Aug 2026· Clinical Ophthalmology· Vol 20· 0 citations· 15 references
Medicine
TL;DR
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).
Abstract
Purpose To investigate the phenomenon of incision gape following subconjunctival oblique limbus incision (SCOLI) cataract surgery and to quantify its relationship with surgically induced astigmatism (SIA). Methods This study enrolled patients with regular corneal astigmatism ≥1.0 diopters (D) undergoing SCOLI. Anterior segment optical coherence tomography (AS-OCT) was used to measure the actual incision gape (ΔG). A theoretical model was developed to calculate the predicted incision gape (theoretical ΔG) based on preoperative keratometry and white-to-white (WTW) distance. The correlation between actual ΔG and SIA was analyzed using linear regression and a multivariate GEE model. Results Thirty-two eyes of 25 patients were analyzed. A significant positive correlation was observed between actual ΔG and SIA (R = 0.392, p = 0.026). In the multivariate GEE model, after adjusting for age (p = 0.195) and CCT (p = 0.070), actual ΔG remained a significant independent factor associated with SIA (B = 0.004; 95% CI, 0.002–0.006; p < 0.001). The theoretical ΔG showed a strong correlation with both the intraoperative ΔG (r = 0.877, p < 0.001) and the actual ΔG (r = 0.508, p = 0.003). Conclusion A macroscopic incision gape is a prevalent phenomenon in SCOLI and is a significant factor associated with SIA. The developed mathematical model provides a foundation for predicting astigmatic outcomes, highlighting the potential for controlling SIA by surgically modulating the incision gape (ΔG).
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 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.
Sadia Humayun, Amna Tariq, Samar Fatima et al.· Journal of the College of Ph...· 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
This study finds a statistically significant difference in vertical keratometry with moderate SIA magnitude, and adds a unique dimension to the literature by explicitly linking a fixed tunnel depth to the SIA vector and keratometric prediction.
P. Krishnacharya, Kedar Janardhan Prabhu, Shreya Nataraj et al.· Romanian Journal of Ophthalm...· 0 citations
Purpose: This study aimed to investigate the relationship between the graft–host junction (GHJ) configuration and postoperative astigmatism in patients who underwent penetrating keratoplasty (PK) or deep anterior lamellar keratoplasty (DALK) and to examine whether variations in epithelial thickness are associated with astigmatic outcomes. Methods: A retrospective analysis was conducted on 54 phakic eyes (30 PK and 24 DALK) with a minimum follow-up of 12 months. GHJ morphology was evaluated using anterior segment optical coherence tomography (AS-OCT). Epithelial thickness was measured in the steepest and flattest corneal areas using RTVue XR. Astigmatism was quantified by auto-refraction, keratometry, and corneal topography. Based on GHJ configuration, eyes were classified as either well-aligned or malaligned. Results: Malalignment of the GHJ was observed in 87.1% of cases. Eyes with malaligned junctions exhibited significantly higher astigmatism across all measurement techniques (P < 0.05). The correlation between GHJ configuration and astigmatism was strong in the DALK group but did not reach statistical significance in the PK group. Malalignment was more frequent following PK than DALK (P = 0.002). The epithelial thickness was significantly lower in the flattest zone (P = 0.006), while the increase in the steepest zone was not significant (P = 0.4). Conclusion: Optimal graft–host junction alignment remains a key determinant of refractive success following corneal transplantation. Integrating intraoperative OCT, femtosecond-assisted trephination, and individualized suturing strategies may help reduce postoperative malapposition and astigmatism. Future prospective studies incorporating epithelial remodeling and visual quality analysis will further clarify the mechanisms linking structural alignment and optical performance after keratoplasty.
H. Hashemian, Zahra Kianzad, Seyed Mohammad Naser Hashemian et al.· Indian Journal of Ophthalmol...· 0 citations
SMILE Pro using the VISUMAX 800 femtosecond laser provides safe and predictable correction of myopic astigmatism with good axis alignment, however, the observed undercorrection in higher cylinders suggests that further optimization of astigmatic nomograms may improve refractive accuracy.
İ. İritaş, Z. Burke· International Journal of Oph...· 0 citations
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