Glaucoma High-Yield Facts for PG Exams (+30 Practice MCQs)

For an exam stem on glaucoma, build the answer in four moves: identify the angle and mechanism, interpret IOP in context, demonstrate structural optic-nerve/RNFL damage, and correlate it with function. Raised IOP is an important risk factor and treatment target, but it is not the definition of glaucoma; glaucomatous optic neuropathy can occur when measured IOP lies within the population reference range.¹ This is education for ophthalmology examinations, not advice for diagnosing or treating an individual patient.

The answer framework that prevents most glaucoma errors

The European Glaucoma Society describes glaucoma as a chronic, progressive optic neuropathy with characteristic structural change and visual-field loss; that wording explains why a single high IOP reading, an isolated OCT “red” sector or a large physiological cup cannot individually settle the diagnosis.¹ In an SBA, first locate the question in one of the four domains. In a viva, state them in that order. It makes the answer auditable.

First, separate the terms examiners deliberately blur

Ocular hypertension means IOP above the statistical reference range without demonstrable glaucomatous damage. Primary open-angle glaucoma (POAG) requires an open angle plus characteristic optic neuropathy, with or without elevated IOP. Normal-tension glaucoma is the clinical label generally used when typical glaucomatous damage occurs with IOP measurements within the conventional normal range; it is not “no-pressure glaucoma”.³ A normal measurement can be incomplete evidence because IOP varies with time, technique and corneal properties.

Glaucoma suspect is a risk category, not a final diagnosis. Suspicion may arise from IOP, disc appearance, RNFL/field findings, angle appearance or history. The exact surveillance and treatment decision is clinical and individualised, so do not turn a revision label into a management instruction.

Pressure: useful, imperfect, and often tested

Goldmann applanation tonometry estimates IOP through an assumption about corneal behaviour. Central corneal thickness and corneal biomechanics affect the measurement, but a candidate should avoid reciting a simplistic “correction factor” as though it yields a true IOP. State that pachymetry informs interpretation and risk assessment; it does not mathematically convert one reading into the patient’s biological pressure.³

Aqueous is produced by the ciliary processes. The conventional route passes through trabecular meshwork, Schlemm canal and episcleral veins; uveoscleral outflow is the other major route. If the stem describes pigment, pseudoexfoliative material, inflammatory cells/debris, angle recession or neovascular membrane, the question is usually asking how that process impairs outflow or closes the angle.

Angle questions: use anatomy before labels

Gonioscopy is the reference examination for angle configuration. A narrow peripheral chamber on slit lamp screening may raise suspicion, but it cannot prove the mechanism or show peripheral anterior synechiae. The AAO primary angle-closure guidance uses gonioscopy in classifying the angle and identifies iridotrabecular contact, elevated IOP, peripheral anterior synechiae and glaucomatous damage as distinct pieces of the clinical picture.²

Pupillary block produces posterior pressure relative to the anterior chamber, forward bowing of the peripheral iris and iris bombe. Plateau iris configuration reflects anteriorly positioned ciliary processes; a peripheral iridotomy may remove the pupillary-block component but the angle may remain narrow. The safe exam statement is therefore “persistent narrowness after a patent iridotomy suggests a non-pupillary-block component such as plateau iris”, not “iridotomy cures every narrow angle”.

In Shaffer grading, grade 4 is a very wide angle and grade 0 is closed. Grades are a descriptive gonioscopic shorthand. Do not use them as an isolated promise that closure can or cannot occur in every eye; clinical context matters.

Disc, RNFL and field: correlate instead of collecting test names

The optic disc is not graded by vertical cup:disc ratio alone. Large discs may have large physiological cups. More concerning patterns include focal rim thinning/notching, progressive cupping, inter-eye asymmetry that fits the disc size and clinical context, RNFL wedge defects and disc haemorrhage. The ISNT rule is a screening heuristic, not a law: normal discs can violate it and glaucomatous discs can appear deceptively orderly.

Functional loss follows retinal nerve fibre bundle anatomy. A nasal step, paracentral defect and arcuate scotoma are classic early or localised patterns; a Bjerrum scotoma occupies the arcuate region. A Seidel scotoma is an early extension of a blind-spot-related arcuate defect. A field should be repeated when reliability or clinical correlation is poor. “Reliable” is not synonymous with “true”; fixation behaviour, false positives, learning effect, cataract and other ocular disease still affect interpretation.¹

OCT adds structural information but is vulnerable to segmentation error, poor signal, high myopia, disc anomalies and database mismatch. The high-mark answer is: inspect the scan and signal, compare with disc/RNFL and field, then seek progression across time. It is weaker to say “OCT red equals glaucoma”.

Secondary and developmental patterns worth anchoring

These are exam associations, not a checklist for real-world diagnosis. Some entities have overlapping findings, and the correct investigation or treatment depends on a supervised clinical assessment.

30 glaucoma MCQs with explanations

Definitions and pressure

1. Which feature defines glaucoma most accurately? Characteristic progressive optic neuropathy, supported by structural and/or functional evidence. Why: IOP contributes risk but is not mandatory.¹

2. Does IOP of 28 mmHg alone prove POAG? No. Why: it supports ocular hypertension/suspicion until angle and damage are assessed.

3. The conventional aqueous pathway ends where? Episcleral venous circulation after trabecular meshwork and Schlemm canal. Why: this is the usual outflow sequence.

4. What is the major alternative outflow route? Uveoscleral outflow. Why: do not call it “accessory drainage” without naming it.

5. Why is a fixed CCT correction factor unsafe? Corneal thickness is only one influence on applanation; biomechanics and clinical context also matter.³

6. What does “normal-tension” mean in glaucoma? Typical glaucomatous damage despite IOP readings in the conventional normal range. Why: it does not remove the need for open-angle and differential assessment.

Angle and mechanism

7. Best examination for angle anatomy? Gonioscopy. Why: screening estimates cannot substitute for direct angle assessment.²

8. A Shaffer grade 4 angle is? Very wide open. Why: grade 0 is closed; remember the ends before memorising intermediate widths.

9. Iris bombe points to which mechanism? Pupillary block. Why: pressure behind the iris bows it forward peripherally.

10. Persistent narrow angle after a patent iridotomy suggests? A non-pupillary-block component, classically plateau iris configuration. Why: the iridotomy addresses pupillary block, not all configurations.

11. Peripheral anterior synechiae are? Permanent iris–angle adhesions. Why: distinguish them from appositional iridotrabecular contact.

12. Is a narrow angle identical to angle-closure glaucoma? No. Why: angle anatomy, IOP, synechiae and optic neuropathy are separate observations.

Disc, OCT and field

13. A vertical cup:disc ratio of 0.7 proves glaucoma? No. Why: disc size and rim configuration must be considered.

14. Which disc feature is more useful than cup ratio alone? Focal neuroretinal rim notching or progressive change. Why: morphology and change carry context.

15. The ISNT rule is best described as? A useful screening heuristic. Why: it has exceptions in both normal and glaucomatous discs.

16. A common localised early field pattern is? Nasal step or paracentral/arcuate defect. Why: defects reflect RNFL bundle anatomy.

17. A Seidel scotoma is related to? Early arcuate extension from the blind spot. Why: do not confuse it with a nasal step.

18. What should precede accepting an OCT RNFL colour-code abnormality? Check signal, segmentation, disc anatomy and structure–function correlation. Why: databases are not diagnoses.

19. Why repeat a field? Reliability and learning effect can alter a result; progression requires longitudinal correlation.¹

20. Is RAPD expected in early symmetric POAG? No. Why: it suggests substantial asymmetric optic-nerve dysfunction, not routine early bilateral disease.

Secondary and developmental glaucoma

21. Krukenberg spindle plus heavy angle pigment suggests? Pigment dispersion syndrome. Why: pigment loading can produce secondary open-angle glaucoma.

22. Pseudoexfoliation glaucoma is generally classified as? Secondary open-angle glaucoma. Why: exfoliative material/pigment impede outflow in an open-angle mechanism.

23. Steroid-induced IOP rise is usually what category? Secondary open-angle glaucoma. Why: state the exposure and outflow effect.

24. Neovascular glaucoma closes the angle by? Contracting fibrovascular tissue and synechial closure. Why: it is not merely “high IOP from diabetes”.

25. Angle recession follows? Blunt trauma. Why: a widened ciliary-body band is a gonioscopic clue.

26. Classic symptom triad in primary congenital glaucoma? Epiphora, photophobia and blepharospasm. Why: enlarged cornea/eye and Haab striae are further clues.

27. Haab striae are breaks in? Descemet membrane. Why: do not confuse them with Vogt striae.

28. Posner–Schlossman syndrome classically involves? Recurrent unilateral IOP elevation with relatively mild anterior uveitis. Why: answer with the syndrome’s pressure–inflammation mismatch.

29. Target IOP is a universal number? No. Why: it is individualised to disease severity, baseline, risk and observed course.³

30. Best one-sentence viva close for suspected glaucoma? “I would correlate gonioscopic angle status, IOP and corneal context with disc/RNFL structure and repeatable visual-field function.” Why: it demonstrates the four-domain framework.

A 40-minute revision circuit

Spend ten minutes drawing aqueous flow and the angle-closure mechanisms. Spend ten minutes on three discs and three fields, stating the correlation aloud. Use the next fifteen minutes for the MCQs above without notes. Use the final five to log only the reason for each error: mechanism, anatomy, classification, test limitation or distractor confusion. Revisit the log in a mixed set two days later. This is far more useful than rereading a list of “facts”.

Two short viva rehearsals

“How do you assess a glaucoma suspect?” Start with history and risk context, then state IOP measurement with corneal context, gonioscopy, disc/RNFL assessment, visual field and baseline comparison. Do not list tests without saying what each contributes. The examiner is looking for an integrated assessment, not a device catalogue.

“Describe this cupped disc.” Give disc size and image quality first. Then describe rim, cup contour, vessel position, RNFL, haemorrhage and asymmetry. Correlate with field and OCT rather than announcing a stage from a photograph. If the disc has pathological myopia or another confounder, say that normative OCT colour coding may be less dependable. This is an inference from test limitations, not a substitute for clinical review.¹

Last-minute discrimination list

Keep these pairs separate: appositional contact versus peripheral anterior synechiae; IRMA (a retina term) versus disc haemorrhage; ocular hypertension versus POAG; narrow angle versus angle-closure glaucoma; and a structural test abnormality versus confirmed progression. A well-written answer often wins marks by refusing the false equivalence built into the distractor.

For organised topic revision, the site’s glaucoma study guide is the relevant hub. The Glaucoma Exam Ready Notes product page and free high-yield MCQs are existing OphthaMCQ resources; neither is an official guideline or a substitute for supervised clinical judgement.

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