ABO NOCE Basic Opticianry Ocular Anatomy and Conditions Questions and Answers 5 — Questions and Answers
Question 1: Which structure separates the anterior and posterior chambers of the eye?
- Cornea
- Iris-lens diaphragm (Correct answer)
- Zonular fibers
- Trabecular meshwork
Correct answer: Iris-lens diaphragm
The iris-lens diaphragm divides the anterior segment into anterior chamber (front of iris) and posterior chamber (behind iris, in front of vitreous).
Question 2: Proliferative diabetic retinopathy differs from non-proliferative diabetic retinopathy by the presence of:
- Microaneurysms
- Hard exudates
- New blood vessel formation (Correct answer)
- Dot and blot hemorrhages
Correct answer: New blood vessel formation
The defining feature of proliferative diabetic retinopathy is neovascularization — growth of fragile new vessels on the retina or optic disc.
Question 3: Which extraocular muscle is responsible for abduction of the eye?
- Medial rectus
- Superior oblique
- Lateral rectus (Correct answer)
- Inferior oblique
Correct answer: Lateral rectus
The lateral rectus, innervated by the abducens nerve (CN VI), is the primary abductor of the eye.
Question 4: A chalazion differs from a hordeolum in that a chalazion is:
- An acute bacterial infection of a meibomian gland
- A chronic lipogranulomatous inflammation of a meibomian gland (Correct answer)
- An inflammation of a lash follicle
- A viral lesion on the eyelid margin
Correct answer: A chronic lipogranulomatous inflammation of a meibomian gland
A chalazion is a sterile, chronic granulomatous inflammation caused by retained meibomian gland secretions, not an acute infection.
Question 5: Which test uses a red-free filter to enhance visibility of nerve fiber layer defects on fundus examination?
- Slit-lamp biomicroscopy
- Red-free fundus photography (Correct answer)
- Fluorescein angiography
- Optical coherence tomography
Correct answer: Red-free fundus photography
Red-free (green light) fundus photography filters out red wavelengths, making nerve fiber layer dropouts and hemorrhages appear more distinct.
Question 6: The ora serrata marks the boundary between which two retinal regions?
- Macula and peripheral retina
- Optic disc and fovea
- Sensory retina and pars plana (Correct answer)
- Choroid and sclera
Correct answer: Sensory retina and pars plana
The ora serrata is the serrated anterior margin where the sensory retina terminates and the pars plana of the ciliary body begins.
Question 7: Congenital color deficiency most commonly affects perception of which color axis?
- Blue-yellow (tritan)
- Red-green (Correct answer)
- Brightness only
- All colors equally
Correct answer: Red-green
Red-green color deficiency is the most common inherited color vision defect, affecting approximately 8% of males, due to anomalies in L or M cone photopigments.
ABO NOCE Basic Opticianry Ocular Anatomy and Conditions Questions and Answers 5
Which structure separates the anterior and posterior chambers of the eye?