Minimally invasive micro sclerostomy (MIMS) procedure in the treatment of open-angle glaucoma

BACKGROUND

To evaluate the safety and efficacy of the Minimally Invasive Micro Sclerotomy (MIMS) procedure in the management of uncontrolled open-angle glaucoma.

METHODS

A prospective, open-label, single-arm clinical evaluation with intra-subject comparisons performed at the Ophthalmologic Center after S.V. Malayan, Yerevan, Armenia. Included were adults with primary open-angle glaucoma (OAG) (N = 114) or exfoliative glaucoma (N = 6) who were uncontrolled (IOP > 21) on tolerated topical medication. Mild (N = 7), moderate (N = 66) and severe (n = 47) cases were prospectively included without preselection. Following subconjunctival Mitomycin C, an ab-interno MIMS procedure was performed alone (N = 100) or combined with phacoemulsification (N = 20). Patients were followed for 52 weeks. Procedure-related complications and adverse events were recorded. Success criteria were defined as -5 < IOP ≤ 21mmHg OR a reduction in IOP of ≥ 20% from baseline with (qualified success) or without (complete success) hypotensive medications.

RESULTS

Mean patient age was 69 ± 10.1 years. The mean duration of the procedure was 2:01 ± 0:41 min:sec. Scleral drainage channels were achieved in all cases. No device malfunctions, intraoperative complications, or serious adverse events were reported. Iris plugging of the sclerostomy site and early spikes in IOP were the most common adverse events. The only reason for failure was final IOP > 21 mmHg on tolerated medication. At 52 weeks (n = 93), mean IOP decreased by 38% from baseline (P < 0.001), from 27.9 ± 3.7 to 17.5 ± 5.3 mmHg, a difference of 10.5 mmHg (95% CI: -11.7, -9.3). One-year qualified success was documented in 82.1% (95% CI: 72.9%,89.2%) of the patients and complete success, in 70.5% (60.3-79.4%). 60% (95 CI:49.4%,69.9%) of the patients achieved maximum IOP level of 14 mmHg or at least 30% reduction in IOP.

CONCLUSIONS

MIMS procedure is a relatively simple, short and safe minimally invasive bleb-forming procedure. Its efficacy, as found in this short-term evaluation, lends it suitable for mild and moderate uncontrolled open-angle glaucoma patients.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT04503590 2019-05-29.

Minimally Invasive Micro Sclerostomy (MIMS) Procedure: A Novel Glaucoma Filtration Procedure

PRCIS

Intermediate-term results suggest that ab interno Minimally Invasive Micro Sclerostomy (MIMS) stent-less subconjunctival filtration procedure is a promising treatment option for patients with open-angle glaucoma (OAG).

PURPOSE

MIMS is a novel ab interno, stent-less, subconjunctival filtration procedure. This study set to investigate the safety, performance, and efficacy of MIMS in OAG patients.

METHODS

Prospective, open-label, single arm clinical trial with intrasubject comparisons. Study participants were adults with OAG who were candidates for a filtration procedure. Patients were operated by a single surgeon (A.A.) in Chennai, India. Following mitomycin-C pretreatment, ab interno MIMS procedure was performed alone or combined with phacoemulsification surgery. Procedure-related complications and adverse events were assessed. Primary outcomes: patients (%) achieving an intraocular pressure (IOP) ≥5 mm Hg and ≤18 mm Hg, and an IOP reduction of >20% as compared with baseline, with or without hypotensive medications, with no need for recurrent surgery.

RESULTS

Twenty-one phacoemulsification-MIMS and 10 standalone MIMS procedures were performed. Mean age was 63.94±6.33 years. Mean duration of MIMS was 1:58±0:25 (min:s). Scleral tunnels were achieved in all cases. No device malfunctions, intraoperative complications, or serious adverse events were reported. Five (16.12%) patients presented with iris clogging 1 to 24 weeks following procedure. Two were treated with laser and 3 required trabeculectomy. Mean IOP change from baseline at 24 weeks was 47.4% (31.2 to 16.4 mm Hg, P<0.0001, n=23). The mean difference was -14.8 mm Hg (95% confidence interval: -17.6, -11.9) with no statistically significant differences between groups. Qualified success was achieved in 21 (84%), 17 (74%), and 13 (93%) after 12, 24, and 52 weeks, respectively. Complete success was achieved in 17 (68%), 13 (57%), and 8 (57%) after 12, 24, and 52 weeks, respectively.

CONCLUSIONS

The interim results suggest that MIMS procedure may be a simple and effective surgical option for early OAG patients requiring target IOP in high teens although iris clogging of incision site is the major concern with this procedure.

Intracameral viscoelastic treatment for hypotony after glaucoma incisional surgery

We report on a minimally invasive treatment of symptomatic hypotony after glaucoma surgery. Hypotony after incisional glaucoma surgery can have severe visual consequences. Refractory symptomatic hypotony often requires surgical intervention to prevent further vision loss. The clinical records of four patients in this interventional case series with symptomatic hypotony and choroidal detachments after incisional glaucoma surgery between 2013 and 2014 were reviewed. Observations were made as the cases progressed. Visual obscuration secondary to refractory hypotony was treated with an intracameral injection of high-molecular-weight ocular viscoelastic devices (HMWOVD). Postinjection, mean intraocular pressure improved from a baseline of 3.6 mm Hg to 24.0, 15.5, and 9 mm Hg at 1 day, 1 month, and 6 months' post-intervention, respectively. The mean visual acuity after injection improved from 20/274 to 20/83 at 6 months. Choroidal detachments resolved within 1 week in all patients. Intracameral HMWOVD for the treatment of symptomatic hypotony post-incisional glaucoma surgery is minimally invasive, avoided reoperation, and led to quick visual recovery.

Ocular hypotony: A comprehensive review

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

Severe Intraocular Pressure Elevation After Intracameral Healon 5 Viscoelastic Support for Postoperative Hypotony After XEN Gel Stent Insertion

PURPOSE

The purpose of this article was to describe (i) a novel case of severe intraocular pressure (IOP) elevation due to intracameral Healon 5 for management of early postoperative (post-op) hypotony following XEN Gel Stent insertion and (ii) the management of this complication.

MATERIALS AND METHODS

A case report.

RESULTS

A 52-year-old man, with primary open-angle glaucoma and suboptimal left IOP control on maximally tolerated medical therapy, was managed with XEN Gel Stent insertion at another tertiary eye unit. Post-op, the IOP was 2 mm Hg with a shallow anterior chamber (AC) and choroidal effusions. Intracameral injections of Provisc on post-op days 1 and 3 failed to reverse hypotony. At 1 week post-op, persistent clinically significant hypotony was managed with Healon 5 injection into the AC. Twelve hours later, the patient experienced significant pain and reduced vision and presented to a different tertiary eye unit, where left visual acuity was hand movements, IOP was 70 mm Hg with a deep AC (complete ophthalmic viscosurgical device fill with Healon 5) and a flat drainage bleb with no external drainage. Emergency AC washout of the Healon 5 was performed with resolution of symptoms, visual acuity, and IOP control.

CONCLUSIONS

We caution against the use of intracameral Healon 5 in the management of post-op hypotony following XEN Gel Stent insertion, given the potential risk for extreme IOP elevation and sight loss.

Practice Preferences for Glaucoma Surgery: A Survey of the American Glaucoma Society

PURPOSE

The purpose of this study is to assess surgical practice patterns among the American Glaucoma Society (AGS) membership.

METHODS

An anonymous online survey evaluating the use of glaucoma surgeries in various clinical settings was redistributed to AGS members. Survey responses were compared with prior results from 1996, 2002, and 2008 to determine shifts in surgical practice patterns. Questions were added to assess the preferred approach to primary incisional glaucoma surgery and phacoemulsification combined with glaucoma surgery.

RESULTS

A total of 252 of 1091 (23%) subscribers to the AGS-net participated in the survey. Percentage use (mean±SD) of trabeculectomy with mitomycin C (MMC), glaucoma drainage device (GDD), and minimally invasive glaucoma surgery (MIGS) as an initial surgery in patients with primary open angle glaucoma was 59%±30%, 23%±23%, and 14%±20%, respectively. Phacoemulsification cataract extraction alone was the preferred surgical approach in 44%±32% of patients with primary open angle glaucoma and visually significant cataract, and phacoemulsification cataract extraction was combined with trabeculectomy with MMC in 24%±23%, with MIGS in 22%±27%, and with GDD in 9%±14%. Although trabeculectomy was selected most frequently to surgically manage glaucoma in 8 of 8 clinical settings in 1996, GDD was preferred in 7 of 8 clinical settings in 2016.

CONCLUSIONS

The use of GDD has increased and that of trabeculectomy has concurrently decreased over the past 2 decades. Trabeculectomy with MMC is the most popular primary incisional surgery when performed alone or in combination with phacoemulsification cataract extraction. Surgeons frequently manage coexistent cataract and glaucoma with cataract extraction alone, rather than as a combined cataract and glaucoma procedure.

Resident Glaucoma Surgical Training in United States Residency Programs

PURPOSE

To determine current trends in resident glaucoma surgical training throughout the United States.

METHODS

A comprehensive survey was sent to the residency director of all 121 ACGME-accredited ophthalmology training programs in the United States.

RESULTS

The mean and median number of glaucoma procedures a resident will complete by the end of their training is 8.6 and 8 respectively for trabeculectomy, 5.3 and 4 for combined trabeculectomy/phacoemulsification, and 3.6 and 2 for tube-shunts. One percent of residents will gain experience as primary surgeon on trabeculectomies during their first year, 32% during their second year, and 67% during their third year. Seventy-five percent of residents are taught more than one trabeculectomy technique by more than one staff surgeon. Eighty-four percent of residents are taught glaucoma surgery almost exclusively by fellowship-trained glaucoma surgeons. Eighty-two percent of residents use antimetabolites (mitomycin C or 5-FU) as an adjunct to trabeculectomy most or all of the time. More than 96% of resident tube-shunt procedures use Ahmed, Baerveldt, or Molteno devices. Eighty percent of residents do not perform any pediatric glaucoma surgeries. Sixty-two percent of residents rotate out of their main facility to perform glaucoma surgery.

CONCLUSIONS

Residents are being exposed to glaucoma surgery early in their residency training. Most are performing a variety of different procedures and techniques, and are taught by fellowship-trained surgeons. Residents gain very little exposure to pediatric glaucoma surgery. All programs reported compliance with minimum RRC requirements for glaucoma filtering surgery.

Stabilization of flat anterior chamber after trabeculectomy with Healon5

A 64-year-old phakic patient had a trabeculectomy complicated by complete shallowing of the anterior chamber 10 days postoperatively. Despite repair of a conjunctival wound dehiscence and reformation of the anterior chamber with sodium hyaluronate 3.0%-chondroitin sulfate 4.0% (Viscoat), he had a flat anterior chamber again the following day with 360 degrees of pupillary synechias and lens-to-cornea touch. Sodium hyaluronate 2.3% (Healon5) instilled through a paracentesis at the slitlamp lysed the synechias, stabilized the anterior chamber, facilitated filtration, and prevented complications from hypotony. The unique properties of Healon5 allowed for a conservative and less invasive approach in the management of this particular complication.