Combined cataract extraction and trabeculotomy by the internal approach for coexisting cataract and open-angle glaucoma: initial results

Short-term evaluation of Trabectome surgery performed on Japanese patients with open-angle glaucoma

PURPOSE

To evaluate the short-term results of Trabectome surgery performed on Japanese patients.

METHODS

Retrospective observational study. Trabectome surgery was performed on 117 eyes from 101 patients at Kitasato University Hospital from December 2010 to June 2013, involving 48 eyes with primary open-angle glaucoma (POAG), 62 eyes with secondary open-angle glaucoma (SOAG), and 7 eyes with developmental glaucoma. Trabectome surgery alone was performed on 34 phakic eyes (the phakic group) and 35 pseudophakic eyes (the pseudophakic group), and Trabectome surgery combined with phacoemulsification (the combined surgery group) was performed on 48 eyes. The main outcomes assessed were intraocular pressure (IOP), number of IOP-lowering medications, and success probabilities using Kaplan-Meier life-table analyses. Failure risk factors were identified using the Cox proportional hazards ratio.

RESULTS

In all cases, after a mean follow-up of 18.5 ± 13.5 months, IOP was reduced from 31.6 ± 9.9 (SD) mmHg using 5.0 ± 1.7 medications to 16.4 ± 5.4 mmHg using 3.8 ± 1.8 medications. One year after surgery, IOP was reduced from 29.4 ± 7.8 to 16.1 ± 3.8 mmHg in POAG, from 33.6 ± 11.1 to 14.7 ± 2.9 mmHg in SOAG, from 33.0 ± 10.2 to 15.7 ± 3.3 mmHg in the phakic group, from 32.6 ± 9.3 to 15.3 ± 3.0 mmHg in the pseudophakic group, and from 29.9 ± 10.0 to 15.2 ± 3.0 mmHg in the combined surgery group. There were no statistically significant differences in IOP at each measurement point, either between POAG and SOAG or among the three procedure subtypes. The POAG and SOAG success rates at 12 months using postoperative IOP ≤ 21 mmHg and ≥20 % reduction in baseline as criteria were 53.9 and 77.2 %, respectively (p = 0.024, log-rank test). Twenty-one eyes (17.9 %) needed additional trabeculectomy. None of the univariate and multivariate risk factors for failure were detected.

CONCLUSIONS

Trabectome surgery is safe and effective for Japanese patients whose target IOP is 18 mmHg or above. However, it is necessary to carefully consider Trabectome surgery for advanced POAG cases.

Evaluation of the long-term results of trabectome surgery

The aim of this study was to investigate the safety and efficacy of ab interno trabeculectomy which is a minimally invasive glaucoma surgery, in the late period, performed via trabectome instrument. A total of 70 eyes followed up with a diagnosis of open-angle glaucoma (OAG) and undertaken trabectome surgery were included in the study. Preoperative and postoperative intraocular pressures (IOPs), number of the drugs used, and complications were retrospectively investigated and the data were evaluated. The criteria of success were accepted as an IOP value ≤21 mmHg or ≥30 % reduction in IOP and no need for a second operation. Mean IOP was decreased by 38 % from a preoperative value of 28.77 ± 5.34 to 17.62 ± 2.81 mmHg at the end of 18 months. Likewise, mean drug usage was decreased by 48 % from a preoperative value of 3.3 ± 1.01 to 1.7 ± 1.16 at the end of 18 months. Both decreases were statistically significant (p < 0.05). Postoperative success rates were 82.8 % in the 6th month, 81.4 % in the 9th month, 77.1 % in the 12th month, and 70 % in the 18th month. Most common complication observed was intraoperative reflux hemorrhage and no serious complication was observed. Trabectome surgery is an effective and safe method in early-stage open-angle glaucoma types that cannot be controlled despite maximal medical therapy. This procedure is a proper surgical option in patients targeted for moderate IOP without the need for a topical medication or with less drug usage.

Combined ab interno trabeculotomy and lens extraction: a novel management option for combined uveitic and chronic narrow angle raised intraocular pressure

Minimally invasive glaucoma surgery is a developing area that has the potential to replace traditional glaucoma surgery, with its known risk profile, but at present there are no randomised controlled data to validate its use. We report on a case where sequential bilateral combined ab interno trabeculotomy and lens extraction surgery was performed on a 45-year-old woman with combined uveitic and chronic narrow angle raised intraocular pressure. Maximal medical management alone could not control the intraocular pressure. At 12-month follow-up, the patient had achieved stable intraocular pressure in both eyes on a combination of topical ocular antiglaucomatous and steroid therapies. This case demonstrates the effectiveness of trabecular meshwork ablation via ab interno trabeculotomy in a case of complex mixed mechanism glaucoma.

Minimally invasive glaucoma surgery: current status and future prospects

Minimally invasive glaucoma surgery aims to provide a medication-sparing, conjunctival-sparing, ab interno approach to intraocular pressure reduction for patients with mild-to-moderate glaucoma that is safer than traditional incisional glaucoma surgery. The current approaches include: increasing trabecular outflow (Trabectome, iStent, Hydrus stent, gonioscopy-assisted transluminal trabeculotomy, excimer laser trabeculotomy); suprachoroidal shunts (Cypass micro-stent); reducing aqueous production (endocyclophotocoagulation); and subconjunctival filtration (XEN gel stent). The data on each surgical procedure for each of these approaches are reviewed in this article, patient selection pearls learned to date are discussed, and expectations for the future are examined.

Review and meta-analysis of ab-interno trabeculectomy outcomes

We analysed all of the PubMed publications on ab-interno trabeculectomy (AIT) with the Trabectome (Neomedix, Irvine, California, USA) to determine the reduction in intraocular pressure (IOP) and medications following the procedure. For IOP outcomes, PubMed was searched for 'trabectome', 'ab interno trabeculotomy' and 'ab interno trabeculectomy' and all available papers retrieved. The meta-analysis used a random-effects model to achieve conservative estimates and assess statistical heterogeneity. To investigate complications, we included all abstracts from the American Glaucoma Society, American Academy of Ophthalmology, American Society of Cataract and Refractive Surgery and the Association for Research in Vision and Ophthalmology. The overall arithmetic mean baseline IOP for standalone Trabectome was 26.71±1.34 mm Hg and decreased by 10.5±1.9 mm Hg (39% decrease) on 0.99±0.54 fewer medications. Defining success as IOP ≤21 with a 20% decrease while avoiding reoperation, the overall average success rate after 2 years was 46±34%. For combined phacoemulsification-Trabectome, the baseline IOP of 21±1.31 mm Hg decreased by 6.24±1.98 mm Hg (27% decrease) on 0.76±0.35 fewer medications. The success rate using the same definition at 2 years was 85±7%. The weighted mean IOP difference from baseline to study endpoint was 9.77 mm Hg (95% CI 8.90 to 10.64) standalone and 6.04 mm Hg (95% CI 4.95 to 7.13) for combined cases. Despite heterogeneity, meta-analysis showed significant and consistent decrease in IOP and medications from baseline to end point in AIT and phaco-AIT. The rate of visually threatening complications was <1%. On average, trabectome lowers the IOP by approximately 31% to a final IOP near 15 mm Hg while decreasing the number of medications by less than one, with a low rate of serious complications. After 2 years, the overall average success rate is 66%.

LONG-TERM RESULTS OF COMBINED AB INTERNO TRABECULOTOMY (TRABECTOME) AND SMALL-GAUGE PARS PLANA VITRECTOMY

PURPOSE

To report outcomes of patients who have undergone combined Trabectome and pars plana vitrectomy.

METHODS

Institutional Review Board-approved retrospective chart review of patients seen at the Cincinnati Eye Institute before January 2014 undergoing combined Trabectome and pars plana vitrectomy for uncontrolled glaucoma and visually significant retina pathology. Charts were reviewed to identify changes in intraocular pressure, visual acuity, and change in glaucoma medication requirement up to 1 year after surgery.

RESULTS

Four patients met the inclusion criteria with 12-month follow-up, and two of the patients were male. All patients underwent 25-gauge pars plana vitrectomy and Trabectome surgery. Mean preoperative LogMAR visual acuity was 0.39 (20/49) and 12-month LogMAR visual acuity was 0.21 (20/32) (P = 0.06). Mean preoperative intraocular pressure was 17 mmHg and mean preoperative glaucoma medication requirement was 2.5 topical medications. Twelve-month mean intraocular pressure was 12.8 mmHg (P = 0.07), and mean topical glaucoma medication requirement was 2.3 medications (P = 0.39). All patients were off steroids and anti-inflammatories at the final visit. One patient developed a hyphema requiring anterior chamber washout at 1 week. No other complications occurred.

CONCLUSION

The results suggest that combined Trabectome and pars plana vitrectomy seems effective in the management of glaucoma in patients with visually significant retina pathology.

Clinical results of Trabectome surgery for open-angle glaucoma

Background

The purpose of this study was to determine outcomes when using Trabectome surgery and to evaluate factors associated with its effects in primary open-angle glaucoma (POAG) and exfoliation glaucoma (EXG).

Methods

This was a prospective, non-randomized, observational, comparative cohort study in which Trabectome surgery was used alone in patients with POAG or EXG. Trabectome surgery was considered to have failed when at least one of the following three criteria was fulfilled: intraocular pressure (IOP) ≥21 mmHg and a <20% reduction below the baseline IOP on two consecutive follow-up visits 3 months or more after surgery; need for additional glaucoma surgery; and an increase in number of medications compared with baseline.

Results

The subjects were 32 males (34 eyes) and 46 females (48 eyes). POAG was observed in 43 eyes and EXG in 39 eyes. IOP after Trabectome surgery decreased significantly from 22.3±6.8 mmHg at baseline to 14.0±3.9 mmHg (23.0% reduction) at month 24 in all cases (P<0.0000). The success rate at 2 years was 51.2% for all cases (POAG, 50.9%; EXG, 49.2%). There was no significant difference in success rate between POAG and EXG (P=0.91). Preoperative IOP (P=0.033) and number of medications (P=0.041) were significant factors for surgical success/failure in multivariate logistic regression. No serious complications were observed.

Conclusion

Trabectome surgery achieved favorable IOP control and was equally effective in patients with POAG and those with EXG. Its effects were influenced by preoperative IOP and number of preoperative medications.

Emerging surgical therapy in the treatment of glaucoma

There is general consensus that surgery gives a better intraocular pressure (IOP) control than medical therapy, but surgery may be affected by complications and failures, and for this reason nowadays, it is reserved to advanced or clearly progressive glaucoma. In recent years, there have been a lot of efforts to enhance safety and efficacy of conventional surgery as to find new techniques more safer and more effective. Actually, this is a field in rapid evolution, and we have a great number of innovative procedures, often working on complete different basis. These procedures are classified according to their mechanism of action and the type of surgical approach, in order to clearly understand of what we are speaking about. From a general point of view, surgical procedures may be divided in procedures that increase outflow and procedures that reduce aqueous production: most of these procedures can be performed with an ab externo or an ab interno approach. The ab interno approach has great advantages and enormous potential of development; probably, its diffusion will be facilitated by the development of new devices for angle visualization. Nevertheless, it is important to remember that actually none of the new procedures has been validated in large controlled clinical trials and none of the new procedures is indicated when IOP target is very low.

Results of Trabectome Surgery Following Failed Glaucoma Tube Shunt Implantation: Cohort Study

To evaluate the safety and efficacy of Trabectome after failed tube shunt surgery.Twenty patients with prior failed tube shunt surgery who underwent Trabectome alone were included. All patients had at least 3 months of follow-up. Outcomes measured included intraocular pressure (IOP), glaucoma medications, and secondary glaucoma surgeries. The success for Kaplan-Meier survival analysis is defined as IOP ≤21 mm Hg, IOP reduced by at least 20% from preoperative IOP, and no secondary glaucoma surgery.Mean preoperative IOP was 23.7 ± 6.4 mm Hg and mean number of glaucoma medications was 3.2 ± 1.5. At 12 months, IOP was reduced to 15.5 ± 3.2 mm Hg (P = 0.05) and number of medications was reduced to 2.4 ± 1.5 (P = 0.44). Survival rate at 12 months was 84% and 3 patients required additional glaucoma surgery with 15 patients reaching 12 months follow-up. Other than failure of IOP control and transient hypotony (IOP < 3 mm Hg) day 1 in 2 cases, there were no adverse events.Trabecular bypass procedures have traditionally been considered an approach appropriate for early-to-moderate glaucoma; however, our study indicates benefit in refractory glaucoma as well. Eyes that are prone to conjunctival scarring and hypertrophic wound healing, such as those who have failed tube shunt surgery, may benefit from procedures that avoid conjunctival incision such as Trabectome. This study indicates potential benefits in this patient population.Trabectome was safe and effective in reducing IOP at 1-year follow-up in patients with prior failed tube shunt surgery, but not effective in reducing medication reliance in these patients.

Ab interno trabeculectomy in the adult patient

Glaucoma is a potentially blinding disease that affects millions of people worldwide. The mainstay of treatment is lowering of intraocular pressure (IOP) through the use of medications, laser and/or incisional surgery. The trabecular meshwork (TM) is thought to be the site of significant resistance to aqueous outflow in open angle glaucoma. Theoretically, an incision through TM or TM removal should decrease this resistance and lead to a significant reduction in IOP. This approach, commonly referred to as goniotomy or trabeculotomy, has been validated in the pediatric population and has been associated with long-term IOP control. In adults, however, removal of TM tissue has been historically associated with more limited and short-lived success. More recent evidence, reveals that even adult patients may benefit significantly from removal of diseased TM tissue and can lead to a significant reduction in IOP that is long-lasting and safe. In this review, we discuss current evidence and techniques for ab interno trabeculectomy using various devices in the adult patient.

Cataract surgery in the glaucoma patient

To summarize the role of cataract surgery in the glaucoma patient, in terms of the effect on intraocular pressure (IOP) as well as diagnostic and therapeutic considerations for those with both conditions. Recent evidence suggests that cataract extraction may produce a significant and sustained IOP reduction in individuals with open-angle glaucoma, ocular hypertension, and angle-closure glaucoma. Cataract removal may improve the practitioner's ability to interpret perimetric testing, and re-establishing perimetric and optic nerve imaging baselines is recommended after cataract surgery. The sequence of cataract surgery relative to glaucoma surgery impacts the likelihood of complications and surgical success. There are multiple benefits to perform cataract surgery prior to glaucoma surgery while cataract surgery after trabeculectomy increases the risk of subsequent filtration failure. As “minimally invasive glaucoma surgeries” continue to improve in terms of efficacy, there is an evolving role for combined cataract and glaucoma surgery in patients with early to moderate stages of glaucoma.

Refractive and visual outcomes after combined cataract and trabectome surgery: a report on the possible influences of combining cataract and trabectome surgery on refractive and visual outcomes

PURPOSE

To compare combined trabectome-cataract surgery with cataract-alone surgery regarding their refractive and visual outcomes and complications.

METHODS

In 137 eyes that underwent combined trabectome-cataract surgery, the postoperative refraction error and best visual acuity after at least 2 months postoperatively were compared to those of an in-house control group of 1,704 eyes that underwent outpatient cataract surgery.

RESULTS

Combined trabectome-cataract surgery showed no significant differences regarding the biometry prediction error (BPE, mean 0.53 D vs. 0.48 D, p = 0.24) or visual outcome (BCVA, 0.81 vs. 0.78, p = 0.06). The rate of postoperative cystoid macular edema was slightly higher in the combined surgery group (2.2 % vs. 1.9 %).

CONCLUSIONS

Refractive and visual outcomes were similar in both groups. Despite the slightly higher rate of postoperative macula edema, we were able to observe that the combination of these two procedures is a feasible method in glaucoma and cataract surgeries.

Outcomes of ab interno trabeculectomy with the trabectome by degree of angle opening

Aim

To analyse ab interno trabeculectomy (AIT) with the trabectome and combined phacoemulsification with AIT (phaco-AIT) by Shaffer angle grade (SG).

Methods

Prospective study of AIT and phaco-AIT with narrow angles of SG≤2 versus open angles ≥3. Outcomes included intraocular pressure (IOP), medications, complications, secondary surgery and success (IOP <21 mm Hg and >20% reduction without further surgery). Exclusion criteria were missing preoperative data and <1 year follow-up.

Results

Of 671 included cases, at 1 year AIT SG≤2 (n=43) had an IOP reduction of 42% from 27.3±7.4 to 15.7±3.0 mm Hg (p<0.01) versus AIT SG≥3 (n=271) with an IOP reduction of 37% from 26.1±7.8 to 16.4±3.9 mm Hg (p<0.01). In phaco-AIT with SG≤2 (n=48), IOP was reduced 24% from 20.7±7.0 to 15.7±3.6 mm Hg (p<0.01) versus phaco-AIT with SG≥3 (n=309) with an IOP reduction of 25% from 22.6±6.4 to 17.0±3.4 mm Hg (p<0.01). There was no difference between SG≤2 and SG≥3 in reduction of IOP or medications, complications, secondary surgery and success rates (p>0.05).

Conclusions

SG≤2 is not associated with worse outcomes in AIT or phaco-AIT.

iStent trabecular micro-bypass stent for open-angle glaucoma

Trabecular micro-bypass stents, commonly known as iStents, are micro-invasive glaucoma surgery (MIGS) devices used to treat open-angle glaucoma. Like other MIGS procedures that enhance trabecular outflow, the iStent lowers intraocular pressure (IOP) by creating a direct channel between the anterior chamber and Schlemm’s canal. iStents are typically implanted at the time of phacoemulsification for patients with open-angle glaucoma and visually significant cataracts. This review summarizes the published data regarding the efficacy, safety, and cost considerations of trabecular micro-bypass stents. Most studies found statistically significant reductions in mean IOP and ocular medication use after combined phacoemulsification with single or double iStent implantation. The devices were found to be very safe, with a safety profile similar to that of cataract surgery. Complications were infrequent, with the most common complications being temporary stent obstruction or malposition, which resolved with observation or secondary procedures. Future studies are needed to evaluate long-term outcomes, patient satisfaction, cost effectiveness, and expanded indications.

Outcomes of ab interno trabeculectomy with the trabectome after failed trabeculectomy

Aim

To evaluate outcomes of ab interno trabeculectomy (AIT) with the trabectome following failed trabeculectomy.

Methods

Prospective study of AITs and phaco-AITs after a failed trabeculectomy. The indication for AIT was intraocular pressure (IOP) above target on maximally tolerated therapy, and for phaco-AIT a visually significant cataract and need to lower IOP or glaucoma medications. Outcomes included IOP, medications, complications, secondary procedures and success, defined as IOP of less than 21 mm Hg and a greater than 20% reduction from baseline without further surgery. Exclusion criteria were trabeculectomy less than 3 months prior to AIT or follow-up under 1 year.

Results

Seventy-three eyes of 73 patients with 1 year follow-up were identified. At 1 year, mean IOP in AIT significantly decreased by 28% from 23.7±5.5 mm Hg, and medications from 2.8±1.2 to 2±1.3 (n=58). In phaco-AIT, the mean IOP decreased 19% from 20±5.9 mm Hg and medications from 2.5±1.5 to 1.6±1.4 (n=15). Transient hypotony occurred in 7%, and further surgery was necessary in 18%. For AIT and phaco-AIT, the 1-year cumulative probability of success was 81% and 87%, respectively.

Conclusions

Both AIT and phaco-AIT showed a reduction in IOP and medication use after 1 year, suggesting that AIT with or without cataract surgery is a safe and effective option following failed trabeculectomy.

Trabeculotomy ab interno with internal limiting membrane forceps for open-angle glaucoma

PURPOSE

To describe a new technique to perform trabeculotomy ab interno on eyes with open-angle glaucoma (OAG).

METHODS

This was a retrospective study. We inserted a 25-gauge forceps that is usually used for internal limiting membrane peeling into the anterior chamber, and grasped and pulled the inner wall of Schlemm's canal away from the canal. The inner wall of Schlemm's canal was stripped for about 100° to 120° in 26 eyes of 23 patients. The intraocular pressure (IOP) and number of glaucoma medications were recorded before, and 1 day, 1 week, 2 weeks, and 1, 3, 6, 10, 12, 15, 17, 19, 24, 27, 30, and 33 months after the surgery. The intra- and postoperative complications were recorded.

RESULTS

The mean ± standard deviation of the preoperative IOP was 20.0 ± 6.8 mmHg with a range from 10 to 38 mmHg (n = 26). The IOP was significantly reduced (P < 0.05; paired t-tests) at 1 week, 2 weeks, and 1, 3, 6, 10, 12, 15, 17, 24, 19, 27, 30, and 33 months after the surgery. The mean preoperative number of glaucoma medications was significantly reduced (P < 0.001; paired t-tests) at 1 week, 2 weeks, and 1, 3, 6, 10, 12, 15, 17, 19, 24, 27, 30, and 33 months after the surgery. No vision-threatening complications were found in any of the cases, but there were blood clots in the anterior chamber postoperatively in 92.3 % of the cases.

CONCLUSIONS

Trabeculotomy ab interno for OAG is effective but with some minor complications. A larger number of patients with longer follow-up periods are needed to determine the long-term effectiveness of this procedure.

Techniques and outcomes of minimally invasive trabecular ablation and bypass surgery

Minimally invasive glaucoma surgeries (MIGS) can improve the conventional, pressure-dependent outflow by bypassing or ablating the trabecular meshwork (TM), or creating alternative drainage routes into the suprachoroidal or subconjunctival space. They have a highly favourable risk profile compared to penetrating surgeries, and lower intraocular pressure with variable efficacy that may depend on the extent of outflow segments accessed. Since they are highly standardised procedures that use clear corneal incisions, they can elegantly be combined with cataract and refractive procedures to improve vision in the same session. There is a growing need for surgeons to become proficient in MIGS to address the increasing prevalence of glaucoma and cataracts in a well-informed, aging population. Techniques of visualisation and instrumentation in an anatomically highly confined space with semitransparent tissues are fundamentally different from other anterior segment surgeries, and present even experienced surgeons with a substantial learning curve. Here, we provide practical tips, and review techniques and outcomes of TM bypass and ablation MIGS.

Update on Minimally Invasive Glaucoma Surgery (MIGS) and New Implants

Traditional glaucoma surgery has been challenged by the advent of innovative techniques and new implants in the past few years. There is an increasing demand for safer glaucoma surgery offering patients a timely surgical solution in reducing intraocular pressure (IOP) and improving their quality of life. The new procedures and devices aim to lower IOP with a higher safety profile than fistulating surgery (trabeculectomy/drainage tubes) and are collectively termed “minimally invasive glaucoma surgery (MIGS).” The main advantage of MIGS is that they are nonpenetrating and/or bleb-independent procedures, thus avoiding the major complications of fistulating surgery related to blebs and hypotony. In this review, the clinical results of the latest techniques and devices are presented by their approach, ab interno (trabeculotomy, excimer laser trabeculotomy, trabecular microbypass, suprachoroidal shunt, and intracanalicular scaffold) and ab externo (canaloplasty, Stegmann Canal Expander, suprachoroidal Gold microshunt). The drawback of MIGS is that some of these procedures produce a limited IOP reduction compared to trabeculectomy. Currently, MIGS is performed in glaucoma patients with early to moderate disease and preferably in combination with cataract surgery.

Selective laser trabeculoplasty following failed combined phacoemulsification cataract extraction and ab interno trabeculectomy

PURPOSE

To assess the effect of selective laser trabeculoplasty (SLT) following failed phacoemulsification cataract extraction combined with ab interno trabeculectomy (AIT) using the Trabectome (phaco-trabectome).

DESIGN

Randomized, interventional case series.

METHODS

Retrospectively, the medical records of patients who underwent SLT between March 2010 and July 2012 by 1 surgeon at a single center after a failed phaco-AIT were evaluated. Inclusion criteria were age ≥18 years with no upper limit and prior failed phaco-AIT attributable to glaucoma progression. Exclusion criterion was performance of any additional glaucoma procedure with influence on intraocular pressure (IOP) during follow-up and a follow-up after surgery of <3 months. Success was defined by reduction of IOP of >3 mm Hg and 20% and number of antiglaucoma medications equal to or less than baseline. Main outcome measures were IOP, antiglaucoma medications, time to failure, and Kaplan-Meier survival curve.

RESULTS

Fourteen eyes of 13 subjects were included. Mean follow-up after SLT was 12.9 ± 8.7 months. Total laser energy was 59.5 ± 8.7 mJ. Baseline IOP was 17.9 ± 3.3 mm Hg and number of antiglaucoma medications at baseline was 2.0 ± 1.0. All SLT procedures failed. Median time to failure after SLT was 3.6 ± 0.8 (range 2.1-5.1) months. Number of antiglaucoma medications did not change.

CONCLUSIONS

In eyes in which the IOP was no longer controlled following phaco-trabectome, SLT had a limited duration of significant IOP-lowering effect. Other alternatives, such as incisional filtration surgery, should be considered following failed phaco-trabectome.

Clinical results of ab interno trabeculotomy using the trabectome for open-angle glaucoma: the Mayo Clinic series in Rochester, Minnesota

PURPOSE

To determine outcomes of ab interno trabeculotomy for treatment of open-angle glaucoma (OAG).

DESIGN

Retrospective interventional single-surgeon, single-center case series.

METHODS

Data were collected from 246 patients undergoing ab interno trabeculotomy between September 1, 2006, and December 1, 2010, with 3 months' follow-up or longer. Kaplan-Meier analysis was performed using Criteria A (postoperative intraocular pressure [IOP] ≤21 mm Hg or ≥20% reduction from preoperative IOP) and Criteria B (IOP ≤18 mm Hg and ≥20% reduction in IOP). Failure included increased glaucoma medications or subsequent surgery. Failure risk factors were identified using Cox proportional hazards ratio (HR).

RESULTS

Of 88 cases of ab interno trabeculotomy-only and 158 cases of ab interno trabeculotomy with cataract extraction, the retention rate was 70% for 1 year and 62% for 2 years. Preoperative mean IOP was 21.6 ± 8.6 mm Hg; the number of glaucoma medications was 3.1 ± 1.1. At 24 months postoperatively, mean IOP was reduced 29% to 15.3 ± 4.6 mm Hg (P < 0.001) and the number of glaucoma medications was reduced 38% to 1.9 ± 1.3 (P < 0.001) with a success rate of 62% (95% CI, 56%-68%) using Criteria A and 22% (95% CI, 16%-29%) using Criteria B. Failure risk factors using Criteria A included primary OAG (HR 3.14, P < 0.01, 95% CI, 1.91-5.17) and past argon laser trabeculoplasty (HR 1.81, P < 0.01, 95% CI, 1.18-2.77). Using Criteria B, the HR for pseudoexfoliative glaucoma was 0.43 (P < 0.01, 95% CI 0.27-0.67). Of the cases, 66 (26.8%) required subsequent surgery on an average of 10 months (2 days to 3.2 years) after ab interno trabeculotomy.

CONCLUSIONS

For criteria involving IOP ≤18 mm Hg, the 24-month survival of ab interno trabeculotomy is low. This surgery is appropriate for patients requiring a target IOP of 21 mm Hg or above.

Evaluation of trabectome in open-angle glaucoma

PURPOSE

To evaluate the outcomes of Trabectome, a surgical device that ablates an arc of trabecular meshwork, in Japanese glaucoma patients.

PATIENTS AND METHODS

Trabectome surgeries were performed on 80 eyes of 69 adult Japanese patients (age range, 14 to 89 y; 50 male and 30 female patients) with or without previous surgery or laser treatment. Goldmann applanation intraocular pressure (IOP), adjunctive medications, corneal endothelial cell density, and best corrected visual acuity were measured before and after surgery. Intraoperative and postoperative adverse events were also tabulated.

RESULTS

Mean preoperative IOP of 26.6 ± 8.1 mm Hg (range, 16 to 50 mm Hg) decreased to a mean postoperative IOP of 17.4±3.4 mm Hg (range, 9 to 24 mm Hg) (28.7% reduction) by 6 months after surgery (N=53). Adjunctive medication decreased from 4.0 ± 1.4 to 2.3 ± 1.2 at 6 months after surgery. Intraoperative blood reflux occurred in 100% of cases. No vision-threatening complications such as choroidal effusion, choroidal hemorrhage, or infection occurred. Thirteen cases (16.3%) received surgical reintervention and 1 case received cataract extraction during follow-up. No significant endothelial cell density change was recognized.

CONCLUSION

Trabectome is an effective and safe alternative to traditional glaucoma surgeries with the expectation of approximately a 30% decrease in IOP through 6 months postoperatively.

[Minimally invasive iridocorneal angle surgery]

The classical filtration surgery with trabeculectomy or drainage of chamber fluid with episcleral implants is the most effective method for permanent reduction of intraocular pressure to lower and normal levels. Even though both operative procedures are well-established the high efficiency of the method causes potentially dangerous intraoperative as well as interoperative complications with a frequency which cannot be ignored. In the past this led to a search for low complication alternatives with non-penetrating glaucoma surgery (NPGS) and the search is still continuing. Trabecular meshwork surgery in particular with continuous development of new operation techniques steered the focus to a complication-poor and minimally invasive, gonioscopic glaucoma surgery.

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.

Novel glaucoma procedures: a report by the American Academy of Ophthalmology

OBJECTIVE

To review the published literature and summarize clinically relevant information about novel, or emerging, surgical techniques for the treatment of open-angle glaucoma and to describe the devices and procedures in proper context of the appropriate patient population, theoretic effects, advantages, and disadvantages.

DESIGN

Devices and procedures that have US Food and Drug Administration clearance or are currently in phase III clinical trials in the United States are included: the Fugo blade (Medisurg Ltd., Norristown, PA), Ex-PRESS mini glaucoma shunt (Alcon, Inc., Hunenberg, Switzerland), SOLX Gold Shunt (SOLX Ltd., Boston, MA), excimer laser trabeculotomy (AIDA, Glautec AG, Nurnberg, Germany), canaloplasty (iScience Interventional Corp., Menlo Park, CA), trabeculotomy by internal approach (Trabectome, NeoMedix, Inc., Tustin, CA), and trabecular micro-bypass stent (iStent, Glaukos Corporation, Laguna Hills, CA).

METHODS

Literature searches of the PubMed and the Cochrane Library databases were conducted up to October 2009 with no date or language restrictions.

MAIN OUTCOME MEASURES

These searches retrieved 192 citations, of which 23 were deemed topically relevant and rated for quality of evidence by the panel methodologist. All studies but one, which was rated as level II evidence, were rated as level III evidence.

RESULTS

All of the devices studied showed a statistically significant reduction in intraocular pressure and, in some cases, glaucoma medication use. The success and failure definitions varied among studies, as did the calculated rates. Various types and rates of complications were reported depending on the surgical technique. On the basis of the review of the literature and mechanism of action, the authors also summarized theoretic advantages and disadvantages of each surgery.

CONCLUSIONS

The novel glaucoma surgeries studied all show some promise as alternative treatments to lower intraocular pressure in the treatment of open-angle glaucoma. It is not possible to conclude whether these novel procedures are superior, equal to, or inferior to surgery such as trabeculectomy or to one another. The studies provide the basis for future comparative or randomized trials of existing glaucoma surgical techniques and other novel procedures.

Ab interno trabeculectomy

Anterior chamber drainage angle surgery, namely trabeculotomy and goniotomy, has been commonly utilized in children for many years. Its’ reported success has ranged between 68% and 100% in infants and young children with congenital glaucoma. However, the long-term success of these procedures has been limited in adults presumably due to the formation of anterior synechiae (AS) in the postoperative phase. Recently, ab interno trabeculectomy with the Trabectome™ has emerged as a novel surgical approach to effectively and selectively remove and ablate the trabecular meshwork and the inner wall of the Schlemm’s canal in an attempt to avoid AS formation or other forms of wound healing with resultant closure of the cleft. This procedure seems to have an appealing safety profile with respect to early hypotony or infection if compared to trabeculectomy or glaucoma drainage device implantation. This might be advantageous in some of the impoverish regions of the Middle East and Africa where patients experience difficulties keeping up with their postoperative visits. It is important to note that no randomized trial comparing the Trabectome to other glaucoma procedures appears to have been published to date. Trabectome surgery is not a panacea, however, and it is associated with early postoperative intraocular pressure spikes that may require additional glaucoma surgery as well as a high incidence of hyphema. Reported results show that postoperative intraocular pressure (IOP) remains, at best, in the mid-teen range making it undesirable in patients with low-target IOP goals. A major advantage of Trabectome surgery is that it does not preclude further glaucoma surgery involving the conjunctiva, such as a trabeculectomy or drainage device implantation. As prospective randomized long-term clinical data become available, we will be better positioned to elucidate the exact role of this technique in the glaucoma surgical armamentarium.

[Minimally invasive angle surgery. The Trabectome]

The Trabectome provides a new perspective in angle surgery for open angle glaucoma. Through a 1.7 mm clear cornea tunnel, the juxtacanalicular meshwork is electroablated under gonioscopic control. Thereby, the collector channels in the outer wall of Schlemm's canal are uncovered and resistance to trabecular outflow is removed. From the literature and from our own experience, a pressure reduction by 30-35% can be achieved with a simultaneous reduction of eye drops by 50%. The Trabectome can conveniently be combined with phako-emulsification. Serious complications have not yet been reported. As the conjunctiva remains completely untouched, trabeculectomy, if necessary, could be performed without prognostic restrictions. With a realistic target pressure of approximately 16 mmHg, Trabectome surgery is indicated in patients with moderate optic nerve damage.

Does phacoemulsification affect the long-term success of non-penetrating deep sclerectomy?

BACKGROUND AND OBJECTIVE

Phaco non-penetrating deep sclerectomy (PhacoNPDS) is an option to simultaneously treat cataract and glaucoma. The authors assessed tensional success of PhacoNPDS and NPDS up to 3 years of follow-up.

PATIENTS AND METHODS

A longitudinal consecutive retrospective study was conducted comparing 376 eyes undergoing NPDS (group 1) and 87 eyes undergoing PhacoNPDS (group 2). Success was defined as complete 1 (intraocular pressure [IOP] < 21 mm Hg without medication); complete 2 (at least a 20% reduction of preoperative IOP without medication), and qualified (IOP < 21 mm Hg with or without medication).

RESULTS

Preoperative IOP and number of medications were 23.7 and 2.7 in group 1 and 23.1 and 2.6 in group 2, respectively. Postoperative IOP (3 years) was 13.1 mm Hg in group 1 and 13.4 mm Hg in group 2 (P = .000). Complete 1, complete 2, and qualified success in 3 years were 57.5%, 53.7%, and 94.5% in group 1 and 56.1%, 56.1%, and 100% in group 2, respectively (P = .861, .772, and .159). Final number of medications was 0.5 in group 1 and 0.3 in group 2.

CONCLUSION

PhacoNPDS seems to achieve similar tensional results as NPDS alone up to 3 years of follow-up.

Impact of laser trabeculoplasty on Trabectome® outcomes

BACKGROUND AND OBJECTIVE

To report the impact of prior laser trabeculoplasty on clinical outcomes of Trabectome (NeoMedix Corporation, Tustin, CA) surgery.

PATIENTS AND METHODS

This is a retrospective, non-comparative study of consecutive cases of Trabectome surgery with 36 months of follow-up. Main outcome measures were intraocular pressure (IOP), number of glaucoma medications, and the occurrence of secondary procedures.

RESULTS

In the trabeculoplasty group, mean IOP measured 16.5 +/- 4.0 mm Hg with an average decrease of 24% from preoperative IOP at 12 months. In eyes without previous trabeculoplasty, IOP measured 15.7 +/- 3.0 mm Hg with an average decrease of 30% at 12 months. Adjunctive medications decreased to 2.1 and 1.5 glaucoma medications, respectively. Secondary procedures were performed in 12% and 10% of eyes in each group.

CONCLUSION

Previous laser trabeculoplasty does not appear to significantly impact IOP, but may increase the need for glaucoma medication in patients undergoing Trabectome surgery.

Canal surgery in adult glaucomas

PURPOSE OF REVIEW

Outflow procedures for glaucoma surgery have remained popular in the last decade, including trabeculectomy, glaucoma drainage devices, and deep sclerectomy/viscocanalostomy. In the last few years, the surgical armamentarium for glaucoma has vastly increased. Surgeons are using more procedures aimed at creating bleb-free surgery. Schlemm's canal surgery is experiencing a renaissance. This article concentrates on three of the more commonly performed canal procedures: trabeculotomy ab interno (Trabectome), Canaloplasty, and trabeculotomy ab externo.

RECENT FINDINGS

Trabeculotomy ab interno performed with the Trabectome has been shown to lower intraocular pressure (IOP) almost 40% by 12 months with minimal complications. Trabectome alone, as well as combined with cataract surgery, appears to lower IOP quite well. Canaloplasty has also been shown to lower IOP by 38% and combined with cataract surgery, IOP was lowered 44% at 24 months. Trabeculotomy lowers IOP well, especially in older adults. Phacotrabeculotomy lowers IOP to 21 mmHg or less in 84% of patients with supplemental use of medications, and in 36% of patients without at 3 years.

SUMMARY

Canal surgery has proven to be an alternative to traditional glaucoma surgery, lowering IOP relatively well. Surgeons must be comfortable with the anatomy and proceed with the procedure in eyes that are amenable to various new surgical advances.

Use of novel devices for control of intraocular pressure

This brief review in honor of Douglas Johnson, MD describes the rationales and initial clinical outcomes in studies to date on Trabectome, Glaukos iStent, iScience (canaloplasty), and Solx (suprachoroidal shunt), all newly developed surgical technologies for treatment of open-angle glaucomas. These new approaches to angle surgery have been demonstrated in preliminary case series to safely lower IOP in the mid-teens with far fewer complications than expected with trabeculectomy and without anti-fibrotics. Trabectome and iStent are relatively non-invasive, aim to improve access of aqueous to collector channels and do not preclude subsequent standard surgery. Canaloplasty, modified from viscocanalostomy, is thought to improve trans-trabecular flow. Solx potentially offers an adjustable aqueous outflow into the suprachoroidal space.