COST Study Guide 2026
Everything you need to pass the COST exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📚 COST Topics to Study (21)
✍️ Sample COST Questions & Answers
1. What role does documentation play in patient safety protocols?
Thorough documentation in patient safety protocols is both a legal requirement and essential for continuity of patient care.
2. Which cells of the retina are primarily responsible for phototransduction in low-light (scotopic) conditions?
Rod photoreceptors contain rhodopsin and are exquisitely sensitive to dim light, making them the primary mediators of scotopic (night) vision.
3. What is the primary route by which aqueous humor drains from the eye to maintain intraocular pressure?
About 80–90% of aqueous outflow occurs through the trabecular meshwork into Schlemm's canal, then into the episcleral venous system.
4. Aqueous-deficient dry eye syndrome is most commonly caused by dysfunction of which structure?
Aqueous-deficient dry eye results from insufficient tear production by the main lacrimal gland, most commonly due to Sjögren's syndrome or lacrimal gland damage.
5. What is the standard of care requirement for patient communication in clinical practice?
The standard of care is defined as what a reasonably competent practitioner with similar training would provide under similar circumstances.
6. The standard of care treatment for a medium-sized choroidal melanoma is:
Episcleral plaque brachytherapy (plaque radiotherapy) is the preferred treatment for medium-sized choroidal melanoma, with survival outcomes equivalent to enucleation per the COMS trial.