Eye Banking and Corneal Transplantation — MCQs
All of the following conditions are immediate priorities in the WHO's "Vision -2020: The Right to sight" except:
Acute corneal hydrops is seen in:
What is the primary mechanism responsible for skin graft survival within the first 48 hours after transplantation?
Among the following organisms, which is the most common cause of postoperative endophthalmitis following corneal transplantation?
Which of the following procedures is not typically covered by the National Programme for Control of Blindness (NPCB) for reimbursement of surgery done by a non-governmental organization (NGO) eye hospital?
What is the most likely complication of the condition shown in the image below?
All of the following are true about Keratoconus, except:
The golden period of eye donation is
A patient complained of gradual diminution of vision. On examination, the patient had dry eyes and a rough corneal surface. What deficiency is most likely causing these manifestations?
In a patient with acute anterior uveitis presenting with raised intraocular pressure, the PRIMARY treatment should be:
Eye Banking and Corneal Transplantation Indian Medical PG Practice Questions and MCQs
Question 1: All of the following conditions are immediate priorities in the WHO's "Vision -2020: The Right to sight" except:
- A. Cataract
- B. Epidemic conjunctivitis (Correct Answer)
- C. Onchocerciasis
- D. Trachoma
Explanation: ***Epidemic conjunctivitis*** - While **epidemic conjunctivitis** can cause significant discomfort and temporary vision impairment, it is generally **self-limiting** and rarely leads to permanent blindness. - It was not identified as one of the top five global causes of avoidable blindness targeted by the Vision 2020 initiative. *Cataract* - **Cataract** is the **leading cause of blindness** globally, accounting for approximately half of all cases. - It is a highly treatable condition through surgery, making it a critical priority for Vision 2020. *Onchocerciasis* - Also known as **river blindness**, onchocerciasis is a parasitic disease that causes severe visual impairment and blindness. - It is a significant public health problem in several regions, particularly in Africa, and was a key focus of Vision 2020 due to its widespread impact and the availability of preventive chemotherapy. *Trachoma* - **Trachoma** is the **leading infectious cause of blindness** worldwide, caused by *Chlamydia trachomatis*. - Given its preventable and treatable nature, and its prevalence in many impoverished areas, it was designated as one of the priority diseases under Vision 2020.
Question 2: Acute corneal hydrops is seen in:
- A. Keratoconus (Correct Answer)
- B. Corneal dystrophy
- C. Anterior staphyloma
- D. Interstitial keratitis
Explanation: ***Keratoconus*** - **Acute corneal hydrops** is a classic complication of advanced **keratoconus**, occurring when a break in **Descemet's membrane** allows aqueous humor to enter the corneal stroma. - This leads to sudden onset of **corneal edema**, pain, and significant vision loss, often presenting with a milky white cornea due to stromal clouding. *Corneal dystrophy* - **Corneal dystrophies** are a group of genetic disorders that affect the clarity and structure of the cornea, typically causing progressive vision loss or recurrent epithelial erosions. - While some dystrophies can lead to corneal edema, **acute hydrops** specifically due to a Descemet's membrane rupture is not a characteristic feature. *Anterior staphyloma* - An **anterior staphyloma** is a bulging scar of the cornea and sclera, usually resulting from severe thinning or perforation, often associated with elevated intraocular pressure. - It is a structural deformation involving the entire globe's anterior segment, distinct from the sudden stromal edema of **corneal hydrops** caused by Descemet's rupture. *Interstitial keratitis* - **Interstitial keratitis** is characterized by non-ulcerative inflammation of the corneal stroma without primary involvement of the epithelium or endothelium, often associated with systemic infections like syphilis or Lyme disease. - It typically results in stromal opacification and vascularization ("salmon patch") but does not involve the acute rupture of Descemet's membrane seen in **hydrops**.
Question 3: What is the primary mechanism responsible for skin graft survival within the first 48 hours after transplantation?
- A. Amount of saline in graft
- B. Plasma imbibition (Correct Answer)
- C. New vessels growing from the donor tissue
- D. Connection between donor and recipient capillaries
Explanation: ***Correct: Plasma imbibition*** - **Plasma imbibition** is the initial process where the transplanted graft absorbs nutrients and oxygen from the recipient bed through diffusion. - This fluid uptake is crucial for the survival of the graft cells before revascularization occurs, typically within the first **24-48 hours**. - The graft acts like a sponge, absorbing serum and plasma from the vascular bed through capillary action and osmosis. *Incorrect: Amount of saline in graft* - While sterile saline is often used to keep donor tissue moist during harvesting and transport, its presence in the graft itself is not the primary mechanism for survival post-transplantation. - Excessive saline could even lead to **edema** and compromise graft take if not properly drained or if it prevents good contact with the recipient bed. *Incorrect: New vessels growing from the donor tissue* - Grafts themselves do not spontaneously grow new vessels; new blood vessels are formed by **angiogenesis** from the recipient bed into the graft over several days. - This process, called **inosculation** and subsequent neovascularization, provides long-term blood supply but is not the primary mechanism of survival within the *first 48 hours*. *Incorrect: Connection between donor and recipient capillaries* - The direct connection of donor and recipient capillaries (inosculation) is a later stage of graft vascularization, typically beginning after **3-5 days**, not within the first 48 hours. - Within the initial 48 hours, the graft relies on diffusion because a complete vascular connection has not yet been established.
Question 4: Among the following organisms, which is the most common cause of postoperative endophthalmitis following corneal transplantation?
- A. Streptococcus
- B. Pseudomonas
- C. Propionibacterium acnes
- D. Staph epidermidis (Correct Answer)
Explanation: ***Staph epidermidis*** - **Coagulase-negative Staphylococcus** (CoNS), including *S. epidermidis*, is the most frequent cause of **postoperative endophthalmitis** after both cataract surgery and corneal transplantation due to its presence on the normal ocular flora. - These organisms can form **biofilms on intraocular lenses** or transplanted corneal tissue, making eradication difficult. *Streptococcus* - While *Streptococcus* species can cause endophthalmitis, they are associated with a **more virulent and rapid onset** of severe inflammation and are not the most common causative agents of postoperative endophthalmitis compared to *S. epidermidis*. - They tend to cause more aggressive infections with often **poorer visual outcomes**. *Propionibacterium acnes* - *Propionibacterium acnes* can cause a **late-onset, indolent form of endophthalmitis**, typically months or even years after surgery. - While it is a recognized cause, it is far **less common** than *Staphylococcus epidermidis* in immediate or early postoperative cases. *Pseudomonas* - **Pseudomonas aeruginosa** is an aggressive and rapid-onset pathogen often associated with **severe keratitis** or **post-traumatic endophthalmitis**. - Although it can cause postoperative endophthalmitis, it is **much less common** than coagulase-negative staphylococci due to its infrequency on normal conjunctival flora.
Question 5: Which of the following procedures is not typically covered by the National Programme for Control of Blindness (NPCB) for reimbursement of surgery done by a non-governmental organization (NGO) eye hospital?
- A. Cataract surgery
- B. Pan retinal photocoagulation for diabetic retinopathy
- C. Syringing and probing of the nasolacrimal duct (Correct Answer)
- D. Trabeculectomy surgery
Explanation: ***Syringing and probing of the nasolacrimal duct*** - While important for lacrimal drainage issues, procedures like **syringing and probing** are generally considered minor and less vision-restoring compared to the major surgeries targeted by the **NPCB**. - The **NPCB** focuses on interventions for leading causes of blindness, primarily **cataract** and other significant vision-threatening conditions, which this procedure typically isn't. *Cataract surgery* - **Cataract surgery** is a cornerstone of the **NPCB's** efforts, as cataracts are the leading cause of reversible blindness. - Reimbursement for **cataract surgery** is a primary objective to improve access and reduce the burden of blindness. *Pan retinal photocoagulation for diabetic retinopathy* - **Diabetic retinopathy** is a major cause of preventable blindness, and **pan retinal photocoagulation (PRP)** is a key intervention to preserve vision. - The **NPCB** includes procedures for **diabetic retinopathy** management due to its significant public health impact. *Trabeculectomy surgery* - **Trabeculectomy** is a surgical procedure for **glaucoma**, which is another significant cause of irreversible blindness. - The **NPCB** includes interventions for **glaucoma** given its severe vision-threatening nature and the need for surgical management in many cases.
Question 6: What is the most likely complication of the condition shown in the image below?
- A. Exposure Keratitis (Correct Answer)
- B. Difficulty in eye movement
- C. Cataract
- D. Glaucoma
Explanation: ***Exposure Keratitis*** - The image shows **proptosis** (exophthalmos) of the right eye, where the eyeball protrudes forward. This condition often leads to incomplete eyelid closure (lagophthalmos). - **Exposure keratitis** occurs when the cornea is inadequately covered by the eyelids, leading to drying and damage due to constant exposure to air and environmental factors. *Difficulty in eye movement* - While **proptosis** can sometimes be associated with restricted eye movements (e.g., in severe Graves' ophthalmopathy due to muscle swelling), it is not the **most likely direct complication** of the exposure itself. - The image primarily depicts the physical displacement of the globe, which predisposes to corneal issues, not necessarily oculomotor dysfunction as the primary complication. *Cataract* - **Cataracts** are opacities of the lens and are typically associated with aging, trauma, or certain systemic conditions (e.g., diabetes, steroid use). - They are not a direct or common complication of **proptosis** or the resulting **exposure of the ocular surface**. *Glaucoma* - **Glaucoma** is a group of conditions characterized by damage to the optic nerve, often due to elevated intraocular pressure. - While severe **proptosis** leading to orbital congestion can theoretically increase intraocular pressure, it is not the most direct or prevalent complication compared to **exposure keratitis**, which is a direct consequence of inadequate globe protection.
Question 7: All of the following are true about Keratoconus, except:
- A. Astigmatism
- B. Increased curvature of cornea and Astigmatism
- C. Thick cornea (Correct Answer)
- D. Fleischer's ring
Explanation: ***Thick cornea*** - Keratoconus is characterized by **progressive corneal thinning** and weakening, not thickening. - This corneal thinning leads to a conical protrusion, causing significant visual distortion and irregular astigmatism. *Increased curvature of cornea and Astigmatism* - Keratoconus features **increased corneal curvature** with progressive steepening into a cone-shaped configuration. - This results in **irregular astigmatism**, a hallmark feature causing distorted vision at all distances. *Astigmatism* - **Irregular astigmatism** is a cardinal feature of keratoconus due to the asymmetric corneal shape. - Causes blurred and distorted vision that is difficult to correct with spectacles alone. *Fleischer's ring* - **Fleischer's ring** is an iron deposit ring at the base of the cone in keratoconus, visible on slit-lamp examination. - It represents hemosiderin deposition in the basal epithelial cells and is a characteristic clinical sign of keratoconus.
Question 8: The golden period of eye donation is
- A. 24 hours
- B. 12 hours
- C. 18 hours
- D. 6 hours (Correct Answer)
Explanation: ***6 hours*** - The **golden period** for eye donation, specifically for the removal of the **cornea**, is ideally within **6 hours** of death. - This timeframe is critical to ensure the **viability and quality** of the corneal tissue for successful transplantation, as cellular degradation begins rapidly after cessation of circulation. *24 hours* - While some tissues can be recovered up to 24 hours post-mortem, the **cornea's viability** for transplantation significantly decreases after the initial 6-hour window. - Beyond 6 hours, the risk of **cellular damage** and reduced graft success rate increases considerably. *12 hours* - A 12-hour window is generally considered too long for optimal **corneal tissue viability**. - While tissue might still be recoverable, the **quality and success rate** of the transplant are significantly lower compared to donation within 6 hours. *18 hours* - An 18-hour period is far beyond the recommended timeframe for **corneal donation**. - At this point, the **cellular integrity** of the cornea is highly compromised, making it unsuitable for transplantation.
Question 9: A patient complained of gradual diminution of vision. On examination, the patient had dry eyes and a rough corneal surface. What deficiency is most likely causing these manifestations?
- A. Iron
- B. Protein
- C. Niacin
- D. Vitamin A (Correct Answer)
Explanation: ***Vitamin A*** - **Vitamin A deficiency** is a common cause of **xerophthalmia**, characterized by **dry eyes** (**xerosis conjunctivae**) and roughening of the **cornea** due to impaired mucin production [1]. In vitamin A deficiency, mucus-secreting cells are replaced by keratin-producing cells [2]. - Progression of ocular epithelial keratinization can lead to **Bitot's spots**, corneal ulceration, and ultimately **blindness** [1], [2]. *Iron* - **Iron deficiency** primarily leads to **iron-deficiency anemia**, causing fatigue, pallor, and weakness, but not directly ocular manifestations like dry eyes or rough cornea. - While severe anemia can cause some visual disturbances, it does not typically present with the specific **xerophthalmic** changes seen here. *Protein* - **Protein deficiency** can lead to conditions like **kwashiorkor** (edema, muscle wasting) or **marasmus** (severe wasting), which broadly impair health and immunity. - However, it does not directly cause the specific ocular signs of **dryness** and **corneal roughening** as a primary deficiency, though it can exacerbate other nutritional deficiencies. *Niacin* - **Niacin (Vitamin B3) deficiency** causes **pellagra**, characterized by the "3 Ds": **dermatitis**, **diarrhea**, and **dementia**. - Ocular symptoms are not a common or primary feature of niacin deficiency; it does not cause **dry eyes** or **corneal roughening**.
Question 10: In a patient with acute anterior uveitis presenting with raised intraocular pressure, the PRIMARY treatment should be:
- A. Topical steroids (Correct Answer)
- B. Topical beta-blockers
- C. Cycloplegics
- D. Miotics
Explanation: ***Topical steroids*** - **Topical corticosteroids** are the primary treatment for **anterior uveitis** to reduce inflammation, which is the underlying cause of both the uveitis and often the raised IOP. - While IOP is elevated, managing the inflammation with steroids is crucial, as the inflammation itself can lead to secondary **IOP elevation** due to trabecular meshwork dysfunction or synechiae formation. *Topical beta-blockers* - **Topical beta-blockers** are used to lower intraocular pressure, but they do not address the underlying **inflammation** in acute anterior uveitis. - Using them alone without treating the inflammation can lead to progression of the uveitis and further ocular damage. *Cycloplegics* - **Cycloplegics** (e.g., atropine, cyclopentolate) are important adjuncts in acute anterior uveitis to relieve pain from ciliary spasm and prevent posterior synechiae formation by dilating the pupil. - They do not, however, treat the **inflammation** directly or primarily address the elevated intraocular pressure. *Miotics* - **Miotics** (e.g., pilocarpine) **constrict the pupil**, which can worsen symptoms in acute anterior uveitis by increasing ciliary body spasm and potentially increasing the risk of posterior synechiae formation. - They are contraindicated in acute anterior uveitis as they exacerbate pain and inflammation, and do not treat the underlying cause.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free