Deep sclerectomy and low dose mitomycin C: a randomised prospective trial in west Africa

A Review to Populate A Proposed Cost-Effectiveness Analysis of Glaucoma Screening in Sub-Saharan Africa

To populate a proposed cost-effectiveness analysis of glaucoma screening in Sub-Saharan Africa (SSA).A complete search was conducted on PubMed, Medline and African Journals Online (AJOL) to obtain relevant published articles, which were included in this review. All relevant articles on prevalence of glaucoma in SSA and among other African-derived populations, severity of glaucoma, cost of diagnosis and management, clinical effectiveness of glaucoma screening and treatment and the different glaucoma screening strategies in SSA were reviewed.Population screening interventions for glaucoma may be considered as follows: standalone screening for glaucoma, screening for glaucoma during cataract outreach, and screening incorporated with diabetic retinopathy image review using tele-ophthalmology. Our review suggests that cost of glaucoma treatment is relatively low with cost of medical treatment ranging from USD 273 to USD 480 per year/patient and surgical treatment cost of USD 283 per patient as with other developing countries. Compliance with medication is moderate to good in about 50% of glaucoma patients. Prevalence of glaucoma is much higher in SSA and almost 50% of glaucoma patients are blind in at least one eye at presentation in clinics (without outreach screening). Our review suggests a moderate sensitivity and specificity in identifying glaucoma with basic equipment (direct ophthalmoscope, contact tonometer and frequency doubling technology) during outreach screening although about a third or fewer take up glaucoma services in clinics.Our review provides the necessary information to conduct a cost-effective analysis of glaucoma screening in SSA using the decision Markov model.

Glaucoma treatment trends: a review

Glaucoma is one of the most common causes of blindness worldwide, and its prevalence is increasing. The aim of the present review is to describe the current medical and surgical treatment trends in the management of open-angle glaucoma. There has been an increase in the availability of glaucoma medications and the use of laser trabeculoplasty over the past decade, with a subsequent decrease in invasive incisional surgery. In addition, a new class of glaucoma procedures, termed microinvasive glaucoma surgery, has emerged, which aims to fill the gap between conservative medical management and more invasive surgery.

Epidemiological properties of primary open angle glaucoma in Nigeria

Background. Primary open angle glaucoma (POAG) is progressive chronic optic neuropathy in adults in which intraocular pressure (IOP) and other currently unknown factors contribute to damage. POAG is the second commonest cause of avoidable blindness in Nigeria. Pattern of Presentation. POAG is characterized by late presentation. Absence of pain which is a driving force for seeking medical help, inadequacy of trained eye care personnel, paucity of facilities, misdistribution of resources, lack of awareness, poor education, and poverty may all contribute to this. Medical and surgical treatment options available are challenging and tasking. Screening for Glaucoma. Screening is the presumptive identification of unrecognized disease (POAG) by applying test(s) which can be applied rapidly. Such test(s) should be of high reliability, validity, yield, acceptable, and cost effective. The test should ideally be sensitive, specific, and efficient. It is difficult to select a suitable test that meets these criteria. Intraocular pressure (IOP) appears to be the easiest option. But, high IOP is not diagnostic nor does normal value exclude the disease. Health education is a possible strategy in early case detection and management. Treatment of POAG. Glaucoma treatment can either be medical or surgical (this includes laser). Considering unavailability, potency, cost, and long-term effects of medication, surgery (trabeculectomy) could be a better option. Laser trabeculoplasty is available in a few centers. Viscocanalostomy is not routinely performed. Patient education is vital to success as management is for life. Conclusion. POAG remains a cause of avoidable blindness in Nigeria. There is need for long-term strategy to identify patients early and institute prompt management. Improvement in training of eye care personnel and provision of up to date equipment is essential in achieving this goal.

Clinical options for the reduction of elevated intraocular pressure

Elevated IOP in clinical practice is usually seen in glaucoma or ocular hypertension. Glaucoma affects 60 million people worldwide and 8.4 million are bilaterally blind from this chronic disease.1 Options for reducing IOP rely on pharmacological agents, laser treatments and surgery which may be penetrating or non-penetrating. The last twenty years has seen significant changes in all of these strategies. This review aims to cover these clinical options and introduce some of the new technologies currently in development for the clinical lowering of IOP.

Systematic overview of the efficacy of nonpenetrating glaucoma surgery in the treatment of open angle glaucoma

BACKGROUND

To evaluate the intraocular pressure (IOP)-lowering effects achieved by nonpenetrating glaucoma surgery (NPGS) and its modifications in patients with open angle glaucoma.

MATERIAL/METHODS

Randomized controlled trials evaluating patients with primary and secondary open angle glaucoma treated with NPGS were identified through systematic searches. The main outcome measures were the percentage IOP reduction and the complete success rate. Complete success was defined as target endpoint IOP (usually less than 21 mm Hg) without medications. The pooled estimates were calculated using the random effects model.

RESULTS

Both deep sclerectomy (DS) and viscocanalostomy (VCO) were less effective than trabeculectomy (TE) in lowering IOP, with the percentage IOP reductions at 2 years being 35.2% for DS, 30.2% for VCO, and 45.6% for TE. Intraoperative use of implants and mitomycin C (MMC) increased IOP-lowering effects of DS, with IOP reductions at 2 years of 41.1% and 41.7%, respectively. The complete success rates at 4 years were 35.4% for DS, and 22.7% for VCO, lower than that of TE (47.6%). The complete success rates of DS with implants and MMC of 64.6% and 52.1%, respectively, at 4 years, were greater than that of primary DS. NPGS caused major complications in fewer patients than did TE.

CONCLUSIONS

Primary deep sclerectomy and primary viscocanalostomy, which can significantly lower IOP, were associated with fewer complications than was TE. However, the IOP-lowering effects of both NPGS seem to be lower than that of primary TE. The efficacy of DS can be improved with the intraoperative use of implants and MMC.

Mitomycin C-augmented deep sclerectomy in primary open-angle glaucoma and exfoliation glaucoma: a three-year prospective study

PURPOSE

To investigate the efficacy and safety of mitomycin C (MMC)-augmented deep sclerectomy with implant (DSCI) in primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG) patients.

METHODS

A total of 68 eyes of 68 patients with POAG and ExG were enrolled consecutively to undergo DSCI with MMC (0.4 mg/ml for 2 min). The intraocular pressure (IOP), number of antiglaucoma medications, neodymium:yttrium-aluminum-garnet (Nd:YAG) laser goniopuncture treatments and complications were compared postoperatively after 36- month follow-up. Surgery was considered as a complete success when IOP was <18 mmHg without antiglaucoma medication.

RESULTS

Preoperatively the mean IOPs were 23 ± 6 mmHg and 25 ± 8 mmHg, and 13 ± 4 mmHg and 11 ± 4 mmHg in the POAG and ExG groups, respectively, at 36 months. At 36 months, 74% and 73% of surgeries were a complete success in the POAG and ExG group, respectively [not significant (NS)]. Two patients (8%) of the POAG group and one of the ExG group (3%) were receiving antiglaucoma medication at 36 months (NS). Nd:YAG laser goniopuncture was performed more often in the ExG group (87%) than in the POAG group (61%, p = 0.024). Postoperatively choroidal detachment occurred in 16% of eyes in the POAG group and in 11% of eyes in the ExG group (NS).

CONCLUSIONS

DSCI with MMC augmentation appears to be as effective in patients with ExG and POAG in lowering IOP to target levels at medium term with few immediate postoperative complications.

Surgical management of glaucoma: evolving paradigms

Surgical intervention is mandatory in the case of documentation of the progression of glaucomatous optic neuropathy despite the administration of maximal tolerated medical therapy, and in cases where compliance is poor. Minimal complications, good long-term intraocular pressure (IOP) control, and precisely titrated target IOPs resulting in avoidance of visual impairment are the primary goals of surgical intervention. This article is an attempt to provide a broad overview of the therapeutic options available to the glaucoma surgeon. The available surgical modalities have undergone modifications and refinements over time, with a view to improve patient outcomes and visual recovery, yet are fraught with intra- and postoperative complications. The risk and benefits of each of the available surgical options must be critically evaluated and customized to fit the needs of the particular patient. There is insufficient evidence at present to establish the superiority of any of these surgeries over the other.

Mitomycin-C-augmented deep sclerectomy in patients with primary open-angle glaucoma and exfoliation glaucoma: a 1-year prospective study

PURPOSE

To investigate the efficacy and safety of mitomycin C (MMC)-augmented deep sclerectomy with implant (DSCI) in patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG).

METHODS

A total of 68 eyes of 68 patients with POAG and ExG were enrolled consecutively to undergo DSCI with MMC (0.4 mg/ml for 2 min). The intraocular pressure (IOP), number of antiglaucoma medications, neodymium:yttrium-aluminum-garnet (Nd:YAG) laser goniopunctures and complications were compared postoperatively. Surgery was considered as a complete success when IOP was < 18 mmHg without antiglaucoma medication.

RESULTS

Preoperatively, the mean IOPs were 23.1 +/- 5.8 and 25.4 +/- 8.3 mmHg, and 13.8 +/- 6.1 and 11.2 +/- 5.6 mmHg in the POAG and ExG groups, respectively, at 12 months. 77.4% and 75.7% of surgeries were a complete success in the POAG and ExG groups, respectively [not significant (NS)]. Five patients (16.1%) in the POAG group but none in the ExG group (0%) were receiving antiglaucoma medication at 12 months (NS). Nd:YAG laser goniopuncture was performed in 29.0% of eyes in the POAG group and in 55.6% of eyes in the ExG group (p = 0.047). Postoperatively, choroidal detachment occurred in 16.1% of eyes in the POAG group and in 10.8% of eyes in the ExG group (NS). We encountered no serious complications related to MMC use.

CONCLUSION

DS with MMC augmentation appears to be equally effective in ExG and POAG patients in lowering IOP to target levels, at least in the short term, with few immediate postoperative complications.

Nonpenetrating glaucoma surgery

Nonpenetrating glaucoma surgeries have been developed in recent years in order to improve the safety of conventional filtering procedures. The goal of nonpenetrating filtering procedures is to reduce intraocular pressure by enhancing the natural aqueous outflow channels, while reducing outflow resistance located in the inner wall of the Schlemm's canal and the juxtacanalicular trabecular meshwork. In the last few years viscocanalostomy and deep sclerectomy with external trabeculectomy have become the most popular nonpenetrating filtering procedures. Both involve removal of a deep scleral flap, the external wall of Schlemm's canal and corneal stroma behind the anterior trabeculum and Descemet's membrane, thus creating an intrascleral space. The aqueous humour leaves the anterior chamber through the intact trabeculo-Descemet's membrane into the scleral space, from where it will egress into different pathways. The technique is associated with a long learning curve. Published clinical trials comparing nonpenetrating glaucoma surgery to full-thickness trabeculectomy have a consensus on the superior safety profile of nonpenetrating glaucoma surgery but are not in agreement when it comes to efficacy, where conflicting results have been found. This article reviews the nonpenetrating surgical techniques, mechanisms of action, indications, contraindications, complications, and results.

Nonpenetrating glaucoma surgery: a critical evaluation

PURPOSE OF REVIEW

Nonpenetrating glaucoma surgery is popular in a number of countries because of its perceived superior safety profile to mitomycin-C trabeculectomy. This article critically evaluates recently published literature relating to nonpenetrating glaucoma surgery.

RECENT FINDINGS

Recent modifications in nonpenetrating glaucoma surgery, including the use of implants, augmentation with antiproliferatives, and use of laser goniopuncture, appear to result in improved intraocular pressure control. Comparative studies suggest a better safety profile with nonpenetrating glaucoma surgery but higher long-term intraocular pressure than after trabeculectomy. Despite this perception, a difference in intraocular pressure control between mitomycin-C trabeculectomy and nonpenetrating glaucoma surgery, when the most recent modification has been incorporated, has not been demonstrated conclusively in randomized trials conducted over sufficiently long periods to be clinically important.

SUMMARY

Nonpenetrating glaucoma surgery continues to evolve. Intraocular pressure-lowering efficacy seems to have improved with recent modifications in technique but the degree and longevity of intraocular pressure-lowering in comparison with trabeculectomy are still uncertain.