Comparison of long-term incidence of posterior capsular opacification between phacoemulsification and phacotrabeculectomy

Pseudophakic cystoid macular oedema and posterior capsular opacification rates after combined phaco-trabeculectomy vs. phaco alone

PURPOSE

To assess the risk for pseudophakic cystoid macular oedema (PCME) and posterior capsular opacification (PCO) associated with combined cataract surgery and trabeculectomy compared to cataract surgery alone.

METHODS

Data analysis of subjects who underwent routine cataract surgery without and with concomitant trabeculectomy at the Department of Ophthalmology, Bristol Eye Hospital, the UK, between January 2008 and December 2017. Odds ratios (ORs) for PCME between the types of surgeries were calculated using univariate and multivariate regression analysis. Multivariate Cox regression controlling for age and gender was used to estimate the hazard ratio (HR) for neodymium-doped yttrium aluminium garnet (Nd:YAG) laser capsulotomies.

RESULTS

This study included 56 973 cataract surgeries without and 288 with concomitant trabeculectomy (phaco-trab) with a mean follow-up time of 6.9 ± 4.2 years. Baseline variables (age and gender, diabetes, pseudoexfoliation, use of pupil expansion device and postoperative follow-up time) were comparable between the groups. Postoperative rates of PCME remained non-significant between the cataract surgery and phaco-trabe groups both in uni- and multi-variate analysis (OR 0.347, 95%CI 0.049-2.477, p = 0.291). Furthermore, in Cox regression analysis adjusted for the patients' age and gender, Nd:YAG laser capsulotomy rates remained non-significant between the cataract surgery and phaco-trabe groups (HR 1.250, 95%CI 0.883-1.769, p = 0.209).

CONCLUSIONS

In our large cohort study, combining trabeculectomy with cataract surgery did not predispose to an increased PCME or Nd:YAG laser capsulotomy rates.

Primary lens extraction for glaucoma management: A review article

Recently, primary lens extraction alone gained more acceptance as an alternative surgical approach for glaucoma management. This view was supported by the advances in phacoemulsification and intraocular lenses with greater safety and visual recovery, in addition to a substantial reduction of intraocular pressure and deepening of the anterior chamber and filtration angle. The decrease in IOP after cataract surgery in primary open-angle glaucoma (POAG) is mild, less predictable, related to baseline levels, and may return to presurgical values after an initial period of reduction. Therefore, the IOP-lowering effect of primary cataract extraction in POAG may be insufficient to achieve adequate IOP control. The IOP reduction after lens extraction is consistently greater in eyes with primary angle closure glaucoma (PACG) than in eyes with POAG. Primary lens extraction in acute PACG eliminates, or at least, reduces the risk of recurrence of acute attacks and deepens the anterior chamber and widens the angle which reduces the risk of progression of peripheral anterior synechiae and development of chronic PACG. Primary lens extraction may be more preferable to glaucoma incisional surgery in mild to moderate PACG eyes with appositional angle closure. The decision to do lens extraction as a primary treatment for glaucoma should be individualized based upon several factors other than the effect on IOP. These factors include patients' characteristics, surgeons' skills and preferences, status of glaucoma control, type of cataract and intraocular lens implanted, and potential harm of laser treatment for late capsular opacification and fibrosis.

Interhospital variation in appropriateness of cataract surgery

OBJECTIVE

The aim of this study was to analyse the inter-hospital variation in the appropriateness of cataract phacoemulsification in Spain.

METHODS

This observational, multicentre, prospective study involved patients aged 18-90 years. Each phacoemulsification intervention was classified as 'necessary', 'appropriate', 'uncertain' or 'inappropriate' according to explicit appropriateness criteria previously established using the RAND/UCLA methodology. A descriptive statistical analysis was performed, followed by univariate and multivariate logistic regression analysis, in order to examine the differences between hospitals.

RESULTS

In total, 5063 patients from 15 hospitals were enrolled. The percentage of patients in each hospital who inappropriately underwent phacoemulsification varied from 1.2% to 24.0% (P < 0.0001). The most common inappropriate scenario was that of patients with a simple, unilateral cataract with no limitation of their visual function, with a pre-surgery visual acuity of ≥ 0.5 in both eyes, and for whom surgical correction would involve low technical complexity.

CONCLUSIONS

The variation in appropriateness of phacoemulsification cannot be attributed solely to the clinical differences between the hospitals' patients. There is room for improvement in the appropriate indication of phacoemulsification. Measures based on the dissemination of appropriateness criteria might improve quality of care.

The influence of posterior capsular opacification removal on anterior segment birefringence parameters as measured by scanning laser polarimetry

PURPOSE

To determine the effect of posterior capsular opacification (PCO) removal on anterior segment birefringence (ASB) and its influence on peripapillary retinal nerve fibre layer (RNFL) retardation measurements obtained by means of scanning laser polarimetry.

METHODS

In this prospective interventional study, scanning laser polarimetry was performed using GDx variable corneal compensation on 26 eyes of 26 patients who developed clinically significant PCO (after uncomplicated cataract surgery and with no other ocular pathology) both before and between 1 and 4 weeks after Nd:YAG capsulotomy. Best-corrected visual acuity (BCVA), intraocular pressure, corneal polarization axis (CPA), corneal polarization magnitude (CPM) were compared using the Student t-test and Wilcoxon signed ranks test. Spearman correlations between changes (differences between values after and before capsulotomy) in the CPA, CPM, BCVA and RNFL data were also performed.

RESULTS

PCO removal is associated with a shift in CPA (from 10.86 to 15.03 degrees, P = 0.004) and CPM (from 28.54 to 37.92 nm, P = 0.004). Significant correlations were found between changes in the parameters of ASB and BCVA. Furthermore, RNFL measurements (nerve fibre indicator, temporal-superior-nasal-inferior-temporal average and superior average) were also well related to the CPA and CPM shifts.

CONCLUSIONS

PCO induces an inaccurate compensation of ASB which affects RNFL assessment. Thus, it is necessary to recompensate ASB after posterior capsulotomy.

Phacotrabeculectomy: Assessment of outcomes and surgical improvements

PURPOSE

To evaluate the outcomes and progress after phacotrabeculectomy at the same clinical setting and/or performed by the same surgeon over the past decade.

SETTING

Eye Institute of Utah, Salt Lake City, Utah, USA.

METHODS

This retrospective study included 60 eyes of 43 patients who had phacotrabeculectomy at a single institute between 1999 and 2005. A modified phacotrabeculectomy surgical technique was used that included a 2-site incision approach, fornix-based flap, use of mitomycin-C, acrylic intraocular lens implantation, sutured scleral and conjunctival flaps, and sutured temporal clear corneal incision.

RESULTS

Over a mean 30-month follow-up, 57 of the 60 eyes (95%) achieved intraocular pressure (IOP) control (<or=21 mm Hg) with or without medication. Thirty eyes (50%) had an IOP of 15 mm Hg or lower, and 34 (57%) had an IOP reduction of at least 30%. The IOP decreased from a preoperative mean of 23.1 mm Hg on a mean number of 1.67 glaucoma medications to a mean of 14.9 mm Hg on a mean of 0.23 medication at the final follow-up (P<.001 for IOP decrease and for reduction in number of medications). Fifty-two eyes (87%) obtained a best spectacle-corrected visual acuity of 20/40 or better. Dysesthetic blebs requiring surgical revision and bleb hemorrhage (each occurring in 2 eyes, 3.3%) were seen in this study, but not previous studies.

CONCLUSIONS

The surgical technique used in this study appears to be effective and superior to a previous technique at restoring visual acuity, lowering IOP, and reducing the postoperative complication rate. The observations are relevant in the context of improvements of technique over the past decade.

Effect of posterior capsular opacification removal on scanning laser polarimetry measurements

PURPOSE

To evaluate the effect of posterior capsular opacification (PCO) on retinal nerve fiber layer (RNFL) retardation measurements obtained during scanning laser polarimetry (SLP). We are unaware of previous studies undertaken in this sense.

METHODS

SLP was performed using GDx variable corneal compensation (VCC) on 28 eyes of 28 non-glaucomatous patients with clinically significant PCO, previous uneventful cataract surgery and no other ocular pathology, both before and after Nd:YAG capsulotomy. Best-corrected visual acuity (BCVA), intraocular pressure (IOP) and SLP examination parameters prior and following PCO removal were compared using the Student t-test and Wilcoxon's test. Spearman correlations between BCVA and SLP measurements before and after capsulotomy were also performed.

RESULTS

PCO removal was associated with an increase of BCVA (P<0.0001), nerve fiber indicator (NFI) (P<0.0001) and typical scan score (TSS) (P<0.0001). In parallel, significant decreases of all absolute parameters were observed after capsulotomy. IOP, symmetry, superior ratio, inferior ratio and temporal-superior-nasal-inferior-temporal (TSNIT) standard deviation (SD) revealed no changes. Before capsulotomy, marked correlation existed between the BCVA and some SLP measurements such as nasal average (r= -0.703; P<0.0001) or NFI (r= 0.564; P=0.0017). After PCO removal these correlations were no longer found.

CONCLUSIONS

PCO removal changes SLP measurements. Therefore, new measurements to serve as a baseline for future comparisons should be obtained after Nd:YAG capsulotomy. Furthermore, some SLP measurements were significantly associated with BCVA before capsulotomy, suggesting that this technology may be useful to quantify PCO degree in non-glaucomatous patients.