A randomised, prospective study comparing trabeculectomy augmented with antimetabolites with a viscocanalostomy technique for the management of open angle glaucoma uncontrolled by medical therapy

Quantification of Postoperative Inflammation in Laser and Surgical Procedures for Glaucoma with Laser Flare Photometry: A Review of the Literature

PURPOSE

To review the application of laser flare photometry (LFP) in the objective quantification of aqueous flare (anterior chamber inflammation) post laser and surgical procedures for glaucoma.

METHODS

A search was undertaken using the following: PubMed (all years), the Web of Science (all years), Ovid MEDLINE (R) (1980 to 30 March 2023), Ovid MEDLINE (R) Daily Update 30 March 2023, MEDLINE and MEDLINE non-indexed items, Embase (1980-2021, week 52), Ovid MEDLINE (R) and Epub Ahead of Print, in-Process & Other Non-Indexed Citations and Daily (1980 to 30 March 2023), CENTRAL (including Cochrane Eyes and Vision Trials Register), metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrial.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (www.who.int/ictrp/search/en). Search terms included "aqueous flare," "anterior chamber inflammation," "tyndallometry," "laser flare photometry" combined with "laser," "iridotomy," "trabeculoplasty," "cataract surgery," "phacoemulsification," "glaucoma surgery," "minimally invasive glaucoma surgery," "trabeculectomy," "aqueous shunt," "glaucoma drainage" and "cyclophotocoagulation."

RESULTS

The majority of studies utilizing laser flare photometry in grading flare have been post laser trabeculoplasty. The degree of flare produced varies according to the type of glaucoma laser or surgery performed, with filtration procedures and glaucoma drainage devices having marked and prolonged detectable levels. Aqueous flare in cyclodestructive procedures positively correlated with intraocular pressure (IOP) reduction.

CONCLUSION

In comparison to clinician grading, laser flare photometry provides a more objective measure of post-surgical inflammation in eyes that have undergone laser and surgery for glaucoma. Further research is warranted into how this instrument can be utilized to identify eyes at high risk of failure and other adverse outcomes after glaucoma surgery.

The surgical management of glaucoma: A review

After a long period of little change, glaucoma surgery has experienced a dramatic rise in the number of possible procedures in the last two decades. Glaucoma filtering surgeries with mitomycin C and glaucoma drainage devices remain the standard of surgical care. Other newer surgeries, some of which are minimally or microinvasive glaucoma surgeries, target existing trabecular outflow, enhance suprachoroidal outflow, create subconjunctival blebs, or reduce aqueous production. Some require the implantation of a device such as the iStent, Hydrus, Ex-PRESS, XEN and PRESERFLO, whilst others do not-Trabectome, Kahook dual blade, Ab interno canaloplasty, gonioscopy-assisted transluminal trabeculotomy, OMNI and excimer laser trabeculotomy. Others are a less destructive variation of an established procedure, such as micropulse transscleral cyclophotocoagulation, endoscopic cyclophotocoagulation and ultrasound cycloplasty. Cataract surgery alone can be a significant glaucoma operation. These older and newer glaucoma surgeries, their mechanism of action, efficacy and complications are the subject of this review.

Efficacy of bleb-independent penetrating canaloplasty in primary angle-closure glaucoma: one-year results

PURPOSE

To report the efficacy and safety of bleb-independent penetrating canaloplasty in the management of primary angle-closure glaucoma (PACG).

METHODS

This single-centre prospective interventional case series enrolled 57 eyes from 53 PACG patients with medically uncontrolled intraocular pressure (IOP) and peripheral anterior synechiae of over 270°. Penetrating canaloplasty, mainly consisted of tensioning suture-aided Schlemm's canal dilation and a trabeculectomy, was performed to create a direct communication between the anterior chamber and the Schlemm's canal. Postoperative IOP, number of glaucoma medications and procedure-related complications were evaluated. Rate of success was defined as IOP ≤ 21, ≤18 and ≤15 mmHg, and a ≥30% IOP reduction without (complete) or with/without (qualified) IOP-lowering medications.

RESULTS

A total of 45 eyes had 360° catheterization successfully completed. The mean preoperative IOP was 33.9 ± 11.7 mmHg (range, 13-59.6 mmHg), on 3.2 ± 0.8 glaucoma medications (range 2-5), which was decreased to 15.4 ± 3.7 mmHg (range, 8.6-22.5) and 0.2 ± 0.6 (range, 0-3) medications at 6 months and 14.8 ± 3.5 mmHg (range, 9-24) and 0.1 ± 0.3 (range, 0-1) medications at 12 months postoperatively. Complete success at 12 months were achieved in 78.9% (95% CI: 0.65-0.93), 71.1% (0.56-0.86) and 50.0% (0.33-0.67) eyes at IOP ≤ 21, ≤18 and ≤15 mmHg, respectively. Transient IOP elevation (>30 mmHg, 26.7%) and hyphema (11.1%) were the most common early surgical complications.

CONCLUSION

Penetrating canaloplasty in PACG appeared to have good efficacy and safety profiles in this pilot study. Further studies are justified.

Treatment choices for newly diagnosed primary open angle and ocular hypertension patients

Despite advances in our knowledge of the aetiology and pathophysiology of glaucoma, the sole proven, effective intervention for treating primary open-angle glaucoma (POAG) and ocular hypertension (OHT) remains lowering of intraocular pressure (IOP) to prevent further progression and visual loss. The purpose of this review is to evaluate the treatment choices available to newly diagnosed POAG and OHT patients. We review the existing literature on treatments currently available to newly diagnosed POAG and OHT patients and discuss their role in the treatment paradigm of POAG and OHT. We consider different factors that may be important when offering a choice of treatment to newly diagnosed POAG and OHT patients as well as describing new glaucoma treatments in development and future directions for treatment.

Comparison of anterior chamber flare among different glaucoma surgeries

Purpose

To compare postsurgical anterior chamber flare (ACF) among conventional (trabeculectomy, LEC) and novel (EX-PRESS Shunt, EXP) filtration surgeries and microhook ab interno trabeculotomy (μLOT), a novel minimally invasive glaucoma surgery (MIGS).

Subjects and methods

This retrospective study included 125 primary open angle glaucoma eyes (89 consecutive subjects) treated with μLOT (n=38), LEC (n=12), or EXP (n=75). The intraocular pressure (IOP), numbers of antiglaucoma medication, and ACF at preoperatively and 2 weeks; 1, 3, and 6 months postoperatively were compared among the surgical groups using a mixed-effects regression model.

Results

The postoperative IOP (p<0.0001) and medication use were significantly (p<0.0001) lower in the LEC and EXP groups than with μLOT for up to 6 months postoperatively. The ACF differed significantly (p=0.0004) among groups; the ACF was significantly higher (p=0.0097, post-hoc Student’s t-test) with μLOT (33.6±52.8 pc/msec) than the EXP (15.7±19.9 pc/msec) at 2 weeks and was significantly (p=0.0111, post-hoc t-test) lower with μLOT (7.9±2.0 pc/msec) than LEC (12.0±6.1 pc/msec) at 6 months.

Conclusion

Considering our observation, although its clinical significance is unclear, not all MIGS are minimally invasive regarding early postsurgical inflammation.

Ocular hypotony: A comprehensive review

Ocular hypotony is an infrequent, yet potentially vision-threatening, entity. The list of differential causes is extensive, involving any condition that may compromise aqueous humor dynamics or the integrity of the globe and sometimes following medical treatments or procedures. Depending on the cause and the clinical impact, treatment options aim to correct the underlying pathology and to reestablish anatomical integrity, as well as visual function. We review the pathophysiology, clinical presentation, different causes, and associated therapeutic options of ocular hypotony.

The efficacy of Viscocanalostomies and combined phacoemulsification with Viscocanalostomies in the treatment of patients with glaucoma: a non-randomised observational study

Background

To evaluate the outcomes of Viscocanalostomy (VC) and Phacoviscocanalostomy (PV) in controlling primary and secondary glaucoma in a large cohort of patients from a single eye unit and performed by a single surgeon.

Methods

This non-randomised, retrospective study was conducted on 620 eyes of 458 patients. All patients who had either viscocanalostomy (VC) or combined phacoemulsification and viscocanalostomy (PV) over a three-year period were included. Intraocular pressures (IOP), number of anti-glaucoma medications used, and any complications were recorded over a 3-year follow up period.

Paired T-Test was used to compare preoperative and post-operative IOP at specified time points. Kaplan–Meier survival models were used to determine success rates over the study period.

Results

Six hundred twenty procedures were performed during the 3-year study period, of which 427 were PV and 193 VC. The mean follow-up was 31.8 months. Overall complete success (IOP ≤ 21 mmHg, without medication) at 3 years was achieved in 65.7% of patients, with qualified success (IOP ≤21 mmHg with or without medication) achieved in 96.0%. Subgroup analysis showed complete success rate of 76.0% for PV and 63.1% for VC (p = 0.005), with qualified success 95.9% for PV and 94.0% for VC (p = 0.668).

Mean pre-operative IOP (mmHg) for all procedures was 23.02 ± 5.6, with PV and VC subgroups at 22.54 ± 5.10 and 24.06 ± 6.45. Post-operatively IOP at month 12 and 36 was 14.74 ± 3.57 and 14.40 ± 3.17 respectively for all procedures, 14.62 ± 3.26 and 14.44 ± 3.10 for PV, and 15.03 ± 4.18 and 14.31 ± 3.33 for VC.

Across all procedures, pre-operatively an average of 3.05 ± 0.96 anti-glaucoma medications were used. This reduced to 0.13 ± 0.39 in 12 months and 0.38 + 0.71 by 36 months.

Sixty-five cases had complications due to trabeculo-Descemet window perforation during viscocanalostomy with 7 cases developing complications from the cataract element. In the 12.9% of patients who had complications there were no differences of IOP noted at 3 years.

Conclusion

VC and PV have good IOP lowering capacity and are both effective at sustaining a reduction in IOP at 3 years. PV achieved a higher success rate without medication. The low complication profile with reduced post-operative care means these procedures may be a preferred option for early surgical intervention.

Viscocanalostomy with Mitomycin-C: A Preliminary Study

Purpose

To compare the results of viscocanalostomy with and without mitomycin-C (MMC).

Methods

Retrospective results of 15 standard viscocanalostomy (VCO) operations (Group 1) were compared with the prospective results of 15 VCO operations performed with intraoperative adjunctive MMC (Group 2). MMC (0.2 mg/mL) was applied over and under the superficial scleral flap for 3 minutes in Group 2 before the deep flap was prepared. Each patient was followed up for at least 1 year, and results of examinations in the first 12 months were used in the statistical comparison of the two groups. Surgical success was defined as intraocular pressure (IOP) ≤ 18 mmHg.

Results

Pr eoperative mean intraocular pressures (IOP) in Group 1 and Group 2 wer e 35.3±11.0 and 39.1±8.9, respectively. Mean IOP levels at the 12th month were 14.4±2.6 and 11.9±4.0, respectively, showing a significant decrease in both groups (p<0.001). Postoperative IOP course appeared to be lower in the MMC group, however, the difference was not statistically significant (p=0.554). Complete success rates without medications were 40% in Group 1 and 67% in Group 2. No significant difference was found between the two groups in terms of early and late postoperative complications, pre- and postoperative number of antiglaucoma medications, and surgical success rates at the end of the study period (p>0.05 for all). A significant difference was verified between the two groups of eyes considering the conjunctival bleb types, as low-lying, localized blebs were the most frequent type in Group 1 and thin-walled, avascular blebs were more predominant in the MMC group (p=0.004).

Conclusions

Intraoperative adjunctive MMC use might improve the long-term results of viscocanalostomy by facilitating subconjunctival filtration and might widen the indication range of the technique.

Effect of glaucoma implant surgery on intraocular pressure reduction, flare count, anterior chamber depth, and corneal endothelium in primary open-angle glaucoma

PURPOSE

To evaluate the effect of filtering surgery using the EX-PRESS device on intraocular pressure (IOP), flare count, anterior chamber (AC) depth, and the corneal endothelium in primary open-angle glaucoma (POAG), including normal-tension glaucoma (NTG).

PATIENTS AND METHODS

The study comprised 63 consecutive patients with POAG or NTG. They underwent complete ophthalmologic examinations, including measurement of visual acuity (VA), IOP, flare count, AC depth, and cell density of the corneal endothelium (CE). Two outcomes were used for surgical success: outcome 1 was defined as a ≥20% reduction in the IOP from the preoperative value, with an IOP ≥ 5 mmHg but ≤18 mmHg, and outcome 2 was defined as a ≥20% reduction in the IOP, with an IOP ≥ 5 mmHg but ≤15 mmHg.

RESULTS

The IOP significantly decreased from 17.7 preoperatively to 12.4 mmHg postoperatively (P < 0.0001). The success rates for outcome 1 at 24 months were 81.3 and 46.7% for POAG and NTG, respectively (P = 0.0065); the corresponding success rates for outcome 2 were 79.4 and 46.7% (P = 0.0120). The flare count significantly increased on postoperative day 1 (P = 0.0002) but recovered to insignificant levels by day 3 (P = 0.0686). A transient decrease in AC depth was observed by 4 weeks after surgery (P = 0.0017). The CE changed from 2529 preoperatively to 2428/mm² at 24 months (P = 0.0089).

CONCLUSION

The advantage of filtering surgery using the EX-PRESS device includes reduced inflammation, and the disadvantages include loss of the CE and reduced effectiveness of NTG.

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.

A New Ultrasound Biomicroscopic Sign seen after Deep Sclerectomy (Dolphin Head Sign)

PURPOSE

To describe a new ultrasound biomicroscopic (UBM) sign seen in patients who underwent deep sclerectomy (DS) as a surgical procedure for the management of uncontrolled primary open-angle glaucoma (POAG). The presence of this sign in ultrasound biomicroscopy is suggested to be an indicator of successful surgery. We would like to name this sign as the "dolphin head sign."

DESIGN

Prospective interventional study.

MATERIALS AND METHODS

Twenty-eight eyes of 17 patients with POAG underwent DS with intraoperative mitomycin C (MMC) 0.3% applied for 2 minutes under the superficial scleral flap. Patients were followed up for a minimum of 6 months. Ultrasound biomicroscopy was done at the third postoperative month to evaluate the surgical area in both successful and failed cases.

RESULTS

The study included 28 eyes of 17 patients. The mean age of the study group was 42.90 ± 14.37 years (20-64 years). The study included 10 females and 7 males. The mean preoperative intraocular pressure (IOP) was 24.57 ± 6.37 mm Hg (20-38 mm Hg). The mean best corrected visual acuity (BCVA) was 0.57 ± 0.3 (0.05-1.00). Complete success has been achieved in 21 eyes (75%) during the follow-up period, with a mean IOP of 12.00 ± 3.86 mm Hg (6-20 mm Hg). The dolphin head sign was demonstrated only in successful cases, whereas the unsuccessful cases failed to show the typical sign.

CONCLUSION

The presence of a "dolphin head" configuration in UBM images could be taken as an indicator of successful DS. How to cite this article: Abdelrahman AM, El Cheweikh HM, El-Fayoumi DMS, Allam RSHM. A New Ultrasound Biomicroscopic Sign seen after Deep Sclerectomy (Dolphin Head Sign). J Curr Glaucoma Pract 2016;10(2):56-59.

Postoperative microhyphema as a positive prognostic indicator in canaloplasty

PURPOSE

To assess risk factors for failure in canaloplasty.

METHODS

  Nonrandomized prospective study involving 51 eyes of 51 patients with medically uncontrolled primary open-angle glaucoma undergoing canaloplasty. Visual acuity, intraocular pressure (IOP) and slit-lamp examinations were performed before and after surgery at 1 and 7 days, and at 1 month and every 3 months thereafter. Factors like age, gender, preoperative IOP and microhyphema on day 1 were evaluated.

RESULTS

  The mean follow-up was 20.6 (SD 8.3) months. The mean preoperative IOP was 26.8 (SD 5.2) mmHg; the mean postoperative IOP was 8.4 (4.2) mmHg at day 1 and 12.7 (1.7) mmHg at month 24. Microhyphema was found in 40 patients (85.1%) on day 1 after surgery. The height of microhyphema was 1.8 mm ± 0.4 (SD) (range 1-2.5), and the time of resorption was 6.6 days ± 2.8 (SD) (range 3-14) on average. No recurrence of hyphema has been observed. IOP < 16 mmHg without medications depended significantly on the presence of microhyphema (hazard ratios, HR 0.03, 95% CI 0.01-0.25, p < 0.001), but not on age (HR 1.00, 95% CI 0.91-1.09, p = 0.32), preoperative IOP (HR 0.98, 95% CI 0.85-1.12, p = 0.80), cup-to-disc ratio (HR 0.15, 95% CI 0.00-20.01, p = 0.45) and gender (HR 0.24, 95% CI 0.05-1.12, p = 0.07). Factors like preoperative IOP, age, gender, cup-to-disc ratio were not associated with microhyphema. There were no significant differences between patients with versus without microhyphema in regard to age, preoperative IOP, morphological and functional glaucomatous damage, number of medications and postoperative day 1 IOP. However, patients with microhyphema had significantly fewer Nd:YAG goniopunctures after surgery than patients without microhyphema (p < 0.001).

CONCLUSION

Microhyphema the first postoperative day seems to be a significant positive prognostic indicator in uneventful canaloplasty in regard to IOP reduction, possibly representing a restored and patent physiologic aqueous outflow system.

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.

Deep sclerectomy with mitomycin C in eyes with failed glaucoma surgery and pseudophakia

PURPOSE

To report outcomes of deep sclerectomy (DS) with intraoperative mitomycin C (MMC) application in eyes with previous failed glaucoma surgery (GS) and/or cataract extraction (CE).

PATIENTS AND METHODS

Single-surgeon case series of 82 eyes of 82 patients undergoing DS with MMC. The patients had previous CE with IOL and/or conjunctival GS and treated intraocular pressure (IOP) >18 mm Hg. MMC (0.2 mg/ml) was applied for 2-3 min before scleral flap dissection. Complete success was defined as IOP between 6 and 21 mm Hg or a reduction of 20% from baseline without medications. Reoperation for glaucoma or related complications, or loss of light perception vision was considered as failure.

RESULTS

Mean follow-up was 57.7 ± 22.4 months with 78% of patients completing the 3-year follow-up. Mean IOP decreased from 24.0 mm Hg (22.3-25.6, 95% confidence intervals) to 13.4 mm Hg (12.0-14.2) at 3 years after surgery (P<0.001). There was a significant decrease in the number of glaucoma medications from 2.0 ± 1 preoperatively, to 0.3 ± 0.7, 3 years after surgery. Kaplan-Meier cumulative success rates were 85.6% at 1 year, 80.0% at 2 years, and 76% at 3 years. At 3 years, IOP was maintained <19 and 15 mm Hg in 83 and 70% of eyes, respectively. Fourteen eyes (17.1%) had complications. Delayed hypotony (IOP <6 mm Hg) was the commonest complication in five eyes (6.1%).

CONCLUSION

DS with MMC appears to be a safe and effective surgical procedure for eyes with previous intraocular surgery.

Phacoemulsification-deep sclerectomy modified by trabeculum microperforations and implantation of lens anterior capsule as autologous scleral implant

OBJECTIVE

To evaluate the efficacy and safety of Phacoemulsification-deep sclerectomy modified by trabeculum microperforations and anterior lens capsule as autologous scleral implant (mPDS) for open-angle glaucoma.

RESEARCH DESIGN AND METHOD

A case series study comprised 127 patients and 127 eyes after mPDS. The applied modification of deep sclerectomy consisted in creating microperforations within the posterior trabeculum and in fixing the anterior lens capsule, removed during phacoemulsification, in the scleral lake as an autologous intrascleral implant. Primary open-angle glaucoma without satisfying intraocular pressure (IOP) control (>or=21 mmHg) despite maximally tolerated medications or with progression of visual field and cataract was the indication for surgery. For statistical analyses paired Student's t-test, the Wilcoxon signed rank test and one-dimensional ANOVA with repeated measures were used; survival analysis was performed using the Kaplan-Meier method.

MAIN OUTCOME MEASURES

IOP, number of medications and best corrected visual acuity (BCVA) were examined. On the basis of the assessment of the anterior and posterior segments of the eye, the character and also the degree of intensification of postoperative complications were established. Follow-up examinations were performed on days 1 and 7, and at 1, 3, 6, 12, 18 and 24 months and thereafter every 6 months. The complete success rate was defined as IOP <or= 18 mmHg without, and the qualified success rate as IOP <or= 18 mmHg with and without antiglaucoma medications.

RESULTS

The mean follow-up was 32.2 +/- 9.1 months. Mean IOP decreased by 30.4%. Mean IOP decreased from 20.1 +/- 5.1 to 14.0 +/- 2.9 mmHg (p < 0.001). The mean number of medications was reduced from 2.2 +/- 0.7 to 0.6 +/- 0.8 (p < 0.001). Complete and qualified success rates were 74.4 % and 93.3 %, respectively. Mean logMAR of BCVA changed from 0.52 +/- 0.40 to 0.16 +/- 0.16 (p < 0.001). Subconjunctival 5-FU injections together with suturolysis because of bleb fibrosis were performed in 20 eyes, which represented 15.7% of the cases operated on. 5-FU-induced complications involved corneal epitheliopathy in nine eyes (7.1 % of cases) and irregular astigmatism in one eye (0.8% of cases). Among early complications the most frequent was transient hypotony observed in 55 eyes (41.7% of cases).

LIMITATIONS

The explanation of the role of the anterior capsule in the mechanism of mPDS requires inclusion into the study of histological observations of surgeries performed on an animal model as well as prospective ultrasound biomicroscopy (UBM) examinations performed in humans.

CONCLUSIONS

Phacoemulsification-deep sclerectomy modified by trabecular microperforations and anterior capsule as a scleral implant lead to an effective decrease in the IOP in medium-term follow-up. The profile of the observed complications indicates that it can be a safe procedure. However, a larger group of patients should be observed to confirm this.

Modified deep sclerectomy (D-lectomy MMC) for primary open-angle glaucoma: preliminary results

PURPOSE

To evaluate the outcome of modified deep sclerectomy [D-lectomy mitomycin C (MMC)] for medically refractory glaucoma patients.

METHODS

In a retrospective comparative study, the surgical outcome in 1 eye each of 31 patients who underwent D-lectomy MMC was compared with that of 91 eyes of 91 patients who underwent trabeculectomy with adjunctive MMC. These eyes had a diagnosis of primary open-angle glaucoma or pseudoexfoliation glaucoma, a record of high intraocular pressure (IOP) exceeding 25 mm Hg, and planned for surgical intervention. In the D-lectomy MMC cases, a slit incision at the trabecular meshwork and peripheral iridectomy were created. The "lake" and trabeculo-Descemet membrane ("window") were examined by ultrasound biomicroscope, gonioscopy, and time-domain optical coherence tomography.

RESULTS

Postsurgical IOP at 1, 3, 6, and 12 months after the D-lectomy MMC and trabeculectomy MMC were comparable (P=0.63-0.97). The filtering bleb was noted in 14 (45%) of the 31 D-lectomy MMC eyes at 3 months, and their survival was significantly less than trabeculectomy MMC subjects in which 81 of 91 eyes had the bleb at 3 months (P<0.0001). The lake was noted in 29 of 31 D-lectomy MMC eyes. The sealing of the once penetrated trabecular meshwork was complete at 3 months in 23 of 29 eyes by ultrasound biomicroscopic and/or gonioscopic examinations, whereas that was incomplete in 6 eyes.

CONCLUSIONS

Addition of a slit incision to the trabecular meshwork and peripheral iridectomy (D-lectomy MMC) improved postsurgical IOP of the deep sclerectomy to the level comparable with trabeculectomy MMC, with a less frequency of the bleb formation.

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.

Randomized comparison of the intraocular pressure-lowering effect of phacoviscocanalostomy and phacotrabeculectomy

PURPOSE

To compare the intraocular pressure (IOP)-lowering effect of combined viscocanalostomy and phacoemulsification and combined trabeculectomy and phacoemulsification with mitomycin C in eyes with primary open-angle glaucoma.

DESIGN

Prospective randomized 1-year trial.

PARTICIPANTS

Forty consecutive patients (40 eyes) with primary open-angle glaucoma and cataract.

INTERVENTION

Eyes were assigned randomly either to trabeculectomy with mitomycin C or to viscocanalostomy in combination with phacoemulsification and intraocular lens implantation.

MAIN OUTCOME MEASURES

Success rate based on IOP.

RESULTS

Mean baseline IOP was 24.0+/-2.0 mmHg in the viscocanalostomy group and 23.7+/-2.6 mmHg in the trabeculectomy group (P = 0.7). Mean postoperative IOP was 13.7+/-2.2 mmHg at 3 months, 14.8+/-3.3 mmHg at 6 months, and 14.9+/-3.0 mmHg at 12 months in the viscocanalostomy group and 12.1+/-4.0 mmHg at 3 months, 13.8+/-4.7 mmHg at 6 months, and 14.1+/-4.4 mmHg at 12 months in the trabeculectomy group. There was no significant difference in the mean IOP between the groups at any time. At 12 months, 17 patients (85%) in the viscocanalostomy group and 16 patients (80%) in the trabeculectomy group achieved an IOP of 20 mmHg or less without medication (P = 0.7). Complications included 2 cases (10%) of flat/shallow anterior chamber and 4 cases (20%) of hypotony in the trabeculectomy group, whereas intraoperative microperforation of Descemet's membrane occurred in 3 cases (15%) in the viscocanalostomy group.

CONCLUSIONS

There was no significant difference in IOP reduction between viscocanalostomy and trabeculectomy with mitomycin C in combination with phacoemulsification and intraocular lens implantation in patients with primary open-angle glaucoma.

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.

Failure of medical therapy despite normal intraocular pressure

The disease glaucoma is now defined by characteristic optic disc and visual field change, without specific reference to the intraocular pressure (IOP). Success of treatment is no longer judged by the mere attainment of IOP less than 21 mmHg. Controversy remains, however, in deciding appropriate management where optic disc and/or visual field damage continues to progress despite a 'normal' IOP having been achieved with medical treatment. A panel of international glaucoma experts has provided management recommendations in four clinical scenarios--open-angle glaucoma, open-angle glaucoma in a myopic contact lens wearer, uveitic glaucoma and open-angle glaucoma in combination with visually significant cataract--where optic nerve and visual field progression has continued despite an IOP less than 21 mmHg on full medical treatment. Surgical intervention with mitomycin trabeculectomy is the most favoured further therapy.

Viscocanalostomy versus trabeculectomy for primary open angle glaucoma: 4-year prospective randomized clinical trial

AIMS

The purpose of this randomized clinical trial was to compare the effectiveness and safety of viscocanalostomy (visco) with trabeculectomy (trab) in the management of primary open angle glaucoma (POAG).

METHODS

Patients were randomized to have a viscocanalostomy (25 eyes) or a trabeculectomy (25 eyes) performed by one surgeon (TDM) and followed up prospectively. Patients were examined preoperatively, at day 1, day 3 if required, day 6, week 2 and thereafter as near as possible to 1, 3, 6, 12, 18, 24, 30, 36, 48, 54, and 60 months. We recorded intraocular pressure (IOP), presence or absence of any complications, presence and description of any bleb, visual acuity with glasses, and full examinations as routine to monitor any progression of the glaucoma. Bleb interventions including needling and antimetabolites were allowed and recorded in both groups. YAG laser goniopuncture was allowed in the viscocanalostomy group.

RESULTS

Mean follow-up was 40 months (SD 15), with a range from 6 to 60 months. Forty-two percent (n=10) of the patients in the trabeculectomy group had a successful outcome (IOP<18 mm Hg with no treatment) at last follow-up visit, compared to 21% (n=5) in the viscocanalostomy group. IOP was lower in the trab group with differences in IOP being statistically significant at month 12 (P=<0.001), 24 (P=<0.001), 30 (P=0.030), 36 (P=<0.001), and 48 (P=0.018). The trabeculectomy group required less postoperative topical IOP-lowering medication (P=0.011).

CONCLUSION

In this study, we found trabeculectomy to be more effective at lowering IOP than viscocanalostomy in POAG patients.

Phaco-viscocanalostomy versus Phaco-trabeculotomy

PURPOSE

To compare the surgical outcomes between phaco-viscocanalostomy and phaco-trabeculotomy in open-angle glaucoma.

PATIENTS AND METHODS

In a nonrandomized, retrospective clinical study, 110 eyes underwent phaco-viscocanalostomy (VCS group), and 110 eyes underwent phaco-trabeculotomy (LOT group). The mean follow-up was 857+/-409 (+/-SD) days (P=0.4777).

RESULTS

The mean preoperative treated intraocular pressure (IOP) values were 20.2+/-3.5 mm Hg in the VCS group and 20.9+/-3.5 mm Hg in the LOT group (P=0.3377). The postoperative IOPs in the VCS group were 15.0+/-3.0 and 16.1+/-3.0 mm Hg at 1 and 3 years, and in the LOT group 16.3+/-2.9 mm Hg (P=0.0088) and 16.5+/-3.3 mm Hg (P=0.4993), respectively. The number of medications used in the VCS group was significantly lower than in the LOT group during the observation periods (P< or =0.0130). The probabilities of achieving IOPs< or =21 mm Hg at 3 years in the VCS group were 92.0% with or without mediations and 58.2% without medications, and were significantly better than those of the LOT group (84.7% and 36.0%, P=0.0334 and P<0.0001 by log-rank test, respectively). The probabilities of achieving IOPs< or =16 mm Hg at 3 years in the VCS group were 30.5% with or without mediations and 30.3% without medications, whereas those in the LOT group were 27.5% (P=0.1799) and 19.4% (P=0.0010), respectively. The visual outcome was similar between the groups. Postoperative hyphema (> or =2 mm) and IOP spikes (> or =30 mm Hg) occurred significantly less in the VCS group (2.7 and 3.6%, respectively) than in the LOT group (26.4 and 28.2%, respectively; P<0.0001). In 13 eyes (11.8%) of the LOT group, the highest IOP level was recorded 40 mm Hg or higher. Vitreous hemorrhage and central visual loss occurred in 1 case each in the LOT group.

CONCLUSIONS

After a middle-term observation, phaco-viscocanalostomy provides better IOP control and a lower incidence of vision-threatening complications than phaco-trabeculotomy.

South-East Scotland trabeculectomy survey

AIM

Assessment of trabeculectomy in South-East Scotland (SESTS) with comparison to National Survey of Trabeculectomy (NST) and outcomes of consultant and trainee surgery.

METHOD

A retrospective study of 304 consecutive, primary trabeculectomies, in two Scottish centres (Edinburgh and Dunfermline) with two glaucoma specialists and higher surgical trainees, was performed. The study group had primary open angle glaucoma (65.5%), pseudoexfoliation (6.9%), normal tension glaucoma (7.6%), pigment dispersion syndrome (1.6%), and other complicated glaucoma (18.4%). All patients underwent trabeculectomy by the glaucoma specialist (57.6%) and higher surgical trainee (42.4%) with close scrubbed supervision.

RESULTS

Compared to the NST, the waiting time for surgery (<3 months) was significantly less in the SESTS (P<0.001). There was also significantly more use of intraoperative antimetabolites (P<0.01), bleb intervention (P<0.001), and a higher rate of early complications (P<0.025). There was no significant difference in outcome at intraocular pressure (IOP)<2/3 listing IOP (qualified and unqualified) between the SESTS and the NST. Significantly, more patients achieved an unqualified success of IOP<21 mmHg (P<0.01) and an unqualified success of IOP<16 mmHg in the SESTS than the NST (P<0.05). At 1 year post surgery, visual loss of greater than one Snellen line was more common in the NST (P<0.01) as was the use of anti-glaucoma medication (P<0.001). Trainee cases returned to theatre more frequently (P<0.025) and merited more bleb intervention (P<0.01) than consultant cases, but the long-term outcome was similar.

CONCLUSION

Our study highlights significant changes in the practice and outcome of trabeculectomy compared to the national survey conducted a decade ago.

Viscocanalostomy Versus Trabeculectomy in Patients with Bilateral High-tension Glaucoma

Results of trabeculectomy (TE) and viscocanalostomy (VCO) were compared in a prospective randomised study in two fellow eyes of 22 consecutive patients with bilateral symmetrical high-tension glaucoma. Rates of overall surgical success with intraocular pressures (IOP) < or = 18 mm Hg with or without medications were 91 for the TE, and 95 for the VCO group after a mean follow-up of 18 months. Complete success rates without medications were 64 and 59 for TE and VCO groups, respectively (p = 0.750). Both procedures significantly reduced IOP, however, IOP course following trabeculectomy was significantly lower (p = 0.026). Rates of complications were not found to be different between the two groups of eyes, except for an apparent--though not significant (p = 0.066)--increase in cataract progression with TE. Various types of conjunctival blebs were detected in all eyes with surgical success in both groups, however, diffuse, elevated or multi-cystic functional blebs appeared to be more predominant in eyes with TE, compared to the VCO group in which low-lying, localised blebs had a higher incidence (p = 0.015). Viscocanalostomy was found to be a safe and effective filtration technique in patients with uncomplicated high-tension glaucoma, though IOP decrease was more pronounced with trabeculectomy.

Ultrasound biomicroscopy in deep sclerectomy

PURPOSE

To evaluate by ultrasound biomicroscopy (UBM) the anatomical characteristics and the intraocular pressure (IOP) lowering mechanisms of deep sclerectomy after long-term follow-up.

METHODS

In all, 22 eyes of 21 consecutive patients who had deep sclerectomy were examined by UBM. Several UBM variables were prospectively evaluated, including the presence and maximum length and height of the intrascleral space, the minimum thickness of residual trabeculo-Descemet membrane (TDM), the presence and type of subconjunctival filtering bleb, and the presence of other possible drainage sites, for example suprachoroidal. Surgical success was considered to be achieved when the IOP was <22 mmHg and the IOP was lowered by more than 20% without the use of any medication. The possible association between UBM variables and the surgical outcome was determined.

RESULTS

The mean time between surgery and the UBM examination was 12.0+/-5.3 months. The mean IOP decreased significantly from a preoperative value of 23.7+/-4.0 to 16.0+/-3.9 mmHg at the time of UBM (P<0.01). There was a poor correlation between the level of IOP at the time of UBM and the length of intrascleral space (r2=0.0016), the height of the intrascleral space (r2=0.136), or the thickness of remaining TDM (r2=0.0009). The presence and type of filtering bleb were not associated with the success.

CONCLUSIONS

In patients undergoing deep sclerectomy, UBM examination after long-term follow-up showed the presence of an intrascleral space and a filtering bleb in most patients. The surgical outcome was not associated with the UBM variables of the surgical area.

Long term effect on IOP of a stainless steel glaucoma drainage implant (Ex-PRESS) in combined surgery with phacoemulsification

AIM

To evaluate the efficacy and safety of a stainless steel miniature glaucoma drainage device (Ex-PRESS R50) for the surgical treatment of primary open angle glaucoma (POAG) and cataract when combined with phacoemulsification.

METHODS

Clinical, prospective, multicentre, single treatment arm, non-randomised, non-masked study. The Ex-PRESS device was implanted at the limbus under a conjunctival flap. Phacoemulsification cataract extraction and in the bag IOL implantation were performed through clear cornea temporally.

PRIMARY OUTCOME

IOP change; secondary outcomes: side effects and VA changes.

RESULTS

26 eyes of 25 patients were implanted with the device. The mean (SD) follow up was 23.9 (10.4) months and the mean age was 75.1 (7.1) years. 17/26 eyes have more than 3 years of follow up. One case was discontinued because of device removal, one because of death, and three were lost to follow up.

EFFICACY

preoperative IOP was 21 (4) mm Hg; at 1, 2, and 3 years IOP was 15.3 (3.1) mm Hg (35% reduction), 16.6 (2.7) mm Hg (29% reduction), and 16 (2.6) mm Hg (22% reduction) respectively. Kaplan-Meyer determined overall success rate (IOP < or = 21 mm Hg at the last visit with or without medications) as 76.9%. The number of antiglaucoma medications was reduced by 95% at year 1. Only six patients (23%) were taking IOP lowering treatment at their last visit, five with one medication and one with two medications. Side effects: early postoperative complications were clinically mild and included six cases of hypotony (IOP <5 mm Hg), three cases of hyphaema (<2 mm) with no clinically significant further effects. Long term complications were two cases (7.7%) of device rotation (one treated by reposition) and three cases (11.5%) of conjunctival erosion at 2 and 3 years.

CONCLUSIONS

The Ex-PRESS implant, combined with phacoemulsification cataract extraction, is clinically safe and effective, maintaining in the long term a large reduction in IOP and in the number of antiglaucoma medications.

Deep sclerectomy augmented with mitomycin C

AIMS

To investigate the comparative efficacy and safety of deep sclerectomy with and without intraoperative mitomycin C (MMC) application for lowering the intraocular pressure (IOP).

METHODS

A total of 71 eyes of 71 consecutive patients who had routine deep sclerectomy (DS), nonaugmented (DS-noMMC) or with mitomycin C (DS-MMC) augmentation (0.2 mg/ml for 2 min) and follow-up of 4 months or more were identified from an ongoing prospective database on glaucoma surgery. Indications for MMC use were the presence of risk factors for subconjunctival scarring and low target IOPs. MMC 0.2 mg/ml was applied in the sub-Tenons space for 2 min.

RESULTS

There were 19 eyes in the DS-noMMC group and 52 eyes in the DS-MMC group. In 11 eyes (15.5%), the procedure was complicated by intraoperative perforation of the trabeculo-Descemet's window. Eyes in the DS-MMC group had significantly lower IOPs (MANOVA, P = 0.04). Kaplan-Meier survival curve analysis showed that the probability of maintaining IOP below target IOP level, below 18 mmHg and below 14 mmHg at 1 year was 51, 67, and 35% for the DS-noMMC group and 80, 86, and 74% for the DS-MMC group. The survival rates of the DS-MMC group were not statistically significant (P = 0.06) when the success criterion was maintaining an IOP less than 18 mmHg but were significant for the other criteria, namely IOP less than target levels (P = 0.03) and less than 14 mmHg (P = 0.03). Nd:YAG goniopuncture to lower IOP to target levels was done more frequently in the DS-noMMC group (13 eyes, 81%) than the DS-MMC group (20 eyes, 45%) and this difference was significant (P = 0.03). The prevalence of avascular areas within filtration blebs and transconjunctival oozing of aqueous was significantly higher in the DS-MMC group (P < 0.01).

CONCLUSIONS

The use of intraoperative MMC during deep sclerectomy has a significant effect on the postoperative IOP and increases the probability of achieving target IOPs. However, our current technique of MMC application is associated with a higher incidence of avascular blebs and transconjunctival oozing.

Primary viscocanalostomy versus trabeculectomy for primary open-angle glaucoma

PURPOSE

To compare the efficacy and safety of viscocanalostomy and trabeculectomy in patients with primary open-angle glaucoma (POAG).

SETTING

Department of Ophthalmology, Ankara Education and Research Hospital, Ankara, Turkey.

METHODS

In this prospective randomized trial, 50 eyes of 50 patients with medically uncontrolled POAG were randomized to have a trabeculectomy (25 eyes) or a viscocanalostomy (25 eyes). Visual acuity, intraocular pressure (IOP), and slitlamp examinations were performed before surgery and 1 day, 1 week, 1, 3, and 6 months, and 1, 2, and 3 years postoperatively.

RESULTS

At 3 years, the mean IOP was 16.0 mmHg +/- 7.07 (SD) in the trabeculectomy group and 17.8 +/- 4.6 mmHg in the viscocanalostomy group (P=.694). Complete success (IOP 6 to 21 mm Hg without medication) was achieved in 66.2% of eyes at 6 months and 55.1% at 3 years in the trabeculectomy group and in 52.9% and 35.3%, respectively, in the viscocanalostomy group (P>.05). Qualified success (IOP 6 to 21 mmHg with medication) was achieved in 95.8% of eyes at 6 months and 79.2% at 3 years in the trabeculectomy group and in 90.7% and 73.9%, respectively, in the viscocanalostomy group (P>.05). Postoperative hypotony and cataract formation occurred more frequently in the trabeculectomy group than in the viscocanalostomy group (P=.002).

CONCLUSIONS

Primary trabeculectomy lowered IOP more than viscocanalostomy in POAG patients. However, the complication rate was lower in the viscocanalostomy group.

A randomised, prospective study comparing trabeculectomy with viscocanalostomy with adjunctive antimetabolite usage for the management of open angle glaucoma uncontrolled by medical therapy

AIMS

To compare trabeculectomy with viscocanalostomy augmented with adjunctive antimetabolite use for the control of intraocular pressure (IOP) in open angle glaucoma (OAG).

METHODS

45 patients (50 eyes) with uncontrolled OAG were randomised to either trabeculectomy (25 eyes) or a viscocanalostomy technique (25 eyes). Preoperatively, all eyes were graded in terms of risk factors for drainage failure and were given intraoperative antimetabolites (5-fluorouracil 25 mg/ml (5-FU), mitomycin C (MMC) 0.2 mg/ml and 0.4 mg/ml) according to a standard protocol.

RESULTS

There were no significant differences between the groups in age, sex, type of OAG, preoperative medications, risk factors for drainage failure, and preoperative IOP. Mean follow up was 20 months (range 3-24 months). It was 12 months or longer in all eyes, except two lost to follow up at 3 months. At 12 months, complete success (IOP<21 mm Hg without antiglaucoma medications) was seen in 91% of eyes undergoing trabeculectomy, but in only 60% of eyes undergoing viscocanalostomy (p<0.02). Similarly, at the last follow up visit (mean 20 months) complete success was seen in 68% of eyes undergoing trabeculectomy and 34% with viscocanalostomy (p<0.05). In terms of qualified success (IOP<21 mm Hg with or without glaucoma medications) and mean IOP measurements postoperatively there were no difference between the groups, although the mean number of antiglaucomatous medications required postoperatively was less with trabeculectomy (0.39) than viscocanalostomy (1.04) (p<0.05). Needling procedures were more commonly required after trabeculectomy (p<0.02). YAG goniotomy was required in three eyes (13%) after viscocanalostomy. Early transient complications such as anterior chamber shallowing and encysted blebs were more common in the trabeculectomy group (p<0.05). Late postoperative cataract formation was similar between the two groups.

CONCLUSION

In terms of complete success and number of antiglaucomatous medications required postoperatively, IOP control appears to be better with trabeculectomy. Viscocanalostomy is associated with fewer early transient postoperative complications.

Primary open-angle glaucoma

Primary open-angle glaucoma is a progressive optic neuropathy and, perhaps, the most common form of glaucoma. Because the disease is treatable, and because the visual impairment caused by glaucoma is irreversible, early detection is essential. Early diagnosis depends on examination of the optic disc, retinal nerve fibre layer, and visual field. New imaging and psychophysical tests can improve both detection and monitoring of the progression of the disease. Recently completed long-term clinical trials provide convincing evidence that lowering intraocular pressure prevents progression at both the early and late stages of the disease. The degree of protection is related to the degree to which intraocular pressure is lowered. Improvements in therapy consist of more effective and better-tolerated drugs to lower intraocular pressure, and more effective surgical procedures. New treatments to directly treat and protect the retinal ganglion cells that are damaged in glaucoma are also in development.

Low first postoperative day intraocular pressure as a positive prognostic indicator in deep sclerectomy

AIM

To study the possibility of using intraocular pressure (IOP) in the first postoperative day after sclerectomy as a prognostic indicator.

METHODS

Non-randomised prospective trial involving 105 eyes of 105 patients with medically uncontrolled primary and secondary open angle glaucoma. Visual acuity, IOP, and slit lamp examinations were performed before and after surgery at 1 and 7 days, and 1, 3, 6, 9, 12, 18, 24, 30, 36, 48, 54, 60, and 66 months. Visual field examinations were repeated every 6 months. A split point on day 1 IOP of less than or equal to 5 mm Hg (61%) versus more than 5 mm Hg (39%) was used. The first postoperative day IOP was examined in relation to the need for subsequent Nd:YAG goniopuncture, the subsequent use of postoperative antiglaucoma medications, and as a stratification variable in the Kaplan-Meier analyses.

RESULTS

The mean follow up was 43.2 (SD 14.3) months. The mean preoperative IOP was 26.8 (SD 7.7) mm Hg; the mean postoperative IOP was 5.1 (3.3) mm Hg at day 1 and 11.8 (3.1) mm Hg at month 60. Patients with IOP </=5 mm Hg had significantly fewer Nd:YAG goniopunctures (p = 0.0478). A significant (log rank test 0.0122) improvement for those with IOP </=5 mm Hg in terms of survival was detected using the most stringent criterion (IOP </=15 mm Hg with no medications). For patients with first postoperative day IOP </=5 mm Hg, the median time to failure was 24 months (95% CI: 12 to 30), but for those with an IOP >5 mm Hg, the median time to failure was only 6 months (CI 2 to 9). No significant difference in postoperative antiglaucoma medications was observed.

CONCLUSION

First postoperative day IOP can be considered to be a significant prognostic indicator in deep sclerectomy.

Reducing intraocular pressure: is surgery better than drugs?

Reducing IOP is presently the evidence based, most accepted and most practised therapeutical approach for glaucoma patients. Currently topical ocular hypotensive medications, with its different classes, as well as filtering surgery (trabeculectomy and non-penetrating glaucoma surgery) are in the forefront of therapeutic modalities for IOP reduction. This article looks at the potential advantages and disadvantages of topical medications versus filtering surgery. It does not directly address the question of initial treatment of glaucoma, or what is the better treatment of glaucoma, as other review articles had, but rather looks in a more specific on the pros and the cons of each in relation to IOP reduction. In other words this article deals with the situation once the decision has been made to reduce IOP.

Viscocanalostomy in patients with glaucoma secondary to uveitis

PURPOSE

To assess the efficacy of viscocanalostomy in eyes with uncontrolled glaucoma secondary to uveitis.

SETTING

Immunology and Uveitis Service, Department of Ophthalmology and Visual Sciences, University Hospital San Raffaele, Milan, Italy.

METHODS

All consecutive patients with glaucoma secondary to uveitis and inadequate intraocular pressure (IOP) control (IOP >21 mm Hg) under maximum-tolerated medical therapy had viscocanalostomy. Patients with active uveitis at the time of surgery, peripheral anterior synechias in the upper quadrant, previous ocular surgery, or sight in only 1 eye were excluded. Eleven eyes of 11 patients with a mean age of 52.2 years +/- 19.9 (SD) were operated on. The etiology of the uveitis was recorded. The ocular variables were IOP, best corrected visual acuity, number of antiglaucoma medications, and complications. Success was defined as an IOP between 6 mm Hg and 21 mm Hg (inclusive) without medication (complete success), or with 1 or more antiglaucoma medications and/or goniopuncture (qualified success). The mean follow-up was 45.9 +/- 11.6 months (range 23 to 56 months).

RESULTS

Viscocanalostomy significantly reduced IOP from a mean baseline value of 35.1 +/- 7.0 mm Hg (range 23 to 48 mm Hg) to a mean final value of 18.1 +/- 4.9 mm Hg (range 12 to 30 mm Hg) (P<.0001). Complete success was achieved in 6 eyes (54.5%) and qualified success, in 10 eyes (90.9%). The mean number of preoperative and final antiglaucoma medications was 3.4 +/- 0.8 (range 2 to 4) and 0.7 +/- 1.2 (range 0 to 3), respectively (P =.0004). Complications were minor and included transient hyphema and postoperative IOP spike.

CONCLUSION

This preliminary study suggests that viscocanalostomy is a safe, effective surgical alternative for treating glaucoma in patients with uveitis.

In vitro release of mitomycin C from collagen implants

PURPOSE

To study Mitomycin C Loaded Collagen Implant (CI) pharmacokinetics behaviour in vitro.

METHODS

The CI were incubated for 15 minutes in different MMC loading solutions with the following concentrations: 0.03 mg/mL (n = 9), 0.3 mg/mL (n = 10) and 3.0 mg/mL (n = 10). The loaded CI were transferred in 100 micro L of 0.9% NaCl. Aqueous flow of 5 micro L/min was simulated. The MMC concentrations of the samples were determined by high performance liquid chromatography (HPLC). Dissolution kinetics were evaluated by a first-order process. The half-life of dissolution and the time of 95% dissolution were determined.

RESULTS

The CI absorbed on average a MMC dose of 0.054, 0.530 and 6.090 micro g when incubated in the different MMC loading solutions containing 0.03 mg/mL, 0.3 mg/mL, 3.0 mg/mL of MMC, respectively. In the release experiments, the mean total dose delivered by CI was 0.0493, 0.585 and 5.291 micro g. A linear correlation between loading concentration and the estimated total dose released was demonstrated. The kinetic parameters showed a fast MMC dissolution. The half-life of the 3 series was 8.8, 10.1 and 10.5 min.

CONCLUSIONS

Commercially available CI can be loaded with MMC, and could provide relatively slower release than sponge delivery of MMC. Clinical implications of these results warrants further studies.