Diseases of the Retina Practice Questions

Q: One year old male child with cat's reflex and raised IOP. What is the most likely diagnosis?

Retinoblastoma. ***Retinoblastoma*** - A **cat's reflex (leukocoria)**, which is a white pupillary reflex, is the most common presenting sign of retinoblastoma in children. - **Raised intraocular pressure (IOP)** can occur in advanced retinoblastoma due to secondary glaucoma caused by tumor growth or neovascularization. *Toxocara canis* - Ocular **toxocariasis** can cause leukocoria and inflammation, but it's typically associated with **granuloma formation** and not usually primary elevated IOP. - This condition is caused by a **parasitic infection** from roundworms, often seen in children with exposure to contaminated soil or pets. *Retinopathy of prematurity* - Primarily affects **premature infants** exposed to high oxygen, leading to abnormal retinal vessel development. - While it can cause leukocoria in severe stages, it would be unusual for a **one-year-old** to present with this primary diagnosis especially with raised IOP. *Toxoplasma gondii infection* - Ocular **toxoplasmosis** typically presents with **chorioretinitis** and can cause inflammation, but **leukocoria** and **raised IOP** are not its primary or most characteristic features. - This is a parasitic infection, congenital or acquired, often presenting with **retinal scars**.

Q: The laser procedure, most often used for treating iris neovascularization is

Panretinal photocoagulation (PRP). ***Panretinal photocoagulation (PRP)*** - **PRP** is the most effective laser procedure for **iris neovascularization** and **neovascular glaucoma**, as it ablates the ischemic retina, reducing the production of **vascular endothelial growth factor (VEGF)**. - By destroying the ischemic peripheral retina, PRP reduces the **angiogenic drive** that leads to new vessel formation on the iris and in the angle. *Laser iridoplasty* - This procedure involves applying laser energy to the peripheral iris to cause contraction and widen the **anterior chamber angle**, primarily used for **angle-closure glaucoma**. - While it can open a closed angle, it does not address the underlying **ischemic drive** causing neovascularization. *Laser trabeculoplasty* - This procedure targets the **trabecular meshwork** to improve aqueous humor outflow, commonly used for **open-angle glaucoma**. - It does not directly affect **iris neovascularization** or the ischemic factors driving its development. *Goniophotocoagulation* - This involves directly lasering new vessels in the **anterior chamber angle**, often as an adjunct to PRP, but it's not the primary treatment to prevent **iris neovascularization**. - It treats existing vessels but does not address the underlying cause of **retinal ischemia** that promotes new vessel growth.

Q: Ocriplasmin is a recombinant protease and it is used to treat:

Vitreomacular adhesion (VMA). ***Vitreomacular adhesion (VMA)*** - **Ocriplasmin** is a *recombinant protease* specifically approved for the treatment of symptomatic **vitreomacular adhesion (VMA)** or *vitreomacular traction (VMT)*. - Its proteolytic activity helps dissolve the proteins at the vitreomacular interface, thereby releasing the traction and potentially preventing progression to other macular pathologies like *macular holes*. *Submacular bleeding* - **Submacular bleeding** is typically managed with anti-VEGF injections, *vitrectomy with subretinal tissue plasminogen activator (tPA)*, or pneumatic displacement, not ocriplasmin. - The goal is to displace or remove blood, which is not the primary mechanism of action for ocriplasmin. *Diabetic macular edema* - **Diabetic macular edema (DME)** is commonly treated with *anti-VEGF agents* (e.g., ranibizumab, aflibercept), corticosteroids, or laser photocoagulation. - DME is characterized by fluid leakage and swelling due to diabetic retinopathy, not vitreomacular adhesion. *Retinal break* - A **retinal break** (tear or hole) is typically managed with *laser photocoagulation* or *cryopexy* to create an adhesion around the break and prevent retinal detachment. - Ocriplasmin does not have a role in the direct treatment or repair of retinal breaks.

Q: All are ophthalmological emergencies except -

CRVO. ***CRVO*** - Central Retinal Vein Occlusion (CRVO) is characterized by painless **vision loss** due to retinal hemorrhage and edema, but it is generally *not* considered an immediate, vision-threatening emergency in the same vein as the other options. - While it requires prompt evaluation and management to preserve vision, CRVO allows for a less urgent intervention compared to conditions that can lead to permanent vision loss within hours. *Endophthalmitis* - **Endophthalmitis** is a severe inflammation of the intraocular fluids and tissues, typically caused by infection, and can lead to rapid and irreversible vision loss if not treated urgently. - It presents with pain, redness, reduced vision, and hypopyon (pus in the anterior chamber), necessitating immediate antibiotic treatment and surgical intervention. *Acute congestive glaucoma* - **Acute congestive glaucoma** (acute angle-closure glaucoma) involves a sudden increase in intraocular pressure, causing severe pain, redness, corneal edema, and profound vision loss. - If left untreated, the high pressure can cause irreversible damage to the optic nerve within hours, making it a true ocular emergency. *CRAO* - **Central Retinal Artery Occlusion (CRAO)** is a sudden, painless loss of vision in one eye due to blockage of the central retinal artery, leading to retinal ischemia. - It is an ocular emergency because irreversible retinal damage and vision loss can occur within 90-120 minutes of the occlusion, requiring immediate intervention to restore blood flow.

Q: Phthisis bulbi is characterized by -

Final end stage of chronic uveitis. ***Correct: Final end stage of chronic uveitis*** - **Phthisis bulbi** is a shrunken, atrophic, disorganized, and non-functional eye representing the end stage of severe ocular disease - **Chronic uveitis** is one of the **most common causes** of phthisis bulbi, as prolonged intraocular inflammation leads to: - Destruction of intraocular structures - **Hypotony** (reduced intraocular pressure) - Globe shrinkage and disorganization - Complete loss of vision - While phthisis bulbi can result from multiple severe conditions (trauma, infection, end-stage glaucoma), **chronic uveitis** remains the most frequent inflammatory cause *Incorrect: Developmental hypoplasia of optic cup* - This describes a **congenital anomaly** (microphthalmia) where the eye is small from birth - Phthisis bulbi is an **acquired condition** resulting from destructive ocular disease - The eye shrinks secondarily after birth, not due to developmental failure - Completely different pathophysiology and timing *Incorrect: Final end stage of chronic scleritis* - While severe chronic scleritis **can** contribute to phthisis bulbi through: - Scleral thinning and perforation - Secondary uveitis - Secondary glaucoma - It is **less commonly** the primary direct cause compared to chronic uveitis - Scleritis primarily affects the sclera, whereas uveitis causes more extensive intraocular destruction *Incorrect: All of the above* - Option A (developmental hypoplasia) is a congenital condition, NOT phthisis bulbi - Phthisis bulbi is specifically an acquired end-stage condition - Therefore, "all of the above" cannot be correct

Q: A-wave in Electroretinogram corresponds to the activity of

Rods and cones. ***Rods and cones*** - The **'a' wave** of the Electroretinogram (ERG) represents the **initial negative deflection**, primarily generated by the activity of the **photoreceptors** (rods and cones) in response to light stimulation. - This wave reflects the **hyperpolarization** of the photoreceptor cells as they absorb light and initiate the visual transduction cascade. *Pigment epithelium* - The **retinal pigment epithelium (RPE)** plays a crucial role in supporting photoreceptor function and has a slower, sustained electrical response, which contributes more to the **c-wave** of the ERG. - While the RPE is vital for retinal function, its primary electrical contribution is not represented by the initial negative a-wave. *Nerve fibre layer* - The **nerve fiber layer** consists of the axons of ganglion cells and does not directly contribute to the primary a-wave or b-wave of the ERG as it is involved in transmitting signals to the brain. - Damage to this layer may affect overall visual function but is not the source of the initial photoreceptor-driven electrical response. *Ganglion cell layer* - The **ganglion cell layer** is responsible for sending visual information to the brain, and its activity is typically reflected in later, more complex components of the ERG or in other electrophysiological tests like pattern ERG. - The initial photoreceptor response (a-wave) occurs upstream of the ganglion cell activity.

Q: True about sympathetic ophthalmia?

Dalen Fuch's Nodules are seen. ***Dalen Fuch's Nodules are seen*** - **Dalen-Fuchs nodules** are characteristic histological findings in sympathetic ophthalmia, consisting of epithelioid cells and lymphocytes between the retinal pigment epithelium and Bruch's membrane. - Their presence is a key diagnostic indicator in the affected eye (sympathizing eye) and the exciting eye (initial injured eye). *It is caused due to corneal injury* - Sympathetic ophthalmia is typically triggered by **penetrating ocular trauma** or **intraocular surgery** involving the **uvea**, not merely corneal injury. - The exposure of **uveal antigens** to the immune system after injury is the initiating event. *It is bilateral non granulomatous uveitis* - Sympathetic ophthalmia is a **bilateral, granulomatous panuveitis**, meaning it involves all layers of the uvea and is characterized by granuloma formation. - The granulomatous nature with **epithelioid cells** and **giant cells** is a hallmark. *Paton's Lines are seen* - **Paton's lines** are radially oriented retinal folds seen around the optic disc, characteristic of **papilledema**. - They are not associated with sympathetic ophthalmia, which primarily affects the uvea and retina due to an autoimmune response.

Q: Pneumoretinopexy is an outpatient procedure in which retinal detachment is sealed with air insufflation. Which of the following gases is used in pneumoretinopexy?

Sulfur hexafluoride. ***Sulfur hexafluoride*** - **Sulfur hexafluoride (SF6)** is a commonly used gas in **pneumatic retinopexy** due to its expansive properties and inertness within the eye. - It provides a **temporary tamponade effect** against the retinal tear, allowing the retina to reattach. - SF6 expands to approximately **twice its injected volume** and provides tamponade for **1-2 weeks**. - **Perfluoropropane (C3F8)** is another gas commonly used in pneumatic retinopexy, which lasts longer (6-8 weeks) but expands more (up to 4 times). *Nitrous oxide* - **Nitrous oxide** is primarily used as an **anesthetic gas** and for pain relief in medical procedures. - It is not suitable for intraocular tamponade due to its rapid absorption and potential to expand existing intraocular gas bubbles dangerously. *Oxygen* - **Oxygen** is essential for cellular respiration and is a fundamental component of the air we breathe. - It is **highly soluble** in intraocular fluids and would be quickly absorbed, making it ineffective for sustained retinal tamponade. *Carbon dioxide* - **Carbon dioxide** is a natural byproduct of metabolism and is used in some surgical contexts (e.g., laparoscopy) to create a working space. - Like oxygen, it is **highly soluble** and would dissipate too quickly to provide the necessary long-term tamponade for retinal reattachment.

Q: Indirect ophthalmoscopy is done for:

Periphery of retina. ***Periphery of retina*** - Indirect ophthalmoscopy offers a **wide field of view** and **stereoscopic imaging**, making it ideal for examining the **peripheral retina**. - It allows for the detection of peripheral retinal lesions like **tears, detachments, and degenerations** that may be missed with direct ophthalmoscopy. *Macula and central retina* - While indirect ophthalmoscopy can visualize the macula, **direct ophthalmoscopy** provides a **higher magnification** and better resolution for detailed examination of the macula and optic disc. - Conditions like **macular degeneration** or **diabetic macular edema** are usually evaluated more precisely with direct ophthalmoscopy or specialized imaging. *Sclera* - The sclera is the **outer white layer of the eye**; its examination is primarily done through **external inspection** of the globe. - Ophthalmoscopy, whether direct or indirect, is focused on visualizing the **fundus** (retina, optic disc, blood vessels), not the sclera. *Angle of ant. chamber* - The **angle of the anterior chamber** is evaluated using **gonioscopy**, a specialized technique involving a contact lens with mirrors. - Ophthalmoscopy is not suitable for visualizing this structure, which is crucial for diagnosing and managing **glaucoma**.

Q: The shifting fluid sign is characteristic of which condition?

Exudative retinal detachment. ***Exudative retinal detachment (fluid accumulation in subretinal space)*** - The **shifting fluid sign** is pathognomonic for **exudative retinal detachment**, as the subretinal fluid can move with changes in head position due to gravity. - This type of detachment is caused by conditions that lead to abnormal accumulation of fluid under the retina, such as **choroidal tumors**, inflammatory processes, or **severe hypertension**. *Retinal hole (localized retinal break)* - A **retinal hole** is a full-thickness defect in the retina, but it does not inherently cause a shifting fluid sign unless it progresses to a rhegmatogenous detachment. - While it can be a precursor to retinal detachment, the fluid itself is not subject to gravitational shifting in the same way as in exudative detachment. *Tractional retinal detachment (retinal pulling forces)* - **Tractional retinal detachments** occur when **fibrovascular membranes** on the retinal surface contract, pulling the retina away from the underlying choroid. - The detachment is usually localized and fixed by the tractional forces, meaning the fluid (if present) does not shift freely with changes in head position. *Rhegmatogenous retinal detachment (retinal break with vitreous fluid entry)* - This type of detachment involves a **retinal break** through which **liquefied vitreous** gains access to the subretinal space. - Although there is subretinal fluid, the fluid is generally trapped and the detachment is less mobile than in an exudative case; thus, a pronounced shifting fluid sign is not typical.

Question 1

One year old male child with cat's reflex and raised IOP. What is the most likely diagnosis?

Accepted Answer

Retinoblastoma

Answer

Toxocara canis

Answer

Retinopathy of prematurity

Answer

Toxoplasma gondii infection

Question 2

The laser procedure, most often used for treating iris neovascularization is

Accepted Answer

Panretinal photocoagulation (PRP)

Answer

Laser iridoplasty

Answer

Laser trabeculoplasty

Answer

Goniophotocoagulation

Question 3

Ocriplasmin is a recombinant protease and it is used to treat:

Accepted Answer

Vitreomacular adhesion (VMA)

Answer

Submacular bleeding

Answer

Diabetic macular edema

Answer

Retinal break

Question 4

All are ophthalmological emergencies except -

Accepted Answer

CRVO

Answer

Endophthalmitis

Answer

Acute congestive glaucoma

Answer

CRAO

Question 5

Phthisis bulbi is characterized by -

Accepted Answer

Final end stage of chronic uveitis

Answer

Developmental hypoplasia of optic cup

Answer

Final end stage of chronic scleritis

Answer

All of the above

Question 6

A-wave in Electroretinogram corresponds to the activity of

Accepted Answer

Rods and cones

Answer

Pigment epithelium

Answer

Nerve fibre layer

Answer

Ganglion cell layer

Question 7

True about sympathetic ophthalmia?

Accepted Answer

Dalen Fuch's Nodules are seen

Answer

It is caused due to corneal injury

Answer

It is bilateral non granulomatous uveitis

Answer

Paton's Lines are seen

Question 8

Pneumoretinopexy is an outpatient procedure in which retinal detachment is sealed with air insufflation. Which of the following gases is used in pneumoretinopexy?

Accepted Answer

Sulfur hexafluoride

Answer

Nitrous oxide

Answer

Oxygen

Answer

Carbon dioxide

Question 9

Indirect ophthalmoscopy is done for:

Accepted Answer

Periphery of retina

Answer

Macula and central retina

Answer

Sclera

Answer

Angle of anterior chamber

Question 10

The shifting fluid sign is characteristic of which condition?

Accepted Answer

Exudative retinal detachment

Answer

Retinal hole

Answer

Tractional retinal detachment

Answer

Rhegmatogenous retinal detachment

Diseases of the Retina — MCQs

Diseases of the Retina — MCQs

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