Glaucoma Diagnosis and Management Flashcards

A 68-year-old male with primary open-angle glaucoma is being monitored for progression. His intraocular pressure is stable on a prostaglandin analog. Which finding on spectral-domain optical coherence tomography (SD-OCT) of the retinal nerve fiber layer (RNFL) is most indicative of early glaucomatous progression?

Answer: Localized thinning of the inferotemporal or superotemporal quadrant that respects the horizontal midline

Early glaucomatous damage typically manifests as localized thinning of the retinal nerve fiber layer, most commonly in the inferotemporal and superotemporal arcuate bundles. This damage respects the horizontal raphe. Diffuse thinning is less specific and can be seen in other conditions or advanced disease. Crossing the midline is not a typical pattern for early glaucoma. Increased signal strength is a measure of scan quality, not a sign of pathology.

A 55-year-old female presents with sudden, severe right eye pain, blurred vision, and nausea. On examination, her intraocular pressure (IOP) is 58 mmHg, the cornea is hazy, and the pupil is mid-dilated and nonreactive. Gonioscopy of the left eye reveals a narrow, occludable angle. What is the most appropriate definitive initial treatment for the affected right eye after the acute attack is medically controlled?

Answer: Laser peripheral iridotomy (LPI)

This patient is experiencing an acute angle-closure glaucoma attack. The definitive treatment to relieve pupillary block and prevent recurrence is a laser peripheral iridotomy (LPI). This procedure creates a new channel for aqueous humor to flow from the posterior to the anterior chamber. Prostaglandin analogs are generally used for open-angle glaucoma. SLT is used for open-angle glaucoma and is not effective for angle-closure. Trabeculectomy is a surgical option for more advanced or uncontrolled glaucoma, not the initial definitive procedure for acute angle-closure.

Which of the following classes of topical glaucoma medications primarily works by increasing the uveoscleral outflow of aqueous humor?

Answer: Prostaglandin analogs

Prostaglandin analogs (e.g., latanoprost, travoprost, bimatoprost) are a first-line treatment for open-angle glaucoma and lower intraocular pressure primarily by increasing the outflow of aqueous humor through the uveoscleral pathway. Beta-blockers and carbonic anhydrase inhibitors decrease aqueous production, while alpha-adrenergic agonists both decrease production and increase trabecular outflow.

A 62-year-old patient is diagnosed with normal-tension glaucoma (NTG). Their intraocular pressures are consistently 15-17 mmHg in both eyes. Humphrey Visual Field testing shows a dense superior arcuate scotoma in the right eye. According to the Collaborative Normal Tension Glaucoma Study (CNTGS), what is the recommended management approach?

Answer: Lowering the intraocular pressure by at least 30% from baseline.

The Collaborative Normal Tension Glaucoma Study (CNTGS) demonstrated that lowering the IOP by at least 30% significantly slowed the rate of visual field progression in patients with NTG. Even though the initial pressure is within the 'normal' range, reducing it further is the only proven treatment to slow disease progression. Observation is only appropriate if there is no evidence of progression. A 10% reduction is less than the target established by the CNTGS, and surgery is typically reserved for cases that progress despite medical or laser therapy.

When interpreting a Humphrey Visual Field (HVF) 24-2 test for a glaucoma suspect, which of the following patterns is most characteristic of early glaucomatous damage?

Answer: A nasal step respecting the horizontal midline

Early glaucomatous visual field defects typically correspond to the pattern of nerve fiber layer loss. A nasal step, which is a scotoma just above or below the horizontal midline in the nasal field, is a classic early sign. This occurs due to damage to the arcuate nerve fibers. A central scotoma is more typical of macular disease or advanced glaucoma. Bitemporal hemianopsia suggests a chiasmal lesion. An enlarged blind spot can be seen in glaucoma but is less specific than a nasal step.

A 70-year-old patient with pseudoexfoliation glaucoma has an intraocular pressure of 28 mmHg in the right eye despite maximal tolerated medical therapy with a prostaglandin analog, a beta-blocker, and a carbonic anhydrase inhibitor. Which of the following is the most appropriate next step in management?

Answer: Perform selective laser trabeculoplasty (SLT).

This patient has inadequately controlled IOP on maximal medical therapy. Selective laser trabeculoplasty (SLT) is a well-established and effective option to further lower IOP when medications are insufficient or not tolerated. Adding a fourth medication often has limited additional effect and increases the complexity and potential for side effects. Switching between prostaglandin analogs may offer a small benefit but is less likely to achieve the required pressure reduction than SLT. Continuing to monitor without intervention is inappropriate given the high IOP and risk of progression.