Glaucoma Lessons for the Next Generation

Noted cataract surgeon Roberto Bellucci MD has seen glaucoma patients regularly for many years in his cataract practice. EuroTimes Editor-in-Chief Sean Henahan spoke with him about what young ophthalmologists need to know when treating these patients.

ET: What part of your practice involves glaucoma management?

RB: Every patient presenting for cataract surgery should be evaluated for dry eye, possible maculopathy, and possible glaucoma. Fortunately, only a minority of these patients are actually affected by glaucoma and require specific management. In hospital departments, the percentage can be 10–15%, but in private practices like mine, this percentage is about 5%.

When performing cataract surgery in a glaucoma patient, the purpose is to reduce the intraocular pressure (IOP) and/or to decrease the number of the medications. Cataract surgery alone is usually enough in angle closure glaucoma when the trabeculum is functional. In open-angle glaucoma, simple lens removal is expected to get the desired result in early glaucoma, while in more advanced cases, we need to add a specific procedure to increase the aqueous outflow.

Procedure selection is driven by several factors, including the experience of the surgeon, the patient perspective, and cost. My preference goes to minimally invasive bleb surgery (MIBS), especially with the Preserflo MicroShunt (Glaukos), a device I implant under subconjunctival anaesthesia at the end of phacoemulsification by simply asking the patient to look at their feet. Trabeculectomy combined with phacoemulsification would be my second choice when a MIBS device is not available, a frequent case in public hospitals in Italy. I have little experience with minimally invasive glaucoma surgery devices, which would be attractive for less advanced glaucoma cases. In the past, I have tried several procedures, such as laser cycloablation and ultrasound application, but without success at my hands.

What role can the cataract/refractive surgeon play in helping patients with glaucoma?

Cataract surgeons can help glaucoma patients in several ways. In angle-closure glaucoma, the removal of the natural lens frequently solves the problem, as was demonstrated by the famous EAGLE study.¹ Many hyperopic patients have a shallow anterior chamber, and a simple evaluation at the slit lamp (Van Herick test) can prompt the cataract surgeon to suggest refractive cataract surgery to these patients years before closed-angle glaucoma develops. Actually, acute glaucoma attacks have almost disappeared in my area precisely because of early cataract surgery.

In the various types of open-angle glaucoma, cataract surgery can improve IOP and/or medication use—also improving our ability to grade the glaucoma damage by removing any lens opacity that might affect visual field testing. Moreover, undetected glaucoma can be confused for a developing cataract by the patient, the optician, and sometimes the ophthalmologist if the lens is very opaque. In this regard, surgery preparation will diagnose any underlying pathology, including glaucoma.

What steps would a young ophthalmologist take to learn more about glaucoma surgery?

Compared with cataract, glaucoma is a completely different disease that requires a specific approach. Those who treat glaucoma are prepared to follow patients with great care and empathy for the patient’s entire life. So, the first step for the doctors approaching glaucoma surgery is to increase their knowledge about glaucoma—how to monitor patients, when to give indications for surgery, how to select the surgery, what complications can be expected even after an uneventful surgery, and how to treat the emerging problems. My suggestion is therefore to study glaucoma, watch surgical videos available on the web, and then join a glaucoma centre for a while, because not everything can be learnt online. After starting a glaucoma surgery practice, maintain relations with mentors to ask opinions and seek help in difficult cases or complications.

Do you have any cautions or caveats about what cataract surgeons should or should not do?

I always fear for glaucoma in my highly myopic patients. Frequently, their IOP is slightly elevated, it is difficult to evaluate the visual field and the fibre layer at optical coherence tomography, the visual field is inconclusive, and they present two to three years later with a white optic nerve. I have learnt to see them frequently, carefully recording the numerical outcome of the examinations. At the same time, surgeons should refrain from suggesting early cataract surgery to highly myopic patients asking for better vision until they are pretty sure the cataract is the problem with their vision.

The second regards the ‘wipe-out’ syndrome, or the sudden loss of the remaining central vision that can occur during surgery (cataract or glaucoma) in end-stage glaucoma. This event is very frustrating both for the patient and the surgeon and should be considered and discussed with the patient preoperatively.

A third caveat is for the postoperative period in pseudophakic, vitrectomised eyes, which sometimes develop glaucoma that goes unnoticed if the postoperative controls are diluted.

There are many others, however—surgeons learn from experience with unfavourable outcomes. Especially in glaucoma, it is easy to forget successes but keep sharp memory of failures.

It seems that cataract surgeons may shy away from selective laser trabeculoplasty (SLT) because of the gonioscopy skills required, but direct SLT (DSLT) is becoming more popular because this is not required. What do you think of some of the newer options such as FLIGHT (ViaLase) and ELIOS (excimer)?

I think the gonioscopic lens required for SLT is a problem more for the patient than for the doctor, with DSLT becoming more popular for this reason. However, SLT is an evolution of the old argon laser trabeculoplasty (as published in 1979) that used to have variable results, and this legacy may have had an impact on the procedure’s acceptance.

Newer laser techniques like FLIGHT and ELIOS are different because they try and achieve a more substantial change of the chamber angle anatomy. We can therefore expect a more reproducible IOP-lowering effect. We can also expect other machines and procedures to be developed in this area—with the common purpose to avoid the burden and the risks involved in trabeculectomy. In this perspective, the surgical management of glaucoma will probably transfer from a single high-risk surgery to a series of small, repeatable surgeries, each with effects that may only last a few years.

A former president of ESCRS, Roberto Bellucci MD is a Consultant Ophthalmologist is Salò, Italy.

1. Azuara-Blanco A, et al. Lancet, 2016 Oct 1; 388(10052): 1389–1397.