Deep sclerectomy in normal-tension glaucoma with and without mitomycin-c

Endophthalmitis and blebitis following deep sclerectomy and trabeculectomy with routine use of mitomycin C

PURPOSE

The purpose of the study was to investigate the incidence for endophthalmitis and blebitis after deep sclerectomy (DS) and trabeculectomy with routine use of Mitomycin C (MMC) 0.4 mg/ml.

METHODS

Electronic medical records of patients who underwent surgery 1/2008-4/2020 were reviewed. Cumulative incidence for bleb-associated infection (BAI), including both endophthalmitis and blebitis, was calculated with cumulative incidence function (CIF) and Kaplan-Meier analysis. Risk factors for BAI were evaluated with univariate competing risk regression analysis and Log-rank analysis. Competing event in CIF was death.

RESULTS

In this retrospective single-centre cohort study, a total of 2653 patients and 3411 eyes underwent surgery: 3478 glaucoma surgeries, 2419 DS and 1059 trabeculectomies. Two cases of endophthalmitis and three of isolated blebitis developed. Median follow-up from the most recent surgery on the eye until the end of the study was 5.5 years, and until last visit at the ophthalmology department was 1.9 years. For the whole follow-up period in CIF-analysis, cumulative incidence for BAI was 0.16% (95% CI 0.06-0.36) at five years. Incidence was higher with eyes not treated with an antifibrotic during surgery (sub-hazard ratio 11.66, 95% CI 1.94-70.21, p = 0.007). Cumulative incidence between surgery and last visit with Kaplan-Meier analysis was 0.21% (95% CI 0.08-0.52) at five years, similarly, not using an antifibrotic increased incidence (Log-rank p < 0.001).

CONCLUSION

Cumulative incidence for BAI was low despite routine use of high-dose MMC.

Augmented Subscleral Trabeculectomy With Beta Radiation and Mitomycin C in Egyptian Glaucoma Patients

PURPOSE

Subscleral trabeculectomy is the most common surgical treatment for glaucoma. However, wound healing and scar formation may result in bleb fibrosis, leading to bleb failure. The healing response of the wound is reported to be the single most important risk factor in determining the final intraocular pressure (IOP) after glaucoma filtration surgery. Thus, we aimed to evaluate the effect of preoperative beta irradiation and intraoperative mitomycin C (MMC) treatment as combined adjuncts to subscleral trabeculectomy in the management of glaucoma in Egyptian patients.

PATIENTS AND METHODS

This prospective, interventional, comparative masked clinical study was performed between October 2016 and January 2018. This study included 50 subjects, 25 of whom underwent trabeculectomy augmented by MMC intraoperatively and beta radiation preoperatively at the bleb area (patient group #1). The remaining 25 subjects underwent trabeculectomy with MMC alone (control group #2). Beta radiation was administered 5 to 7 days before the surgery as a single dose (1000 cGy) using a strontium-90 probe. MMC (0.2 mg/mL) was administered for 2 minutes.

RESULTS

There was a statistically significant difference in postoperative IOP between the groups from the second week. Intraoperative hyphema occurred in 6 cases in the control group #2, whereas no intraoperative hyphema was observed in patient group #1; this difference was statistically significant.

CONCLUSIONS

Subscleral trabeculectomy augmented by beta radiation and MMC gives greater control over IOP. Therefore, we recommend using beta radiation before trabeculectomy in patients who may have a high risk of developing conjunctival fibrosis.

Nonpenetrating Deep Sclerectomy for Progressive Glaucoma: Long-term (5-year) Follow-up of Intraocular Pressure Control and Visual Field Survival

Purpose

To monitor 5-year outcomes of nonpenetrating deep sclerectomy (NPDS) with mitomycin C (MMC) in a new consecutive patient cohort.

Materials and methods

All eyes undergoing NPDS surgery between 1/08 and 6/12 were monitored for intraocular pressure (IOP), number of antiglaucoma medications (meds), and visual field indices [mean deviation (MD) and corrected pattern standard deviation (CPSD)], relative to the preoperative baseline using the two-tailed paired Student's t test.

Results

Of 106 eyes undergoing NPDS with MMC, mean IOP was 19.7 ± 0.5 [sem] mm Hg preoperatively, 11.9 ± 0.5 at 3 months, 12.5 ± 0.6 at 6 months, 12.4 ± 0.5 at 12 months, 12.6 ± 0.6 at 18 months, 11.1 ± 0.6 at 2 years, 11.8 ± 0.5 at 2.5 years, 11.0 ± 0.5 at 3 years, 11.7 ± 0.5 at 3.5 years, 10.7 ± 0.7 at 4 years, 11.6 ± 0.5 at 4.5 years, and 12.4 ± 0.7 at 5 years (average IOP reduction of 7.8 mm Hg or 37%; p < 10⁻⁶) at 5 years. About 92% of eyes had stable IOP ≥5 and ≤21 mm Hg at 5 years. Mean preoperative meds 2.7 ± 0.1 was reduced to 0.40 ±0.09 at 3 months, 0.51 ± 0.1 at 6 months, 0.38 ± 0.08 at 12 months, 0.49 ± 0.09 at 18 months, 0.41 ± 0.09 at 2 years, 0.39 ± 0.09 at 2.5 years, 0.49 ± 0.1 at 3 years, 0.58 ± 0.1 at 3.5 years, 0.49 ± 0.1 at 4 years, 0.64 ± 0.1 at 4.5 years, and 0.52 ± 0.1 at 5 years, corresponding to mean reduction of 2.2 meds (81%; p < 10⁻²²) at 5 years. Mean deviation and CPSD were stable relative to baseline at all time intervals (R = 0.83–0.94; p < 0.0001).

Conclusion

With appropriate postoperative management, eyes undergoing NPDS can maintain excellent IOP control with minimal medication use and maintain very stable visual fields over an extended time frame.

How to cite this article

Slagle G, Groth SL, Montelongo M, et al. Nonpenetrating Deep Sclerectomy for Progressive Glaucoma: Long-term (5-year) Follow-up of Intraocular Pressure Control and Visual Field Survival. J Curr Glaucoma Pract 2020;14(1):3–9.

Evaluation of the Early to Mid-term Efficacy and Safety of Deep Sclerectomy without an Intrascleral Spacer for Open-angle Glaucoma in an Australian Population

Purpose

This study aims to evaluate the early to the midterm efficacy of deep sclerectomy (DS) without an intra-scleral spacer for open-angle glaucoma (OAG) patients.

Materials and methods

Retrospective study of 99 eyes (88 patients) with open-angle glaucoma who underwent DS were recruited in a consecutive order following informed consent. Intraocular pressure (IOP) was collected up to 60 months post operation (mean 19.87 ± 15.13 months). Criteria of success were defined as the qualified success (QS) or complete success (CS) with IOP level less than 21, 18 and 15 mm Hg and a reduction of more than 20% IOP from baseline. QS includes additional medication post-DS, while CS requires no other medications or surgery post-DS. Further analysis includes comparing the criteria of success based on several factors. The data were analyzed using statistical package for social sciences (SPSS version 21) statistical software.

Results

The QS at 60 months for IOP less than 21, 18 and 15 mm Hg is 71.3% (45.12 ± 2.46), 63.9% (40.41 ± 2.75) and 48.7% (35.62 ± 2.85), respectively. The CS at 60 months for IOP less than 21, 18 and 15 mm Hg are 69.3% (47.51 ± 2.77), 57.9% (40.41 ± 2.75) and 45.2% (35.62 ± 2.85), respectively. There was no significant difference between QS and DS post-DS based on the level of experience of the surgeons; intraoperation complication; age and gender. There was a significant reduction in IOP post operation (p < 0.001).

Conclusion

DS is observed to be an effective surgical method with a favorable safety profile to manage patients with open-angle glaucoma. It has a better safety profile compared to trabeculectomy (TE) and can be performed by surgeons of different experience safely and successfully.

Clinical significance

To our knowledge, this is the first report of DS in an Australian population with up to 60 months of follow-up. It is an effective procedure for IOP control in patients with OAG and has fewer complications compared to TE. DS is less popular than TE primarily due to a perceived steep learning curve, but most of the literature on DS describe single surgeon results. Our study compared the outcome of five surgeons with a variety of experience and found no significant differences in the rate of success for all levels of IOP.

How to cite this article

Hui MM, Clement CI. Evaluation of the Early to Mid-term Efficacy and Safety of Deep Sclerectomy without an Intrascleral Spacer for Open-angle Glaucoma in an Australian Population. J Curr Glaucoma Pract 2018;12(3):107-112.

Long-term results of deep sclerectomy in normal-tension glaucoma

PURPOSE

To study the long-term outcome of deep sclerectomy with and without mitomycin-C (MMC) in patients with normal-tension glaucoma (NTG).

METHODS

We prospectively analysed consecutive patients randomized to surgery performed either with (MMC group) or without (non-MMC) MMC. Surgery was considered totally successful if, after surgery, the preoperative intra-ocular pressure (IOP) level was reduced by 25% without medication, and a qualified success if medication was required to achieve the same limits.

RESULTS

A total of 37 patients were enrolled, 15 in the MMC and 22 in the non-MMC group. The median (range) follow-up was 7.9 (1.0-9.0) years, with a drop-out of three (8%) patients. The preoperative IOP was 15 (11-21) mmHg in the MMC and 15 (10-19) mmHg in the non-MMC group. At the last 6- to 9-year follow-up, IOP was significantly reduced to 9 (2-13) mmHg (p = 0.002) and 10 (5-13) mmHg (p < 0.001). The overall (groups combined) complete and qualified success rates were 50% and 71%, with no significant difference between groups (p = 0.48 and p = 0.25). Goniopuncture was performed in 87% and 100% of eyes in the MMC and non-MMC groups (p = 0.14). Needling with MMC injection was performed 0 (0-1) times in the MMC group and 0.5 (0-4) times in the non-MMC group (p = 0.056). We encountered no cases of hyphema, shallow anterior chamber, hypotony maculopathy, choroidal effusion, late bleb leakage, blebitis, endophthalmitis or malignant glaucoma.

CONCLUSION

In NTG, long-term significant IOP reduction can be achieved with deep sclerectomy with a low incidence of sight-threatening complications.

Evaluation of the learning curve of non-penetrating glaucoma surgery

PURPOSE

To evaluate the learning curve of non-penetrating glaucoma surgery (NPGS).

METHODS

The study included 32 eyes of 27 patients' (20 male and 7 female) with medically uncontrolled glaucoma. Non-penetrating glaucoma surgeries performed by trainees under control of an experienced surgeon between 2005 and 2007 at our tertiary referral hospital were evaluated. Residents were separated into two groups. Humanistic training model applied to the one in the first group, he studied with experimental models before performing NPGS. Two residents in the second group performed NPGS after a conventional training model. Surgeries of the residents were recorded on video and intraoperative parameters were scored by the experienced surgeon at the end of the study. Postoperative intraocular pressure, absolute and total success rates were analyzed.

RESULTS

In the first group 19 eyes of 16 patients and in the second group 13 eyes of 11 patients had been operated by residents. Intraoperative parameters and complication rates were not statistically significant between groups (p > 0.05, Chi-square). The duration of surgery was 32.7 ± 5.6 min in the first group and 45 ± 3.8 min in the second group. The difference was statistically significant (p < 0.001, Student's t test). Absolute and total success was 68.8 and 93.8% in the first group and 62.5 and 87.5% in the second group, respectively. The difference was not statistically significant.

CONCLUSIONS

Humanistic and conventional training models under control of an experienced surgeon are safe and effective for senior residents who manage phacoemulsification surgery in routine cataract cases. Senior residents can practice these surgical techniques with reasonable complication rates.

Update on Normal Tension Glaucoma

Normal tension glaucoma (NTG) is labelled when typical glaucomatous disc changes, visual field defects and open anterior chamber angles are associated with intraocular pressure (IOP) constantly below 21 mmHg. Chronic low vascular perfusion, Raynaud's phenomenon, migraine, nocturnal systemic hypotension and over-treated systemic hypertension are the main causes of normal tension glaucoma. Goldmann applanation tonometry, gonioscopy, slit lamp biomicroscopy, optical coherence tomography and visual field analysis are the main tools of investigation for the diagnosis of NTG. Management follows the same principles of treatment for other chronic glaucomas: To reduce IOP by a substantial amount, sufficient to prevent disabling visual loss. Treatment is generally aimed to lower IOP by 30% from pre-existing levels to 12-14 mmHg. Betaxolol, brimonidine, prostaglandin analogues, trabeculectomy (in refractory cases), systemic calcium channel blockers (such as nifedipine) and 24-hour monitoring of blood pressure are considered in the management of NTG. The present review summarises risk factors, causes, pathogenesis, diagnosis and management of NTG.

Deep Sclerectomy in Primary Open-Angle Glaucoma and Exfoliative Glaucoma

Purpose

To study the effect of deep sclerectomy (DS) in primary open-angle glaucoma (POAG) and exfoliative glaucoma (EXG).

Methods

We retrospectively analyzed the intraocular pressure (IOP)-lowering effect of DS in 235 consecutive eyes. Eyes were divided into 2 groups according to glaucoma subtype: POAG (127 eyes) and EXG (108 eyes). Postoperative IOP was the main outcome measurement. We recorded complete and qualified surgical success, need for YAG-laser goniopuncture, and need for postoperative glaucoma medication. We studied factors related to outcome of surgery in a Cox regression model.

Results

In the POAG group, the mean (SD) IOP decreased from 22.6 (5.1) mm Hg preoperatively to 16.8 (7.5) mm Hg, with qualified success achieved in 70% of eyes. Postoperatively, 57% were without medication. In the EXG group, IOP decreased from 25.5 (6.5) mm Hg preoperatively to 16.5 (7.8) mm Hg postoperatively, with qualified success achieved in 66% of eyes. Postoperatively, 50% were without medication. Decrease in IOP was statistically significant in both groups (p<0.001). In the POAG group, 12%, and in the EXG group, 24% needed a reoperation in the follow-up period (p = 0.037). In the Cox regression model, 1 week IOP between 2 and 14 mm Hg without medication lowered the hazard rate of losing complete success by 34% (p = 0.031) and the hazard rate of losing qualified success by 54% (p = 0.004).

Conclusions

The IOP 1 week postoperatively seems to be a prominent indicator of surgical success. Deep sclerectomy is effective in reducing IOP in POAG and EXG subgroups, with reoperations more common in EXG eyes.

Biodegradable PTLGA Terpolymers versus Collagen Implants Used as an Adjuvant in Trabeculectomy in Rabbit Eye

Purpose. To evaluate the effectiveness and safety of three biodegradable terpolymers prepared from L-lactide, trimethylene carbonate, and glycolide (PTLGA) as an aid for trabeculectomy compared with the Ologen (OLO). Methods. Trabeculectomy was carried out on rabbits with implantation made from OLO or three PTLGA terpolymers. Intraocular pressure (IOP) was recorded 1, 2, 3, and 6 months postoperatively and bleb evaluations were performed using ultrasound biomicroscopy (UBM) 3 months after surgery, optical coherence tomography (OCT) every month, and transmission electron microscopy (TEM) six months after surgery followed by histological examination 1, 2, 3, and 6 months postoperatively. Result. IOP was significantly reduced in all groups after surgery. There were no significant differences in the IOL between groups at any time after implantation. There was no significant difference between the groups examined by OCT, UBM, and TEM. Exposure of the implant was observed in one eye from the OLO group and one eye in the P1. Subconjunctiva hyperblastosis was observed in one eye from group P3 and two eyes from the OLO group. Conclusions. Subconjunctival implantation of filtering devices made from PTLGA may present a safe and effective additional surgical tool for the treatment of filtering surgery. Fewer complications were observed in the group with P2 implants compared to other groups.