Diseases of the Retina — MCQs

Diseases of the Retina Indian Medical PG Practice Questions and MCQs

Question 181: Schaffer's sign is seen in which condition?

A. Retinitis pigmentosa
B. Retinal detachment (Correct Answer)
C. Central retinal vein occlusion (CRVO)
D. Central retinal artery occlusion (CRAO)

Explanation: **Explanation:** **Schaffer’s Sign** (also known as the "Tobacco Dust" sign) refers to the presence of fine, pigment granules in the anterior vitreous. It is a pathognomonic clinical finding for a **Rhegmatogenous Retinal Detachment (RRD)** or a full-thickness retinal tear. **Why it occurs:** When a retinal tear occurs, the Retinal Pigment Epithelium (RPE) cells are released from the subretinal space into the vitreous cavity. On slit-lamp biomicroscopy, these cells appear as brownish-red dust-like particles suspended in the vitreous. Its presence is a high-yield clinical marker, as it strongly suggests a retinal break even if the break is not immediately visible. **Analysis of Incorrect Options:** * **Retinitis Pigmentosa:** Characterized by "bone-spicule" pigmentation in the mid-peripheral retina and arteriolar attenuation, not free-floating vitreous pigment. * **CRVO:** Presents with a "blood and thunder" fundus (diffuse hemorrhages, dilated tortuous veins, and disc edema). * **CRAO:** Characterized by a "cherry-red spot" at the fovea and a pale, edematous retina due to ischemia. **Clinical Pearls for NEET-PG:** * **Tobacco Dust Sign:** Always associated with RPE cell release (Retinal tear/detachment). * **Weiss Ring:** A ring-shaped opacity indicating a Posterior Vitreous Detachment (PVD), which often precedes Schaffer's sign. * **Management:** A patient with new-onset flashes (photopsia), floaters, and a positive Schaffer’s sign requires urgent surgical intervention (e.g., Scleral buckling or Vitrectomy) to prevent permanent vision loss.

Question 182: What condition is caused by excessive oxygen concentration in neonates?

A. Retrolental fibroplasias (Correct Answer)
B. Respiratory distress syndrome
C. Hyaline membrane disease
D. Anaemic retinopathy

Explanation: ### Explanation **Correct Answer: A. Retrolental fibroplasia** **Medical Concept:** Retrolental fibroplasia, now more commonly known as **Retinopathy of Prematurity (ROP)**, is caused by the administration of high concentrations of supplemental oxygen to premature neonates. In a premature infant, the retinal vasculature is incompletely developed. Excessive oxygen causes **vasoconstriction** and damage to the immature endothelial cells. When the infant is later returned to room air, the relative hypoxia triggers a surge in **VEGF (Vascular Endothelial Growth Factor)**, leading to pathological neovascularization. These fragile new vessels can bleed and cause fibrous scarring, which pulls on the retina, leading to tractional retinal detachment (the "fibroplasia" behind the lens). **Analysis of Incorrect Options:** * **B & C. Respiratory Distress Syndrome (RDS) / Hyaline Membrane Disease:** These are synonymous terms for a pulmonary condition caused by a deficiency of surfactant in preterm infants. While RDS is the *reason* why neonates are given supplemental oxygen, it is not the ocular condition caused by the oxygen itself. * **D. Anaemic Retinopathy:** This occurs in adults or children with severe anemia (usually Hb < 8g/dL). It is characterized by retinal hemorrhages (often Roth spots), exudates, and venous tortuosity, but it is unrelated to oxygen therapy in neonates. **High-Yield Clinical Pearls for NEET-PG:** * **Screening Criteria:** Infants born at **≤32 weeks** gestation or with a birth weight **≤1500g** must be screened for ROP. * **Zone of Involvement:** The retina is divided into three zones centered on the optic disc. **Zone I** involvement is the most severe. * **Plus Disease:** Indicates significant shunting and is characterized by dilatation and tortuosity of posterior pole retinal vessels. * **Treatment:** The gold standard for "Type 1 ROP" is **Laser photocoagulation** of the avascular peripheral retina. Anti-VEGF injections (e.g., Ranibizumab) are also increasingly used.

Question 183: What is the earliest feature of Diabetic Retinopathy?

A. Microaneurysms (Correct Answer)
B. Cotton wool spots
C. Dot-and-blot hemorrhages
D. Hard exudates

Explanation: **Explanation:** **Microaneurysms** are the hallmark and the **earliest clinically detectable sign** of Diabetic Retinopathy (DR). Pathologically, they represent focal saccular outpouchings of the retinal capillaries. This occurs due to the loss of **pericytes** (which provide structural support to capillary walls) and the weakening of the basement membrane. On fundoscopy, they appear as tiny, round, red dots, typically located in the inner nuclear layer of the retina. On Fluorescein Angiography (FFA), they appear as "pinpoint leaks." **Analysis of Incorrect Options:** * **Cotton wool spots:** These represent focal areas of retinal ischemia in the nerve fiber layer (axoplasmic stasis). They are a feature of Pre-Proliferative Diabetic Retinopathy (PPDR), appearing much later than microaneurysms. * **Dot-and-blot hemorrhages:** These occur when microaneurysms or capillaries rupture within the deeper layers of the retina. While common in Non-Proliferative DR (NPDR), they typically follow the formation of microaneurysms. * **Hard exudates:** These are yellowish deposits of lipids and lipoproteins in the outer plexiform layer, resulting from chronic vascular leakage. They indicate "leakage" rather than the initial vascular structural change. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest Pathological Change:** Loss of pericytes (Pericyte:Endothelial cell ratio drops from 1:1 to 1:0). * **Earliest Clinical Sign:** Microaneurysms. * **First Sign on FFA:** Microaneurysms (seen as hyperfluorescent spots). * **IRMA (Intraretinal Microvascular Abnormalities):** A key feature of Severe NPDR (4-2-1 rule), acting as a precursor to neovascularization. * **Most common cause of vision loss in DR:** Macular Edema.

Question 184: Which of the following is NOT a sign of diabetic retinopathy?

A. Microaneurysms
B. Cotton wool spots
C. Hard exudates
D. Choroidal neovascularization (Correct Answer)

Explanation: **Explanation:** The correct answer is **D. Choroidal neovascularization (CNV)**. Diabetic Retinopathy (DR) is primarily a **microangiopathy** affecting the retinal precapillary arterioles, capillaries, and venules. The hallmark of DR is retinal ischemia and increased vascular permeability. **Choroidal Neovascularization (CNV)**, however, involves the growth of new vessels from the choroid through Bruch’s membrane into the subretinal space. This is the classic feature of **"Wet" Age-Related Macular Degeneration (ARMD)**, not diabetic retinopathy. **Analysis of Incorrect Options:** * **A. Microaneurysms:** These are the **earliest clinical sign** of DR. They represent focal out-pouchings of retinal capillaries due to pericyte loss. * **B. Cotton wool spots:** Also known as soft exudates, these represent focal areas of retinal ischemia (infarction of the nerve fiber layer) and are a key feature of Pre-proliferative Diabetic Retinopathy (PPDR). * **C. Hard exudates:** These are yellowish deposits of lipids and lipoproteins in the outer plexiform layer, resulting from chronic vascular leakage (increased permeability). **High-Yield Clinical Pearls for NEET-PG:** * **Earliest Pathological Change:** Loss of pericytes and basement membrane thickening. * **Earliest Clinical Sign:** Microaneurysms (seen as tiny red dots). * **Proliferative DR (PDR):** Characterized by **Neovascularization elsewhere (NVE)** or **at the Disc (NVD)**. Note that these are *retinal* new vessels, unlike the *choroidal* vessels in CNV. * **Investigation of Choice:** Optical Coherence Tomography (OCT) for macular edema; Fundus Fluorescein Angiography (FFA) to detect ischemia or neovascularization.

Question 185: Retinitis pigmentosa inheritance is by which mode?

A. X linked recessive
B. Autosomal recessive
C. Digenic inheritance
D. Autosomal dominant (Correct Answer)

Explanation: **Explanation:** Retinitis Pigmentosa (RP) is a genetically heterogeneous group of rod-cone dystrophies. While it exhibits multiple patterns of inheritance, **Autosomal Dominant (AD)** is the correct answer in the context of most standard examinations when asked for a single mode, as it represents the most common inheritance pattern in many clinical cohorts and generally carries the best visual prognosis. * **Why Autosomal Dominant is correct:** It is the most frequent mode of inheritance. The most common gene mutation associated with AD-RP is the **Rhodopsin (RHO) gene**. Patients with AD-RP typically have a later onset and a slower rate of progression compared to other forms. * **Why others are incorrect:** * **Autosomal Recessive (AR):** This is also very common (especially in consanguineous populations) and often presents with intermediate severity. * **X-linked Recessive (XLR):** This is the **most severe form**, characterized by early-onset legal blindness (by age 30-40). It is caused primarily by mutations in the *RPGR* gene. * **Digenic Inheritance:** This is a rare form involving mutations in two different genes (e.g., *ROM1* and *Peripherin/RDS*) simultaneously. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Triad:** Bony spicule pigmentation (perivascular), Arteriolar attenuation (narrowing), and Waxy pallor of the optic disc. * **Earliest Symptom:** Nyctalopia (Night blindness) due to rod dysfunction. * **Earliest Sign:** Scanty pigmentary changes in the mid-periphery. * **Gold Standard Investigation:** Electroretinogram (ERG) – shows a "subnormal" or "extinguished" (flat) scotopic response early in the disease. * **Associated Conditions:** Usher Syndrome (RP + Sensorineural hearing loss) and Laurence-Moon-Biedl Syndrome (RP + Obesity + Polydactyly + Hypogonadism + Intellectual disability).

Question 186: What is the treatment of threshold retinopathy of prematurity?

A. Laser photocoagulation (Correct Answer)
B. Slow reduction in oxygen
C. Retinal reattachment
D. Antioxidants

Explanation: **Explanation:** **Retinopathy of Prematurity (ROP)** is a vasoproliferative disorder affecting preterm infants, characterized by abnormal retinal vascularization due to exposure to high oxygen levels followed by relative hypoxia. **Why Option A is Correct:** The goal of treating **Threshold ROP** is to ablate the peripheral avascular retina, which is the source of Vascular Endothelial Growth Factor (VEGF). **Laser photocoagulation** (specifically Diode laser) is the current gold standard. It destroys the ischemic peripheral retina, thereby reducing VEGF production, preventing further neovascularization, and reducing the risk of retinal detachment. Cryotherapy was used previously but has been largely replaced by laser due to better outcomes and fewer complications. **Why Other Options are Incorrect:** * **Option B:** While high oxygen is a risk factor, once threshold ROP has developed, simply reducing oxygen is insufficient to reverse the pathological neovascularization already in progress. * **Option C:** Retinal reattachment (Vitrectomy/Scleral buckling) is indicated for **Stage 4 or 5 ROP** (total or partial detachment). Threshold ROP occurs at Stage 3, where the goal is to prevent detachment from occurring. * **Option D:** Antioxidants (like Vitamin E) have been studied for prevention, but they are not a definitive treatment for established threshold ROP. **High-Yield Clinical Pearls for NEET-PG:** * **Threshold ROP Definition:** Stage 3 ROP in Zone I or II, involving 5 contiguous or 8 cumulative clock hours, associated with **Plus disease**. * **Plus Disease:** Characterized by dilatation and tortuosity of posterior pole retinal vessels. * **Screening Criteria (India):** All infants <1750g birth weight OR <34 weeks gestational age should be screened. * **Timing:** The first screening should be done at **4 weeks** of postnatal age or **31 weeks** of post-conceptional age (whichever is later). * **Recent Trend:** Intravitreal Anti-VEGF (e.g., Ranibizumab) is increasingly used, especially for Zone I disease.

Question 187: Retinitis pigmentosa is a feature of all the following syndromes except?

A. Lowe's syndrome (Correct Answer)
B. Refsum's syndrome
C. Usher's syndrome
D. Hallgren's syndrome

Explanation: **Explanation:** **Retinitis Pigmentosa (RP)** is a group of inherited rod-cone dystrophies characterized by progressive vision loss, night blindness (nyctalopia), and "bone-spicule" pigmentation. While often isolated, it is associated with several systemic syndromes. **1. Why Lowe’s Syndrome is the Correct Answer:** **Lowe’s Syndrome (Oculocerebrorenal syndrome)** is an X-linked recessive disorder characterized by the triad of **congenital cataracts**, mental retardation, and renal tubular dysfunction (Fanconi syndrome). It is notably associated with **glaucoma**, but it does **not** feature Retinitis Pigmentosa. **2. Analysis of Incorrect Options (Syndromes associated with RP):** * **Usher’s Syndrome:** The most common syndromic cause of RP. It involves sensorineural hearing loss and RP. * **Refsum’s Syndrome:** A metabolic disorder (phytanic acid storage disease) presenting with RP, peripheral neuropathy, and cerebellar ataxia. It is high-yield because it is one of the few treatable causes of RP (via diet). * **Hallgren’s Syndrome:** A rare autosomal recessive condition characterized by RP, vestibulocerebellar ataxia, and congenital deafness (similar to Usher’s Type I). **Clinical Pearls for NEET-PG:** * **Classic Triad of RP:** Bone-spicule pigmentation, arteriolar attenuation (narrowing), and waxy pallor of the optic disc. * **Other RP-associated syndromes:** Bassen-Kornzweig (Abetalipoproteinemia), Bardet-Biedl (polydactyly, obesity, hypogonadism), and Kearns-Sayre (CPEO + heart block). * **Lowe’s Syndrome Mnemonic:** Remember the "3 Cs" of Lowe’s: **C**ataract (congenital), **C**ognitive impairment, and **C**ystinosis-like renal issues (Fanconi).

Question 188: Which of the following is NOT a cause of exudative retinal detachment?

A. Scleritis
B. Toxemia of pregnancy
C. Dysthyroid eye disease (Correct Answer)
D. Central serous retinopathy

Explanation: Exudative (Serous) Retinal Detachment (ERD) occurs when fluid accumulates in the subretinal space due to damage to the Blood-Retinal Barrier (BRB) or the Retinal Pigment Epithelium (RPE), without the presence of a retinal break or vitreoretinal traction. **Why Dysthyroid Eye Disease (Graves' Ophthalmopathy) is the correct answer:** Dysthyroid eye disease primarily affects the extraocular muscles and orbital fat through autoimmune inflammation and deposition of glycosaminoglycans [1]. While it can cause proptosis, exposure keratopathy, and compressive optic neuropathy, it **does not** typically involve the subretinal space or cause exudative retinal detachment. **Analysis of Incorrect Options:** * **Scleritis:** Posterior scleritis is a classic cause of ERD. Intense inflammation of the sclera spreads to the choroid, leading to increased vascular permeability and fluid leakage into the subretinal space. * **Toxemia of Pregnancy (Preeclampsia/Eclampsia):** Severe systemic hypertension and vasospasm lead to choroidal ischemia and dysfunction of the RPE, causing bilateral serous retinal detachments in approximately 1% of patients with severe preeclampsia. * **Central Serous Retinopathy (CSR):** CSR is characterized by a localized serous detachment of the neurosensory retina at the macula, caused by idiopathic leakage from the choriocapillaris through a defect in the RPE. **NEET-PG High-Yield Pearls:** * **Most common cause of ERD:** Systemic hypertension/Toxemia. * **Most common intraocular tumor causing ERD:** Malignant Melanoma of the choroid. * **Vogt-Koyanagi-Harada (VKH) Syndrome:** A multisystem autoimmune disease and a frequent "favorite" exam topic for causing bilateral exudative RD. * **Shifting Fluid Sign:** The hallmark clinical sign of exudative RD, where subretinal fluid moves to the most dependent part of the retina with changes in head position.

Question 189: Sudden loss of vision in a patient with diabetic retinopathy is most commonly due to what condition?

A. Cataract
B. Glaucoma
C. Vitreous hemorrhage (Correct Answer)
D. Papilledema

Explanation: **Explanation:** In the context of Diabetic Retinopathy (DR), the keyword **"sudden"** is the clinical differentiator. **1. Why Vitreous Hemorrhage is correct:** Proliferative Diabetic Retinopathy (PDR) is characterized by **neovascularization** (growth of fragile new blood vessels) due to retinal ischemia. These vessels lack structural integrity and easily rupture, bleeding into the vitreous cavity. This results in a sudden, painless loss of vision or the appearance of "floaters" and "cobwebs." It is the most common cause of acute vision loss in diabetic patients. **2. Why the other options are incorrect:** * **Cataract:** While diabetics are prone to "Snowflake cataracts" or early-onset senile cataracts, the vision loss is **gradual and progressive**, not sudden. * **Glaucoma:** Neovascular glaucoma can occur in PDR, but it usually presents with a painful red eye and gradual visual field loss rather than sudden total loss of vision. * **Papilledema:** This refers to optic disc swelling due to increased intracranial pressure. While it can occur in malignant hypertension (sometimes seen in diabetic renal patients), it is not a primary complication of diabetic retinopathy itself. **Clinical Pearls for NEET-PG:** * **Most common cause of gradual vision loss in DR:** Diabetic Macular Edema (DME). * **Most common cause of sudden vision loss in DR:** Vitreous Hemorrhage. * **Other causes of sudden vision loss in DR:** Tractional Retinal Detachment (TRD) and Central Retinal Vein Occlusion (CRVO). * **Investigation of choice for Vitreous Hemorrhage (when the fundus is not visible):** B-Scan Ultrasonography (to rule out underlying retinal detachment).

Question 190: All of the following are true for acquired cytomegalic inclusion disease except?

A. It occurs only in immunosuppressed patients
B. The infection is acquired from the infected cervix of the mother during sexual intercourse (Correct Answer)
C. Typical lesion is acute necrotizing retinitis
D. Exudative retinal detachment may occur

Explanation: **Explanation:** Cytomegalovirus (CMV) is a member of the Herpesvirus family. In the context of ophthalmology, it is the most common opportunistic ocular infection in patients with AIDS (typically when CD4 counts fall below 50 cells/µL). **Why Option B is the Correct Answer (The False Statement):** The question asks about **acquired** cytomegalic inclusion disease. While CMV can be transmitted sexually or via birth canal contact, the statement "acquired from the infected cervix of the mother during sexual intercourse" is a factual mismatch. Transmission from the mother's cervix to a neonate during birth results in **neonatal/congenital** infection, not the "acquired" form seen in adults. Acquired CMV in adults is typically transmitted through respiratory droplets, blood transfusions, organ transplants, or sexual contact (semen/vaginal secretions), but the specific phrasing in Option B describes a vertical/perinatal transmission route. **Analysis of Other Options:** * **Option A:** Acquired CMV retinitis is almost exclusively seen in **immunosuppressed patients** (AIDS, post-transplant, or those on systemic chemotherapy). It rarely affects immunocompetent hosts. * **Option C:** The hallmark of CMV retinitis is **acute necrotizing retinitis**. It presents as "pizza-pie" or "crushed tomato and cheese" fundus, characterized by areas of white retinal necrosis with associated hemorrhage. * **Option D:** As the virus causes full-thickness retinal necrosis, it can lead to both **exudative retinal detachment** (due to inflammation) and, more commonly, rhegmatogenous retinal detachment (due to multiple necrotic retinal breaks). **Clinical Pearls for NEET-PG:** * **Classic Appearance:** "Pizza-pie fundus" or "Bush-fire" appearance. * **Drug of Choice:** Intravenous **Ganciclovir** (or Valganciclovir). Foscarnet and Cidofovir are alternatives. * **CD4 Threshold:** High risk when **CD4 < 50 cells/mm³**. * **Histology:** "Owl’s eye" intranuclear inclusion bodies.

Practice by Chapter

Retinal Anatomy and Physiology

Practice Questions

Age-Related Macular Degeneration

Practice Questions

Diabetic Retinopathy

Practice Questions

Retinal Vascular Diseases

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Retinal Detachment

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Hereditary Retinal Dystrophies

Practice Questions

Inflammatory Retinal Diseases

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Retinal Tumors

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Retinopathy of Prematurity

Practice Questions

Retinal Imaging Techniques

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Intravitreal Pharmacotherapy

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Vitreoretinal Surgery

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