Viscocanalostomy and deep sclerectomy for the surgical treatment of glaucoma: a longterm follow-up

Efficacy and safety of non-penetrating glaucoma surgery with phacoemulsification versus non-penetrating glaucoma surgery: a Meta-analysis

AIM

To compare the clinical efficacy and safety of non-penetrating glaucoma surgery (NPGS) plus phacoemulsification (Phaco-NPGS) and NPGS-alone.

METHODS

We systematically searched various databases and reviewed studies that had evaluated the effects of Phaco-NPGS or NPGS-alone for patients with glaucoma. Primary outcomes included postoperative intraocular pressure (IOP) and the number of postoperative antiglaucoma medications. Secondary outcomes were the prevalence of complications, incidence of needling or goniopuncture, and surgical success rate.

RESULTS

In total, 380 and 424 eyes in NPGS-alone and Phaco-NPGS groups respectively were included. Both postoperative IOP and number of medications were significantly lowered in the Phaco-NPGS group than that in the NPDS-alone group [weighted mean difference (WMD)=-1.12, 95% confidence interval (CI): -2.11 to -0.12, P=0.03; WMD=-0.31, 95%CI: -0.53 to -0.09, P=0.006]. Moreover, Phaco-NPGS had a significantly lower prevalence of complications and postoperative procedures compared to NPGS-alone, while no significant difference existed for surgical success.

CONCLUSION

Phaco-NPGS superior to NPGS-alone in the reduction of IOP and medications. Phaco-NPGS can be recommended for glaucoma patients with coexisting cataracts owing to its superior efficacy, fewer complications, and postoperative procedures.

Retrospective analysis of the comparison between carbon dioxide laser-assisted deep sclerectomy combined with phacoemulsification and conventional trabeculectomy with phacoemulsification

PURPOSE

To compare outcomes of laser assisted deep sclerectomy (LADS) and conventional trabeculectomy both combined with phacoemulsification.

METHODS

We divided 36 eyes into 2 groups, one group with LADS and the other Trabeculectomy. Patients were measured post operatively at 1, 3, 6, 9 months, 1, 2, 3 years for intraocular pressure (IOP), best corrected visual acuity (BCVA) and number of medications.

RESULTS

In the trabeculectomy group, after 3 year follow up, IOP was 14.67 ± 3.14, 15.27 ± 4.28 and 17.00 ± 7.79, BCVA improved to 0.17 ± 0.18, 0.24 ± 0.20 and 0.24 ± 0.27 and number of medications reduced to 0.6 ± 0.6, 1.1 ± 1.2, and 1.5 ± 1.5. Complete success rate after 3 years was 100%, 80.0% & 80.0% and Qualified success rate was 100%, 88.9% & 88.9%. In the LADS group, after 3 years follow up, IOP was 14.11 ± 3.91, 16.07 ± 5.51, 15.80 ± 6.07, BCVA improved to 0.13 ± 0.11, 0.10 ± 0.15, 0.11 ± 0.13 and medications reduced to 1 ± 1.1, 1.5 ± 1.0 and 1.8 ± 1.0. Complete success after 3 years was 85.7%, 57.1% & 57.1% whereas qualified success was 92.3%, 84.6% & 84.6%.

CONCLUSION

Main limitations of our study were small sample size and lack of prospective comparison. However we were able to perfom the surgery comfortably due to the relatively shorter learning curve compared to conventional NPDS.

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.

Meta-analysis of the efficacy and safety of combined surgery in the management of eyes with coexisting cataract and open angle glaucoma

AIM

To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma.

METHODS

We performed a systematic search of the related literature in the Cochrane Library, PubMed, EMBASE, Web of Science databases, CNKI, CBM and Wan Fang databases, with no limitations on language or publication date. The primary efficacy estimate was identified by weighted mean difference of the percentage of intraocular pressure reduction (IOPR%) from baseline to end-point, the percentage of number of glaucoma medications reduction from pre- to post-operation, and the secondary efficacy evaluations were performed by odds ratio (OR) and 95% confidence interval (CI) for complete and qualified success rate. Besides, ORs were applied to assess the tolerability of adverse incidents. Meta-analyses of fixed or random effect models were performed using RevMan software 5.2 to gather the consequences. Heterogeneity was evaluated by Chi² test and the I² measure.

RESULTS

Ten studies enrolling 3108 patients were included. The combined consequences indicated that both glaucoma and combined cataract and glaucoma surgery significantly decreased IOP. For deep sclerectomy vs deep sclerectomy plus phacoemulsification and canaloplasty vs phaco-canaloplasty, the differences in IOPR% were not all statistically significant while trabeculotomy was detected to gain a quantitatively greater IOPR% compared with trabeculotomy plus phacoemulsification. Furthermore, there was no statistical significance in the complete and qualified success rate, and the rates of adverse incidents for trabeculotomy vs trabeculotomy plus phacoemulsification.

CONCLUSION

Compared with trabeculotomy plus phacoemulsification, trabeculectomy alone is more effective in lowering IOP and the number of glaucoma medications, while the two surgeries can not demonstrate statistical differences in the complete success rate, qualified success rate, or incidence of adverse incidents.

Laser intervention on trabeculo-Descemet's membrane after resistant viscocanalostomy: Selective 532 nm gonioreconditioning or conventional 1064 nm neodymium-doped yttrium aluminum garnet laser goniopuncture?

Purpose:

To compare the results of conventional 1064 nm neodymium-doped yttrium-aluminum garnet laser goniopuncture (Nd:YAG-GP) and selective 532 nm Nd:YAG laser (selective laser trabeculoplasty [SLT]) gonioreconditioning (GR) on trabeculo-Descemet's membrane in eyes resistant to viscocanalostomy surgery.

Methods:

Thirty-eight eyes of 35 patients who underwent laser procedure after successful viscocanalostomy surgery were included in the study. When postoperative intraocular pressure (IOP) was above the individual target, the eyes were scheduled for laser procedure. Nineteen eyes underwent 532 nm SLT-GR (Group 1), and the remaining 19 eyes underwent conventional 1064 nm Nd:YAG-GP (Group 2). IOPs before and after laser (1 week, 1 month, 3 months, 6 months, 1 year, and last visit), follow-up periods, number of glaucoma medications, and complications were recorded for both groups.

Results:

Mean times from surgery to laser procedures were 17.3 ± 9.6 months in Group 1 and 13.0 ± 11.4 months in Group 2. Mean IOPs before laser procedures were 21.2 ± 1.7 mmHg in Group 1 and 22.8 ± 1.9 mmHg in Group 2 (P = 0.454). Postlaser IOP measurements of Group 1 were 12.1 ± 3.4 mmHg and 13.8 ± 1.7 mmHg in the 1^st week and last visit, respectively; in Group 2, these measurements were 13.6 ± 3.7 mmHg and 14.9 ± 4.8 mmHg, respectively. There were statistically significant differences (P < 0.001) in IOP reduction at all visits in both groups; the results of the two groups were similar (P > 0.05). Mean follow-up was 16.6 ± 6.4 months after SLT-GR and 18.9 ± 11.2 months after Nd:YAG-GP.

Conclusions:

While conventional Nd:YAG-GP and SLT-GR, a novel procedure, are both effective choices in eyes resistant to viscocanalostomy, there are fewer complications with SLT-GR. SLT-GR can be an alternative to conventional Nd:YAG-GP.

Outcomes of combined phacoemulsification and deep sclerectomy: a 10-year UK single-centre study

PURPOSE

To report the outcomes of combined phacoemulsification and -deep sclerectomy (phaco-DS) from a single UK centre over a 10-year period.

METHODS

Retrospective analysis of phaco-DS data extracted from an ongoing glaucoma surgery database within Calderdale and Huddersfield NHS Trust. Two hundred and ninety-six eyes of 282 patients were included. Data included patient demographics, pre- and postoperative intraocular pressure (IOP), use of mitomycin C (MMC), spacer device implantation, and follow-up details including surgical success rates. IOP success criteria were: (A) IOP <19 mm Hg and/or 20% decrease from baseline and (B) IOP <16 mm Hg and/or 30% drop from baseline.

RESULTS

Mean follow-up was 63.5 ± 35.3 months. MMC was applied in 145 eyes (49%). Kaplan-Meier success rates in all eyes for criteria A were 89.1% and 80% with glaucoma medications (qualified success) and 81.2% and 68.3% without medications (unqualified success) at 2 and 5 years, respectively. Qualified success for criteria B was 72.4 and 61.4% and unqualified rates were 67.2 and 55.2% for the same time periods. Repeated-measures ANOVA showed significantly lower IOP in the phaco-DS with MMC group up to 3 years postoperatively (P = 0.002). Cox's proportional hazards for criteria B, however, showed no significant effect of MMC application in the long term (P = 0.2). Increasing age and laser goniopuncture were positively associated with success, whereas the absence of spacer devices was negatively associated. At last follow-up, 20% of eyes were on glaucoma medications. Complication rates were low with hypotony rates of 0.68%.

CONCLUSIONS

This study confirms the long-term safety and efficacy of phaco-DS as a primary glaucoma procedure.

Incidence, efficacy and safety of YAG laser goniopuncture following nonpenetrating deep sclerectomy at a university hospital in Riyadh, Saudi Arabia

Purpose

Assessing the frequency and evaluating the efficacy and safety of Neodymium:Yttrium Aluminum Garnet (Nd:YAG) Laser goniopuncture (LGP) following nonpenetrating deep sclerectomy (NPDS).

Design

Retrospective cohort study.

Patients and methods

We retrospectively reviewed the outcome of 197 eyes of 153 patients with open angle glaucoma who underwent either NPDS or NPDS combined with cataract extraction between January 2005 and September 2010 at King Abdulaziz University Hospital (KAUH). Both demographic and clinical data were retrieved and analysed.

Results

Goniopuncture (GP) was needed in 48 (24.4%) of the eyes which had NPDS or NPDS with cataract extraction after a mean post operative interval of 9.78 (±11.16) months. The mean IOP had significantly decreased from 23.3 (±5.9) mmHg prior to Nd:YAG LGP procedure to 14.6 (±4.4) mmHg at the last post-procedure assessment. At the last follow-up; Nd:YAG LGP was successful in controlling IOP in 27 eyes (56.3%). Mean Nd:YAG LGP failure time was 6.04 (±5.80) months. Young age (<50 years) (p = 0.001); type of glaucoma (secondary versus primary open angle, p = 0.0258) and the use of drainage implant (p = 0.038) were the identified predicting factors for the need of Nd:YAG LGP. Complications following Nd:YAG LGP occurred in 5 eyes (iris touch to TDM (4.2%), Hyphema (2.1%), hypotony maculopathy (2.1%) and choroidal detachment (2.1%).

Conclusions

LGP is an efficient IOP lowering procedure after NPDS, when it is indicated. It is a simple and noninvasive procedure. However, certain precautions should be taken to avoid complications.

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.

The efficacy of viscocanalostomy for uncontrollable primary open-angle glaucoma in a developing country

PURPOSE

To evaluate the safety and efficacy of viscocanalostomy in the management of medically uncontrollable primary open-angle glaucoma (POAG) in a developing country.

MATERIALS AND METHODS

This is a prospective, non-randomized case series of 14 consecutive eyes with medically uncontrollable POAG, all subjected to viscocanalostomy. The main outcome measure was success rate based on the intraocular pressure (IOP) level achieved post-operatively. The procedure was considered a complete success if IOP was less than 21 mmHg without any anti-glaucoma medication. Qualified success was defined as IOP of less than 21 mmHg with anti-glaucoma medication. All patients had a regular follow-up of at least 12 months.

RESULTS

IOP was reduced from a mean baseline value of 27.9 ± 7.3 mmHg (range: 21-40 mmHg) to a mean final value of 16.0 ± 2.7 mmHg (range: 13-22 mmHg), which was statistically highly significant (P < 0.005). The mean number of pre-operative anti-glaucoma medications was 3.0 ± 0.4 (range: 2-4), which was reduced significantly (P < 0.0001) to 0.3 ± 0.6 (range: 0-2) at the last follow-up visit. One year post-operatively, complete success was achieved in 71% and qualified success was observed in 21.4% of patients, summing up to an overall success rate of 92.4%. There were no major complications in any of the patients.

CONCLUSION

Viscocanalostomy could be performed effectively and safely for control of POAG in developing countries.

[Viscocanalostomy: preliminary clinical results]

PURPOSE

Filtration surgery has shifted in the past 20 years to a nonperforating surgery to reduce complications. The purpose of this study was to assess the short-term clinical results and complications of viscocanalostomy.

PATIENT AND METHODS

In a prospective and nonrandomized study, 107 consecutive eyes of 67 patients who underwent viscocanalostomy were analyzed. The surgeon conducted postoperative care. The minimal follow-up was 1 year, with a mean follow-up of 13.1 months (range, 12-18 months). The criteria for success were defined as intraocular pressure (IOP) less than 21 mmHg without treatment.

RESULTS

The mean preoperative intraocular pressure was 28.3 mmHg while the mean postoperative intraocular pressure was 5.4 mmHg on the first day and 10.2 mmHg at 13 months. The rate of patients who had intraocular pressure below 21 mmHg with or without treatment was 98% at 13 months. The complete success rate without treatment was 80% at 13 months. Seven cases of ocular hypotony lasting more than 1 month were noted.

CONCLUSION

Viscocanalostomy is a promising procedure because in the short term it provides good tonometric results in glaucomatous patients without the complications of trabeculectomy. However, it remains a technique with a learning curve.

Nd:YAG laser goniopuncture after deep sclerectomy: outcomes

PURPOSE

This study aimed to investigate the safety and efficacy of Nd:YAG laser goniopuncture (LGP) in lowering intraocular pressure (IOP) after deep sclerectomy (DS).

METHODS

We reviewed the outcomes in 258 eyes of 258 consecutive patients who underwent DS or combined phacoemulsification and DS between August 2001 and December 2003. Mitomycin C was used during surgery in 192 eyes (74.4%).

RESULTS

Mean follow-up was 40 +/- 11 months after DS and 31 +/- 12 months after LGP. Laser goniopuncture was performed in 173 eyes (67.0%). The mean interval between LGP and DS was 10.3 +/- 8.7 months. The probability of LGP being performed was 63.1% (95% confidence interval [CI] 57.3-69.4) at 36 months after surgery. At 2 years after LGP, the probability of maintaining IOP < 15 mmHg with a 20% decrease from the pre-laser IOP and no further glaucoma procedure or medication was 49.7% (95% CI 41.9-57.1). Iris covering the trabeculo-Descemet's membrane was the only factor significantly associated with the failure of LGP (hazard ratio 3.0, p < 0.001). Complications observed after LGP included peripheral anterior synechiae in 23 (13.2%), hypotony in seven (4.0%), late acute IOP rise in three (1.7%), delayed bleb leak in one and blebitis in two eyes. Argon laser iridoplasty was performed in 45 (26.0%) and needle revision in 41 (23.7%) eyes.

CONCLUSIONS

ND:YAG laser goniopuncture is an effective procedure to further lower IOP after DS. An IOP of < 15 mmHg is achieved and maintained for > or = 2 years in about 50% of cases after a single LGP procedure. There are potentially serious complications associated with the procedure. Regular gonioscopy is recommended following LGP to detect any occlusion of the goniopuncture by the iris.

Bimanual microincisional phacoemulsification combined with viscocanalostomy plus deeper sclerectomy

PURPOSE

The aim of the study was to evaluate the safety and effectiveness of a new technique, two-site bimanual microincisional cataract surgery combined with viscocanalostomy plus deeper sclerectomy (two-site bimanual MICS-VC-DS), in patients with cataract and glaucoma.

DESIGN

Noncomparative, interventional case series.

METHODS

From December 2005 to October 2007, a consecutive series of 12 patients (12 eyes) with uncontrolled primary open angle glaucoma (POAG) and cataract have undergone two-site bimanual MICS-VC-DS. Postoperative evaluation included visual acuity (VA), intraocular pressure (IOP), average retinal nerve fiber layer (RNFL) thickness measurement, and gonioscopic, biomicroscopic, and funduscopic examination. Paired-samples t test was used. A p value of <0.05 was taken as significant.

RESULTS

The mean duration of follow-up was 14.6 months (SD 5.8). At 9 months, mean IOP was 17.0 (SD 4), the mean IOP reduction was 13.2 mmHg (SD 5.86). At 9 months post-surgery, the complete success rate was 75%. Qualified success was achieved in 100% of patients. At 9 months, the mean number of antiglaucoma medications was 0.58 (SD 1.24) (p<0.05). Visual acuity improved by a mean value of 2.8 lines. Average RNFL thickness did not change significantly during the follow-up period (p=0.781).

CONCLUSIONS

Two-site bimanual MICS-VC-DS appears to be an effective and safe procedure with quick visual rehabilitation, acceptable mid-term IOP control, and the advantage of having fewer 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.

SKGEL® implant versus T-Flux® implant in the contralateral eye in deep sclerectomy with phacoemulsification: long-term follow-up

Purpose:

To intraindividually compare the efficacy and safety of the SKGEL^® implant versus the T-Flux^® implant in deep sclerectomy.

Methods:

In a retrospective analysis 17 patients were identified who underwent combined phacoemulsification-deep sclerectomy and implantation of SKGEL^® in one eye and T-Flux^® in the contralateral eye.

Results:

In eyes with SKGEL^® the IOP decreased from 20.6+7.3 mm Hg to 14.8+5.3 mm Hg (-5.8 mm Hg or -28.1%), and in eyes with T-Flux^® from 19.9+7.2 mm Hg to 14.7+3.3 mm Hg (-5.2 mm Hg or -26.1%, no statistically significant difference, p >0.05). Antiglaucoma medications with either implant decreased from initially 2.0+0.8 to 0.3+0.7. A qualified success was found in 17/17 eyes with T-Flux^® and in 16/17 eyes with SKGEL^®. Complete success was achieved in 14/17 eyes with T-Flux^® and in 13/17 eyes with SKGEL^®.

Conclusions:

The IOP-lowering effect and safety of SKGEL^® and T-Flux^® seem to be comparable.

Non-penetrating glaucoma surgery augmented with mitomycin C or 5-fluorouracil in eyes at high risk of failure of filtration surgery: long-term results

PURPOSE

To investigate the long-term efficacy and safety of non-penetrating glaucoma surgery (NPGS) augmented with mitomycin C (MMC) or 5-fluorouracil (5FU) in eyes at high risk of failure of glaucoma filtration surgery.

METHODS

Prospective study of all eyes, undergoing NPGS with 0.04% MMC (1 to 2 min topical or 0.04 mL subconjunctival injection into the superior fornix) or 5FU (25 mg/mL topically for 5 min). Complete success was an intraocular pressure (IOP)<or=21 mmHg on no medication and qualified success an IOP<or=21 mmHg with topical medication. An additional criterion for success was a >or=20% drop in IOP or a reduction of at least two medications.

RESULTS

Twenty-three eyes of 22 patients with a mean follow up of 41.4 months were reviewed. Fifteen eyes had failed trabeculectomy and seven had uveitic glaucoma. Mean preoperative IOP reduced from 25.8+/-7.8 to 15.4+/-4.9 mmHg at final visit, a mean change of 41%. Median number of preoperative medications decreased from 3 to 0 postoperatively. Cumulative probability of success was 100% at 2 years, 94% at 3 years and 85% at 4 years. No patient developed any long-term complications. Complete success was achieved in 11 eyes and qualified success in 10 eyes. Two eyes failed and required further surgery.

CONCLUSION

NPGS augmented with small-volume MMC/5FU provides good long-term IOP control in eyes at high risk of failure with a lower incidence of complications compared with augmented trabeculectomy and eliminates the need for postoperative bleb or suture manipulation.

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.

Seven-year follow-up of combined cataract extraction and viscocanalostomy

PURPOSE

To investigate the long-term success and complications of phacoemulsification combined with viscocanalostomy (phacoviscocanalostomy) in eyes with coexisting cataract and medically uncontrolled glaucoma.

SETTING

Department of Ophthalmology, Warrington Hospital, Warrington, United Kingdom.

METHODS

A prospective nonrandomized study evaluated 165 consecutive eyes (114 patients) that had phacoviscocanalostomy. The main outcome measures were intraocular pressure (IOP), visual acuity, requirement for topical antiglaucoma medication, and the presence or absence of drainage blebs or bleb complications.

RESULTS

The mean follow-up was 38.7 months +/- 19.3 (SD) (range 12 to 90 months). There was a statistically significant decrease in IOP, from 24.1 +/- 5.1 mm Hg preoperatively to 13.8 +/- 8.1 mm Hg 1 day after surgery (P<.001), 16.0 +/- 4.1 mm Hg at 5 years (P<.001), and at all evaluations to the last follow-up. The mean number of medications per eye decreased significantly from 2.5 +/- 0.9 before surgery to 0.1 +/- 0.5 at last follow-up (P<.001). At the final follow-up, IOP was reduced by 33.2% (16.2 mm Hg versus 24.1 mm Hg). Complete success, defined as an IOP reduction of more than 30% from preoperative level without medications, was achieved in 48.5% of eyes, with 42% of eyes having an IOP of less than 16 mm Hg. The percentage fall in IOP was linearly related to the preoperative IOP level (P<.001). No eye developed a trabeculectomy-type bleb, and there were no bleb-related complications.

CONCLUSIONS

Phacoviscocanalostomy was safe and effective for the management of eyes with coexisting cataract and medically uncontrolled glaucoma. It provided a stable and sustained reduction in IOP with a minimum requirement for topical medication.

Trabecular bypass: effect of schlemm canal and collector channel dilation

PURPOSE

To theorize the effect of Schlemm canal (SC) and/or collector channel (CC) dilation combined with a trabecular bypass on intraocular pressure (IOP) in eyes with primary open angle glaucoma.

METHODS

The elliptic shaped SC is dilated in conjunction with a trabecular bypass and its expanded height is largest at the bypass and linearly deceases to the nondilated height over the dilated circumferential length. The CC dilation is modeled with a reduced outflow resistance of second order polynomial over the same dilated length. Equations governing the pressure and circumferential flow in SC are solved numerically for both the unidirectional and bidirectional bypasses. The reduced IOP is deduced from the solution.

RESULTS

IOP is reduced substantially with moderate SC dilation from the normal height of 20 microm to 40 to 50 microm at the bypass; additional IOP reduction diminishes with further dilation. SC dilation is more effective for eyes with smaller SC. CC dilation also lower IOP significantly. With the trabecular bypass alone, the elevated IOP in primary open angle glaucoma is expected to drop to the mid-to-high teens. IOP can be further reduced by another 3 to 6 mm Hg with moderate SC and CC dilation. The circumferential length of dilated SC affects the efficacy of IOP reduction. In theory, the dilation of SC with a trabecular bypass is analogous to a partial trabeculotomy in terms of IOP reduction.

CONCLUSIONS

In theory, a moderate dilation of SC and CC in conjunction with a trabecular bypass reduces the IOP to the low-to-mid teens.

Experimental studies on nonpenetrating filtration surgery using the CO2 laser

BACKGROUND

This study evaluated the use of a CO2 laser for performing deep sclerectomy in nonpenetrating filtration surgery.

METHODS

Three experimental models were performed: enucleated sheep and cow eyes (n=18) to determine optimal irradiation parameters, live rabbit eyes (n=20) to test feasibility, and cadaver eyes (40 procedures in 20 eyes) to study effects in human eyes tissue. After a half-thickness scleral flap was created, deep sclerectomy was performed by CO2 laser applications on the scleral bed down to the trabeculo-Descemet's membrane.

RESULTS

Fluid percolation was repeatedly achieved without penetration in sheep and cow eyes using scanned laser energy of 5-10 W at a pulse duration of 200 micros and a working distance of 35 cm. In live rabbits, deep sclerectomy was achieved without perforation in 19/20 eyes. Intraocular pressure was significantly decreased on the first postoperative day (10.3+/-5.1 mmHg lower, on average, than in the nonoperated fellow eye; P<0.001), and this persisted for 21 days. Operations on all cadaver eyes resulted in effective fluid percolation. Penetration of the scleral wall occurred in five cases only after repeated laser applications with high energy. Histologically, a thin sclerocorneal intact wall was demonstrated at the sclerectomy bed. Collateral tissue damage did not extend beyond 100 microm, and adjacent structures remained unharmed.

CONCLUSIONS

CO2 laser-assisted deep sclerectomy is a feasible and apparently safe procedure.

Deep sclerectomy for the treatment of exfoliation and primary open-angle glaucoma

PURPOSE

To retrospectively compare the efficacy of deep sclerectomy in the treatment of primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG).

METHODS

Deep sclerectomy with either collagen or hyaluronate implants was performed in 31 eyes (45%) with POAG and 38 eyes (55%) with ExG. Pre- and postoperative intraocular pressure (IOP) was recorded, as was the number of glaucoma medications used pre- and postoperatively in each group. The follow-up data referred to a mean period of 18 months (range: 2 weeks to 36 months).

RESULTS

At 18 months, complete success had been achieved in 56.3% of POAG eyes and 44.9% of ExG eyes. Qualified success had been achieved in 83.1% and 71.6% of POAG and ExG eyes, respectively. The mean IOP was 18.6 mmHg in POAG eyes and 16.3 mmHg in ExG eyes. YAG-descemetotomies were performed in nine eyes in each group. There were no statistically significant differences between the groups in IOP (except at 1 week postoperatively in favour of POAG; p = 0.05), success rates, need for postoperative glaucoma medication or number of complications. Reoperations were required in three (10%) POAG eyes and seven (18%) ExG eyes.

CONCLUSIONS

Deep sclerectomy is equally effective in controlling IOP in both POAG and ExG and has low rates of serious complications, even when the surgeon is inexperienced in the technique. Both survival rates and IOP control were similar between the groups, and there were no serious intra- or postoperative complications.

Control of intraocular pressure after deep sclerectomy

AIM

To study the long-term outcome of deep sclerectomy in patients with open angle glaucoma.

METHODS

Prospective consecutive series of 43 eyes (38 patients) with medically uncontrolled open-angle glaucoma undergoing deep sclerectomy. All patients underwent clinical assessment before and after surgery at day 7 and at months 1, 3, 6, 12, 18, 24, 36. Surgical success was considered if the patient's intraocular pressure (IOP) < 22 mmHg and the IOP was lowered by more than 20% without the use of any medication. Kaplan-Meier survival curves were used to evaluate the success rate.

RESULTS

The mean follow-up time was 28.1 +/- 8.2 months. Mean IOP decreased significantly from a preoperative value of 24.6 +/- 5.5 mmHg to a postoperative value of 18.5 +/- 4.6 mmHg at 36 months (P < 0.001). Microperforation of TDM occurred in three cases (7.0%) and ciliary body prolapse in one case (2.3%) but did not prevent completion of the operation. Postoperatively, hyphaema was detected in one case and shallow anterior chamber in another case and both were treated conservatively. Bleb encapsulation with elevation of IOP occurred in two cases (4.7%) and was treated with 5-fluorouracil subconjunctival injection. Goniopuncture with neodymium : YAG laser was performed in two cases (4.7%). There were no other late complications with the exception of failure of the operation. On the life-table analysis the success rate at 12, 24, and 30 months were 61.4, 36.6, and 18.9%, respectively.

CONCLUSION

Deep sclerectomy reduced the IOP temporarily while minimising the risk of postoperative complications commonly encountered with standard trabeculectomy. However, after long-term follow-up surgery failed to maintain a low IOP.

A pilot study of deep sclerectomy with implantation of chromic suture material as a collagen implant: medium-term results

AIMS

A pilot study of the safety and efficacy of deep sclerectomy with a chromic suture implant (DSCI) for open angle glaucoma.

METHODS

This prospective trial involved 23 eyes of 16 consecutive patients with uncontrolled open angle glaucoma. The DSCI procedure involved radial suturing of a 2 mm piece of 1/0 chromic suture as an implant. Intraocular pressure (IOP) measurements and eye examinations were performed preoperatively and regularly postoperatively for up to 66 months.

RESULTS

The mean follow-up period was 36.3 (SD 19.9) months. The mean preoperative IOP was 26.3 (SD 8.5) mmHg. The mean postoperative IOP was 14.1 (SD 2.8) mmHg at month 12, and 16.5 (SD 2.3) mmHg at 36 months. Complete success rate, defined as an IOP lower than 21 mmHg without medication was 77% of eyes at 36 months. Qualified success rate, defined as an IOP lower than 21 mmHg with medication, was 100% at 36 months. Paired t-test and Wilcoxon test analysis of preoperative vs postoperative IOP at 36 months indicated a significant reduction in IOP. Intraoperative complications included rupture of the trabecular meshwork in seven eyes. Exclusion of these patients from the results analysis revealed a mean follow-up of 37.1 months (SD 9), preoperative mean IOP was 25.9 mmHg (SD 4.1), 12-month mean IOP was 13.4 mmHg (SD 2.8), and 36-month mean IOP 16.6 mmHg (SD 2.1). Early postoperative complications included hyphaema in two eyes and dislocation of implant in one eye. One eye developed a central retinal vein occlusion and cataract progression occurred in one eye. The mean postoperative duration of use of topical dexamethasone was 5.4 months (SD 2).

CONCLUSIONS

DSCI using a chromic suture implant provides good control of IOP at medium-term follow-up with few postoperative complications. Prolonged use of postoperative anti-inflammatory medication was necessary.

Surgical strategies in patients with combined cataract and glaucoma

PURPOSE OF REVIEW

In the elderly population, the combined presence of cataract and glaucoma is a frequent condition. In this situation, several surgical options are possible: cataract surgery only and later maybe trabeculectomy, trabeculectomy only and later maybe cataract surgery, or combined cataract and glaucoma surgery. This review compares the different surgical options on the basis of their achievable postoperative intraocular pressure (IOP) level and success and complication rates.

RECENT FINDINGS

The impression of better IOP regulation with trabeculectomy than with phacotrabeculectomy has been recently confirmed by an evidence-based review. Contrary to this finding, the success of deep sclerectomy or trabeculotomy does not seem to be compromised by simultaneous phacoemulsification. In eyes with previous glaucoma-filtering surgery, cataract surgery with clear corneal incision has no effect on mean IOP but increases the 3-year failure probability. For phacotrabeculectomy, moderate evidence of a beneficial effect of MMC on IOP regulation and only weak evidence for separating the incisions has been recently reported by another evidence-based review.

SUMMARY

The choice of the preferred surgical method depends on the target pressure, the amount of glaucomatous damage, and the grade of visual disturbance caused by the cataract. Phacotrabeculectomy combined with mitomycin C achieves the best IOP lowering of all types of combined cataract and glaucoma surgery currently possible but is associated with potentially sight-threatening complications. In the absence of a low target pressure, phacotrabeculotomy or the combination of phacoemulsification with viscocanalostomy or deep sclerectomy may be the therapy of choice.