Diseases of the Retina

Diseases of the Retina Indian Medical PG Question 1: Retinopathy is most likely to be seen with which of the following conditions?

• A. Gestational diabetes
• B. Juvenile diabetes started before puberty
• C. Type 2 diabetes of 8 years duration (Correct Answer)
• D. Type 1 diabetes of 5 years duration

Diseases of the Retina Explanation: **Type 2 diabetes of 8 years duration** - **Diabetic retinopathy** is a common microvascular complication of diabetes mellitus [1]. - The risk of retinopathy increases with the **duration of diabetes** and the **severity of hyperglycemia**, making an 8-year duration with type 2 diabetes a significant risk factor [1]. *Type 1 diabetes of 5 years duration* - While type 1 diabetes can cause retinopathy, a 5-year duration is generally considered relatively short for the development of significant retinopathy, especially in early stages. - The risk of retinopathy in **Type 1 diabetes** becomes more pronounced after 10-15 years, though it can occur earlier. *Gestational diabetes* - **Gestational diabetes** is a temporary condition occurring during pregnancy and does not typically lead to chronic complications like retinopathy. - Retinopathy is rare in gestational diabetes because the disease duration is short and usually resolves post-partum. *Juvenile diabetes started before puberty* - **Juvenile diabetes** is synonymous with Type 1 diabetes [2]. Although early onset of diabetes increases lifetime risk, the duration of diabetes is a more critical factor for retinopathy development. - Without a specified duration, it's less predictive than an established longer duration of Type 2 diabetes.

Diseases of the Retina Indian Medical PG Question 2: Anterior choroidal artery is a branch of which of the following arteries?

• A. Basilar artery
• B. Anterior cerebral artery
• C. Posterior cerebral artery
• D. Internal carotid artery (Correct Answer)

Diseases of the Retina Explanation: ***Correct: Internal carotid artery*** - The **anterior choroidal artery** is a direct branch of the **internal carotid artery**, specifically originating from its **supraclinoid segment**. - It supplies crucial structures such as the **choroid plexus of the lateral ventricle**, parts of the **hippocampus**, **amygdala**, and the **posterior limb of the internal capsule**. - This is a clinically important vessel, as occlusion can lead to significant neurological deficits. *Incorrect: Basilar artery* - The basilar artery is part of the **posterior circulation**, formed by the union of the vertebral arteries. - It gives rise to branches like the **pontine arteries**, **superior cerebellar arteries**, and **posterior cerebral arteries**, but not the anterior choroidal artery. *Incorrect: Anterior cerebral artery* - The anterior cerebral artery is a terminal branch of the **internal carotid artery**, but it primarily supplies the **medial surface of the frontal and parietal lobes**. - It does not give rise to the anterior choroidal artery; instead, the anterior choroidal artery branches off the internal carotid artery more **proximally**, before the terminal bifurcation. *Incorrect: Posterior cerebral artery* - The posterior cerebral artery is a terminal branch of the **basilar artery** and is part of the posterior circulation. - It supplies the **occipital lobe** and parts of the **temporal lobe**. - Its branches include **posterior choroidal arteries** (not anterior choroidal artery), which supply the choroid plexus of the third ventricle and lateral ventricles.

Diseases of the Retina Indian Medical PG Question 3: A 2-year-old child presents with unilateral leukocoria and poor vision. What is the most likely diagnosis?

• A. Congenital cataract
• B. Retinoblastoma (Correct Answer)
• C. Endophthalmitis
• D. Coats disease

Diseases of the Retina Explanation: ***Retinoblastoma*** - **Leukocoria** (white pupillary reflex) is the **most common presenting sign** of retinoblastoma, occurring in approximately 60% of cases - The combination of **unilateral leukocoria** and **poor vision** in a **2-year-old child** (peak age 18-24 months) is highly suggestive - It is a **rapidly growing malignant intraocular tumor** arising from the neural retina, requiring urgent evaluation and treatment - Other presenting features may include **strabismus**, **red eye**, and in advanced cases, **proptosis** *Congenital cataract* - Can also present with **leukocoria** due to opacification of the lens - However, congenital cataracts are typically **bilateral** (75% of cases) and diagnosed earlier in infancy - The **static, non-progressive nature** distinguishes it from the rapidly growing retinoblastoma - Family history and associated systemic conditions (TORCH infections, metabolic disorders) are common *Endophthalmitis* - Severe **intraocular infection** affecting vitreous and aqueous humor - Typically presents with **acute pain**, **severe redness**, **hypopyon**, and **rapid vision loss** - Usually follows **penetrating trauma** or **intraocular surgery**, which would be uncommon in a 2-year-old - **Leukocoria without acute inflammatory signs** makes this diagnosis unlikely *Coats disease* - Characterized by **abnormal telangiectatic retinal vessels** with **exudative retinal detachment** and **yellow subretinal exudates** - Can present with leukocoria (yellow reflex due to lipid deposits) in young children - However, it typically affects **older children** (mean age 5-8 years), is predominantly **unilateral**, and has a **more indolent course** - More common in **males** and usually lacks the rapid progression of retinoblastoma

Diseases of the Retina Indian Medical PG Question 4: A diabetic patient presents to you with visual acuity of 6/9 in one eye. Further investigations revealed preretinal hemorrhages with neovascularization at the optic disc. What is the next step in management?

• A. Focal laser photocoagulation
• B. Pan-retinal photocoagulation (Correct Answer)
• C. Grid laser photocoagulation
• D. Scleral buckling

Diseases of the Retina Explanation: ***Pan-retinal photocoagulation*** - The presence of **preretinal hemorrhages** and **neovascularization at the optic disc (NVD)** indicates **high-risk proliferative diabetic retinopathy (PDR)**. - **NVD is a high-risk characteristic** for severe vision loss and requires urgent treatment with **pan-retinal photocoagulation (PRP)**. - PRP aims to ablate ischemic peripheral retina, which reduces the production of **VEGF** and other angiogenic factors that stimulate neovascularization. *Focal laser photocoagulation* - This treatment targets discrete leaking microaneurysms in cases of **clinically significant macular edema (CSME)**, which is not the primary issue here. - It is used for **non-proliferative diabetic retinopathy** with macular involvement, not for neovascularization. *Grid laser photocoagulation* - Grid laser is a type of focal laser used for **diffuse macular edema** where specific leaking microaneurysms cannot be identified. - It is not indicated for **neovascularization** or **preretinal hemorrhages**, which are signs of PDR. *Scleral buckling* - **Scleral buckling** is a surgical procedure primarily used to treat **retinal detachment** by indenting the sclera to relieve vitreoretinal traction. - It is not the initial or primary treatment for **proliferative diabetic retinopathy** or **neovascularization**.

Diseases of the Retina Indian Medical PG Question 5: All of the following take part in the blood supply of the optic chiasm except:

• A. Anterior cerebral artery
• B. Middle cerebral artery (Correct Answer)
• C. Anterior communicating artery
• D. Internal carotid artery

Diseases of the Retina Explanation: ***Middle cerebral artery*** - The **middle cerebral artery (MCA)** primarily supplies the lateral surface of the cerebral hemispheres, including portions of the frontal, parietal, and temporal lobes, but does not typically contribute to the direct blood supply of the **optic chiasm** [2]. - Its branches are more directed towards the **sylvian fissure** and cortical structures, rather than the deep midline structures like the optic chiasm [2]. *Anterior cerebral artery* - The **anterior cerebral artery (ACA)**, through its branches, including the **anterior communicating artery**, helps supply the anterior part of the optic chiasm [3]. - It forms part of the **Circle of Willis**, from which small perforating arteries can arise to supply deep brain structures [1]. *Anterior communicating artery* - The **anterior communicating artery (AComA)** connects the two anterior cerebral arteries and gives rise to small branches that directly contribute to the vascular supply of the **optic chiasm** [3]. - These branches are crucial for maintaining blood flow to this critical visual pathway structure. *Internal carotid artery* - The **internal carotid artery (ICA)** gives rise to the **ophthalmic artery** and the **anterior cerebral artery**, both of which contribute to the blood supply of the optic chiasm [3]. - Perforating branches from the ICA itself, particularly its terminal portion before bifurcating, can also directly supply the optic chiasm [3].

Diseases of the Retina Flashcard 1 of 5

Question: Treatment of cystoid macular edema (CME) consists of instillation of intravitreal _____ or anti-VEGF agents; or use of operative therapy like macular grid laser

Answer: steroids

Diseases of the Retina Flashcard 2 of 5

Question: _____ is the second most common retinal vascular disorder after diabetic retinopathy.

Answer: Retinal vein occlusion (RVO)

Diseases of the Retina Flashcard 3 of 5

Question: _____ is characterized by drusen, which is deposition of yellowish extracellular material in between Bruch's membrane and the retinal pigment epithelium

Answer: Dry macular degeneration

Diseases of the Retina Flashcard 4 of 5

Question: _____ is the most common hereditary fundus dystrophy

Answer: Retinitis pigmentosa

Diseases of the Retina Flashcard 5 of 5

Question: In _____ phase of FFA, there is complete filling of retinal arterioles and capillaries followed by laminar filling of veins

Answer: arteriovenous