Postoperative Visual Loss — MCQs
Which of the following is the most important factor in the prevention of endophthalmitis in cataract surgery?
Which of the following is the LEAST significant risk factor for postoperative pulmonary complications?
A patient presents with eye ache and difficulty in vision after watching a movie. What will be the first line of management?
Sudden loss of vision without pain - Which of the following is NOT a cause?
A 56 year old patient presents after 3 days of cataract surgery with a history of increasing pain and diminution of vision after an initial improvement. The most likely cause would be:
Which of the following is not a risk factor for postoperative pulmonary complication?
A 60-year-old man presents with sudden loss of vision in one eye. Fundoscopy shows a cherry-red spot. What is the most likely diagnosis?
All are ophthalmological emergencies except -
Which of the following is a key distinguishing feature of delirium compared to dementia?
A patient presents with sudden onset vision loss and is diagnosed with occlusion of the posterior cerebral artery. Which part of the brain is most affected?
Postoperative Visual Loss Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is the most important factor in the prevention of endophthalmitis in cataract surgery?
- A. Preoperative preparation with povidone iodine (Correct Answer)
- B. One week antibiotic therapy prior to surgery
- C. Trimming of eyelashes
- D. Use of intravitreal antibiotics
Explanation: **Preoperative preparation with povidone iodine** - **Povidone-iodine (5%)** applied to the ocular surface is the **single most evidence-based intervention** for preventing endophthalmitis in cataract surgery. - Multiple randomized controlled trials, including the **ESCRS study**, demonstrate up to **75% reduction** in endophthalmitis risk with proper povidone-iodine antisepsis. - It rapidly reduces bacterial load on the conjunctiva and periocular skin, which are the primary sources of intraocular contamination. *One week antibiotic therapy prior to surgery* - Prolonged preoperative antibiotic therapy is **not recommended** and lacks evidence for reducing endophthalmitis. - Can lead to **antibiotic resistance** and disruption of normal ocular flora without proven benefit. - Current guidelines do not support routine preoperative systemic or prolonged topical antibiotic prophylaxis. *Trimming of eyelashes* - **Not routinely recommended** and may actually increase bacterial counts temporarily due to microtrauma. - While maintaining a clean surgical field is important, eyelash trimming has **no proven benefit** in reducing endophthalmitis rates. - Good draping technique is more important than eyelash manipulation. *Use of intravitreal antibiotics* - **Intravitreal antibiotics** are injected into the vitreous cavity and are used for **treating established endophthalmitis**, not for prophylaxis. - For prophylaxis, **intracameral antibiotics** (e.g., cefuroxime or moxifloxacin injected into the anterior chamber at surgery end) are sometimes used, but they are adjunctive measures, not the primary preventive intervention. - **Povidone-iodine antisepsis** remains the most critical and cost-effective prophylactic measure with the strongest evidence base.
Question 2: Which of the following is the LEAST significant risk factor for postoperative pulmonary complications?
- A. Age >70
- B. Patient with 7 pack years of smoking
- C. Upper abdominal surgery
- D. BMI>30 (Correct Answer)
Explanation: ***BMI>30*** - While **obesity (BMI >30)** is associated with some surgical risks, it is generally considered a less significant independent risk factor for postoperative pulmonary complications compared to other factors like age, smoking, and surgical site. - The impact of obesity on pulmonary function is complex and varies depending on the type of surgery and presence of comorbid conditions like **sleep apnea**. *Age >70* - **Advanced age (>70)** is a significant independent risk factor due to decreased physiological reserve, reduced pulmonary function (e.g., decreased lung elasticity, impaired cough reflex), and increased prevalence of comorbidities. - Older patients are more susceptible to **atelectasis**, **pneumonia**, and **respiratory failure** postoperatively. *Patient with 7 pack years of smoking* - Even a relatively low cumulative smoking history of **7 pack-years** can impair mucociliary clearance, increase bronchial secretions, and cause airway inflammation, significantly increasing the risk of pulmonary complications. - Smoking compromises lung function and increases the risk of **bronchospasm** and infection. *Upper abdominal surgery* - **Upper abdominal surgery** is a significant risk factor because incisions close to the diaphragm interfere with diaphragmatic movement, leading to reduced lung volumes, impaired cough, and increased risk of **atelectasis** and **pneumonia**. - Pain from the incision further restricts deep breaths and coughing, contributing to pulmonary complications.
Question 3: A patient presents with eye ache and difficulty in vision after watching a movie. What will be the first line of management?
- A. Mannitol with Moxifloxacin
- B. Mannitol with Atropine
- C. Mannitol with lubricating eye drops
- D. Mannitol with Pilocarpine (Correct Answer)
Explanation: ***Mannitol with Pilocarpine*** - This combination is appropriate for **acute angle-closure glaucoma (AACG)**, which can be triggered by pupillary dilation (e.g., in a dark movie theater). **Mannitol** is an osmotic diuretic that rapidly reduces intraocular pressure. - **Pilocarpine** is a miotic agent that constricts the pupil, pulling the iris away from the trabecular meshwork and opening the drainage angle to facilitate aqueous humor outflow. *Mannitol with Moxifloxacin* - While mannitol helps with intraocular pressure, **Moxifloxacin is an antibiotic** used to treat bacterial infections. - There is no indication of an ocular infection in this scenario, so an antibiotic would not be the first-line treatment for sudden eye pain and vision difficulty after watching a movie. *Mannitol with Atropine* - Adding **Atropine, a cycloplegic agent**, would cause further pupillary dilation, which would worsen acute angle-closure glaucoma and increase intraocular pressure. - Atropine is contraindicated in AACG and would exacerbate the patient's condition. *Mannitol with lubricating eye drops* - While mannitol helps with intraocular pressure, **lubricating eye drops** are used for dry eyes or surface irritation, not for acute angle-closure glaucoma. - Lubricating drops do not address the underlying pathology of increased intraocular pressure due to angle closure.
Question 4: Sudden loss of vision without pain - Which of the following is NOT a cause?
- A. CRAO
- B. CSR
- C. Acute congestive glaucoma (Correct Answer)
- D. Vitreous Hemorrhage
Explanation: ***Acute congestive glaucoma*** - This condition is characterized by **sudden, severe eye pain** along with blurred vision, redness, and a fixed, mid-dilated pupil. - The pain arises from abrupt elevation of **intraocular pressure**, which differentiates it from painless vision loss. *CRAO* - **Central Retinal Artery Occlusion** (CRAO) typically presents as **sudden, profound, painless monocular vision loss**. - Funduscopic examination often reveals a **cherry-red spot** in the fovea with generalized retinal whitening. *CSR* - **Central Serous Retinopathy** (CSR) causes **sudden, painless blurred vision** or a scotoma, often described as a "watery" or "shimmering" effect. - It involves leakage of fluid under the retina, typically in the macula. *Vitreous Hemorrhage* - Presents as **sudden, painless loss of vision** or a shower of floaters, often described as cobwebs or clouds. - It results from bleeding into the **vitreous cavity**, which can obscure the retina.
Question 5: A 56 year old patient presents after 3 days of cataract surgery with a history of increasing pain and diminution of vision after an initial improvement. The most likely cause would be:
- A. Endophthalmitis (Correct Answer)
- B. Central retinal vein occlusion
- C. Posterior capsular opacification (PCO)
- D. Retinal detachment
Explanation: ***Endophthalmitis*** - **Endophthalmitis** is a severe inflammation of the intraocular fluids (vitreous and aqueous humor), most commonly caused by infection following cataract surgery. - The presentation of **increasing pain** and **diminution of vision** a few days after initial improvement is a classic sign of acute post-operative endophthalmitis. *Central retinal vein occlusion* - **Central retinal vein occlusion (CRVO)** typically causes sudden, painless vision loss. - It is not commonly associated with **increasing pain** or a temporal relationship to recent cataract surgery in this manner. *Posterior capsular opacification (PCO)* - **Posterior capsular opacification (PCO)** develops weeks or months after cataract surgery, not within a few days. - It presents as gradual, painless blurring of vision without significant pain. *Retinal detachment* - **Retinal detachment** typically presents with sudden vision loss, flashes of light (photopsia), and floaters. - While it can occur after cataract surgery, it is less likely to present with **increasing pain** as the primary symptom described.
Question 6: Which of the following is not a risk factor for postoperative pulmonary complication?
- A. Normal BMI (18.5-24.9) (Correct Answer)
- B. Age 25-40 years
- C. Upper abdominal surgery
- D. Patient with 20 pack years of smoking
Explanation: ***Patient with 20 pack years of smoking*** - This is a significant risk factor for postoperative pulmonary complications, as **chronic smoking** impairs lung function and mucociliary clearance. - Patients with a history of **20 pack-years or more** are at a substantially increased risk of developing atelectasis, pneumonia, and respiratory failure after surgery. *Normal BMI (18.5-24.9)* - A **normal BMI** is not considered a risk factor for postoperative pulmonary complications; instead, it is associated with a lower risk compared to obesity or underweight states. - Patients with a normal BMI generally have **better respiratory mechanics** and lung volumes, reducing their susceptibility to pulmonary issues. *Age 25-40 years* - This age range is generally associated with a **lower risk** of postoperative pulmonary complications compared to very young or elderly patients. - Younger adults typically have **better physiological reserves** and healthier lungs, contributing to a reduced incidence of respiratory problems post-surgery. *Upper abdominal surgery* - **Upper abdominal surgery** is a significant risk factor for postoperative pulmonary complications due to its proximity to the diaphragm. - It often leads to **diaphragmatic dysfunction**, reduced lung volumes, and increased pain, all of which predispose patients to atelectasis and pneumonia.
Question 7: A 60-year-old man presents with sudden loss of vision in one eye. Fundoscopy shows a cherry-red spot. What is the most likely diagnosis?
- A. Macular degeneration
- B. Retinal detachment
- C. Optic neuritis
- D. Central retinal artery occlusion (Correct Answer)
Explanation: ***Central retinal artery occlusion*** - **Sudden, painless loss of vision** in one eye, combined with a **cherry-red spot** on fundoscopy, is the classic presentation of a central retinal artery occlusion (CRAO). - The cherry-red spot is caused by retinal edema making the fovea, which is avascular, appear redder against the pale ischemic retina. *Macular degeneration* - This condition typically causes a **gradual loss of central vision** and metamorphopsia, not sudden and complete vision loss. - Fundoscopic findings include **drusen** and pigmentary changes, not a cherry-red spot. *Retinal detachment* - Characterized by symptoms like **flashing lights**, floaters, and a **curtain-like visual field defect**. - Fundoscopy reveals the detached retina, which appears elevated and often wrinkled, not a cherry-red spot. *Optic neuritis* - Presents with **painful loss of vision** and often **color desaturation**. - Fundoscopy may show a swollen optic disc (papillitis) in some cases, but a cherry-red spot is not a feature.
Question 8: All are ophthalmological emergencies except -
- A. Endophthalmitis
- B. CRVO (Correct Answer)
- C. Acute congestive glaucoma
- D. CRAO
Explanation: ***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.
Question 9: Which of the following is a key distinguishing feature of delirium compared to dementia?
- A. Visual hallucinations
- B. Gradual memory loss
- C. Acute onset of confusion and disorientation (Correct Answer)
- D. Difficulty in recognizing familiar people
Explanation: ***Acute onset of confusion and disorientation*** - Delirium is characterized by a **sudden (acute) onset** of mental status changes, including fluctuations in attention, awareness, and cognition, often presenting as **confusion and disorientation**. - Its symptoms typically develop over hours to days, contrasting sharply with the more chronic and insidious progression of dementia. *Gradual memory loss* - **Gradual memory loss** is a hallmark symptom of **dementia**, a neurocognitive disorder characterized by a progressive decline in cognitive function over months to years. - While memory impairment can occur in delirium, its onset is rapid and associated with a fluctuating course, not a steady decline. *Visual hallucinations* - While visual hallucinations can occur in **delirium**, they are not its most unique distinguishing feature from **dementia**, as they can also be prominent in certain types of dementia, such as **Lewy body dementia**. - The acute, fluctuating nature of **cognitive impairment** is a more defining characteristic of delirium. *Difficulty in recognizing familiar people* - **Prosopagnosia** or the inability to recognize familiar faces, is a symptom that can manifest in advanced stages of **dementia** due to widespread brain atrophy. - While patients with delirium might appear confused or disoriented to the point of not recognizing familiar individuals, this is usually part of a global, acute cognitive impairment and not a primary, isolated deficit.
Question 10: A patient presents with sudden onset vision loss and is diagnosed with occlusion of the posterior cerebral artery. Which part of the brain is most affected?
- A. Frontal lobe
- B. Parietal lobe
- C. Temporal lobe
- D. Occipital lobe (Correct Answer)
Explanation: ***Occipital lobe*** - The **posterior cerebral artery (PCA)** primarily supplies the **occipital lobe**, which is critical for **visual processing** [1]. - Occlusion of the PCA commonly leads to vision loss because the **primary visual cortex** [2] is located in the occipital lobe [3]. *Frontal lobe* - The **frontal lobe** is primarily involved in executive functions, motor control, and language, and is mainly supplied by the **anterior** and **middle cerebral arteries**. - Damage to the frontal lobe typically results in problems with personality, decision-making, or motor deficits, not isolated vision loss. *Parietal lobe* - The **parietal lobe** plays a role in sensory processing, spatial awareness, and navigation, and is mostly supplied by the **middle cerebral artery**. - Lesions here can cause sensory deficits or neglect, but not direct vision loss as the primary symptom. *Temporal lobe* - The **temporal lobe** is involved in auditory processing, memory, and language, and is supplied by branches from the **middle** and **posterior cerebral arteries** [2]. - While it has some visual processing areas (e.g., visual association cortex), PCA occlusion’s most prominent and direct impact on vision is through its supply to the occipital lobe.
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