Two Different Corneal Incision Designs for Correcting Corneal Astigmatism During Cataract Surgery With Multifocal Intraocular Lens Implantation

Background: Multifocal intraocular lenses (IOLs) is very intolerant to residual corneal astigmatism and patients with more than 1.0 D of residual corneal astigmatism are not suitable candidates for implantation of multifocal IOLs. The purpose of this study was to evaluate the efficacy of a single clear corneal incision (CCI) or an opposite clear corneal incision (OCCI) made on a steep meridian for correction of low to moderate corneal astigmatism during implantation of multifocal IOLs.Methods: This is a retrospective cohort study. A total of 80 patients with pre-operative total corneal astigmatism, ranging between 0.5 and 2.0 diopters (D), who underwent cataract surgery and received multifocal IOLs were included. Correction of corneal astigmatism was done via single CCIs on steep meridians in patients with 0.5–1.2 D total corneal astigmatisms, and OCCIs in patients with 1.3–2.0 D total corneal astigmatisms. Visual acuity, corneal astigmatism, ocular aberrations, corneal aberrations, and subjective vision quality were evaluated after surgery.Results: At 12-weeks post-surgery, the mean uncorrected distance vision acuity (UDVA) was 0.06±0.09 logarithm of the minimum angle of resolution (logMAR) and 0.03±0.09 logMAR, and the mean uncorrected near vision acuity(UNVA) was 0.08±0.11 logMAR and 0.09±0.09 logMAR in the CCI and OCCI groups, respectively. The change in corneal astigmatism was 0.52 ± 0.22D and 1.06 ± 0.23D in the CCI and OCCI groups, respectively (P<0.001). Total corneal higher-order aberrations (HOAs) and trefoil increased in both groups (P<0.05); however, there was no difference in the change in total corneal HOAs between the two groups (P>0.05). Conclusions: CCI and OCCI made on a steep axis could be an option for correction of mild-to-moderate astigmatism during cataract surgery with multifocal IOL implantation.

Incisional correction of corneal astigmatism during ‎phacoemulsification – a randomized trial

Background: Phacoemulsification is regarded as a type of refractive surgery by which it is possible to ‎reduce pre-existing corneal stigmatism.‎ This study aimed to evaluate the efficacy and safety of on-axis corneal incision with or without opposite clear corneal incisions (OCCI) to correct preoperative corneal astigmatism during uncomplicated phacoemulsification ‎surgeries.‎ Methods: A randomized, prospective, parallel two-arm interventional study, which included a ‎total 40 eyes from 40 patients, was conducted.‎ Patients were divided into two groups: 20 patients as controls underwent phacoemulsification with on-axis incision (CCI group), and 20 patients underwent phacoemulsification with OCCI (OCCI group). Results: Mean astigmatic correction was significantly higher in the OCCI group (0.665 vs 0.265 diopters, p-value <0.001), compared to the CCI group. Most of the parameters (surgical induced astigmatism, magnitude of error, and correction index) were significantly higher in the OCCI group compared to the CCI group (p-value <0.01). There were no ‎incision-related complications. Conclusions: Both incisional methods are useful methods for correction of preoperative corneal ‎astigmatism but OCCIs correct a higher amount of astigmatism than the on-axis clear ‎corneal incision.‎ Registration: ClinicalTrials.gov NCT04418986 (05/06/2020).

Long-term outcomes of “open iridectomy” for secondary anterior chamber epithelial iris cysts

Epithelial cysts run a high risk of recurrence and conversion to sheet-like ingrowth after surgical intervention. In this retrospective study, we introduced a modified iridectomy for treatment of secondary epithelial iris cysts (EICs) in the anterior chamber. Twenty-nine patients (29 eyes) aged 2–61 years received “open iridectomy” for EICs between April 1995 and July 2019. After viscodissection, most of the cyst wall was cut using a 20-gauge aspiration cutter via a 2.5-mm clear corneal incision. The residue closely adhering to the iris stroma was remained to avoid photophobia and diplopia. At 3 months, best corrected visual acuity was ≥ 20/100 in 55.5% (15/27, except two pediatric patients with poor cooperation) of patients. Among the eight patients suffering partial corneal edema preoperatively, six patients received surgery treatment at 3–6.5 months, and the cornea in the other two patients became transparent after medication. In a mean follow-up of 47.4 months, recurrence occurred in 3 patients at 7, 37, and 118 months, respectively. The percentage of treatment success was 96%, 87%, and 65% at 1, 5, and 10 years, respectively. “Open iridectomy” was effective for EICs, with a minimal invasion, less damage to the corneal endothelium, and a low recurrence rate.

Effect of phacoemulsification on intraocular pressure and bleb function in eyes with previous trabeculectomy

AIM: To observe the intraocular pressure (IOP) control and bleb function after phacoemulsification in patients with previous history of successful/qualified success mitomycin-C augmented trabeculectomy. METHODS: This was a retrospective cohort study. Data of patients who had undergone trabeculectomy with subsequent cataract surgery were extracted from server. All patients had previous either success/qualified success trabeculectomy done. They went through uncomplicated phacoemulsification via clear corneal incision. Postoperative follow-up, review of bleb and IOP readings using Goldmann tonometer were taken. Details that were investigated include postoperative IOP control, visual improvement, number of anti-glaucoma medications, as well as the timing from trabeculectomy to phacoemulsification. Comparison with control group was made. RESULTS: Fifteen eyes from thirteen patients fulfilled the criteria for study and had undergone uncomplicated phacoemulsification between January 2014 to June 2016 on a post-trabeculectomy eye. Two of the eyes had secondary glaucoma while the other thirteen had primary glaucoma. All phacoemulsifications were done at least 6mo after trabeculectomy (mean 14.7±4.3mo). There was only 1 eye (6.7%) requiring anti-glaucoma medications before the cataract surgery. This number increased to 4 (26.7%) at 1-year post phacoemulsification. The number further increased to eight (53.3%) at 2y post-phacoemulsification. The number of anti-glaucoma drops needed after surgery at 2y ranged from 2-4. In all the 15 eyes, there was no statistically significant change in IOP control between pre-cataract surgery (mean 13.4±2.9 mm Hg) compared to 1y (mean 14.1±3.2 mm Hg, P=0.357) and 2y (mean 15.1±3.3 mm Hg, P=0.212) post phacoemulsification. Visual improvement after phacoemulsification however is significant, from a preoperative average visual acuity of logMAR 1.52±1.00 to a postoperative average visual acuity of 0.53±0.54 (P=0.000, paired t-test). CONCLUSION: This analysis shows significant visual improvement following cataract surgery in post-trabeculectomy patients without compromising IOP control. However, a reduced bleb function is noted following the surgery evidenced by the increase in number of anti-glaucoma drops used after surgery especially two years after the cataract surgery. Patients should be counselled regarding the possibility of restarting on anti-glaucoma medications post-phacoemulsification. The timing and sequence of cataract and glaucoma surgery should be optimized for best outcome.

Comparison of Mean and Centroid of Surgically Induced Astigmatism After Standard Cataract Surgery

Purpose: To compare the arithmetic mean of surgically induced astigmatism (M-SIA) and the centroid of surgically induced astigmatism (C-SIA) after standard cataract surgery.Methods: We retrospectively examined 200 eyes of 100 consecutive patients undergoing bilateral cataract surgery through a 2.8 mm temporal clear corneal incision. We quantitatively measured the magnitude and axis of corneal astigmatism preoperatively and 3 months postoperatively using an automated keratometer (TONOREFF-II, Nidek). We assessed the M-SIA, the C-SIA, and the double angle plots for the display of the individual SIA distributions.Results: For bilateral data analysis, the magnitude of corneal astigmatism significantly increased from 0.66 ± 0.39 D preoperatively to 0.74 ± 0.46 D postoperatively (paired t-test, p = 0.012). The M-SIA was 0.50 ± 0.36 D. On the other hand, the C-SIA was 0.18 ± 0.60 D at an axis of 97°. For unilateral analysis, we obtained similar outcomes between the right and left eye groups.Conclusions: According to our experience, standard cataract surgery induces the M-SIA by approximately 0.5 D. The magnitude of the C-SIA largely decreased to approximately 40% of the M-SIA, and the direction of the C-SIA showed a tendency toward with-the-rule astigmatism. It should be noted that the M-SIA was considerably different from the C-SIA, especially when selecting the appropriate toric IOL model and power.

Two Different Corneal Incision Designs for Correcting Corneal Astigmatism During Cataract Surgery With Multifocal Intraocular Lens Implantation

Background: Multifocal intraocular lenses (IOLs) is very intolerant to residual corneal astigmatism and patients with more than 1.0 D of residual corneal astigmatism are not suitable candidates for implantation of multifocal IOLs. The purpose of this study was to evaluate the efficacy of a single clear corneal incision (CCI) or an opposite clear corneal incision (OCCI) made on a steep meridian for correction of low to moderate corneal astigmatism during implantation of multifocal IOLs.Methods: This is a retrospective cohort study. A total of 50 patients with pre-operative total corneal astigmatism, ranging between 0.5 and 2.0 diopters (D), who underwent cataract surgery and received multifocal IOLs were included. Correction of corneal astigmatism was done via single CCIs on steep meridians in patients with 0.5–1.2 D total corneal astigmatisms, and OCCIs in patients with 1.3–2.0 D total corneal astigmatisms. Visual acuity, corneal astigmatism, ocular aberrations, corneal aberrations, and subjective vision quality were evaluated after surgery.Results: At 12-weeks post-surgery, the mean uncorrected distance vision (UCDV) was 0.06±0.09 logarithm of the minimum angle of resolution (logMAR) and 0.03±0.09 logMAR, and the mean uncorrected near vision (UCNV) was 0.08±0.11 logMAR and 0.09±0.09 logMAR in the CCI and OCCI groups, respectively. The change in corneal astigmatism was 0.52 ± 0.22D and 1.06 ± 0.23D in the CCI and OCCI groups, respectively (P<0.001). Total corneal higher-order aberrations (HOAs) and trefoil increased in both groups (P<0.05); however, there was no difference in the change in total corneal HOAs between the two groups (P>0.05). Conclusions: CCI and OCCI made on a steep axis could be an option for correction of mild-to-moderate astigmatism during cataract surgery with multifocal IOL implantation.