Biaxial microincision cataract surgery versus conventional coaxial cataract surgery: Metaanalysis of randomized controlled trials

Narrative review after post-hoc trial analysis of factors that predict corneal endothelial cell loss after phacoemulsification: Tips for improving cataract surgery research

PURPOSE

Identifying pre/perioperative factors that predict corneal endothelial-cell loss (ECL) after phacoemulsification may reveal ways to reduce ECL. Our literature analysis showed that 37 studies have investigated one or several such factors but all have significant limitations. Therefore, the data of a large randomized controlled trial (PERCEPOLIS) were subjected to post-hoc multivariate analysis determining the ability of nine pre/perioperative variables to predict ECL.

METHODS

PERCEPOLIS was conducted in 2015-2016 to compare two phacoemulsification techniques (subluxation and divide-and-conquer) in terms of 3-month ECL. Non-inferiority between the techniques was found. In the present study, post-hoc univariate and multivariate analyses were conducted to determine associations between ECL and age, sex, cataract density, preoperative endothelial-cell density, phacoemulsification technique, effective phaco time (EPT), and 2-hour central-corneal thickness. The data are presented in the context of a narrative review of the literature.

RESULTS

Three-month data were available for 275 patients (94% of the randomized cohort; mean age, 74 years; 58% women). Mean LOCSIII cataract grade was 3.2. Mean EPT was 6 seconds. Mean ECL was 13%. Only an older age (beta = 0.2%, p = 0.049) and higher EPT (beta = 1.2%, p = 0.0002) predicted 3-month ECL. Cataract density was significant on univariate (p = 0.04) but not multivariate analysis. The other variables did not associate with ECL.

CONCLUSIONS

Older age may amplify ECL due to increased endothelial cell fragility. EPT may promote ECL via cataract density-dependent and -independent mechanisms that should be considered in future phacoemulsification research aiming to reduce ECL. Our literature analysis showed that the average ECL for relatively unselected consecutively-sampled cohorts is 12%.

Kataraktoperation beim Vorliegen einer Fuchs-Endotheldystrophie

Bei Betroffenen mit einer Fuchs-Endotheldystrophie beginnen die Probleme mit den Augen häufig in einem Alter, in dem sich auch schon erste Anzeichen einer Katarakt zeigen. Und umgekehrt findet man in der augenärztlichen Praxis immer wieder Patient*innen mit einer deutlichen Katarakt und einer Cornea guttata als Nebenbefund. In beiden Situationen stellt sich dann die Frage, ob zunächst nur eine posteriore lamelläre Keratoplastik (in Deutschland meist als DMEK) bzw. nur eine Kataraktoperation erfolgen oder ob gleich ein kombiniertes Vorgehen (sog. Triple-Operation) angestrebt werden sollte. Nur bei jungen Betroffenen mit einer fortgeschrittenen Fuchs-Endotheldystrophie ohne jeglichen Hinweis auf eine Katarakt und gut erhaltener Akkommodation kann, je nach individuellen Gegebenheiten, eine alleinige DMEK sinnvoll sein, in allen anderen Fällen erscheint eine Triple-Operation geeigneter. Dabei erscheint ein sequenzielles Vorgehen in diesen Situationen weniger angebracht, da sich in zahlreichen Studien zeigte, dass der Verlauf und die Ergebnisse nach einer Triple-Operation mit denen nach einem sequenziellen Vorgehen vergleichbar sind. Beim Vorliegen einer signifikanten Katarakt und einer Cornea guttata fällt die Entscheidung im Hinblick auf das operative Vorgehen deutlich schwerer. Hierbei gibt es unterschiedliche Aspekte in der Anamnese sowie den ophthalmologischen Untersuchungen (z. B. zentrale Hornhautdicke, Endothelzelldichte), die einem bei der Entscheidung helfen können. Soll dann zunächst nur eine Kataraktoperation erfolgen, sollten geeignete Maßnahmen ergriffen werden, um ein möglichst optimales Ergebnis trotz Vorliegen der Cornea guttata zu erreichen. Im folgenden Beitrag soll auf die wichtigsten prä-, peri- und postoperativen Aspekte im Hinblick auf die bestmögliche operative Versorgung von Betroffenen mit Fuchs-Endotheldystrophie und Katarakt eingegangen werden.

Corneal endothelial cell density loss following glaucoma surgery alone or in combination with cataract surgery: A systematic review and meta-analysis

TOPIC

Corneal endothelial cell density (ECD) loss following glaucoma surgery with or without cataract surgery.

CLINICAL RELEVANCE

Corneal ECD loss may occur due to intraoperative surgical trauma in glaucoma surgery or postoperatively with chronic endothelial cell trauma or irritation.

METHODS

Trabeculectomy, glaucoma filtration surgery or microinvasive glaucoma surgery in participants with ocular hypertension, primary and secondary open angle glaucoma, normal tension glaucoma and angle-closure glaucoma were included. Pediatric populations and participants with pre-existing corneal disease were excluded. Laser treatments and peripheral iridotomy were excluded. Electronic databases searched in December 2021 included MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov and The International Prospective Register of Systematic Reviews (PROSPERO), FDA PMA and FDA 510(k).

RESULTS

39 studies were included in quantitative synthesis. 12 months following suprachoroidal MIGS mean ECD loss was 282 cells/mm² (95% Confidence Interval (CI) 220 to 345; p <0.00001; Chi² = 0.06; I² = 0%; 2 studies; very low certainty). Mean ECD loss after Schlemm's canal implantable devices was 338 cells/mm² (95% CI 185 to 491; p<0.0001; Chi² = 0.08; I² = 0%; 2 studies; low certainty) at 12 months. When compared to phacoemulsification alone, Schlemm's canal implants combined with phacoemulsification showed statistically significant mean ECD reduction at 24 months; mean difference of ECD was -19% (95% CI -37% to -2%; p=0.03; Chi² = 3.04; I² = 34%; 3 studies; low certainty). Mean ECD loss was 64 cells/mm² (95% CI 21 to 107; p=0.004; Chi² = 4.55; I² = 0%; 6 studies; low certainty) following Schlemm's canal procedures (without implantable devices) at 12 months. At 12 months the mean ECD loss after trabeculectomy was 33 cells/mm² (95% CI -38 to 105, p=0.36, Chi² = 1.17; I² = 0%; moderate certainty). At 12 months mean ECD loss was 121 cells/mm² (95% CI 53 to 189; p=0.0005; Chi² = 3.00; I² = 0%; 5 studies; low certainty) after Express implantation. When compared to control fellow eye, aqueous shunt surgery reduced ECD by 5.75% (95% CI -0.93 to 12.43; p=0.09 Chi² = 1.32; I² = 0%; low certainty) and 8.11% ECD loss (95%CI 0.06 to 16.16 p=0.05; Chi²= 1.93; I²=48%) at 12 and 24 months, respectively.

CONCLUSIONS

Overall there is low certainty evidence to suggest that glaucoma surgery involving long-term implants has a greater extent of ECD loss than glaucoma filtration surgeries without the use of implants. The results of this review support long-term follow-up (beyond 36 months) to assess ECD loss and corneal decompensation following implantation of glaucoma drainage implants.

Effect of Central Corneal Thickness on Corneal Higher Order Aberrations After Cataract Surgery

PURPOSE

To investigate the changes of corneal higher order aberrations (HOAs) before and after phacoemulsification in patients with different central corneal thickness (CCT).

METHODS

In this retrospective non-randomized, non- comparative cases series, 51 eyes of 51 patients who underwent phacoemulsification were enrolled. The corneal total HOAs and Zernike coefficients (3rd and 4th order) over the 3- and 4-mm zones were measured by the iTrace aberrometer (Tracey Technologies). Participants were divided into three groups (528 µm or less, 529 to 550 µm, and greater than 550 µm) depending on the CCT tested by the LenStar LS900 (Haag Streit AG). The corneal aberrations between groups were compared with analysis of variance, the variation of corneal aberrations before and after phacoemulsification was analyzed by the paired-samples t test, and generalized linear models were used to compare postoperative aberrations between groups.

RESULTS

Significant differences were found in oblique trefoil at 3 mm and vertical trefoil, oblique trefoil, and HOAs at 4 mm in the 528 µm or less group; vertical trefoil, oblique trefoil, oblique quadrafoil, and oblique secondary astigmatism at 3 mm and oblique trefoil and oblique secondary astigmatism at 4 mm in the 529 to 550 µm group; and vertical quadrafoil at 3 mm in the greater than 550 µm group. After corrected deviation of preoperative aberrations, there were significant differences in postoperative vertical coma and oblique secondary astigmatism at 4 mm when compared to the 528 µm or less and greater than 550 µm groups.

CONCLUSIONS

The lower the CCT, the greater the change in corneal aberrations in patients with cataract after phacoemulsification. Surgeons should be aware of the potential for worse visual quality related to surgically induced aberrations in patients with thin corneas. [J Refract Surg. 2021;37(12):842-847.].

Long-Term Visual Quality after Microincision Cataract Surgery

Purpose

Few studies have focused on long-term postoperative visual quality. This study aimed to evaluate the long-term visual quality after microincision cataract surgery (MICS).

Methods

96 patients (144 eyes) diagnosed with age-related cataracts were enrolled in this one-year study. The patients underwent MICS and received aspheric monofocal intraocular lens implants. Uncorrected distance visual acuity (UDVA) was evaluated together with best-corrected distance visual acuity (BCDVA), best-corrected near visual acuity (BCNVA), contrast sensitivity, and surgically induced astigmatism (SIA).

Results

Compared to preoperative measurements, UDVA, BCDVA, and BCNVA were significantly better after surgery (P < 0.001), and they remained stable throughout follow-up. Contrast sensitivity was also significantly better after surgery (P < 0.001). Mean SIA during follow-up was 0.57 ± 0.33 D at 1 week, 0.36 ± 0.25 D at 3 months, and 0.18 ± 0.16 D at 1 year. SIA decreased significantly during the postoperative period (P < 0.001). The 1-year postoperative absolute residual diopter value was 0.32 ± 0.28 D.

Conclusion

MICS can provide excellent visual quality as soon as on postoperative day 1, which persists during the follow-up period of 1 year. In contrast to previous studies, SIA decreases over time and may not completely stabilize for as long as 1 year postoperatively.

Identification and Description of Reliable Evidence for 2016 American Academy of Ophthalmology Preferred Practice Pattern Guidelines for Cataract in the Adult Eye

Importance

Trustworthy clinical practice guidelines require reliable systematic reviews of the evidence to support recommendations. Since 2016, the American Academy of Ophthalmology (AAO) has partnered with Cochrane Eyes and Vision US Satellite to update their guidelines, the Preferred Practice Patterns (PPP).

Objective

To describe experiences and findings related to identifying reliable systematic reviews that support topics likely to be addressed in the 2016 update of the 2011 AAO PPP guidelines on cataract in the adult eye.

Design, Setting, and Participants

Cross-sectional study. Systematic reviews on the management of cataract were searched for in an established database. Each relevant systematic review was mapped to 1 or more of the 24 management categories listed under the Management section of the table of contents of the 2011 AAO PPP guidelines. Data were extracted to determine the reliability of each systematic review using prespecified criteria, and the reliable systematic reviews were examined to find whether they were referenced in the 2016 AAO PPP guidelines. For comparison, we assessed whether the reliable systematic reviews published before February 2010 the last search date of the 2011 AAO PPP guidelines were referenced in the 2011 AAO PPP guidelines. Cochrane Eyes and Vision US Satellite did not provide systematic reviews to the AAO during the development of the 2011 AAO PPP guidelines.

Main Outcomes and Measures

Systematic review reliability was defined by reporting eligibility criteria, performing a comprehensive literature search, assessing methodologic quality of included studies, using appropriate methods for meta-analysis, and basing conclusions on review findings.

Results

From 99 systematic reviews on management of cataract, 46 (46%) were classified as reliable. No evidence that a comprehensive search had been conducted was the most common reason a review was classified as unreliable. All 46 reliable systematic reviews were cited in the 2016 AAO PPP guidelines, and 8 of 15 available reliable reviews (53%) were cited in the 2011 PPP guidelines.

Conclusions and Relevance

The partnership between Cochrane Eyes and Vision US Satellite and the AAO provides the AAO access to an evidence base of relevant and reliable systematic reviews, thereby supporting robust and efficient clinical practice guidelines development to improve the quality of eye care.

New ophthalmic dual-viscoelastic device in cataract surgery: a comparative study

Objective

To compare the performance and safety in cataract surgery of two ophthalmic viscoelastic devices (OVDs), each having separate dispersive and cohesive characteristics and different concentrations.

Methods and analysis

In this prospective, randomised, controlled clinical study, one eye of each patient was injected with OVD1 (Viscopack14) or OVD2 (DuoVisc) during phacoemulsification and intraocular lens implantation. Endothelial cell count, intraocular pressure (IOP), central corneal thickness (CCT), intraocular inflammation and corrected distance visual acuity (CDVA) were compared 3 months postoperatively.

Results

The study enrolled 127 patients. Randomisation assigned 50 eyes of as many patients to each arm of the study. The postoperative mean endothelial cell loss was 14.4% and 7.1% from baseline in the OVD1 and OVD2 groups, respectively (p=0.08). The incidence of IOP spikes at 2 hours was 0% and 8%, respectively (p=0.02). There were intergroup differences in postoperative IOP values, the OVD2 group showed significantly higher values at all of the follow-up visits starting from the 24 hours examination (p<0.05). There was no statistically significant difference in the CCT, intraocular inflammation and CDVA at the end of follow-up.

Conclusion

Both OVDs showed similar clinical performances and were equally effective during cataract surgery. Viscopack14 showed more corneal endothelial cell reduction, while DuoVisc had more occurrences of IOP values and spikes. Future studies are mandatory to support these preliminary results.

Accuracy of toric intraocular lens implantation using automated vs manual marking

BACKGROUND

Accurate alignment of toric intraocular lens (TIOL) to steep corneal astigmatic axis is important to achieve effective postoperative results. The authors compare the accuracy of astigmatism correction using automated and manual marking in TIOL implantation during cataract surgery.

METHODS

One hundred thirty-two eyes with nuclear density from Grade 2 to 4 were randomly subdivided into 2 groups (automated and manual marking). All patients underwent manual marking and the steep axis was compared to SensoMotoric Instruments (SMI). After phacoemulsification, 62 patients underwent toric IOL implantation using the SMI and 70 patients underwent toric IOL implantation using manual marking. Intraoperative measurement was the steep axis difference. Clinical measurements included preoperative and postoperative best corrected visual acuity (BCVA), and TIOL axis.

RESULTS

The intraoperative steep axis difference between SMI and manual marking was 7.86 ± 6.4 degrees. The difference between the preoperative steep axis and the postoperative TIOL axis using SMI (3.63 ± 1.12 degrees) was significantly lower than that using manual marking (8.29 ± 2.23 degrees) (P < 0.05).

CONCLUSIONS

The steep axis measurements may be different when using SMI vs. manual marking. The SMI is more accurate than manual marking for TIOL implantation during cataract surgery.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN12294725 , Retrospectively registered, on 20 July 2018.

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.

Correction of low corneal astigmatism in cataract surgery

AIM

To evaluate and compare aspheric toric intraocular lens (IOL) implantation and aspheric monofocal IOL implantation with limbal relaxing incisions (LRI) to manage low corneal astigmatism (1.0-2.0 D) in cataract surgery.

METHODS

A prospective randomized comparative clinical study was performed. There were randomly recruited 102 eyes (102 patients) with cataracts associated with corneal astigmatism and divided into two groups. The first group received toric IOL implantation and the second one monofocal IOL implantation with peripheral corneal relaxing incisions. Outcomes considered were: visual acuity, postoperative residual astigmatism, endothelial cell count, the need for spectacles, and patient satisfaction. To determine the postoperative toric axis, all patients who underwent the toric IOL implantation were further evaluated using an OPD Scan III (Nidek Co, Japan). Follow-up lasted 6mo.

RESULTS

The mean uncorrected distance visual acuity (UCVA) and the best corrected visual acuity (BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up the UCVA was statistically better in the patients with toric IOL implants compared to those patients who underwent implantation of monofocal IOL plus LRI. The mean residual refractive astigmatism was of 0.4 D for the toric IOL group and 1.1 D for the LRI group (P<0.01). No difference was observed in the postoperative endothelial cell count between the two groups.

CONCLUSION

The two surgical procedures demonstrated a significant decrease in refractive astigmatism. Toric IOL implantation was more effective and predictable compared to the limbal relaxing incision.

Advances in cataract surgery: preserving the corneal endothelium

PURPOSE OF REVIEW

Cataract surgery is known to lead to some degree of corneal endothelial cell loss (ECL). The purpose of this review is to describe how recent technological advancements such as femtosecond laser-assisted cataract surgery (FLACS) affect corneal endothelium during cataract surgery.

RECENT FINDINGS

It has been suggested that FLACS may reduce the amount of required ultrasound energy used in cataract surgery, a factor known to be directly related to ECL. Several recent studies demonstrate either no difference or less ECL with FLACS than with standard phacoemulsification 1-3 months after surgery. However, results at 6 months show comparable ECL between the two techniques. Other recent advancements in surgical technique, such as biaxial microincision surgery, result in similar ECL rates to that of standard phacoemulsification. The use of ultraviolet light in the newly developing light-adjustable intraocular lenses does not increase ECL. Studies show either similar results or less ECL with the use of the newer viscous-dispersives when compared with other viscoelastic devices. Other aspects such as the use of intracameral injections have no adverse effects on corneal endothelium.

SUMMARY

Newly emerging cataract surgical techniques cause comparable ECL to that of conventional phacoemulsification. Femtosecond laser-assistance may reduce ECL, but likely only in the early postoperative period. Further studies are needed to better elucidate short and long-term effects of FLACS on the corneal endothelium. Viscous dispersives may offer equal or increased protection of the corneal endothelium during surgery compared with viscoelastic devices currently in wide use, but further studies are required to support these results.

Clinical outcomes of TECNIS toric intraocular lens implantation after cataract removal in patients with corneal astigmatism

PURPOSE

To evaluate safety and effectiveness of the TECNIS toric intraocular lenses (IOLs).

DESIGN

Prospective, multicenter, 2-armed, bilateral, 6-month clinical trial following the American National Standards Institute (ANSI) standard for Toric IOLs.

PARTICIPANTS

Subjects implanted with a TECNIS toric IOL (n = 172) or a TECNIS 1-piece control IOL (ZCB00; n = 93).

METHODS

Subjects underwent standard cataract surgery with IOL implantation. The randomized control arm consisted of subjects requiring cylinder correction of 0.75 to 1.50 diopters (D) who were implanted with either toric (ZCT150) or nontoric (ZCB00) IOLs. The open-label arm (OLA) consisted of subjects requiring cylinder correction of 1.50 to 3.62 D and implanted with ZCT225, ZCT300, or ZCT400 IOLs.

MAIN OUTCOME MEASURES

Assessments were at 1 day, 1 week, and 1, 3, and 6 months and included uncorrected distance visual acuity (UCDVA) and best-corrected distance visual acuity (BCDVA), manifest refraction, keratometry, adverse events, spectacle use, and photographic documentation of IOL rotational stability.

RESULTS

Mean percent reduction in cylinder (± standard deviation) was statistically significantly greater (P < 0.0001) for ZCT150 eyes (74.53 ± 72.25%) versus ZCB00 eyes (31.61 ± 78.73%). In the OLA, mean percent reduction in cylinder was 76.27 ± 33.09%. A UCDVA of 20/20 or better was achieved by 43.6% (44/101) of ZCT150 eyes and by 23.7% (22/93) of ZCB00 eyes (P = 0.0026). In the OLA, 38.0% (27/71) achieved 20/20 or better UCDVA. Mean UCDVA was 0.10 ± 0.14 for ZCT150 eyes and 0.16 ± 0.16 for ZCB00 eyes (P = 0.0009); in the OLA, mean UCDVA was 0.11 ± 0.12. The BCDVA was 20/40 or better for all eyes. Mean absolute lens rotation between visits for toric eyes pooled was less than 3°. Lens rotation of 5° or less occurred in 92.9% of toric eyes between 1 and 3 months and in 94.1% between 3 and 6 months, exceeding the ANSI standard for stability (≥ 90% of eyes with ≤ 5° of rotation between visits). Four lenses (2.3%) were repositioned during the study.

CONCLUSIONS

The TECNIS toric IOLs successfully reduce ocular astigmatism and are a safe and effective treatment for cataract patients with corneal astigmatism.

Bimanual microincision versus standard coaxial small-incision cataract surgery: meta-analysis of randomized controlled trials

PURPOSE

This meta-analysis aimed to evaluate the outcomes of bimanual microincision cataract surgery (B-MICS) through a 1.2- to 1.5-mm incision versus standard coaxial small-incision cataract surgery (C-SICS) through a 2.8- to 3.2-mm incision.

METHODS

A comprehensive literature search was performed according to the Cochrane Collaboration methodology to identify randomized controlled clinical trials comparing B-MICS with standard C-SICS. Main outcome measures were mean surgical time, mean phacoemulsification power, effective phacoemulsification time, best-corrected visual acuity, surgically induced astigmatism (SIA), mean laser flare photometry values, mean endothelial cell loss, mean increased central corneal thickness, and intraoperative and postoperative complications.

RESULTS

We identified 14 randomized controlled clinical trials that included 1235 eyes diagnosed with cataracts. No statistically significant differences were detected between the 2 surgical procedures in terms of best-corrected visual acuity (p&gt;0.05), SIA at postoperative 1 month (p = 0.09), laser flare photometry values (p = 0.38), mean endothelial cell loss (p = 0.53), increased central corneal thickness at postoperative 1 month (p = 0.64) or 3 months (p = 0.88), intraoperative complications (p = 0.68), and postoperative complications (p = 0.30); however, statistically significant differences were apparent for mean surgical time (p&lt;0.00001), mean phacoemulsification power (p = 0.008), effective phacoemulsification time (p = 0.0009), SIA at postoperative 3 months (p = 0.02), and increased central corneal thickness at postoperative 1 day (p = 0.04).

CONCLUSIONS

The meta-analysis shows that the 2 techniques have similar outcomes in terms of final visual acuity and complications. Bimanual MICS has the advantage of less SIA and phaco time whereas C-SICS has the advantage of quicker surgery and less likelihood of early-onset corneal edema.

Pupil-expansion ring implantation through a 0.9 mm incision

Disposable square and hexagonal Bhattacharjee pupil-expansion rings are made of 5-0 nylon, have notches at the corners, and flanges at the sides in a single 0.1 mm thin plane. To insert the ring, a flange is held with a 23-gauge forceps and the ring is inserted through a 0.9 mm (20-gauge) or larger main- or side-port incision. Alternate flanges are tucked under the iris using a Kuglen hook. A 23-gauge forceps and an iris hook can also be used to tuck the flanges bimanually. The ring is removed by disengaging 2 notches and pulling it out of a 0.9 mm (20-gauge) incision. No snagging of the incision occurs at insertion or removal. No injector is required. The device is useful in standard coaxial phacoemulsification, femtosecond laser-assisted cataract surgery, biaxial microincision cataract surgery (MICS), coaxial sub-2.0 mm MICS, and small-pupil microincision vitreous surgery and in eyes with shallow anterior chambers.

FINANCIAL DISCLOSURE

Dr. Bhattacharjee has a pending international patent application (PCT-WIPO) for the pupil-expansion devices.

Comparative outcomes of bimanual MICS and 2.2-mm coaxial phacoemulsification assisted by femtosecond technology

PURPOSE

To compare the efficacy and safety outcomes of bimanual microincision cataract surgery (MICS) versus 2.2-mm coaxial phacoemulsification assisted by Femtosecond LenSx (Alcon-LenSx Inc., Aliso Viejo, CA).

METHODS

This prospective, randomized, observational, comparative case series comprised 50 cataractous eyes of 50 patients receiving femtosecond laser refractive lens surgery followed by a bimanual MICS technique with two 1-mm incisions (25 patients) (FemtoMICS group) and a coaxial phacoemulsification technique with a 1-mm paracentesis and a 2.2-mm principal incision (25 patients) (FemtoCoaxial group). The main outcomes measures were: ultrasound power, effective phacoemulsification time, postoperative spherical equivalent, higher-order aberrations (corneal and internal), corneal thickness, endothelial cell count, macular thickness, and complications during and after surgery. Both groups were absolutely comparable for all variables preoperatively.

RESULTS

Mean ultrasound power was 1.8% ± 0.9% for MICS and 14.7% ± 4.9% for 2.2-mm incisions (P < .001). Effective phacoemulsification time values for MICS and 2.2-mm incisions were 1.5 ± 0.9 and 4.5 ± 2.9 sec, respectively (P = .002). Mean postoperative spherical equivalent was −0.26 for FemtoMICS and −0.33 for FemtoCoaxial (P > .05). The efficacy index at 1 month postoperatively was 160.2% for FemtoMICS and 149% for FemtoCoaxial. No significant differences were found in corneal thickness, endothelial cell count, and macular thickness. Complications included posterior capsule rupture (4%) and anterior capsule rupture with no posterior capsule tear (4%) for FemtoMICS and bridges due to incomplete capsulorhexis (4%) for FemtoCoaxial.

CONCLUSIONS

MICS and coaxial phacoemulsification techniques assisted by the Femtosecond LenSx achieved excellent safety and efficient outcomes. The FemtoMICS technique was surgically and statistically more efficient than the FemtoCoaxial technique.

Femtosecond laser-induced macular changes and anterior segment inflammation in cataract surgery

PURPOSE

To compare femtosecond laser-assisted cataract surgery with standard phacoemulsification concerning the incidence of postoperative clinical or subclinical macular edema and the correlation between macular thickness and postoperative intraocular inflammation values.

METHODS

One hundred four eyes of 104 patients were treated by laser-assisted cataract surgery and the fellow 104 eyes underwent phacoemulsification using pulsed ultrasound energy and intraocular lens implantation in this prospective randomized study. Laser flare photometry was measured preoperatively and at 2 hours, 3 to 4 days, 1 month, 3 months, and 6 months postoperatively. Retinal thickness was measured by spectral-domain optical coherence tomography.

RESULTS

Two hundred two eyes (97%) were included and analyzed at 6 months postoperatively. The mean center thickness in the laser group was 210 ± 24 μm at 4 days postoperatively, 214 ± 22 μm at 1 month postoperatively, 219 ± 20 μm at 3 months postoperatively, and 215 ± 22 μm at 6 months postoperatively. The mean center thickness in the standard group was 211 ± 32 μm at 4 days postoperatively, 210 ± 34 μm at 1 month postoperatively, 217 ± 29 μm at 3 months postoperatively, and 209 ± 30 μm at 6 months postoperatively. Laser flare photometry showed higher levels in the standard group at the first postoperative visit 2 hours after surgery compared with the laser group.

CONCLUSIONS

Femtosecond laser-assisted cataract surgery did not obviously influence the incidence of postoperative macular edema.

Femtosecond laser assisted cataract surgery followed by coaxial phacoemulsification or microincisional cataract surgery: differences and advantages

PURPOSE OF REVIEW

This review outlines the advantages and the differences of femtosecond laser-assisted cataract surgery (FLACS) following a coaxial or microincision cataract surgery phacoemulsification in the surgical outcome and greater control of cataract surgery.

RECENT FINDINGS

FLACS offers minimal tissue damage and extreme precision during corneal incision creation, continuous circular capsulorhexis (CCC) and nuclear fragmentation. It also allows diminishing the mean average ultrasound power to emulsify the nucleus followed by a coaxial or a biaxial procedure. The impact of reduced phacoemulsification energy on the corneal endothelium is an interesting topic that is being investigated. Despite its benefits, this technology has relevant financial issues and a high learning curve.

SUMMARY

FemtoMICS appears to be surgically and statistically more efficient than the FemtoCoaxial technique and Femtoincisions prove to be stable and do not change the corneal high order aberration significantly with favorable results of the triplanar configuration.

Sealed-capsule irrigation with distilled deionized water to prevent posterior capsule opacification--prospective, randomized clinical trial

PURPOSE

To evaluate the efficacy and safety of sealed-capsule irrigation (SCI) using distilled water (DW) to prevent posterior capsule opacification (PCO).

MATERIALS AND METHODS

Phacoemulsification was performed in 60 patients. Patients were randomly selected into groups. In the control the capsular bag was mechanically cleaned (MC), in the DW group DW for 3' in SCI was additionally applied. SN60WF IOL was implanted in all eyes. Examinations were performed before and 1, 30, 180 days, one and two years after surgery. Uncorrected and corrected distance visual acuity (UDVA, CDVA), intraocular pressure (IOP), surgically induced astigmatism (K2-SIA), spherical equivalent (SEQ), endothelial cell and the complications were examined. Total PCO score in the area of 1 and 3 mm zone and capsulorhexis (CAPS) were determined using EPCO 2000. One patient was withdrawn from the DW group as he did not report for the examinations.

RESULTS

As far as safety parameters are concerned, no differences were observed between groups in two-year follow-up (p > 0.05). However, in the DW group the endothelial cell loss was higher (p < 0.05). Total PCO score differences were observed in both groups between the areas (p < 0.05). In the CAPS area, both Total PCO score and PCO area were decreased in the DW group (p < 0.05). PCO was also lower within 3 mm zone in the DW group (p < 0.05).

CONCLUSIONS

SCI is a safe procedure and the endothelial cells loss can be associated with the Perfect Capsule™ device (Milvella) in the anterior chamber insertion. DW irrigated for 3' reduces PCO in long-term follow-up.