUDY
Design
A quasi-experimental study. Place and Duration of the Study: Department of Eye, Combined Military Hospital, Lahore, Pakistan, from May to September 2024.
METHODOLOGY
A total of 142 eyes underwent phacoemulsification with a 2.75-mm limbal incision placed on the steep axis. Keratometric (K) readings, including flat K (K1) and its axis, steep K (K2) and its axis, and astigmatism and its axis, were measured by the same technician before surgery and again 6 weeks postoperatively using an optical biometer (Tomey AL 100). Uncorrected visual acuity (UCVA) and corrected distance visual acuity (CDVA) were recorded for all patients preoperatively and postoperatively. SIA was calculated using the ASSORT online calculator, and changes in astigmatism, UCVA, and CDVA were analysed using the Wilcoxon signed-rank test (SPSS version 26), with statistical significance set at p < 0.05.
Results
The mean age of participants was 62.9 ± 6.9 years, with 60.6% males. Preoperative astigmatism averaged 0.88 ± 0.52 dioptres (D) and decreased to 0.65 ± 0.48 D postoperatively, representing a mean reduction of 0.23 ± 0.30 D (p < 0.001). The mean SIA was 0.58 ± 0.50 D, and target-induced astigmatism was 0.45 ± 0.45 D. Both UCVA and CDVA improved significantly (p <0.001). Nearly 70% of eyes gained three or more Snellen lines of corrected vision.
Conclusion
A 2.75-mm on-axis limbal incision during phacoemulsification produces low and predictable SIA, a statistically significant reduction in corneal astigmatism and substantial improvement in visual acuity. This approach provides a practical, cost-neutral option for astigmatism management in cataract surgery.
KEY WORDS
Phacoemulsification, Astigmatism, Cataract extraction, Cornea/surgery, Visual acuity.
Background: Surgically Induced Astigmatism (SIA) remains a major determinant of uncorrected visual acuity following manual Small-Incision Cataract Surgery (SICS). Incision configuration is a modifiable factor influencing postoperative refractive outcomes. To compare postoperative visual acuity and surgically induced astigmatism among straight, frown and chevron incisions in manual SICS.
Materials and methods: This prospective observational analytical study was conducted at a tertiary care hospital in Bangladesh from February 2022 to January 2023. A total of 110 patients aged 40 years with uncomplicated age-related cataract and with-the-rule astigmatism were enrolled. Patients underwent manual SICS using straight (n=37) frown (n=49) or chevron (n=24) incisions by a single experienced surgeon. Postoperative uncorrected and best-corrected visual acuity, keratometric astigmatism, and SIA were evaluated at six weeks. SIA was calculated using SIA Calculator version 2.1. Data were analyzed using SPSS version 25.0.
Results: Baseline demographic and preoperative visual parameters were comparable among groups. At six weeks, best-corrected visual acuity 6/18 was achieved in nearly all patients across all incision types. However, uncorrected visual acuity was significantly better in the frown and chevron groups compared to the straight incision group (p=0.034). Mean SIA was highest in the straight incision group (0.95 D) and significantly lower in the frown (0.58 D) and chevron (0.57 D) groups (p<0.001).
Conclusion: Frown and chevron incisions in manual SICS result in significantly lower surgically induced astigmatism and better early uncorrected visual outcomes compared to straight incisions. These incision techniques may be preferred to optimize refractive outcomes in high-volume, resource-limited settings.
JCMCTA 2026 ; 37 (1) : 138-144
M. Uddin, Rezina Islam, Tanuja Tanzin et al.· Journal of Chittagong Medica...· 0 citations
A macroscopic incision gape is a prevalent phenomenon in SCOLI and is a significant factor associated with SIA, highlighting the potential for controlling SIA by surgically modulating the incision gape (ΔG).
Xin Fan, P. Lai, Shaofeng Yang et al.· Clinical Ophthalmology· 0 citations
Background: Surgically induced astigmatism (SIA) is a critical factor influencing visual quality following manual small incision cataract surgery (MSICS). The architecture of the scleral tunnel may significantly influence postoperative refractive stability and visual recovery. Methods: This comparative study included 480 eyes undergoing MSICS, equally assigned to four incision groups: Chevron, Back-cut Straight, Frown, and Straight (n = 120 each). Baseline ocular characteristics were comparable. Uncorrected and best-corrected visual acuity (UDVA, BCVA) and SIA (vector analysis) were assessed at postoperative Day 1, Week 1, Week 4, and Week 6. Results: By the sixth week, the Chevron group achieved the most favorable outcomes, recording a mean UDVA of 0.18 ± 0.13 logMAR and BCVA of 0.08 ± 0.07 logMAR. Back-cut Straight incisions produced intermediate results, followed by Frown, while Straight incisions yielded the least improvement. Mean SIA was lowest in the Chevron group (0.48 ± 0.36 D) and highest in the Straight group (1.12 ± 0.62 D) (p < 0.001). Residual cylinder ≤0.50 D was highest in Chevron (70.0%) and lowest in Straight incision cases (31.7%). Conclusion: Chevron incisions demonstrated the greatest refractive predictability and visual recovery in MSICS. Back cut Straight incisions may serve as a practical alternative for achieving controlled astigmatism while maintaining technical simplicity. Tailoring incision design can enhance visual outcomes without additional instrumentation.
Dr Sachin Tammannavar, Dr Ramya Karjol, Darshan Devarmani· Genetics and Molecular Resea...· 0 citations
Background: Cataract is one of the most common preventable causes of blindness in the world, and the gold standard surgical treatment is phacoemulsification (PHACO) with intraocular lens (IOL) implantation. This study aimed to assess the changes in anterior segment biometry, particularly ACD, before and after PHACO with IOL, using A-scan biometry.
Methods: This prospective observational study was conducted at Mugda Medical College Hospital, Dhaka, from July 2024 to December 2025. 100 patients who had uncomplicated PHACO with PCIOL implantation were enrolled. The A-scan ultrasonic biometer was used to measure ACD at baseline (preoperative) and on the 7th postoperative day (POD) and at one month postoperatively. Data were entered and analyzed on SPSS version 26.
Results: The mean age was 61.8 ± 8.7 years, and 56% were male. Age-related cataract was the commonest diagnosis, 62%. Mean ACD increased significantly from 2.92 ± 0.28 mm preoperatively to 3.54 ± 0.31 mm on the 7th POD and 3.58 ± 0.30 mm at one month. The mean increases were 0.62 mm and 0.66 mm, respectively, both statistically significant, P < 0.001.
Conclusions: PHACO, along with IOL, results in a clinically and statistically significant deepening of the ACD, especially in patients with shallow preoperative ACD. These biometric changes are well monitored by A-scan ultrasonic biometry.
S. Bhuiyan, Mahfuza Akter, Taiaba Sultana· Annals of International medi...· 0 citations
Phacoemulsification shows a modest, non-significant advantage in early visual recovery, but both techniques remain effective and safe in patients with senile cataract.
Maninee Suman, Pradeep Kumar, Nandani Priyadarshini· International Journal of Pha...· 0 citations
Background and Objectives: To assess refractive and visual outcomes following phacoemulsification using a novel algorithm for toric intraocular lens (IOL) surgery. Setting: Private practice, Spain. Design: Prospective observational study. Materials and Methods: The algorithm was designed to control the topographic position of the principal meridians (flat and steep) after cataract surgery in eyes without associated corneal pathology or previous corneal surgery. It is well known that a toric IOL must be positioned along the steep meridian. Therefore, it is crucial to predict both the postoperative position of the steep meridian and its magnitude. Data from patients who were planned for refractive lens exchange or cataract surgery using the Pešić-Barraquer algorithm and implantation of a toric IOL in eyes with different degrees of astigmatism were used to assess the effect of residual astigmatism on 6-month postoperative monocular uncorrected and corrected distance logMAR visual acuity values (UDVA and CDVA). Vector analysis was performed with J0 and J45 evaluations, and centroid errors in postoperative refractive astigmatism prediction error were calculated in the spectacle plane using the “Astigmatism Double-Angle Plot Tool”. Results: Three hundred and six eyes of 250 patients with a mean age of 69.0 years ± 8.6 were enrolled in the study. The mean preoperative corneal astigmatism measured with Pentacam was 1.43 D ± 0.83 (SD). One hundred and eighty-four eyes (60.13%) had “against-the-rule” (ATR) astigmatism, 67 (21.90%) had “with-the-rule” (WTR) astigmatism, and 55 (17.97%) eyes had “oblique” corneal (OBL) astigmatism preoperatively. The mean absolute astigmatic prediction error in residual astigmatism was 0.31 D ± 0.28. Eyes with preoperative ATR corneal astigmatism had lower mean absolute errors compared to the eyes with WTR astigmatism (0.29 D ± 0.26 and 0.34 D ± 0.31, respectively). Centroid error in predicted residual astigmatism was 0.08 D ± 0.41 @4°. All eyes achieved residual refractive astigmatism within the 1.00 D range, and 55.23% had no residual astigmatism in the spectacle plane. Mean postoperative refractive astigmatism at the spectacle plane was 0.24 D ± 0.29. There were no postoperative complications. Additional statistical analysis of 310 eyes confirmed that when the main incision is not placed on one of the three meridians (flat, steep, or 45-degree bisector), the axis of astigmatism induced by the incision is significantly altered. Exploratory subgroup analyses demonstrated comparable prediction accuracy across incision positions, preoperative astigmatism types, and surgeons, further supporting the robustness of the proposed algorithm. Conclusions: In addition to enabling more accurate prediction of postoperative refractive residual astigmatism in patients undergoing toric IOL implantation, our newly proposed algorithm provides surgical pearls to facilitate preoperative and intraoperative management of corneal astigmatism, highlighting the importance of precise incision placement for optimal refractive outcomes.
Milan Pešić, S. Salvador, Iva Krolo et al.· Medicina· 0 citations
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