MIGS is a solution for Open Angle Glaucoma, a disease of increased pressure in eye.
Open angle glaucoma (OAG) is an illness impacting an estimated 2.8 million people in the USA. It represents an approximate cost of $1.5 billion annually. Preliminary therapy for OAG usually consists of drops that can assist in lowering aqueous humor production or boosting aqueous humor discharge uveoscleral pathway. Furthermore, laser trabeculoplasty is an additional alternative for the therapy of very early, mild, open angle glaucoma. Long-term efficiency has actually been discovered to be comparable to clinical management with drops. Commonly, pharmacologic and also laser therapy have actually been the mainstays of treatment up until the condition advances to a phase that calls for the need for trabeculectomy. This treatment is commonly reserved for those with moderate to advanced cases of glaucoma as a result of the invasiveness of the treatment and also possible complications. While surgical alternatives had been reserved for individuals with moderate to severe glaucoma, creating micro invasive glaucoma surgical treatments (MIGS treatments) are creating brand-new alternatives for those that do not fulfill the requirements for trabeculectomy. These treatments have a greater safety profile with fewer complications and also a much more quick recovery time than various other intrusive methods. They have actually been revealed to be reliable in lowering IOP along with a patient’s need for medications, which is necessary provided a commonly reduced conformity rate for medication adherence.
Patients that are prospects for micro-invasive glaucoma surgery are:
Patients with mild-moderate glaucoma.
Primary open-angle glaucoma, pseudo-exfoliation glaucoma, or pigmentary dispersion glaucoma.
Glaucoma is uncontrolled with optimum pharmacologic treatment or there are obstacles preventing sufficient medication dosing.
Age more than 18.
Those Patients who have clinically significant cataract, their surgery may be performed simultaneously.
All patients should have a pre-operative extensive eye examination including gonioscopy and a thorough case history.
Contraindications for this treatment may include angle-closure glaucoma, secondary glaucoma moderate-advanced glaucoma, previous glaucoma surgical treatment, or significantly unrestrained IOP. Various other factors to consider include patients with previous refractive procedures along with monocular patients.
Minimally invasive glaucoma surgical treatment work by increasing trabecular outflow.
Trabectome is a surgical treatment established by NeoMedix (Tustin, CA). It was introduced in 2004 that allows a trabeculotomy to be executed through an interior technique. The system works by eliminating a strip of trabecular meshwork and also the internal wall surface of Schlemm’s canal in order to produce a course for the drainage of aqueous humor. The device itself consists of a one-use, disposable hand piece that is utilized for electro-cautery, irrigation, and aspiration. It is connected to a generator with a frequency of 550 kHz that enables adjustments in 0.1 watt increments as well as is managed through a 3-stage Foot Pedal Control that initiates irrigation, aspiration, as well as electro-cautery in sequence. Constant irrigation as well as aspiration allows for removal of debris as well as regulation of temperature. Furthermore, the suggestion of the Trabectome is curved at a 90 ° angle to develop a protective triangular footplate and also enable less complicated insertion right into Schlemm’s canal as well as coated to allow smoother movement within the canal. Ablation of 60 ° -120 ° enables re-establishment of the water drainage pathway. Maeda et al reviewed the end result of surgical procedures making use of Trabectome in 80 eyes of 69 patients. A mean preoperative IOP of 26.6 ± 8.1 mmHg was found to reduce to a mean postoperative IOP of 17.4 ± 3.4 mmHg within 6 months after the surgical treatment. Average number of medicines likewise lowered from 4.0 ± 1.4 to 2.3 ± 1.2 at 6 months. The research study reported no major complications, including chorodial effusion, chorodial hemorrhage, or infection.
The device is a heparin-coated, non-ferromagnetic titanium stent with a snorkel shape to assist in implantation. The device is placed using a single-use, sterilized inserter through a 1.5 mm corneal incision. The applicator is inserted right into the anterior chamber and across the nasal angle. The pointed tip allows penetration of the trabecular meshwork and insertion into Schlemm’s canal as well as 3 retention arches ensure that the device will certainly be held in place. The iStent itself is the smallest FDA approved device, measuring at 0.3 mm in height and 1mm in length. In a prospective randomized clinical trial, the effectiveness of phacoemulsification as well as stent placement compared to cataract surgery alone was assessed in 239 patients, with 116 patients receiving the stent. Patients associated with the research were those with mild-moderate glaucoma who had an un-medicated IOP in between 22 and 36 mmHg.
The device itself is a polymide, supraciliary device for ab-interno implantation. The objective of the device is to create a regulated cyclodialysis with stented outflow to the supraciliary space. The stent is 6.35 mm long with an outer diameter of 0.51 mm. throughout surgery, the implant is loaded onto a retracting overview wire, inserted through the preliminary phacoemulsification incision, and also advanced towards the sclera spur. The overview wire is utilized to execute blunt dissection of the ciliary body in order to permit passage into the supraciliary space where the stent can be placed. In the CyCLE study, 238 patients received the CyPass Micro-Stent in addition to cataract surgery treatment. In general, the device has actually shown in initial trials that there can be a considerable decrease in number of medicines used in addition to a considerable reduction in uncontrolled IOP or maintenance of a controlled IOP. This device has been recalled due to corneal problems.
XEN Glaucoma Implant
The XEN Glaucoma Implant (AqueSys Implant) was created by AqueSys Inc and is an investigational device that is presently going through medical trials. The implant itself is constructed out of a soft, collagen-derived, gelatin that is known to be non-inflammatory. The goal of implantation is to create an aqueous humor outflow path from the anterior chamber to the sub-conjunctival space. The implant is infused through a small corneal incision with using an inserter similar to those used for IOLs. Similar to various other implants, it can be done along with cataract surgical treatment. While minimal, there is company offered data readily available from worldwide trials. In general there have actually been 118 topics that have actually received the implants. The mean preoperative IOP was 23 mmHg with approximately 3 medicines. At the 12 and 18 month postoperative follow ups, the mean IOP had actually decreased to 15.4 ± 4.5 mmHg and after that 14.5 ± 3.1 mmHg, respectively. At 24 months, it was 14.3 ± 5.1 mmHg. At all-time points, the typical variety of medicines was one and 33% of patients were using no medications at 24 months.
It is a device which is implantable, flexible, a metal nitinol (Nickel Titanium) tube with windows (open-back stent) pre-loaded onto a hand-held delivery system which is used to implant the stent. The Hydrus ® Microstent is meant to decrease eye pressure (intraocular pressure, or IOP) in grown-up individuals with moderate to modest primary open angle glaucoma (POAG) by functioning as a support structure in one part of the natural drainage path of the eye (Schlemm’s canal). POAG is a kind of glaucoma where there is associated eye disease causing increased eye pressure and also where the eye pressure normally increases gradually. This progressive increase in eye pressure can be related to damages to the optic nerve which will impair vision significantly.
Gonioscopy Assisted Transluminal Trabeculotomy (GATT)
GATT is a kind of ab interno trabeculotomy which was defined by Grover et al in 2014. Under the guidance of a gonioscopy lens, a goniotomy is made in the nasal trabecular meshwork which functions as the entry point for the iTrack micro-catheter (iScience Interventional Corp, Menlo Park, CA), which has a 250 micron diameter. A customized method has actually likewise been explained using 4-0 nylon suture rather than the micro-catheter. Microsurgical forceps are used to advance the micro-catheter into Schlemm canal circumferentially 360 degrees, tracking its development with its illuminated distal suggestion. Once it has actually been gone through the entire canal, the catheter is externalized to create a 360-degree trabeculotomy. In their original evaluation, Grover et al reported on the 6 as well as yearend results of 85 patients; 57 patients with primary open angle glaucoma showed an average IOP decrease of 11.1 ± 6.1 mm Hg as well as fewer medications. For the 28 patients with secondary glaucoma, IOP reduced approximately 19.9 ± 10.2 mm Hg and 1.9 fewer medications. One of the most usual problem was a short-term hyphema reported in 30% of patients which resolved by one month. Considering that the original publication, Grover and colleagues have actually reported the effective use of the GATT technique in primary congenital glaucoma, juvenile open angle glaucoma, and also even eyes with prior incisional glaucoma surgical treatment. These very early results an appealing, conjunctival sparing method that can be utilized in conjunction with, or independent of cataract surgical procedure.
In patients with mild-moderate glaucoma with an IOP that has actually been unable to be controlled by medicines or who have poor medication compliance, micro invasive glaucoma surgery appears to be a feasible option. Clinical trials have actually revealed there to be a substantial decrease in IOP over periods of up to 24 months along with a significant reduction medication usage. The procedure has maintained a high safety and security profile with minimal adverse impacts. While the Trabectome as well as iStent are presently the only FDA authorized devices, there are several brand-new devices pending. Micro invasive glaucoma surgery can provide a technique of treatment for glaucoma patients that reduces dependence on medicines without the risks of more invasive procedures.