Electronic Low Vision Devices — MCQs
A 50-year-old patient has difficulty reading close objects. Likely diagnosis?
Vision 2020 "The right to sight" includes all except-
What is the true statement about retinoscopy with a plane mirror?
Treatment of choice for clinically significant macular edema in a diabetic is?
Which finding excludes BIRADS 3 categorization?
Under Vision 2020, to check visual acuity, a teacher will refer a school child to
Vision 2020 includes all of the following, except?
All are true about phakic IOLs EXCEPT:
In the electron transport chain, electrons travel from which energy state to which energy state?
The K nail can be used for all of the following types of fractures except -
Electronic Low Vision Devices Indian Medical PG Practice Questions and MCQs
Question 1: A 50-year-old patient has difficulty reading close objects. Likely diagnosis?
- A. Hypermetropia
- B. Astigmatism
- C. Myopia
- D. Presbyopia (Correct Answer)
Explanation: ***Presbyopia*** - This condition is characterized by the **loss of elasticity** in the lens of the eye, which occurs naturally with age, making it difficult to focus on **near objects**. - Its typical presentation, as seen in this 50-year-old patient, is **difficulty reading close objects** or performing other tasks requiring near vision. *Hypermetropia* - Often causes **farsightedness**, meaning distant objects are seen clearly, but near objects appear blurry due to the eye attempting to constantly accommodate. - While it can make near vision difficult, it is not primarily an age-related loss of accommodation and can affect individuals of various ages. *Astigmatism* - Results from an **irregular curvature of the cornea or lens**, causing blurred or distorted vision at all distances, rather than specifically difficulty with close objects. - This condition makes it difficult for the eye to focus light uniformly on the retina, leading to multiple focal points or streaks. *Myopia* - This is commonly known as **nearsightedness**, where distant objects appear blurry while near objects are seen clearly. - It occurs when the eyeball is too long or the cornea is too steeply curved, causing light to focus in front of the retina.
Question 2: Vision 2020 "The right to sight" includes all except-
- A. Measles induced blindness (Correct Answer)
- B. Onchocerciasis
- C. Trachoma
- D. Cataract
Explanation: ***Measles induced blindness*** - Vision 2020 primarily targets conditions that are either preventable or treatable with *cost-effective interventions* and contribute significantly to *avoidable blindness*. - While measles can cause blindness, the specific program focuses on a defined list of priority diseases for intervention, and measles-related blindness is generally addressed through broader public health initiatives (vaccination) rather than direct "right to sight" surgical or direct medical interventions for established blindness. *Onchocerciasis* - **Onchocerciasis** (river blindness) is a major focus of Vision 2020 due to its profound impact on sight, particularly in endemic areas. - It is a **preventable** and **treatable** cause of blindness through mass drug administration. *Trachoma* - **Trachoma** is recognized as one of the leading infectious causes of blindness globally and is explicitly targeted by Vision 2020 through the **SAFE strategy** (Surgery, Antibiotics, Facial cleanliness, Environmental improvement). - It is a highly **preventable** and **treatable** condition, fitting the program's objectives. *Cataract* - **Cataract** is the leading cause of blindness worldwide and is highly **treatable** through a relatively simple and cost-effective surgical procedure. - Providing cataract surgery is a cornerstone of the Vision 2020 initiative to restore sight.
Question 3: What is the true statement about retinoscopy with a plane mirror?
- A. In myopia, the red glow moves in the same direction.
- B. Retinoscopy is done at 1 meter away from the patient. (Correct Answer)
- C. In hypermetropia, the red glow moves in the opposite direction.
- D. In emmetropia, the red glow moves in the opposite direction.
Explanation: ***Retinoscopy is done at 1 meter away from the patient.*** - Retinoscopy is typically performed at a **working distance** of 67 cm or 1 meter, to allow for the examiner to observe the reflex and to incorporate a working distance lens in the final calculation. - A 1-meter working distance requires a **-1.00 D sphere correction** to be subtracted from the spherical power found in retinoscopy to find the patient's actual refractive error. *In myopia, the red glow moves in the same direction.* - In **myopia**, using a plane mirror, the retinal reflex appears to move in the **opposite direction** to the movement of the retinoscope. - This "against" movement needs **concave (minus)** lenses to neutralize it. *In hypermetropia, the red glow moves in the opposite direction.* - In **hypermetropia**, using a plane mirror, the retinal reflex appears to move in the **same direction** as the movement of the retinoscope. - This "with" movement needs **convex (plus)** lenses to neutralize it. *In emmetropia, the red glow moves in the opposite direction.* - In **emmetropia**, the light from the retinoscope is focused on the retina, and the reflex also moves in the **same direction** as the retinoscope (when using a plane mirror) until neutralization. - An **emmetropic eye** theoretically requires no corrective lens, other than the working distance correction, to neutralize the reflex.
Question 4: Treatment of choice for clinically significant macular edema in a diabetic is?
- A. Intravitreal anti-VEGF injections (Correct Answer)
- B. Control of Diabetes
- C. Panretinal Photocoagulation
- D. Focal Photocoagulation
Explanation: ***Intravitreal anti-VEGF injections*** - **Anti-VEGF agents** (e.g., ranibizumab, aflibercept) are the first-line treatment for **clinically significant diabetic macular edema (DME)** as they effectively reduce vascular leakage and improve vision. - They target **vascular endothelial growth factor (VEGF)**, a key mediator of increased vascular permeability and neovascularization in diabetic retinopathy. *Control of Diabetes* - While essential for preventing the **progression of diabetic retinopathy** and overall health, it is not the primary direct treatment for *existing* clinically significant macular edema. - Good glycemic control can reduce the *risk* of developing DME but does not acutely resolve established edema. *Panretinal Photocoagulation* - **Panretinal photocoagulation (PRP)** is primarily used for **proliferative diabetic retinopathy (PDR)** to ablate ischemic retina and reduce neovascularization. - It is not the treatment of choice for macular edema, as it can sometimes worsen macular function and visual acuity due to treatment-induced damage. *Focal Photocoagulation* - **Focal laser photocoagulation** was historically used for DME, targeting discrete leaking microaneurysms. - While effective for specific focal leakage, it has largely been superseded by **anti-VEGF injections** due to their superior efficacy in diffuse edema and better visual outcomes, especially when edema involves the fovea.
Question 5: Which finding excludes BIRADS 3 categorization?
- A. Normal lymph node
- B. Simple cyst
- C. Architectural distortion (Correct Answer)
- D. Focal asymmetry
Explanation: ***Architectural distortion*** - **Architectural distortion** refers to a disruption of the normal breast parenchymal architecture in the absence of a discrete mass, often indicating an underlying malignancy. - This finding is suspicious enough to warrant a recommendation of **biopsy (BI-RADS 4 or 5)**, thus **excluding BI-RADS 3**, which implies a probably benign finding with a low likelihood of malignancy (<2%). - Architectural distortion has a high association with malignancy and cannot be categorized as BI-RADS 3. *Normal lymph node* - A **normal lymph node** within the breast or axilla is a common and benign finding, characterized by an oval shape, fatty hilum, and thin cortex. - Its presence does not increase the suspicion of malignancy and is classified as **BI-RADS 1 or 2** (definitely benign). - This does NOT exclude BI-RADS 3; it is simply a more benign finding. *Simple cyst* - A **simple cyst** is a very common and benign fluid-filled sac, readily identifiable by clear sonographic criteria (anechoic, thin smooth walls, posterior acoustic enhancement). - It is classified as **BI-RADS 2** (benign finding), meaning it is definitely not malignant. - This does NOT exclude BI-RADS 3; it is simply a more benign finding that does not require follow-up. *Focal asymmetry* - **Focal asymmetry** refers to an area of fibroglandular tissue that is visible on only one mammographic projection or is less conspicuous than a mass. - If it has **no associated suspicious features**, it can be appropriately categorized as **BI-RADS 3**, requiring short interval follow-up. - This does NOT exclude BI-RADS 3 categorization.
Question 6: Under Vision 2020, to check visual acuity, a teacher will refer a school child to
- A. Centre for excellence
- B. Vision centre (Correct Answer)
- C. Training centre
- D. Service centre
Explanation: ***Vision centre*** - Under Vision 2020 initiatives, a **Vision Centre** serves as the primary point of contact for basic ophthalmic services, including **visual acuity screening** and referral. - These centers are designed to be accessible in local communities, allowing teachers and other local caregivers to refer school children for initial checks and appropriate management. *Centre for excellence* - A **Centre for Excellence** typically refers to a highly specialized institution with advanced diagnostic and treatment capabilities, research facilities, and complex surgical procedures, which is **beyond the scope** of basic visual acuity checking and initial referral. - Such centers handle more **complex or rare conditions** and are not the first point of contact for routine school-based screening. *Training centre* - A **Training Centre** is primarily dedicated to educating and skilling healthcare professionals, not to providing direct patient care or screening services to the general public. - While essential for developing skilled personnel, it is **not the appropriate facility** for a teacher to refer a child for a visual acuity check. *Service centre* - The term **Service Centre** is too broad and can refer to various types of facilities that provide any kind of service, but it does not specifically denote a healthcare facility for ophthalmic care under the Vision 2020 program. - It lacks the **specific medical context** and structured role established for vision screening.
Question 7: Vision 2020 includes all of the following, except?
- A. Diabetic Retinopathy
- B. Refractive Errors
- C. Cataract
- D. Age-related Macular Degeneration (Correct Answer)
Explanation: ***Age-related Macular Degeneration*** - **Age-related macular degeneration (AMD)** was originally **not included** as one of the priority diseases in the initial "Vision 2020: The Right to Sight" initiative. - The initial focus was on conditions with a high burden of preventable blindness that were readily treatable or preventable with widely available interventions. *Diabetic Retinopathy* - **Diabetic retinopathy** is a major cause of preventable blindness and was specifically targeted by Vision 2020 efforts due to its increasing prevalence globally. - Early detection and treatment through retinal screening are crucial components of preventing vision loss from diabetic retinopathy. *Refractive Errors* - **Uncorrected refractive errors** are a leading cause of visual impairment worldwide, and their correction with spectacles is a simple and cost-effective intervention. - Vision 2020 emphasized accessible and affordable refractive error services to improve vision in affected populations. *Cataract* - **Cataract** is the leading cause of blindness globally, and its surgical removal is a highly effective and widely accessible treatment. - Vision 2020 prioritized increasing the number of cataract surgeries to restore sight to millions.
Question 8: All are true about phakic IOLs EXCEPT:
- A. Better quality vision (Correct Answer)
- B. Suitable for thin cornea
- C. Higher endothelial loss
- D. Reversible procedure
Explanation: ***Better quality vision*** - This is the EXCEPT answer because "better quality vision" is a **comparative claim** rather than an absolute characteristic of phakic IOLs - While phakic IOLs can provide excellent optical quality, claiming they provide "better" vision is **not universally established** compared to modern LASIK or SMILE techniques - The other options describe **objective, established characteristics** specific to phakic IOLs (suitability for thin corneas, endothelial loss risk, reversibility) - Vision quality depends on multiple factors including proper sizing, centration, and absence of complications like cataract formation or glaucoma *Suitable for thin cornea* - **TRUE** - Phakic IOLs are implantable lenses placed without removing the natural lens, making them ideal for patients with **thin corneas** who are not candidates for LASIK or PRK - They do not alter corneal tissue, avoiding issues related to corneal ectasia or instability - This is a **key indication** for phakic IOL surgery *Higher endothelial loss* - **TRUE** - Phakic IOLs, especially anterior chamber types, are associated with **chronic endothelial cell loss** due to proximity to the corneal endothelium - Posterior chamber ICLs (Implantable Collamer Lens) also cause endothelial loss, though typically less than anterior chamber IOLs - Regular **endothelial cell count monitoring** is mandatory post-implantation - This is a well-documented **complication and concern** with phakic IOLs *Reversible procedure* - **TRUE** - Phakic IOL implantation is **reversible** as the lens can be explanted if complications arise or refractive needs change - This is a **major advantage** over irreversible corneal ablative procedures like LASIK or PRK - The natural crystalline lens remains intact, preserving accommodation in young patients
Question 9: In the electron transport chain, electrons travel from which energy state to which energy state?
- A. From high energy to low energy state (Correct Answer)
- B. Two way
- C. One way irrespective of the potential
- D. From low to high redox potential
Explanation: ***From high to low potential (high energy to low energy)*** - In the electron transport chain, electrons move from carriers with **lower (more negative) reduction potentials** (higher energy state) to carriers with **higher (more positive) reduction potentials** (lower energy state). - This "downhill" energy movement releases energy that is used to pump protons and synthesize ATP. - **Key concept**: Low redox potential = High energy; High redox potential = Low energy. - Electrons flow spontaneously from **more negative to more positive redox potential**, which represents movement from **high to low energy state**. *One way irrespective of the potential* - Electron flow is indeed **unidirectional** in the electron transport chain, but it is NOT independent of potential. - The flow is entirely **dependent on the redox potential gradient** between successive carriers. - Electrons move specifically due to the thermodynamically favorable reduction potential differences. *Two way* - The electron transport chain is a **strictly unidirectional process** under normal physiological conditions. - Electrons flow in one direction: from NADH/FADH₂ through the complexes to molecular oxygen. - There is **no backward or reversible flow** of electrons along the chain. *From low to high redox potential* - While electrons do move from **low (more negative) to high (more positive) redox potential** in terms of voltage values, this is from **high energy to low energy** state. - This option is technically correct regarding redox potential values but may confuse the energy relationship. - The question asks about energy state movement, and thermodynamically, electrons move "downhill" from high to low energy.
Question 10: The K nail can be used for all of the following types of fractures except -
- A. Isthmic femur shaft fractures
- B. Intertrochanteric fractures (Correct Answer)
- C. Low subtrochanteric fractures
- D. Distal femur shaft fractures
Explanation: ***Intertrochanteric fractures*** - The K nail (specifically, the Kuntscher nail) is a **straight intramedullary nail** primarily designed for diaphyseal fractures. - It is **not suitable for intertrochanteric fractures** as these are metaphyseal and involve the proximal femur, requiring implants that offer greater stability in this region, such as cephalomedullary nails or plates. *Isthmic femur shaft fractures* - The **Kuntscher nail** was originally developed for and is well-suited for **isthmic femur shaft fractures** due to the narrow canal providing good cortical fixation. - Its design as a straight, broad nail fits snugly in the isthmus, providing excellent stability. *Low subtrochanteric fractures* - While more challenging, **K nails can be used for low subtrochanteric fractures**, especially if the fracture extends into the diaphyseal region. - However, newer implants like **cephalomedullary nails** are often preferred due to better biomechanical stability in this region. *Distal femur shaft fractures* - **K nails can be employed for distal femoral shaft fractures** if the fracture pattern allows for adequate fixation distal to the isthmus without compromising knee joint function. - The nail must be long enough to achieve stability, and the lack of proper locking mechanisms in traditional K nails may be a limiting factor compared to locked intramedullary nails.
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