Corneal Optical Quality Following Sub 1.8 mm Micro-Incision Cataract Surgery vs. 2.2 mm Mini-Incision Coaxial Phacoemulsification

Effective Lens Position According to Incision Width in Cataract Surgery Using Phacoemultification and Posterior Chamber Lens Implantation

PURPOSE

To compare effective lens position (ELP) after phacoemulsification between micro-incision (2.25 mm) and small-incision (2.75 mm) groups.

METHODS

Sixty-seven eyes with age-related cataracts were randomly divided into two groups based on the width of the corneal incision (micro-incision [n = 33] and small-incision groups [n = 34]). Participants underwent clear corneal incision phacoemulsification combined with intraocular lens implantation. Uncorrected visual acuity, refractive error, corneal astigmatism, and ELP were measured preoperatively and at 2 months postoperatively. ELP was calculated using the Sheimpflug method.

RESULTS

Postoperative mean visual acuity and refractive error did not differ between the groups (logMAR 0.02 vs. logMAR 0.04, P = 0.108; -0.30 diopter [D] vs. + 0.07 D, P = 0.339). The postoperative surgically-induced corneal astigmatism was higher in the small-incision group than it was in the micro-incision group, although the difference did not reach statistical significance (+ 0.01 D vs. -0.36 D, P = 0.063). The mean difference between the pre and postoperative ELP values was significantly higher in the small-incision group than that in the micro-incision group (-0.04 mm vs. -0.51 mm, P = 0.024).

CONCLUSIONS

Although there was no significant difference in postoperative refractive error and corneal astigmatism between the micro- and small-incision phacoemulsification groups, the mean error between pre and postoperative ELP was higher in eyes that underwent phacoemulsification with larger corneal incisions than it was in those that underwent smaller incisions.

Evaluation of clinical outcomes following implantation of a sub-2-mm hydrophilic acrylic MICS intraocular lens

PURPOSE

To evaluate clinical outcomes following sub-2-mm microincision cataract surgery (MICS) and intraocular lens (IOL) implantation.

SETTING

Five EU clinical sites.

DESIGN

Prospective, multicenter, open-label, single-arm, non-randomized.

METHODS

Preoperative assessment involved visual acuity (VA), intraocular pressure and biometry measurements. 1.4-mm wound-assisted or 1.8-mm MICS was performed. Follow-up visits were made 1 day, 1-2 weeks, 1-2 and 4-6 months after surgery. The incision size, corrected distance VA (CDVA), uncorrected distance VA, manifest refraction spherical equivalent (MRSE), refraction predictability/stability and IOL decentration were assessed. At 12-, 18-, and 24-month, long-term centration, posterior capsular opacification (PCO) and Nd:YAG capsulotomy rates were investigated.

RESULTS

A total of 103 eyes were implanted with the study IOL (INCISE, Bausch & Lomb), 96 of which were included in visual outcome analysis. A mean 6-month CDVA of - 0.02 logMAR (20/20 + 1) was observed and 75 eyes (79.8%) and 93 eyes (98.3%) achieved a visual acuity of at least 20/20 or 20/40. Mean MRSE was - 0.20 ± 0.60 D. Mean absolute predictive error was 0.44 ± 0.36 D, with 90.4% within 1.00 D of target. Mean total decentration was 0.35 ± 0.36 mm at 6 months and 0.32 ± 0.14 mm at 24 months (p > 0.05). 24-month evaluation of posterior capsular opacification score was 0.03 for the central area. A Nd:YAG rate of 3.4% was observed at 24 months.

CONCLUSIONS

The new MICS IOL provided excellent visual outcomes and was safe and effective for the sub-2-mm procedure. The MICS IOL demonstrated long-term centration, stability and a low rate of PCO development.

Different-sized incisions for phacoemulsification in age-related cataract

BACKGROUND

Age-related cataract is the principal cause of blindness and visual impairment in the world. Phacoemulsification is the main surgical procedure used to treat cataract. The comparative effectiveness and safety of different-sized incisions for phacoemulsification has not been determined.

OBJECTIVES

The aim of this systematic review was to assess the effectiveness and safety of smaller versus larger incisions for phacoemulsification in age-related cataract. The primary outcome of this review was surgically induced astigmatism at three months after surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 10), MEDLINE Ovid (1946 to 28 October 2016), Embase Ovid (1947 to 28 October 2016), PubMed (1948 to 28 October 2016), LILACS (Latin American and Caribbean Health Sciences Literature Database) (1982 to 28 October 2016), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com; last searched 13 May 2013), ClinicalTrials.gov (www.clinicaltrials.gov; searched 28 October 2016), and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp; searched 28 October 2016). We did not use any date or language restrictions in the electronic searches for trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing different-sized incisions in people with age-related cataract undergoing phacoemulsification.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 26 RCTs with a total of 2737 participants (3120 eyes). These trials were conducted in Bosnia and Herzegovina, China, France, India, Italy, Korea, Spain, Switzerland, and Turkey. Half of the 26 trials were conducted in China. We judged all trials as mostly at unclear to low risk of bias. The included RCTs compared four different-sized incisions:<= 1.5 mm, 1.8 mm, 2.2 mm, and approximately 3.0 mm. These incisions were performed using three different techniques: coaxial and biaxial microincision phacoemulsification (C-MICS and B-MICS) and standard phacoemulsification. Not all studies provided data in a form that could be included in this review. Five studies had three arms.Fifteen trials compared C-MICS (2.2 mm) with standard phacoemulsification (about 3.0 mm). Very low-certainty evidence suggested less surgically induced astigmatism in the C-MICS group at three months compared with standard phacoemulsification (mean difference (MD) -0.19 diopters (D), 95% confidence interval (CI) -0.30 to -0.09; 996 eyes; 8 RCTs). There was low-certainty evidence that both groups achieved similar best-corrected visual acuity (MD 0.00 logMAR, 95% CI -0.02 to 0.02; 242 eyes; 3 RCTs). There was low-certainty evidence of little or no difference in endothelial cell loss and central corneal thickness comparing C-MICS with standard phacoemulsification (MD -7.23 cells/mm², 95% CI -78.66 to 64.20; 596 eyes; 4 RCTs) and (MD -0.68 μm, 95% CI -3.26 to 1.90; 487 eyes; 5 RCTs).Nine trials compared C-MICS (1.8 mm) with standard phacoemulsification (about 3.0 mm). Very low-certainty evidence suggested less astigmatism at three months in the C-MICS group compared with standard phacoemulsification group (MD -0.23 D, 95% CI -0.34 to -0.13; 561 eyes; 5 RCTs). Low-certainty evidence suggested little or no difference in best-corrected visual acuity, endothelial cell loss, and central corneal thickness in the two groups at three months (MD -0.02 logMAR, 95% CI -0.03 to -0.00; 192 eyes; 3 RCTs), (MD 7.56 cells/mm², 95% CI -67.65 to 82.77; 380 eyes; 5 RCTs), and (MD -1.52 μm, 95% CI -6.29 to 3.25; 245 eyes; 3 RCTs).Six studies compared C-MICS (1.8 mm) with C-MICS (2.2 mm). There was low-certainty evidence that astigmatism, visual acuity, and central corneal thickness were similar in the two groups at three months (MD 0.04 D, 95% CI -0.09 to 0.16; 259 eyes; 3 RCTs), (MD 0.01 logMAR, 95% CI -0.01 to 0.04; 200 eyes; 3 RCTs), and (MD 0.45 μm, 95% CI -2.70 to 3.60; 100 eyes; 1 RCT). Very low-certainty evidence suggested higher endothelial cell loss in the 1.8 mm group (MD 213.00 cells/mm², 95% CI 11.15 to 414.85; 70 eyes; 1 RCT).Four studies compared B-MICS (<= 1.5 mm) with standard phacoemulsification (about 3.0 mm). Astigmatism was similar in the two groups at three months (MD -0.01 D, 95% CI -0.03 to 0.01; 368 eyes; 2 RCTs; moderate-certainty evidence). There was low-certainty evidence on visual acuity, suggesting little or no difference between the two groups (MD -0.02 logMAR, 95% CI -0.04 to -0.00; 464 eyes; 3 RCTs). Low-certainty evidence on endothelial cell loss and central corneal thickness also suggested little or no difference between the two groups (MD 55.83 cells/mm², 95% CI -34.93 to 146.59; 280 eyes; 1 RCT) and (MD 0.10 μm, 95% CI -14.04 to 14.24; 90 eyes; 1 RCT).None of the trials reported on quality of life. One trial reported that no participants experienced endophthalmitis or posterior capsule rupture; they also reported little or no difference between incision groups regarding corneal edema (risk ratio 1.02, 95% CI 0.40 to 2.63; 362 eyes).

AUTHORS' CONCLUSIONS

Phacoemulsification with smaller incisions was not consistently associated with less surgically induced astigmatism compared with phacoemulsification with larger incisions. Coaxial microincision phacoemulsification may be associated with less astigmatism than standard phacoemulsification, but the difference was small, in the order of 0.2 D, and the evidence was uncertain. Safety outcomes and quality of life were not adequately reported; these should be addressed in future studies.

Bimanual Microincision Cataract Surgery versus Coaxial Microincision Cataract Surgery: A Meta-Analysis of Randomized Controlled Trials and Cohort Studies

PURPOSE

This meta-analysis was conducted to compare the intraoperative and postoperative outcomes of bimanual microincision cataract surgery (B-MICS) and coaxial microincision cataract surgery (C-MICS).

METHODS

Three databases were searched for papers that compared B-MICS and C-MICS from inception to June 2016. The following intraoperative and postoperative outcomes were included in the final meta-analysis: ultrasound time (UST), effective phacoemulsification time (EPT), balanced salt solution use (BSS use), mean surgery time, best-corrected visual acuity (BCVA), central corneal thickness (CCT), and increased CCT.

RESULTS

There were no statistically significant differences in mean surgery time, UST, BSS use, BCVA, CCT, or increased CCT (one subgroup at postoperative day 7-8 and another subgroup at postoperative day 30). However, there was less EPT needed during surgery (p < 0.01) and lower levels of increased CCT at postoperative day 1 (p = 0.02) in the B-MICS group compared with the C-MICS group.

CONCLUSIONS

The EPT was shorter and increased CCT was less at postoperative day 1 in the B-MICS group. There were no statistically significant differences in other intraoperative and postoperative outcomes between the B-MICS group and the C-MICS group. B-MICS is an efficient and safe cataract surgery procedure.

Clinical results after microincision biaxial cataract surgery and implantation of an Incise intraocular lens

PURPOSE

To evaluate clinical outcomes after uncomplicated microincision biaxial cataract surgery and implantation of Incise intraocular lens (IOL).

METHODS

This study included 47 eyes of 29 patients (mean age 62.2 ± 8.6 years), who underwent 1.4-mm biaxial cataract surgery with implantation of the Incise IOL (Bausch and Lomb). At third month, surgically induced astigmatism (SIA) was calculated. Three, 6 and 12 months postoperatively, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corrected near visual acuity (CNVA) LogMAR ETDRS, spherical equivalent refraction (SER), photopic distance corrected contrast sensitivity (CS) with and without glare (85 cd/m²) (CSV-1000) were assessed. One year after surgery, late complications were assessed and subjects were questioned for subjective symptoms.

RESULTS

Mean of SIA was equal 0.29 ± 0.16 D. Three months postoperatively: mean UDVA improved from 0.83 to 0.04 (p < 0.001), CDVA from 0.58 to -0.05 (p < 0.001) and CNVA from 0.58 to -0.02 (p < 0.001) and all were stable during 1-year follow-up. Three months postoperatively, the mean SER was equal 0.07 ± 0.61 D and was within ±0.5 D in 79%, and within 1 D in 88% of eyes. During follow-up period, corrected CS with and without glare for distance was found to be within normal limits. The only late complication was posterior capsule opacification (PCO). Subjective quality of vision was very high; none of patients complained about glare.

CONCLUSIONS

Biaxial cataract surgery with implantation of the Incise IOL provided excellent clinical outcomes by minimizing SIA, stable refraction and low incidence of PCO.

Effect of Limbal relaxing incisions during implantable collamer lens surgery

Background

The limbal relaxing incisions (LRIs) technique is a safe and an inexpensive procedure, which is simple for experts to perform. It can effectively reduce astigmatism and result in a rapid visual rehabilitation. But there are few reports about reducing pre-existing corneal astigmatism by LRI in ICL surgery. Our research was aimed to study the effect of limbal relaxing inci sions during implantable collamer lens (ICL) surgery.

Methods

A prospective analysis reviewing consecutive cases of corneal astigmatism that had either independent ICL surgery (control group) or combined with LRIs (LRIs group). The study population consisted of 45 patients, 85 eyes, with high myopia and regular corneal astigmatism more than 0.50 diopter (D) and less than 3.00 D. The first group received ICL surgery combined with LRIs (limbal relaxing incisions); the control group received only ICL surgery alone. The outcomes considered were uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (BCVA), refraction, keratometry, slit lamp biomicroscopy, indirect ophthalmoscopy, corneal topography, corneal astigmatism, endothelial cell count, and patient satisfaction. The follow-up period covered 12 months.

Results

The mean uncorrected distance visual acuity (UDVA) and the best corrected visual acuity (BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up period, the UCVA was statistically better for the patients with LRIs compared with those underwent ICL surgery alone. The LRIs group showed significant reduction in the mean topographic astigmatism from 1.48 ± 0.35 D preoperatively to 0.37 ± 0.14 D postoperatively (P < .0001) after one month. The control eyes did not show a statistically significant change (P > 0.05). The mean magnitude of the surgically induced astigmatism (SIA) read 1.10 ± 0.35 D,1.13 ± 0.34D,1.13 ± 0.34D,1.11 ± 0.35D by the end of the 1st, the ^3rd, the ^6th and the 12th month postoperatively in LRIs group, which was slightly lower than the target-induced astigmatism (TIA). The difference in SIA between the LRI and the control group was statistically significant by the end of the 1st, the ^3rd, the ^6th and the 12th month postoperatively (P < 0.001). The mean correction index (CI) was less than 1, which indicated undercorrection effect of limbal relaxing incision. No difference was observed in the postoperative endothelial cell count between the two groups. There was no intraoperative and postoperative ocular or systemic complication.

Conclusion

Limbal relaxing incision is an effective method in reducing corneal astigmatism during implantable collamer lens surgery.

Trial registration

The trial was retrospectively registered in 14 April 2017. (NO:ChiCTR-ONR-17011147).

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-017-0458-7) contains supplementary material, which is available to authorized users.

Effect of biaxial versus coaxial microincision cataract surgery on optical quality of the cornea

Context:

Visual function is determined by a combination of the cornea, which has a larger effect and internal aberrations generated by the intraocular lens and those induced by the surgery. These corneal refractive changes are related to the location and size of the corneal incision. The smaller the incision, the lower the aberrations and the better the optical quality.

Aims:

To compare the effect of uneventful coaxial versus biaxial microincision cataract surgery (MICS) on the corneal aberrations.

Settings and Design:

Retrospective interventional nonrandomized comparative case study comprised 40 eyes of 36 patients with primary senile cataract.

Subjects and Methods:

They were divided into two groups: Group I (20 eyes) had operated by biaxial MICS and Group II (20 eyes) had operated by coaxial MICS. Each group were assessed by corneal topography and wavefront analysis over 6 mm pupil size preoperatively and 1-month postoperatively.

Statistical Analysis Used:

Statistical analysis was performed using SPSS for Windows (version 17.0.1, SPSS, Inc.). The paired t-test was used to compare the mean values of corneal aberrations preoperatively and 1-month postoperatively in each group.

Results:

There was a significant increase in trefoil and quatrefoil in biaxial MICS (P = 0.063, 0.032 respectively) while other aberrations insignificantly changed. The coaxial MICS showed a significant increase in root mean square (RMS) of total high order aberrations (HOAs) (P = 0.02) and coma (0.028), but not the others. In comparison to each other, there was the insignificant difference as regards astigmatism, RMS of individual and total HOAs.

Conclusions:

Coaxial and biaxial MICS are neutral on corneal astigmatism and aberrations.

Visual and refractive outcomes after cataract surgery with implantation of a new toric intraocular lens

Purpose

The aim of this study was to evaluate and report the visual, refractive and aberrometric outcomes of cataract surgery with implantation of the new aspheric Tecnis ZCT toric intraocular lens (IOL) in eyes with low to moderate corneal astigmatism.

Methods

We conducted a prospective study of 19 consecutive eyes of 17 patients (mean age: 78 years) with a visually significant cataract and moderate corneal astigmatism [higher than 1 diopter (D)] undergoing cataract surgery with implantation of the aspheric Tecnis ZCT toric IOL (Abbott Medical Optics). Visual, refractive and aberrometric changes were evaluated during a 6-month follow-up. Ocular aberrations as well as IOL rotation were evaluated by means of the OPD-Station II (Nidek).

Results

The six-month postoperative spherical equivalent and power vector components of the refractive cylinder were within ±0.50 D in all eyes (100%). Postoperative logMAR uncorrected and corrected distance visual acuities (UDVA/CDVA) were 0.1 (about 20/25) or better in almost all eyes (94.74%). The mean logMAR CDVA improved significantly from 0.41 ± 0.23 to 0.02 ± 0.05 (p < 0.01). No significant changes were found in corneal astigmatism (p = 0.73). The mean IOL rotation was 3.33 ± 1.94°. This parameter did not correlate with higher-order aberrations (r = −0.09, p = 0.73). A significant improvement in the Strehl ratio was also observed (p < 0.01), which was consistent with the significant reduction in higher-order aberrations (p = 0.02).

Conclusion

Cataract surgery with implantation of the aspheric Tecnis ZCT IOL is a predictable and effective procedure for visual rehabilitation in eyes with cataract and low to moderate corneal astigmatism, providing an excellent postoperative ocular optical quality.