Central corneal thickness assessment after phacoemulsification: Subluxation versus Divide-and-Conquer

Corneal Edema after Cataract Surgery

This systematic review investigates the prevalence and underlying causes of corneal edema following cataract surgery employing manual phacoemulsification. A comprehensive search encompassing databases such as PubMed, Embase, ProQuest, Cochrane Library, and Scopus was conducted, focusing on variables encompassing cataract surgery and corneal edema. Two independent reviewers systematically extracted pertinent data from 103 articles, consisting of 62 theoretical studies and 41 clinical trials. These studies delved into various aspects related to corneal edema after cataract surgery, including endothelial cell loss, pachymetry measurements, visual performance, surgical techniques, supplies, medications, and assessments of endothelial and epithelial barriers. This review, encompassing an extensive analysis of 3060 records, revealed significant correlations between corneal edema and endothelial cell loss during phacoemulsification surgery. Factors such as patient age, cataract grade, and mechanical stress were identified as contributors to endothelial cell loss. Furthermore, pachymetry and optical coherence tomography emerged as valuable diagnostic tools for assessing corneal edema. In conclusion, this systematic review underscores the link between corneal edema and endothelial cell loss in manual phacoemulsification cataract surgery. It highlights the relevance of factors like patient demographics and diagnostic modalities. However, further research is essential to unravel the complexities of refractive changes and the underlying mechanisms.

Corneal Endothelial Cell Loss After Endocapsular and Supracapsular Phacoemulsification: The PERCEPOLIS Randomized Clinical Trial

PURPOSE

Subluxation techniques are superior to divide-and-conquer in procedure duration, pain, and ultrasound quantity, but their safety in endothelial cell loss (ECL) is unclear. This randomized single-blind noninferiority clinical trial aimed to determine whether subluxation supracapsular phacoemulsification techniques are inferior to a reference endocapsular technique (divide-and-conquer) regarding postoperative corneal ECL.

METHODS

Patients (aged18 years or older) with greater than +0.2 logarithm of the minimum angle of resolution best spectacle-corrected visual acuity and normal to severe density cataract were randomized to subluxation or divide-and-conquer phacoemulsification in 2015 to 2016. Follow-up with ophthalmic tests was conducted on day 4 and months 1, 3, and 12. The primary study outcome was ECL at all time points. Secondary study end points were operative variables, including effective phaco time and procedure duration. A clinically relevant noninferiority ECL limit was established on the basis of the literature.

RESULTS

In total, 292 patients (mean age, 73 yrs; 59% female) were randomized and underwent subluxation (n = 148) or divide-and-conquer (n = 144). Day 4 and month 1, 3, and 12 data were available for 243, 270, 275, and 198 patients, respectively. The unexpectedly high dropout at 12 months meant that the 12-month ECL data could only be assessed qualitatively. Surgery was successful in all patients. Subluxation was noninferior to divide-and-conquer in ECL. Effective phaco times were similar, but subluxation associated with shorter procedure duration.

CONCLUSIONS

The subluxation technique was noninferior to divide-and-conquer regarding postoperative ECL, at least in the first 3 months, and associated with reduced intervention time. Subluxation techniques may be suitable alternatives to endocapsular techniques.Clinical Trial Registration-URL: ClinicalTrials.gov. Unique identifier: NCT02535819.

Eye-Related Factors That Can Be Associated With the Plane of Phacoemulsification

Purpose: To evaluate the effect of eye-related factors such as biometric and surgical parameters, nuclear sclerosis (NS) grade, and pupil and capsulorhexis diameters on the plane of phacoemulsification (PP).

Material and Methods: This prospective study included 328 eyes of 328 patients who underwent phacoemulsification surgery. The phaco-chop technique was performed in all patients and changes in PP that occurred during surgery were recorded. Patients were grouped as follows: Group 1, > 75% of lens nucleus emulsified in the capsular bag; Group 2, > 75% of lens nucleus emulsified at the pupillary plane; and Group 3, > 50% of lens nucleus emulsified in the anterior chamber. The association between PP and eye-related factors was evaluated.

Results: There were 153 patients (46.7 %) in Group 1, 104 patients (31.7 %) in Group 2 and 71 patients (21.6 %) in Group 3. The factors associated with PP were anterior chamber depth (ACD) (p = 0.020) and NS grade (p = 0.028). No significant relationship was detected between PP and age, surgical parameters or other biometric values. Moreover, PP was found to be more anterior in patients with soft cataracts and deeper ACD values (p values were 0.002 and 0.036, respectively).

Conclusion: The present study has reported that PP may move to more anterior, as softer cataracts may increase the fear of posterior capsule rent. Moreover, PP may move to more posterior due to shallow anterior chambers or high-grade cataracts that could potentially increase the fear of endothelial injury.

Stabilization of refractive error and associated factors following small incision phacoemulsification cataract surgery

BACKGROUND

Accumulating evidence suggests that refractive stabilization occurs rapidly following small incision cataract surgery. Nonetheless, many guidelines still suggest waiting four to 6 weeks before prescribing corrective lenses. This study was undertaken to supplement the existing literature regarding refractive stabilization, and evaluate multiple contributing factors that could dissuade clinicians from confidently correcting refractive error in the early post-operative course following routine cataract surgeries.

METHODS

Adult patients undergoing phacoemulsification cataract surgery with uncomplicated surgeries and post-surgical courses at the Calgary Ophthalmology Centre (Calgary, Alberta, Canada) were included in this prospective observational case series. Exclusion criteria included known corneal dystrophies, infectious keratitis, complicated surgery or toric/multifocal IOLs. Data was collected at weekly intervals for a total of 6 weeks. Collected data included autorefraction, visual acuity, corneal pachymetry, and effective lens position.

RESULTS

One hundred six eyes of 104 patients were included in this study. Post-operative sphere, cylinder and spherical equivalent were not significantly different at any post-operative week compared with week six, and 80-86% of patients were within 0.5D of last follow-up spherical equivalent at any week. The secondary outcomes of central corneal thickness, effective lens position and visual acuity did, however, exhibit significant differences between early post-operative weeks and last follow-up values.

CONCLUSIONS

These data suggest that refractive error can be effectively measured and corrected as early as one-week post-operatively in the majority of patients, though other measures of post-operative stability including central corneal thickness, effective lens position and visual acuity can require up to 4 weeks to stabilize. Thus a conservative and pragmatic approach may be to wait until 4 weeks post-operatively prior to obtaining refractive correction following uncomplicated phacoemulsification cataract surgery.

Supracapsular phacoemulsification: Description of the "Garde à vous" technique and comparative clinical results

Phacoemulsification techniques can be divided into 2 categories: endocapsular and supracapsular techniques. Supracapsular techniques involve phacoemulsification of the nucleus outside and above the capsular plane. The "Garde-à-vous" technique described in this manuscript is a modified and improved version of the supracapsular procedure with up-to-date technology in micro-coaxial surgery. It maintains the known advantages of supracapsular techniques such as faster surgical times and lower rates of capsular tears and brings a standardized technique with well-defined surgical steps in order to achieve tilting of the nucleus in a vertical or oblique position in almost 100% of cases by performing a double-wave hydro-dissection. The authors also give the results of a non-randomized prospective study, comparing the "Garde-à-vous" technique and the standard "cracking" technique in 2856 cases. The results show that for the "Garde-à-vous group", the patients were significantly younger (P<0.001), the power of ultrasound used was greater (P<0.001) for lower UST (ultrasound time or average phacoemulsification time APT) and EPT (effective phacoemulsication time) (P<0.001), the duration of the procedure was shorter (P<0.001), patient discomfort was less (P<0.001), and the power of the implants used was lower (P<0.01). With regard to the gender of the patients, the percentage of topical anesthesia and the rate of intraoperative complications (posterior capsular rupture), there was no statistically significant difference.