Is anterior chamber lens implantation after intracapsular cataract extraction safe in rural black patients in Africa? A pilot study in KwaZulu-Natal, South Africa

Phacoemulsification compared with phacotrabeculectomy surgery: a within-person observational cohort study

AIM

To compare reduction in intraocular pressure (IOP) and gain in visual acuity (VA) following phacotrabeculectomy (PT) and phacoemulsification(phaco) in Tanzanian patients with primary open angle glaucoma(POAG).

SETTING

CCBRT Hospital, Dar es Salaam, Tanzania.

DESIGN

Within-person observational cohort study.

METHODS

Within each patient, one eye had PT and the other phaco. Patients were followed for up to 5-1/2 years, and IOP and VA in each eye were assessed. For a small group of patients, two additional postoperative time points were compared.

RESULTS

52 patients (34 male) with a mean age of 70 years (SD 8 years) were enrolled in the study. For those with 250 days or more follow-up, both operations resulted in lower IOPs and improved VA (p<0.001). The average drop in IOP was 50% (95%CI 45% to 55%) for PT and 41% (95% CI 36% to 46%) for phaco. Mean IOP was lower in the PT group 12.9 mm Hg vs 16.8 mm Hg (p=0.004). Extended follow-up in nine patients showed a rise in IOP of 1.8 mm Hg for PT and 4.2 mm Hg for phaco eyes between first (mean, 337 days) and second (mean 1482 days) follow-up (p=0.18).

CONCLUSION

In this small study in African patients, PT resulted in lower IOPs than phacoemulsification alone but the difference between the procedures was relatively small. Phacoemulsification alone was effective in reducing IOP and improving VA for several years in this population. Given the relative simplicity of phacoemulsification, it is a therapeutic option worthy of consideration in some settings.

Aphakia correction by injection of foldable intra ocular lens in the anterior chamber

We assessed the outcomes of the use of anterior chamber foldable lens for unilateral aphakia correction at the University Teaching Hospital of Yaounde. In this retrospective, non-comparative, consecutive case series study, we reviewed the records of patients who underwent an operation for aphakia correction by the means of injection of an angular supported foldable lens between January 2009 and December 2011 in the University Teaching Hospital Yaounde. Student's paired t-test was carried out to compare pre-operative and post-operative visual acuity (VA) and intraocular pressure (IOP). P-values less than 0.05 were considered statistically significant. Twenty-one patients were included in the study; twelve were male (57.1%) and nine were female (42.9%). The mean age was 55.38 ± 17.67 years (range 9-75 years). The mean follow-up duration was 5.95 ± 3.14 months (range 2-12 months). The mean log-MAR visual acuity was 1.26 ± 0.46 pre-operatively and 0.78 ± 0.57 post-operatively (P = 0.003). The change in intraocular pressure was not statistically significant. Complications included intraocular hypertension (over 21 mmHg) in 3 patients (14.3%) and macular edema, pupillar ovalization, and retinal detachment in one patient each. The results indicate that injection of an angular support foldable lens in the anterior chamber is a useful technique for the correction of aphakia in eyes without capsular support. More extended follow-up, however, and a larger series of patients are needed to ascertain the effectiveness and safety of this procedure.

Surgical interventions for age-related cataract

BACKGROUND

Cataract accounts for 50% of blindness globally and remains the leading cause of visual impairment in all regions of the world, despite improvements in surgical outcomes (WHO 2005). This number is expected to rise due to an aging population and increase in life expectancy. Although cataracts are not preventable, their surgical treatment is one of the most cost-effective interventions in healthcare.

OBJECTIVES

To compare the effects of different surgical interventions for age-related cataract.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE up to July 2006, NRR Issue 3 2005, the reference lists of identified trials and we contacted investigators and experts in the field for details of published and unpublished trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTS).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and discrepancies were resolved by discussion. Where appropriate, risk ratios, odds ratios and weighted mean differences were summarised after assessing heterogeneity between the studies.

MAIN RESULTS

We identified 17 trials that randomised a total of 9627 people. Phacoemulsification gave a better visual outcome than extracapsular surgery but similar average cost per procedure in Europe but not in poorer countries. Extracapsular surgery with posterior chamber lens implant and ICCE with or without an anterior chamber intraocular lens (IOL) implant gave acceptable visual outcomes but extracapsular surgery had less complications. Manual small incision surgery provides better visual outcome than ECCE but slightly inferior unaided visual acuity compared to phacoemulsification.

AUTHORS' CONCLUSIONS

This review provides evidence from seven RCTs that phacoemulsification gives a better outcome than ECCE with sutures. We also found evidence that ECCE with a posterior chamber lens implant provides better visual outcome than ICCE with aphakic glasses. The long term effect of posterior capsular opacification (PCO) needs to be assessed in larger populations. The data also suggests that ICCE with an anterior chamber lens implant is an effective alternative to ICCE with aphakic glasses, with similar safety. Phacoemulsification provides the best visual outcomes but will only be accessible to the poorer countries if the cost of phacoemulsification and foldable IOLs decrease. Manual small incision cataract surgery provides early visual rehabilitation and comparable visual outcome to PHACO. It has better visual outcomes than ECCE and can be used in any clinic that is currently carrying out ECCE with IOL. Further research from developing regions are needed to compare the cost and longer term outcomes of these procedures e.g. PCO and corneal endothelial cell damage.

A comparison of anterior and posterior chamber lenses after cataract extraction in rural Africa: a within patient randomised trial

BACKGROUND

Extracapsular cataract extraction (ECCE) with a posterior chamber intraocular lens (PC IOL) is the preferred method of cataract surgery in developed countries. However, intracapsular cataract extraction (ICCE) with an anterior chamber lens (AC IOL) may be appropriate in rural Africa. A randomised controlled trial was carried out to compare these surgical strategies.

METHODS

Participants over 50 years requiring bilateral cataract surgery were recruited from outreach clinics in rural north and east Uganda. One eye was randomly allocated to AC IOL or PC IOL, the other eye being allocated to the second strategy. The main outcome measure was WHO distance visual acuity (VA) category after a minimum of 1 year. Secondary outcomes were numbers and causes of complications and refractive corrections.

RESULTS

Of the 110 participants recruited, 98 (89%) were assessed at least 1 year after the operation (median follow up 17.5 months). Nine eyes randomised to PC IOL were converted to AC IOL; one eye randomised to AC IOL inadvertently received PC IOL. There was no difference in VA between 95 pairs of eyes for which data for both eyes were available (uncorrected VA, p = 0.26; corrected VA, p = 0.59). 80 (82%, 95% CI 73 to 89) and 82 (84%, 95% CI 75 to 90) eyes randomised to AC IOL and PC IOL respectively had corrected VA of 6/18 or better. 16 (16%, 95% CI 10 to 25) and eight (8%, 95% CI 4 to 15) eyes respectively had secondary procedures or other complications.

CONCLUSIONS

Where both strategies are available, ECCE with PC IOL should be first choice because of fewer complications. Where ECCE with PC IOL is not immediately feasible, ICCE with AC IOL is an acceptable interim technique.

Does prospective monitoring improve cataract surgery outcomes in Africa?

AIMS

To determine if prospective monitoring influences cataract surgical outcomes in east Africa.

METHODS

A prospective observational study of all routine extracapsular cataract extractions with posterior chamber lens implants carried out at Kikuyu Eye Unit, Kenya, between 1 January 1999 and 31 December 1999.

RESULTS

Out of 1845 eligible eyes 1800 were included in the study. Two months' follow up was available in 67.2% of patients. The proportion achieving a good outcome increased steadily from 77.1% in the first quarter to 89.4% in the fourth quarter (chi(2) for trend, p<0.001). There was no change in the incidence of operative complications; however, the proportion of patients achieving a good visual outcome following vitreous loss increased from 47.2% in the first 6 months to 71.0% in the last 6 months (chi(2) p<0.05). Of the eyes with poor outcome (best corrected acuity <6/60 at 2 months) half were due to pre-existing eye diseases. The proportion of patients with known ocular comorbidity decreased from 10.2% in the first quarter to 5.9% in the fourth quarter (chi(2) for trend, p<0.05). Poor outcome was associated with age over 80 years, known diabetes, preoperative bilateral blindness, any ocular comorbidity, and intraoperative vitreous loss.

CONCLUSIONS

This study demonstrates improvement in visual outcome results after cataract surgery over a 1 year period. Monitoring of outcomes appears to be associated with a change in surgeons' attitudes, leading to greater emphasis on appropriate case selection, better management of surgical complications, and improved visual outcomes.

Surgical interventions for age-related cataract

BACKGROUND

Cataract is the major cause of global blindness, accounting for 40 to 80% of all blindness in developing countries. The number of people blind from cataract is expected to rise due to the changing age distribution and increasing life expectancy. There is currently no proven intervention to prevent cataract and surgery is the only form of treatment.

OBJECTIVES

The objective of this review is to compare the effects of different surgical interventions for age-related cataract.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register - CENTRAL/CCTR, which contains the Cochrane Eyes and Vision Group specialised register (Cochrane Library Issue 3 2001), MEDLINE (1966 to August 2001), EMBASE (1980 to September 2001), the reference lists of identified trials, and we contacted investigators and experts in the field for details of published and unpublished trials.

SELECTION CRITERIA

We included randomised controlled trials evaluating surgical treatment for people with age-related cataract.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and discrepancies were resolved by discussion. Where appropriate, relative risks, odds ratios and weighted mean differences were summarised after assessing heterogeneity between the studies. We used a fixed effect model due to the low number of trials in each comparison.

MAIN RESULTS

We identified six trials that randomised a total of 7828 people. Phacoemulsification gave a better visual outcome than extracapsular surgery and gave a similar average cost per procedure in one trial conducted in the UK. Extracapsular surgery with posterior chamber lens implant and intracapsular surgery with or without an anterior chamber intraocular lens implant gave acceptable visual outcomes at 12 to 24 months after surgery. In three large trials in south Asia, best-corrected visual acuity of less than 6/60 ranged from 0.5 to 4%. Higher rates of poor outcome were observed in a multicentre study with 19 surgeons compared to a single-centre study with two surgeons.

REVIEWER'S CONCLUSIONS

This review provides evidence from one randomised controlled trial that phacoemulsification gives a better visual outcome than extracapsular extraction with sutures. However, this trial was conducted in a developed country specialised hospital setting and extrapolation to other settings must be made with caution. This review also found evidence that extracapsular cataract extraction with a posterior chamber lens implant provides better visual outcome than intracapsular extraction with aphakic glasses. This finding is also based on the results of a single trial. The long term effects of posterior capsular opacification need to be assessed in larger populations. The data in the review suggest that intracapsular extraction with an anterior chamber lens implant is an effective alternative to intracapsular extraction with aphakic glasses, with similar safety. Further data from developing regions are needed to compare all aspects of intraocular lens surgery with the three main surgical procedures - intracapsular extraction with an anterior chamber lens, extracapsular surgery with a posterior chamber lens with or without sutures.

Long term clinical outcome of a randomised controlled trial of anterior chamber lenses after high volume intracapsular cataract surgery

BACKGROUND

Age related cataract remains the major cause of blindness throughout the world. In many countries, the majority of cataract surgery continues to be done by the intracapsular cataract extraction (ICCE) method. The results of a large randomised controlled trial of multiflex open loop anterior chamber intraocular lenses (ACIOL) were reported from a busy eye hospital in Nepal.

METHODS

There was a randomised controlled trial of 2000 people with bilateral cataract reducing vision to less than 6/36. Interventions were ICCE with an ACIOL compared with ICCE with aphakic spectacles (+11 dioptres). Participants were followed at discharge, 6 weeks, 1 year, and 1 1/2-5 years after surgery. Visual acuity and clinical outcome were measured. A poor outcome was defined as vision <6/60.

RESULTS

Visual outcome was comparable in the two groups. More of the control group experienced functional blindness due to loss of aphakic spectacles at 1 year. The majority of cases of poor outcome occurred in the first year after surgery. There was no indication of any lens related problems after 1 year.

CONCLUSION

Multiflex open loop anterior chamber lenses are safe for up to 1 year of follow up when used by experienced surgeons, and the available evidence of 2-5 years of follow up suggests that the complication rate is reasonably low. An ACIOL at the time of cataract surgery offers benefits over routine ICCE surgery with aphakic spectacle correction as it avoids the problem of replacing lost and broken spectacles.