A Short Quiz On Ophthalmology!

1. Afferent component of corneal reflex is mediated by:

Vagus nerve

Facial nerve

Trigeminal nerve

Glossopharyngeal nerve

The afferent component of the corneal reflex is mediated by the trigeminal nerve. This nerve is responsible for transmitting sensory information from the cornea to the brain. When the cornea is stimulated, such as by a foreign object or a gust of air, sensory signals are sent through the trigeminal nerve to the brain, triggering a reflexive blinking response to protect the eye from potential harm. The other nerves listed, the vagus, facial, and glossopharyngeal nerves, are not involved in mediating the afferent component of the corneal reflex.

Explanation

The afferent component of the corneal reflex is mediated by the trigeminal nerve. This nerve is responsible for transmitting sensory information from the cornea to the brain. When the cornea is stimulated, such as by a foreign object or a gust of air, sensory signals are sent through the trigeminal nerve to the brain, triggering a reflexive blinking response to protect the eye from potential harm. The other nerves listed, the vagus, facial, and glossopharyngeal nerves, are not involved in mediating the afferent component of the corneal reflex.

2. Bitemporal hemianopia field defect is characteristic of?

Glaucoma

Optic neuritis

Pituitary tumour

Retinal detachment

Pituitary tumors compress the optic chiasma and cause bitemporal hemianopia.

Explanation

Pituitary tumors compress the optic chiasma and cause bitemporal hemianopia.

3. Afferent pathway for pupillary light reflex is:

Trigeminal nerve

Optic nerve

Abducent nerve

Ciliary nerve

The afferent pathway for the pupillary light reflex refers to the pathway through which sensory information from the eye is transmitted to the brain. In the case of the pupillary light reflex, the optic nerve is responsible for carrying this information. The optic nerve is specifically designed to transmit visual information from the retina to the brain, making it the correct answer for this question. The other options listed, such as the trigeminal nerve, abducent nerve, and ciliary nerve, are not involved in the afferent pathway for the pupillary light reflex.

Explanation

The afferent pathway for the pupillary light reflex refers to the pathway through which sensory information from the eye is transmitted to the brain. In the case of the pupillary light reflex, the optic nerve is responsible for carrying this information. The optic nerve is specifically designed to transmit visual information from the retina to the brain, making it the correct answer for this question. The other options listed, such as the trigeminal nerve, abducent nerve, and ciliary nerve, are not involved in the afferent pathway for the pupillary light reflex.

4. The average distance of the fovea from the temporal margin of the optic disc is:

1 disc diameter

2 disc diameter

3 disc diameter

4 disc diameter

The correct answer is 2 disc diameter. The fovea is a small depression in the retina that is responsible for central vision. The optic disc is the point where the optic nerve exits the eye, and it is located on the nasal side of the retina. The average distance between the fovea and the temporal margin of the optic disc is 2 disc diameters. This means that the fovea is typically located about twice the distance of the diameter of the optic disc away from the temporal margin.

Explanation

The correct answer is 2 disc diameter. The fovea is a small depression in the retina that is responsible for central vision. The optic disc is the point where the optic nerve exits the eye, and it is located on the nasal side of the retina. The average distance between the fovea and the temporal margin of the optic disc is 2 disc diameters. This means that the fovea is typically located about twice the distance of the diameter of the optic disc away from the temporal margin.

5. Band shaped keratopathy is caused by:

Amyloid

Calcium

Monopolysaccharide

Lipid

Band shaped keratopathy occurs due to the accumulation of calcium salts in a band pattern in the anterior corneal layers.

Explanation

Band shaped keratopathy occurs due to the accumulation of calcium salts in a band pattern in the anterior corneal layers.

6. The magnification obtained with a direct ophthalmoscope is:

5 times

10 times

15 times

20 times

The magnification obtained with a direct ophthalmoscope is 15 times. This means that when using a direct ophthalmoscope, the image seen through the instrument appears 15 times larger than it actually is. This level of magnification allows for a detailed examination of the retina and other structures within the eye.

Explanation

The magnification obtained with a direct ophthalmoscope is 15 times. This means that when using a direct ophthalmoscope, the image seen through the instrument appears 15 times larger than it actually is. This level of magnification allows for a detailed examination of the retina and other structures within the eye.

7. Which of the following is not of prognostic significance in choroidal melanoma?

Presence of retinal detachment

Size of the tumor

Cytology of the tumor cells

Presence of extraocular extension

Prognoistic factors in choroidal melanoma:
Extent of metastatic disease
Age
Size of intraocular tumour
Extent of extrascleral tumour extension
Ciliary body involvement
Histopathological and cytogenetic features

Explanation

Prognoistic factors in choroidal melanoma:
Extent of metastatic disease
Age
Size of intraocular tumour
Extent of extrascleral tumour extension
Ciliary body involvement
Histopathological and cytogenetic features

8. Which of the following is NOT a common refractive error of the eye?

Myopia (nearsightedness)

Hyperopia (farsightedness)

Astigmatism

Glaucoma

Glaucoma is a serious eye condition that damages the optic nerve, often due to increased pressure within the eye. It is not a refractive error, which refers to how the eye bends light to focus images on the retina. The other options are common refractive errors: myopia (difficulty seeing distant objects), hyperopia (difficulty seeing near objects), and astigmatism (blurred vision due to an irregularly shaped cornea).

Explanation

Glaucoma is a serious eye condition that damages the optic nerve, often due to increased pressure within the eye. It is not a refractive error, which refers to how the eye bends light to focus images on the retina. The other options are common refractive errors: myopia (difficulty seeing distant objects), hyperopia (difficulty seeing near objects), and astigmatism (blurred vision due to an irregularly shaped cornea).

9. The retina receives its blood supply from all, except:

Posterior ciliary artery

Central retinal artery

Retinal arteries

Plexus of Zinn and Haller arteries

The retina receives its blood supply from the central retinal artery, retinal arteries, and the plexus of Zinn and Haller arteries. The posterior ciliary artery does not supply blood to the retina.

Explanation

The retina receives its blood supply from the central retinal artery, retinal arteries, and the plexus of Zinn and Haller arteries. The posterior ciliary artery does not supply blood to the retina.