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

The Efficacy of Fibrin Sealant in Sutureless Deep Sclerectomy-Preliminary Outcomes

PRCIS

Deep sclerectomy (DS) with fibrin adhesive can constitute a safe alternative to the classic procedure using sutures, providing nonallergenic, nontoxic, and secure adhesion with no sign of aqueous humor outflow obstruction postoperatively.

OBJECTIVE

To evaluate short and medium-term postoperative results of DS with a fibrin sealant.

PATIENTS AND METHODS

This prospective, noncomparative, interventional case series involves 12 eyes of 12 patients with uncontrolled open angle glaucoma who underwent DS with Esnoper (Clip or V2000) implant between February 2021 and March 2022. A novel method of wound closure (sclera, Tenon fascia, and conjunctiva) employing fibrin glue was used instead of classic sutures. Surgical outcomes assessed include: intraocular pressure and glaucoma therapy reduction, best-corrected visual acuity changes, and number of complications registered peri and postoperatively. All measurements were performed preoperatively, as well as at 1 day, at 1 and 2 weeks, and at 1, 2, 3, 6, 9, and 12 months after surgery.

RESULTS

The mean intraocular pressure decreased from 24.0 ± 9.1 mm Hg to 13.8 ± 6.3 mm Hg at 1 year postoperatively ( P < 0.001). Kaplan-Meier survival analysis revealed complete and qualified success rates of 83.3% and 91.7%. The mean glaucoma therapy decreased from 3.2 ± 1.1 to 0.8 ± 1.3 drugs 12 months after surgery ( P < 0.001). Nd:YAG goniopunture was performed in 2 eyes at 1 and 12 months postoperatively. No significant best-corrected visual acuity changes were registered. Perioperatively, we noted a trabeculo-descemet microperforation in 1 eye, transient hypotony in 5 eyes, and mild hyphema in 2 eyes.

CONCLUSIONS

Fibrin adhesive provided an effective closure in sutureless DS in the patients included in our study. This modification of classical DS may simplify the surgical technique, ensure secure wound adaptation, optimize healing, and lower the risk of inflammation and fibrosis postoperatively.

Canaloplasty in Pseudoexfoliation Glaucoma. Can It Still Be Considered a Good Choice?

Purpose: The aim of this study was to assess the long-term outcomes of canaloplasty surgery in pseudoexfoliation glaucoma (PEXG) patients. Material and Methods: A total of 116 PEXG patients with an intraocular pressure (IOP) > 21 mm/Hg and maximum tolerated local medical therapy who underwent canaloplasty from February 2008 to January 2022 were considered. Every six months, all subjects underwent a complete ophthalmic examination. The period of follow-up ranged from 2 to 167 months. Inclusion criteria included only patients for whom the entire procedure could be completed with a follow-up of at least 2 years. Results: Amongst the 116 PEXG patients, the entire procedure could not be performed in 10 eyes (8.6%), and thus they were not considered in the analysis. Twenty-three patients did not reach the two-year follow-up and another 16 patients during this time period were lost. A total of 67 patients with a mean follow-up of 49 ± 32.3 months were considered in the analysis. The pre-operative mean IOP was 31.2 ± 8.7 mm/Hg (range 20−60). The mean IOP at the two-year follow-up was 17.2 ± 6.7 mmHg, with a mean reduction from baseline of 44.9%. After two years, the qualified success rates according to three different criteria (IOP ≤ 21, ≤18 and ≤16 mmHg) were 80.6%, 73.1% and 61.0%, respectively. The total number of medications used pre- and at the follow-up at 2 years was 3.5 ± 0.8 and 1.2 ± 1.4, respectively. Early complications included: hyphema, in about 30% of cases; Descemet membrane detachment (4.9%); and IOP spikes > 10 mmHg (9.7%). A late failure with an acute IOP rise of up to 50 mmHg was observed in 41 cases (61.2%) after 3 to 72 months. Conclusions: Long-term post-operative outcomes of canaloplasty in PEXG patients appear to be quite good on average; however, an acute rise in IOP can be observed in more than 60% of the cases after a long period of satisfactory IOP control. For this reason, canaloplasty may not be suitable in eyes with PEXG, especially in patients with severe functional damage.

Five-year results of non-penetrating deep sclerectomy with demineralized cancellous bone xenogenically derived collagen glaucoma implant

PURPOSE

To investigate the long-term effectiveness of non-penetrating deep sclerectomy (NPDS) with xenogenically derived cancellous bone collagen glaucoma implant (XCB-CGI) implantation in patients with primary open-angle glaucoma (POAG).

MATERIALS AND METHODS

Retrospective chart review of patients with POAG stages 2 and 3 was treated with NPDS and XCB-CGI. Follow-up was at 6 months, 1, 2, 3, 4 and 5 years after surgery. Main outcomes were intraocular pressure (IOP) and medication burden. Secondary outcomes were visual acuity, corneal hysteresis (CH), visual field (VF) and optical coherence tomography (OCT) parameter analysis.

RESULTS

Among 71 patients (71 eyes), the mean age was 72.7 ± 9.8. Average initial IOP was 27.7 ± 7.9 and average initial med load was 2.36 ± 0.99. At 6 months, 1, 2, 3, 4 and 5 years, the average IOP was 14.9 ± 3.3 mm Hg (46.2% reduction), 15.3 ± 4.0 mm Hg (44.7% reduction), 14.2 ± 3.8 mm Hg (48.7% reduction), 15.2 ± 3.3 mm Hg (45.0% reduction), 15.5 ± 3.3 mm Hg (44.0% reduction) and 14.2 ± 2.8 mm Hg (48.7% reduction), respectively. In 5 years, the success rate was 34% and 67%, without, and with medications (1.8 ± 0.8 meds required), respectively. Visual acuity was not significantly different (P > .05) at all follow-up visits from baseline. Mean CH increased by 2.1 ± 0.8 (P = .05). No glaucomatous deterioration of the VF and OCT parameters was detected in 56 eyes at the 5-year follow-up.

CONCLUSION

NPDS with XCB-CGI implantation is an effective procedure to normalize the level of IOP, stabilize glaucomatous changes and decrease the number of meds needed for glaucoma control.

Recent Advances in the Surgical Management of Glaucoma in Exfoliation Syndrome

Surgical and laser procedures traditionally used in the management of exfoliation glaucoma (XFG) include laser trabeculoplasty, trabeculectomy, and glaucoma drainage implant surgery. Having demonstrated similar safety and efficacy in XFG compared with primary open-angle glaucoma, trabeculectomy remains the most commonly performed surgery in XFG. Recent trends in practice patterns in developed nations demonstrate a shift towards glaucoma drainage implant surgery, which is currently the procedure of choice in XFG for many, particularly in developed nations. In addition, cataract surgery alone may significantly decrease intraocular pressure in patients with XFG, may prevent glaucoma development in patients with exfoliation syndrome, and is recommended to be performed early in the course of the disease. With the relatively recent introduction of nonpenetrating glaucoma surgery and the ongoing evolution of minimally invasive glaucoma surgery, several other surgical procedures have now become part of the glaucoma surgeon's armamentarium when treating XFG, including the Ex-PRESS shunt, deep sclerectomy, viscocanalostomy, Trabectome, as well as angle procedures. These techniques have demonstrated promising results in various types of glaucoma. More research is, however, needed to establish the safety and efficacy of these procedures in XFG.

Oxidized low-density lipoprotein, lipid and calcium aggregates reveal oxidative stress and inflammation in the conjunctiva of glaucoma patients

PURPOSE

Conjunctival specimens from primary open-angle glaucoma (POAG), exfoliation glaucoma (ExG) patients and controls were histologically analysed for oxidized low-density lipoprotein (ox-LDL), lipid and calcium aggregates. Our goal was to use them as biomarkers of oxidative stress and inflammation and to evaluate their correlation with glaucoma and impact on surgical outcome.

METHODS

Conjunctival samples were obtained from POAG (n = 14) and ExG (n = 17) patients and from control subjects (n = 11) operated for macular hole, retinal detachment or strabismus. Immunohistochemistry was performed using the antibody against ox-LDL. Lipids and calcium were analysed by histochemical stainings with Nile red and Alizarin red S, respectively.

RESULTS

Immunoreaction for ox-LDL was significantly increased in POAG (p = 0.049) and the number of lipid aggregates was significantly higher in ExG (p = 0.009) when compared to control. When POAG and ExG patients were grouped according to the outcome of deep sclerectomy (DS) surgery, the number of lipid (p < 0.001) and calcium aggregates (p = 0.014) were significantly higher in the conjunctival stroma of patients whose surgery failed within a three-year follow-up period.

CONCLUSIONS

The lipid-mediated alterations suggested the presence of oxidative stress and inflammation in the conjunctiva of glaucoma patients. The present data further support the role of oxidative stress and inflammation in the wound healing process leading to excessive scarring and failure in DS surgery.

Deep Sclerectomy with Nonabsorbable Implant (T-Flux) in Patients with Pseudoexfoliation Glaucoma

Purpose. To evaluate the effectiveness of deep sclerectomy with T-flux implant (DS T-flux) in patients with pseudoexfoliation glaucoma (PExG). Methods. 20 eyes of 18 patients with medically uncontrolled PExG have undergone DS T-flux implantation. Postoperatively we evaluated the IOP values and the frequency of complications. The minimum follow-up time was 12 months (20 eyes) and the maximum 24 months (10 eyes). Results. The mean preoperative IOP was 36.8 ± 8.7 mmHg. The IOP significantly decreased throughout all postoperative periods (P < 0.05) and reached 1 day after surgery 11.45 ± 6.6 mmHg; 3 months 13.45 ± 3.6 mmHg; 12 months 14 ± 2.8 mmHg; and 24 months 14.80 ± 2.4 mmHg. Complete success rate, defined as IOP ≤ 18 mmHg without medication, was 85% (17/20 eyes) at 12 months. Qualified success rate, defined as IOP ≤ 18 mmHg with or without medication, was 100% (20/20 eyes). The most frequent postoperative complications were mild hyphaema (9 patients, 45%), choroidal detachment (3 patients, 15%), and hypotony—IOP < 5 mmHg (2 patients, 10%). Conclusions. DS with T-flux implant is a safe and effective surgical treatment method for medically uncontrolled PExG. The number of complications is low.

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.

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.

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

PURPOSE

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

METHODS

We prospectively analysed the results of 37 eyes of 37 consecutive patients with NTG (age; mean ± SD; 64 ± 7 years) who underwent DS with a collagen implant. Patients were randomized to the MMC and non-MMC groups. Subconjunctival MMC (0.4 mg/ml for 3 min) was used intraoperatively in 15 of 37 eyes. We defined total success as 25% reduction in intraocular pressure (IOP) without medication. Follow-up time was 12 months.

RESULTS

The mean preoperative IOP was significantly reduced from 15.2 ± 2.8 mmHg to 9.3 ± 2.7 (p < 0.001) in the MMC group after 12-month follow-up and from 15.1 ± 2.9 mmHg to 11.8 ± 2.0 (p < 0.001) in the non-MMC group. At 12 months, the mean IOP was significantly lower in the MMC group (p = 0.003) compared with the non-MMC group. Total success was achieved in 10 of 15 eyes (67%) in MMC group and in nine of 22 eyes (41%) in non-MMC group (p = 0.12). The number of glaucoma medications was decreased from 2.2 ± 0.8 to 0.5 ± 1.2 in MMC group (p = 0.001) and from 2.6 ± 1.0 to 0.5 ± 0.7 in non-MMC group (p < 0.001). Goniopuncture was performed in seven eyes (47%) in the MMC group, compared with 16 eyes (73%) in the non-MMC group (p = 0.13). IOP < 10 mmHg was achieved in seven of 15 eyes in the MMC group and in two of 22 in the non-MMC group (p = 0.009). Complication rate was low, and no difference between groups was evident.

CONCLUSION

Deep sclerectomy seems to be effective and safe in reducing IOP in patients with NTG. Intraoperative use of MMC results in lower postoperative IOP 12-month postoperatively without increased rate of complications.

[Filtering surgery in glaucoma: comparative study of three surgical approaches]

INTRODUCTION

The multiple complications observed with trabeculectomy encouraged the re-emergence of non penetrating glaucoma surgery (NPGS) in the 1980's. Since then, several modifications have been developed in order to improve success rates and safety. We describe a new variation of deep sclerectomy (DS) in which we include an autologous corneal stromal implant soaked in mitomycin C and sutured to the scleral bed. Next, we compare intraocular pressure (IOP) at 2 years in three groups: I: DS; II: DS with autologous implant soaked in mitomycin C; III: conventional trabeculectomy.

PATIENTS AND METHODS

All surgeries were performed by the same surgeon. There were 40, 22 and 15 eyes with medically uncontrolled primary open angle glaucoma (POAG) in groups I, II and III, respectively. All patients underwent the usual pre- and postoperative exams over 24 months. Selected patients underwent Visante OCT (Optical Coherence Tomography) (Carl Zeiss, Meditec, Inc. Germany) examination of their anterior segments.

RESULT

Age and sex distribution in all three groups showed no statistical difference. Mean preoperative IOP was 24 ± 11 mmHg, 26 ± 14 mmHg and 25 ± 9 mmHg in group I, II and III, respectively (P>0.8). Mean postoperative IOP was 14 ± 3 mmHg, 10 ± 3 mmHg and 13 ± 4 mmHg (P=0.05) at six months; 16 ± 4 mmHg, 13 ± 3 mmHg and 11 ± 4 mmHg (P=0.02) at 12 months; and 15 ± 4 mmHg, 12 ± 3 mmHg and 14 ± 4 mmHg (P=0.2) at 24 months. Mean number of eye medications dropped from 1.85, 2.18 to 1.92 (P>0.05) preoperatively in group I, II, and III, respectively, to and 0.25, 0.05 to 0.18 (P=0.02) at 24 months. Patients with a visible implant under the bleb at 24 months had a better outcome.

DISCUSSION

DS with autologous implant significantly reduced IOP at 12 and 24 months. The results seem better than those obtained with collagen implants, most likely due to the persistence of the corneal implant under the bleb at 2 years. Its non-resorption and the minimal fibrosis at the level of the scleral bed may be related to the fact that it is an autologous material which has been soaked with mitomycin C.

CONCLUSION

DS with autologous implant soaked in mitomycin C, an inexpensive technique, demonstrates medium-term efficacy in the surgical management of POAG. Our results suggest that our technique may enhance both success rate and efficacy in lowering IOP. Further long-term studies are needed.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Factors associated with non-penetrating deep sclerectomy failure in controlling intraocular pressure

PURPOSE

To identify factors related to non-penetrating deep sclerectomy (NPDS) failure in controlling intraocular pressure (IOP).

METHODS

A case-control study was performed through a logistic regression modelling. All cases and controls had at least 2 years of follow-up. Cases comprised eyes that had undergone an NPDS and presented an end-point IOP > 18 mmHg; controls consisted of eyes that had undergone an NPDS and achieved an end-point IOP < 18 mmHg without medication. Cases and controls were paired by sex and postoperative time. The following independent variables were tested: race, previous ocular surgery, number of topical medications prior to surgery, age, preoperative IOP, severity of glaucomatous visual field loss, use of mitomycin C (MMC), YAG laser goniopuncture and IOP in the first day after surgery.

RESULTS

Two hundred and sixty-nine eyes were studied (136 cases and 133 controls). Absence of intraoperative MMC and high preoperative IOP were related to an end-point IOP > 18 mmHg after 2 years of follow-up.

CONCLUSION

Two factors seem to be associated to NPDS failure: the absence of intraoperative MMC and preoperative IOP.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

The effect of deep sclerectomy on intraocular pressure of normal-tension glaucoma patients: 1-year results

PURPOSE

To study the intraocular pressure (IOP)-reducing effect of deep sclerectomy on normal-tension glaucoma (NTG) patients.

METHODS

We retrospectively analysed 21 eyes of 18 consecutive NTG patients who had undergone deep sclerectomy with mitomycin-C and a collagen implant.

RESULTS

Median (range) preoperative IOP was 15.1 mmHg (9.3-20.8) and median follow-up time 13 months (12-18). At the 1-year follow-up visit, median IOP was significantly (P < 0.001) reduced to 10.5 mmHg (4-15) with median IOP reduction from preoperative values of 37% (12-78). Laser goniopuncture was performed in 10 eyes (48%) 1-16 months postoperatively. After 13 months' follow-up, a complete success at 20%, 25% and 30% IOP reduction levels was achieved in 67%, 62% and 52% of eyes, respectively. Few complications were encountered, but these included reduced visual acuity, problems with conjunctiva, microperforation, hyphaema, Dellen formation and encapsulated bleb. We encountered no complications related to postoperative hypotony.

CONCLUSION

Deep sclerectomy with a collagen implant and mitomycin-C was a safe and effective method for reducing IOP in NTG patients during 1-year follow-up.

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.

The management of exfoliative glaucoma

Exfoliation syndrome (XFS) is an age-related, generalized disorder of the extracellular matrix characterized by the production and progressive accumulation of a fibrillar extracellular material in many ocular tissues and is the most common identifiable cause of open-angle glaucoma worldwide. XFS plays an etiologic role in open-angle glaucoma, angle-closure glaucoma, cataract, and retinal vein occlusion. It is accompanied by an increase in serious complications at the time of cataract extraction, such as zonular dialysis, capsular rupture, and vitreous loss. It is associated systemically with an increasing number of vascular disorders, hearing loss, and Alzheimer's disease. XFS appears to be a disease of elastic tissue microfibrils. The characteristic fibrils, composed of microfibrillar subunits surrounded by an amorphous matrix comprising various glycoconjugates, contain predominantly epitopes of elastic fibers, such as elastin, tropoelastin, amyloid P, vitronectin, and components of elastic microfibrils, such as fibrillin-1, fibulin-2, vitronectin, microfibril-associated glycoprotein (MAGP-1), and latent TGF-beta binding proteins (LTBP-1 and LTBP-2), the proteoglycans syndecan and versican, the extracellular chaperone clusterin, the cross-linking enzyme lysyl oxidase, and other proteins. A recent milestone study showed that two common single nucleotide polymorphisms in the coding region of the lysyl oxidase-like 1 (LOXL1) gene located on chromosome 15 were specifically associated with XFS and XFG. LOXL1 is a member of the lysyl oxidase family of enzymes, which are essential for the formation, stabilization, maintenance, and remodeling of elastic fibers and prevent age-related loss of elasticity of tissues. LOXL1 protein is a major component of exfoliation deposits and appears to play a role in its accumulation and in concomitant elastotic processes in intra- and extraocular tissues of XFS patients. This discovery should open the way to new approaches and directions of therapy for this protein disorder.

Cataract and glaucoma surgery in pseudoexfoliation syndrome: a review

Pseudoexfoliation syndrome is a risk factor in cataract surgery because of the increased weakness of zonular apparatus and reduced pupillary dilatation. The surgical outcome of using phacoemulsification in the central zone, inducing minimal stress on the zonules, inserting a capsular tension ring in selected cases, and stretching the pupil mechanically in eyes with miotic pupils, may turn out to be uneventful in most cases. Postoperative fibrosis with subsequent shrinkage of the capsule is increased in these eyes, and these centripetal forces will further loosen the zonular fibres. Late in-the-bag intraocular lens dislocation is therefore anticipated to become a growing problem in the future. Despite the dysfunctioning of the blood-aqueous barrier in eyes with pseudoexfoliation syndrome, the frequency of postoperative inflammatory reaction is low due to the improvements made in surgical technique and equipment in recent years. Glaucoma frequently occurs in eyes with pseudoexfoliation syndrome. Compared with primary open-angle glaucoma, optic damage is more pronounced in these eyes at the time of diagnosis and response to medical therapy is poorer. Although responses to argon laser therapy and filtering surgery are roughly similar between the two types of glaucoma, there are indications that primary laser trabeculoplasty has a higher success rate in pseudoexfoliation glaucoma than in primary open-angle glaucoma.