Ophthalmic MCQ Explanations Part:35

1. Hyperemia is minimal at:

• A. Palpebral conjunctiva: This is the conjunctiva lining the eyelids. It has a rich blood supply and shows significant redness (hyperemia) in inflammatory conditions.
•  B. Limbus: This is the junction between the cornea and the sclera. Ciliary injection (redness around the limbus) is characteristic of deeper inflammation (like keratitis or uveitis), but superficial conjunctival hyperemia is often less pronounced here compared to the fornices or palpebral conjunctiva in general conjunctivitis. However, in ciliary injection, the hyperemia is maximal at the limbus and fades towards the fornices. The question asks where hyperemia is minimal. In conjunctival injection (typical conjunctivitis), the redness is most prominent in the fornices and palpebral conjunctiva and fades towards the limbus. Therefore, the limbus often appears relatively less hyperemic in generalized conjunctivitis compared to the fornices.
•  C. Fornices: These are the junctional areas where the palpebral conjunctiva folds back to become the bulbar conjunctiva. They are loose tissues with abundant blood vessels and typically show the most intense hyperemia in conjunctivitis.
•  D. Equal everywhere: Hyperemia is rarely equal everywhere; its pattern helps differentiate types of inflammation.
•  Answer: B. Limbus. In typical conjunctival injection seen in conjunctivitis, redness is most marked in the fornices and palpebral conjunctiva and fades towards the limbus, making the limbus the area of minimal hyperemia for that specific type of redness.

2. Which of the following entropion type is usually a temporary condition:

• A. Senile (Involutional): This is due to age-related weakening and laxity of eyelid tissues. It’s typically progressive and requires surgical correction.
• B. Mechanical: Caused by masses (like tumors) or swelling pushing the eyelid margin inwards. It resolves if the underlying cause is treated.
• C. Cicatricial: Caused by scarring of the conjunctiva and tarsal plate (e.g., from trachoma, chemical burns, Stevens-Johnson syndrome). It’s permanent unless surgically corrected.
• D. Acute spastic: Caused by excessive contraction (spasm) of the orbicularis oculi muscle, often due to ocular irritation or inflammation. It usually resolves once the underlying irritation is treated.
• Answer: D. Acute spastic. This type is directly related to temporary factors like irritation or spasm.

3. Inversion of the lid margin:

• A. Entropion: This is the medical term for the inward turning (inversion) of the eyelid margin, causing eyelashes to rub against the eye.
• B. Ectropion: This is the outward turning (eversion) of the eyelid margin.
• C. Trichiasis: This refers to the misdirection of eyelashes towards the globe, even if the eyelid margin position is normal.
• D. Ptosis: This is the drooping of the upper eyelid.
• Answer: A. Entropion.

4. Poliosis is:

• A. Double row of lashes: This is called Distichiasis.
• B. Multiple row of lashes: Irregular multiple rows can occur but aren’t termed poliosis.
• C. Whitening of lashes: This is the definition of poliosis, which can be associated with conditions like Vogt-Koyanagi-Harada syndrome or Waardenburg syndrome, or simply aging.
• D. Absence of lashes: This is called Madarosis.
• Answer: C. Whitening of lashes.

5. False about Bitot spots is?

• A. accumulation of keratinized epithelial debris: This is true. Bitot spots are composed of keratinized epithelial cells, debris, and Corynebacterium xerosis.
• B. appear on the conjunctiva: This is true. They are typically found on the temporal bulbar conjunctiva.
• C. appear on the cornea: This is false. Bitot spots are characteristic signs of Vitamin A deficiency appearing on the conjunctiva, not the cornea. Corneal involvement in Vitamin A deficiency presents as xerosis and keratomalacia.
• D. develop into xerophthalmia if not treated: This is true. Bitot spots are a sign of xerophthalmia (dry eye due to Vitamin A deficiency), which can worsen if untreated.
• Answer: C. appear on the cornea.

6. Corneal nerves are not enlarged in:

• A. Keratoconus: Corneal nerves can become more visible in keratoconus due to stromal thinning, but they are not typically described as enlarged.
• B. Leprosy: Enlarged, beaded corneal nerves are a characteristic finding in leprosy.
• C. Herpes simplex keratitis: While HSV keratitis affects corneal sensation, significant nerve enlargement is not a typical feature compared to other conditions listed. Dendritic ulcers are the hallmark.
• D. Neurofibromatosis: Enlarged corneal nerves can be seen in neurofibromatosis. Multiple endocrine neoplasia type 2B (MEN 2B) is also notably associated with prominent corneal nerves.
• Answer: C. Herpes simplex keratitis. While sensation is affected, gross enlargement isn’t the characteristic feature as it is in leprosy or neurofibromatosis. Keratoconus makes nerves more visible but not necessarily enlarged. (Note: The provided answer key says C, but some sources might list A as well, as simple visibility isn’t the same as enlargement).

7. Substance deposited in Band Shaped Keratopathy is?

• A. calcium phosphate: This is the primary substance deposited in the Bowman layer and anterior stroma in band-shaped keratopathy, appearing as a whitish-grey band across the interpalpebral cornea.
• B. magnesium phosphate: Not the primary deposit.
• C. magnesium sulphate: Not the primary deposit.
• D. Iron: Iron deposition occurs in conditions like siderosis or as Fleischer rings (in keratoconus), not typically in band keratopathy.
• Answer: A. calcium phosphate.

8. Iridis circulus major is situated at:

• A. Pupil: The pupil is the central aperture.
• B. Ciliary body: The circulus arteriosus iridis major (major arterial circle of the iris) is located within the ciliary body, near the iris root. It supplies the iris and ciliary body.
• C. Root of iris: While close, the vessel ring itself lies within the ciliary body stroma adjacent to the iris root.
• D. Collarette: This is a zig-zag line on the anterior iris surface separating the pupillary and ciliary zones. The minor arterial circle is located here.
• Answer: C. Root of iris. (Note: Anatomically it’s more precise to say it’s in the ciliary body near the iris root, but among the options, ‘Root of iris’ is the closest landmark).

9. Ankyloblepharon is:

• A. Adhesion of both lid margin: This is the definition of ankyloblepharon – partial or complete fusion of the upper and lower eyelid margins.
• B. Adhesion of palpebral conjunctiva and bulbar conjunctiva: This is called Symblepharon.
• C. Double row of lashes: This is Distichiasis.
• D. None: Option A is correct.
• Answer: A. Adhesion of both lid margin.

10. HSV can be associated with:

• A. Keratitis: Herpes Simplex Virus (HSV) is a very common cause of infectious keratitis (inflammation of the cornea), often presenting as dendritic ulcers.
• B. Uveitis: HSV can cause anterior uveitis (inflammation of the iris and ciliary body).
• C. Retinitis: HSV can cause acute retinal necrosis (ARN), a severe form of retinitis.
• D. All the above: Since HSV can cause keratitis, uveitis, and retinitis, this option is correct.
• Answer: D. All the above.