Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges.

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

Extreme intraocular pressure and steroid-dependent iritis.

A 50-year-old ophthalmic technician was referred by her retina specialist for urgent consultation due to markedly elevated intraocular pressure (IOP) unresponsive to medical therapy. Her history included chronic polyarticular juvenile rheumatoid arthritis and chronic uveitis requiring ongoing topical steroid therapy. She had a sub-Tenon injection of Kenalog (triamcinolone) 18 months prior to referral. Chronic topical anti-inflammatory therapy included nepafenac (Ilevro) and prednisolone acetate 2 times a day. Attempts to discontinue topical steroid resulted in worsening inflammation. The patient was referred when the IOP measured 44 mm Hg in the left eye despite aggressive medical therapy, including acetazolamide. The IOP improved slightly when loteprednol was substituted for prednisolone acetate. Current medications in the left eye include brimonidine 3 times a day, loteprednol 2 times a day, nepafenac 2 times a day, and fixed combination latanoprost + netarsudil at bedtime. Her only medication in the right eye was travoprost. She is intolerant to dorzolamide. She was also taking acetazolamide 500 mg 2 times a day. She was not taking any anticoagulants. Past surgical history included cataract surgery in each eye. She has not had laser trabeculoplasty in either eye. Examination revealed uncorrected visual acuity of J1+ in the right eye (near) and 20/30 in the left eye (mini-monovision). There was no afferent pupillary defect. There was mild band keratopathy in each eye while the central cornea was clear in both eyes without keratic precipitates. Here angles were open to gonioscopy without peripheral anterior synechia. There was mild to moderate flare in each eye with trace cells. The IOP was 17 mm Hg in the right eye and 31 mm Hg in the left. Central corneal thickness measured 560 µm and 559 µm in the right and left eye respectively. There was a well-positioned intraocular lens within each capsule with a patent posterior capsulotomy. There was mild vitreous syneresis but no vitreous cell. The cup to disc ratio was 0.5 in each eye with a symmetrical neural rim. The retina was flat without macular edema. Visual field was normal in both eyes (Figures 1 and 2). Optical coherence tomography of retinal nerve fiber layer (RNFL) is shown in Figure 3 and retinal ganglion cell layer is shown in Supplemental Figure 1 (http://links.lww.com/JRS/A756).JOURNAL/jcrs/04.03/02158034-202301000-00020/figure1/v/2022-12-26T045736Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202301000-00020/figure2/v/2022-12-26T045736Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202301000-00020/figure3/v/2022-12-26T045736Z/r/image-tiff Please comment on your management of this patient's left eye.

Managing coexistent cataract and glaucoma with iStent.

The iStent is an intraocular implant that resides within Schlemm canal and allows for direct bypass of the trabecular meshwork by aqueous fluid. It is one of several procedures termed microinvasive glaucoma surgery. The prominence of microinvasive glaucoma surgery is growing because of its role in lowering intraocular pressure in mild to moderate glaucoma combined with its favorable safety profile. With transcleral glaucoma filtering surgery, there is an increased potential for significant complications including hypotony, suprachoroidal hemorrhage, and long-term risk of endophthalmitis. In comparison, the iStent minimizes this risk and has been shown to be similar to cataract surgery in terms of associated complications. As will be discussed, multiple publications have addressed both the safety and efficacy of the implant. This review additionally presents an overview of implantation technique as well as what to expect postoperatively. Looking forward, the second-generation models may ease implantation and the use of multiple stents may potentially play a role in more advanced disease.