While the majority of glaucoma is mild or moderate, all comprehensive ophthalmologists will encounter those with severe glaucoma. For one reason or another, several of such patients may benefit most from remaining in the comprehensive practitioner’s care.

Fortunately, we are currently enjoying an era that is exploding with technologies for glaucoma management. This includes the advent of microinvasive glaucoma surgery (MIGS) as well as the availability of new laser therapies such as selective laser trabeculoplasty (SLT) and MicroPulse laser (Iridex). Beyond these surgical options, novel pharmacotherapies include second-generation prostaglandin analogs and Rho kinase inhibitors.

Comprehensive ophthalmologists comfortable with these approaches will be able to manage many cases of advanced glaucoma themselves, allowing the patient to receive care from the doctor who has known them for many years in the practice environment that is most convenient for them.

Here are some thoughts on how the comprehensive ophthalmologist can manage advanced disease.

DRUG CLASSES TO CONSIDER

When tackling complex glaucoma situations, there are a few examples of low-hanging fruit that are often ignored by comprehensive ophthalmologists. The myotic class of agents remains an underutilized therapy in facilitating aqueous outflow. Additionally, oral carbonic anhydrase inhibitors such as acetazolamide are generally safe and well tolerated for patients who need a dramatic short-term reduction in IOP.

Oral agents are a staple in my practice. If the patient looks like they will require pharmaceutical treatment in the long term, I will typically arrange for blood work after several weeks. Communication with the patient’s primary medical doctor is helpful in these cases, as comorbidities such as hepatic or renal impairment may preclude extended use.

Potent prostaglandin analogs, such as latanoprostene bunod (Vyzulta, Bausch + Lomb) and bimatoprost, certainly have a role for glaucoma patients. This is the most powerful class of IOP-lowering medications we have. In my experience, patients with a history of macular edema or intraocular inflammation are often deprived prostaglandin analogs, even though they could help lower the pressure without causing any safety concerns.

Finally, Rho kinase inhibitors offer consistent IOP reductions from the high teens to the low teens in many patients who are already on maximum therapy. This is a significant class of pressure-lowering drops that one should not overlook, particularly in patients for whom their ample medication burden would permit adequate insurance coverage.

LASER THERAPIES

As SLT has emerged as a primary therapy, it cannot be stressed enough that this procedure should be employed for patients who are not at target pressure on drops alone.¹ This category includes many patients with advanced glaucoma. In my practice, I offer SLT to every advanced open-angle glaucoma patient, even if their pressure is close to target. This not only reduces fluctuating IOPs, but also provides an insurance policy if the patient misses drops or runs out of a prescription. Such a concern is particularly relevant in this era of supply-chain issues and unpredictable availability of generic medications such as dorzolamide.

MicroPulse transscleral cyclophotocoagulation is a unique treatment that offers powerful pressure reduction with fewer of the risks that can be associated with traditional glaucoma surgeries such as a shallow anterior chamber, or hyphema or infection. This non-incisional procedure releases a series of short bursts of diode laser energy to ablate the ciliary bodies. Though usable in the office setting, the laser can deliver pressure reduction that rivals a tube or trabeculectomy.^2,3

MicroPulse laser treatment makes particular sense for comprehensive ophthalmologists. This treatment can help them avoid a referral to a glaucoma specialist by achieving dramatic pressure reductions for patients without the need to manage the complications seen with tube shunts and trabeculectomy. The comprehensive ophthalmologist may need to manage some side effects such as intraocular inflammation and/or dry eye, but both are well within their scope of practice.

STANDALONE MIGS

Finally, standalone MIGS offers yet another minimally invasive and safe approach for pressure reduction, even in patients with advanced glaucoma. The on-label procedures for patients with advanced glaucoma that can be performed without cataract extraction include goniotomy and canaloplasty. These can be performed with the Kahook Dual Blade (New World Medical), Omni Surgical System (Sight Sciences), iStent (Glaukos), Streamline (New World Medical) and TrabEx (MicroSurgical Technology).

Keep in mind that many patients with advanced glaucoma are already pseudophakic. Having previously received an ocular surgery, some may seek to avoid a tube or trabeculectomy given their risks for complications. A standalone glaucoma procedure such goniotomy or canaloplasty can reduce pressure significantly with a more favorable safety profile. Again, the postoperative management is generally well within the scope of practice of a comprehensive ophthalmologist. Persistent hyphema is the primary complication that may require a return to the operating room.

Standardized filtration procedures such as the Xen 45 (Allergan) are also techniques that could be adapted by comprehensive ophthalmologists. These procedures significantly decrease the likelihood of shallow anterior chambers and choroidal effusions, two of the more technically challenging side effects of trabeculectomy surgery. The Xen implant can allow many comprehensive ophthalmologists to provide transscleral pressure-lowering, bleb-forming procedures and help them address advanced glaucoma within their practice. Of note, the Xen is capable of achieving IOPs in the low teens, in some cases without the use of any drops, which is what many patients with advanced glaucoma need.

CONCLUSION

The obvious caveat here is that patients who cannot be controlled with the aforementioned approaches may require referral to an appropriate glaucoma specialist. Referrals should be considered especially when the patient has already received some form of surgical intervention without achieving target pressure and/or if the glaucoma continues to progress despite multiple strategies. Though issues like significant travel may pose an obstacle for patients, urgency to protect vision should be impressed upon those with recalcitrant cases

I hope that this review of approaches for patients with advanced glaucoma has been helpful and will allow you to better care for these patients within your practice. OM

REFERENCES

1. Gazzard G, Konstantakopoulou E, Garway-Heath D, et al. Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial [published correction appears in Lancet. 2019 Jul 6;394(10192):e1]. Lancet. 2019;393(10180):1505-1516.
2. Sarrafpour S, Saleh D, Ayoub S, Radcliffe NM. Micropulse transscleral cyclophotocoagulation: A look at long-term effectiveness and outcomes. Ophthalmol Glaucoma. 2019;2:167-171.
3. Grippo TM, de Crom RMPC, Giovingo M, et al. Evidence-based consensus guidelines series for MicroPulse transscleral laser therapy: Dosimetry and patient selection. Clin Ophthalmol. 2022;16:1837-1846. Published 2022 Jun 7.

Nathan M. Radcliffe, MD, is clinical associate professor of ophthalmology at New York Eye and Ear Infirmary of Mount Sinai in New York City. Email him at drradcliffe@gmail.com. Disclosures: Dr. Radcliffe is a consultant and speaker for Aerie Pharmaceuticals, Allergan, Bausch + Lomb, Glaukos, Iridex, New World Medical and Sight Sciences.

Nicholas E. Tan, BA, is a fourth-year medical student at SUNY Downstate Health Sciences University in Brooklyn, NY.