An 88-year-old female with ocular surface disease (OSD) and mild primary open-angle glaucoma (POAG) in both eyes was referred by her local eye care provider for worsening vision, eye irritation, and elevated intraocular pressure (IOP). She had been struggling with ocular surface irritation for years. Previous treament with cyclosporine (Restasis; Allergan) and lifitegrast (Xiidra; Novartis) had been discontinued due to both ineffectiveness and intolerance. She had also undergone bilateral lower punctal plug placement, and she used preservative-free artificial tears frequently throughout the day. These measures minimally improved her symptoms. Other ocular history included early, nonexudative age-related macular degeneration, uncomplicated cataract surgery, and posterior YAG capsulotomy in both eyes. She was on 3 different topical glaucoma medications in both eyes: latanoprost at bedtime, brimonidine twice daily, and timolol twice daily.

On exam, best-corrected visual acuity was 20/70-2 in the right eye and 20/60-2 in the left eye. Her IOP was 19 mmHg in the right eye and 21 mmHg in the left with normal pachymetry. Slit-lamp examination showed impressive ocular surface disease bilaterally, with meibomian gland dysfunction, low tear lakes, epithelial basement membrane dystrophy, moderately decreased corneal sensation, and diffuse superficial punctate keratitis. Dilated exam showed good posterior-chamber intraocular lens positions with open posterior capsules, optic nerves with cup-to-disc ratios of 0.75 in both eyes, and few fine macular drusen bilaterally. Visual field testing (Humphrey SITA Faster) was reliable and showed paracentral scotomas in both eyes with possible early superior arcuate changes in the left eye (Figure 1A). On optical coherence tomography (OCT) imaging, the retinal nerve fiber layer was normal in the right eye and showed early inferior thinning on the left (Figure 1B). Epithelial cell mapping showed irregularity bilaterally (Figure 2).

Treatment Options

This patient had severe, multifaceted OSD, including meibomian gland dysfunction, aqueous deficiency, and epithelial basement membrane dystrophy, all exacerbated by toxicity to her topical glaucoma drops. Yet, her IOP remained borderline on 3 different glaucoma medications. This situation is commonly experienced by eye care providers, who regularly attempt to balance glaucoma treatment with ocular surface health.

The side effects of topical glaucoma medications are well known and contribute to poor patient compliance to glaucoma drop regimens.¹ Preservative-free options have been formulated to alleviate the toxic effects of many glaucoma drugs, but these can be expensive with inconsistent insurance coverage. For patients who require continued IOP control but are not tolerating topical options, alternative IOP-lowering treatments should be considered. Selective laser trabeculoplasty (SLT) is an effective option for IOP lowering and is now considered a first-line therapy.² This patient’s corneal disease on presentation unfortunately prevented good visualization of the iridocorneal angle for accurate application of SLT. Minimally invasive glaucoma surgeries (MIGS) are another alternative to topical medications. For mild glaucoma, MIGS are typically performed in conjunction with cataract surgery. Our patient was already pseudophakic in both eyes, so a MIGS procedure would have required another trip to the operating room. For these reasons, it was decided to place a sustained-release bimatoprost implant (Durysta; Allergan) intracamerally in the clinic to give the patient a holiday from her glaucoma medications.

The Durysta bimatoprost implant was FDA approved in March 2020. It is currently recommended for one-time use in patients with any stage of glaucoma or ocular hypertension.³ The phase 1 and 2 studies of Durysta showed that patients receiving the approved 10-µg implant achieved an average 7.4 mmHg IOP lowering from washout baseline IOP. Drug elution occurs over a 3-month to 4-month period, although following placement of a single implant, 68% of study eyes showed continued efficacy at 6 months, 40% at 12 months, and 28% at 24 months.⁴ Repeat dosing of the implant is not yet recommended because this may incur an increased risk of endothelial cell loss that appears to be time-interval dependent.^3-5

Case Outcome

After Durysta implantation, all 3 of this patient’s glaucoma drops were discontinued. In addition, she was treated with autologous serum eye drops 4 times daily in both eyes. At her return visit a month after treatment, her eye irritation had subjectively improved and her visual acuity increased to 20/50+2 in both eyes. Her IOP remained stable at 18 mmHg in the right eye and 20 mmHg in the left eye. Further treatment plans include SLT if needed for her mild glaucoma and phototherapeutic keratectomy for the epithelial basement membrane dystrophy. GP

Caroline Wilson, MD, is a cornea, glaucoma, and refractive surgery fellow at Vance Thompson Vision in Sioux Falls, South Dakota. She reports no relevant disclosures. Reach her at caroline.wilson@vancethompsonvision.com.

References

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2. Garg A, Vickerstaff V, Nathwani N, et al. Primary selective laser trabeculoplasty for open-angle glaucoma and ocular hypertension: clinical outcomes, predictors of success, and safety from the Laser in Glaucoma and Ocular Hypertension Trial. Ophthalmology. 2019;126(9):1238-1248. doi:10.1016/j.ophtha.2019.04.012
3. Shirley M. Bimatoprost implant: first approval [published correction appears in Drugs Aging. 2020 Jul;37(7):549]. Drugs Aging. 2020;37(6):457-462. doi:10.1007/s40266-020-00769-8
4. Craven ER, Walters T, Christie WC, et al. 24-month phase i/ii clinical trial of bimatoprost sustained-release implant (bimatoprost SR) in glaucoma patients. Drugs. 2020;80(2):167-179. doi:10.1007/s40265-019-01248-0
5. Medeiros FA, Walters TR, Kolko M, et al. Phase 3, randomized, 20-month study of bimatoprost implant in open-angle glaucoma and ocular hypertension (ARTEMIS 1). Ophthalmology. 2020;127(12):1627-1641. doi:10.1016/j.ophtha.2020.06.018