Glaucoma and Quality of Life: Balancing Drop Burden and Patient Compliance

Welcome to the first episode of Pressure Points Glaucoma! This series is hosted by Justin Schweitzer, OD, FAAO, and will feature glaucoma experts reviewing case reports and discussing their treatment approaches for tricky cases.

Dr. Schweitzer is the optometric externship director and a practicing optometrist at Vance Thompson Vision in Sioux Falls, South Dakota.

In this episode, Dr. Schweitzer is joined by Walter Whitley, OD, MBA, FAAO, to assess treatment options for a glaucoma patient with seemingly well-controlled intraocular pressure (IOP) and concomitant ocular surface disease (OSD).

Dr. Whitley is a nationally recognized lecturer who serves as the Director of Professional Relations and Residency Program Supervisor at Virginia Eye Consultants in Norfolk, Virginia.

Case report

Baseline

A 71-year-old male patient presented to the clinic complaining of irritated eyes. He had a relevant medical history of hypertension (HTN) and a family history of HTN as well as diabetes mellitus (DM). The patient’s best-corrected visual acuity (BCVA) was 20/25-1 OU.

The patient had been diagnosed with glaucoma previously and was prescribed a prostaglandin analog (PGA) qd OU and a fixed combination agent bid OU.

The clinical examination revealed:

T-Max: 32 OD, 29 OS
IOP: 17mmHg OD, 18mmHg OS
Cup to disc ratio (C/D): 0.80/0.80 OD, 0.65/0.65 OS
Pachymetry: 510 OD, 514 OS
Corneal hysteresis (CH): 10.5 OD, 10.6 OS
Gonioscopy: Open to ciliary body (CB) OU with trace pigment in the trabecular meshwork (TM)

Dr. Schweitzer noted that based on the initial exam, it seemed as though the topical glaucoma medications were working well to control the patient’s pressure, and the relatively high CH indicated that the patient had less of a risk of progression.¹ However, this assessment changed as he reviewed more imaging.

Figure 1: Slit lamp photograph of the patient; significant superficial punctate keratitis (SPK) can be visualized.

^{Figure 1: Courtesy of Justin Schweitzer, OD, FAAO.}

Image 2: Collected images of visual field testing (VF) OD from October 26, 2012 to October 22, 2020; the visual field index (VFI), mean deviation (MD), and pattern standard deviation (PSD) indicate consistent VF loss over time, although the patient’s IOP is well controlled (shown by the T-Max values). There is a nasal step and a worsening arcuate defect as well.

^{Figure 2: Courtesy of Justin Schweitzer, OD, FAAO.}

Figures 3 and 4: Near-infrared reflectance (NIR) and OCT imaging OD of the patient on May 28, 2020 and October 22, 2020; the temporal inferior and superior retinal nerve fiber layer (RNFL) thinning continued to worsen between visits.

^{Figure 3: Courtesy of Justin Schweitzer, OD, FAAO.}

^{Figure 4: Courtesy of Justin Schweitzer, OD, FAAO.}

Initial reflections on the case report

Dr. Whitley noted that this case reflected a common glaucoma patient for many optometrists, in which the patient seems well controlled in terms of their IOP, but the slit lamp shows signs of dryness, and OCTs/VFs demonstrate signs of progression.

For these patients, the first question Dr. Whitley asks himself is why they are continuing to progress. In this case, because the slit lamp image showed dense SPK, one of the key issues to come to mind is reduced adherence due to OSD.

Studies have shown that many topical glaucoma medications, particularly those preserved with benzalkonium chloride (BAK), have been associated with exacerbating OSD due to their cytotoxic effects on the corneal and conjunctival epithelium.²

Meaning if a glaucoma patient experiences OSD symptoms and instills a glaucoma drop with preservatives, they may feel stinging and burning and be even less likely to adhere to the treatment regimen because it is uncomfortable.

As compliance is already a concern with once-a-day dosing, optometrists must be even more attentive to glaucoma patients on multiple drops daily, as studies have indicated that adherence decreases to 49% in patients with qd or bid dosing and 39% in more than bid dosing.³

Finally, the central defect in the VFs demonstrated that the patient, in fact, had advanced glaucoma that required further intervention.

Key questions to consider for this patient:

Is the patient taking their drops?
Is their IOP low enough?

Potential treatment approaches for this glaucoma patient

Dr. Whitley explained that there are many treatment options available for this patient to fully address the concomitant OSD and glaucoma:

Treating the ocular surface
- Determine if the patient is using lubricating drops and, due to the severity of the SPK, prescribe a dry eye therapy such as lifitegrast, cyclosporine, or varenicline (an ocular-sparing treatment)
- In patients with significant staining, consider neurotrophic keratitis (NK) as a potential differential diagnosis
- Prescribe preservative-free glaucoma medications
Controlling the patient’s IOP
- Educate patients on alternative treatments to drops for controlling IOP, such as:
  - A subconjunctival stent (Xen gel stent, Allergan, an AbbVie company) to improve outflow and reduce drop reliance
  - Intracameral implants, including the bimatoprost sustained release (SR) implant (Durysta, Allergan, an AbbVie company) or the travoprost implant (iDose TR, Glaukos Corporation)
  - Selective laser trabeculoplasty (SLT) as a surgical approach to reducing the patient’s medication burden
  - Microinvasive glaucoma surgery (MIGS), especially if the patient hasn’t undergone cataract surgery yet
- Following surgery or an implant, potentially reduce drops if IOPs are well controlled or at target after surgery
- Order compounded glaucoma drops for patients who have reached their maximum medical therapy and continue to progress

Case conclusion

Dr. Schweitzer prescribed the patient bimatoprost SR OD and OS in addition to SLT OU for IOP control and added a soft steroid for 2 weeks qid to manage ocular surface inflammation. He also had the patient stop glaucoma medications for a drop holiday following the SLT.

At the 6-week follow-up:

IOP was 16mmHg OU
The cornea was essentially clear
Placed punctal plugs and considered adding an ocular-sparing dry eye treatment (ex., varenicline nasal spray)
The patient will be monitored closely and likely will need further intervention due to the severity of the glaucoma, all while keeping the ocular surface in mind