Ophthalmic Surgery — MCQs

Ophthalmic Surgery Indian Medical PG Practice Questions and MCQs

Question 31: Dacryocystorhinostomy is contraindicated in all EXCEPT?

A. Atrophic rhinitis
B. Deviated nasal septum (DNS)
C. Carcinoma of the lacrimal gland
D. Chronic dacryocystitis (Correct Answer)

Explanation: **Explanation:** **Dacryocystorhinostomy (DCR)** is a surgical procedure performed to create a bypass between the lacrimal sac and the nasal cavity (middle meatus) to restore tear drainage. **Why Chronic Dacryocystitis is the Correct Answer:** Chronic dacryocystitis, typically caused by a **Nasolacrimal Duct Obstruction (NLDO)**, is the **primary indication** for DCR. The surgery bypasses the blocked duct, allowing the infected/distended sac to drain directly into the nose, thereby resolving the epiphora and recurrent infection. **Analysis of Contraindications (Incorrect Options):** * **Atrophic Rhinitis (Option A):** This is a **relative/absolute contraindication**. The nasal mucosa in these patients is thin, crusty, and unhealthy. A DCR requires a healthy mucosal flap to create a functional anastomosis; in atrophic rhinitis, the flap will likely fail or necrose. * **Deviated Nasal Septum (Option B):** A severe DNS to the side of the surgery is a **mechanical contraindication**. It prevents surgical access to the lateral nasal wall and limits the space for the osteotomy. While it can be corrected simultaneously (Septo-DCR), it remains a contraindication for a standalone DCR. * **Carcinoma of the Lacrimal Sac/Gland (Option C):** If a malignancy is suspected, DCR is **strictly contraindicated**. Performing a DCR would involve cutting through the sac, potentially seeding malignant cells into the nasal cavity and surrounding tissues. The management here is wide surgical excision (Dacryocystectomy), not a bypass. **High-Yield Clinical Pearls for NEET-PG:** * **Ideal Site for DCR:** The lacrimal sac is anastomosed to the **Middle Meatus** of the nose. * **Success Rate:** DCR has a high success rate (>90%) for post-saccal obstructions. * **Age Factor:** In very elderly patients with fragile health, **Dacryocystectomy (DCT)** is often preferred over DCR as it is a shorter, less invasive procedure, though it does not relieve epiphora. * **Pre-requisite:** Always perform a **Syringing/Lacrimal Probing** test and a nasal examination before DCR to confirm the site of block and nasal patency.

Question 32: What is the treatment for nasolacrimal duct obstruction?

A. Syringing
B. Probing
C. Dacryocystorhinostomy (DCR)
D. All of the above (Correct Answer)

Explanation: **Explanation:** The treatment for Nasolacrimal Duct Obstruction (NLDO) is a **step-wise approach** that depends on the patient's age and the severity/duration of the obstruction. 1. **Syringing (Diagnostic & Therapeutic):** In adults, syringing is primarily diagnostic to confirm the site of blockage. In partial or functional obstructions, the pressure of the fluid can sometimes clear minor debris or mucus plugs, acting therapeutically. 2. **Probing:** This is the treatment of choice for **Congenital NLDO** if conservative management (Crigler’s massage) fails. It is typically performed between 12–18 months of age. A Bowman’s probe is used to mechanically rupture the persistent membrane (usually the Valve of Hasner). 3. **Dacryocystorhinostomy (DCR):** This is the definitive surgical treatment for **acquired permanent NLDO** or failed probing in children. It involves creating a bypass anastomosis between the lacrimal sac and the nasal mucosa of the middle meatus, bypassing the obstructed duct. **Why "All of the above" is correct:** Since the question does not specify the age group (pediatric vs. adult) or the type of obstruction (congenital vs. acquired), all three modalities are recognized components of the management spectrum for NLDO. **High-Yield Clinical Pearls for NEET-PG:** * **Congenital NLDO:** Most common cause is a persistent membrane at the **Valve of Hasner**. * **Initial Management:** Digital pressure (Crigler’s massage) has a 90% success rate in the first year of life. * **DCR Indications:** Chronic dacryocystitis due to NLDO. The most common complication of DCR is hemorrhage. * **Dacryocystectomy (DCT):** Indicated if DCR is contraindicated (e.g., lacrimal sac tumor, elderly patients with atrophic rhinitis, or tuberculosis of the sac).

Question 33: Recovery in cataract surgery is fastest with which of the following procedures?

A. Intracapsular cataract extraction (ICCE)
B. Extracapsular cataract extraction (ECCE)
C. Phacoemulsification (Correct Answer)
D. Extracapsular cataract extraction (ECCE) with intraocular lens (IOL) implantation

Explanation: **Explanation:** The speed of visual and physical recovery in cataract surgery is primarily determined by the **size of the incision** and the method of **wound closure**. **Phacoemulsification** is the correct answer because it utilizes a "micro-incision" (typically 2.2 to 2.8 mm). This small incision is often self-sealing (sutureless), leading to minimal **surgically induced astigmatism (SIA)**. Because the corneal curvature remains stable and the wound heals rapidly, patients achieve "walk-in, walk-out" recovery with functional vision often returning within 24–48 hours. **Analysis of Incorrect Options:** * **ICCE (Option A):** Involves a large 120–150 degree superior limbal incision (approx. 10–12 mm) to remove the entire lens with the capsule. It requires multiple sutures, leading to high SIA and a prolonged recovery period (weeks to months). * **ECCE (Option B & D):** Conventional ECCE requires a 9–11 mm incision to express the nucleus. Even with IOL implantation, the large wound and necessary sutures result in significant astigmatism and a slower stabilization of vision compared to phacoemulsification. **NEET-PG High-Yield Pearls:** * **Gold Standard:** Phacoemulsification is currently the gold standard for cataract surgery worldwide. * **SICS (Manual Small Incision Cataract Surgery):** Often compared to Phaco; it uses a 6–7 mm valvular tunnel. While faster than ECCE, it is still slower in recovery than Phacoemulsification. * **A-Constant:** A value specific to each IOL model used in biometry (SRK formula: $P = A - 2.5L - 0.9K$) to calculate IOL power. * **Most common complication:** Posterior Capsular Opacification (PCO), also known as "After Cataract," treated with YAG Laser Capsulotomy.

Question 34: Inferior oblique muscle is most weakened by which surgical procedure?

A. Disinsertion
B. Recession
C. Myotomy
D. Anteriorization (Correct Answer)

Explanation: **Explanation:** The **Inferior Oblique (IO)** muscle is unique because it is the only extraocular muscle that originates from the anterior orbital floor. Surgical management of IO overaction involves weakening procedures, but their efficacy varies based on how they alter the muscle's functional anatomy. **Why Anteriorization is the Correct Answer:** Anteriorization (or anterior transposition) involves reattaching the IO muscle lateral and anterior to the lateral insertion of the inferior rectus muscle. This procedure does more than just relax the muscle; it **changes the functional vector** of the IO. By moving the insertion anterior to the equator, the IO is converted from an elevator into a **depressor** in the abducted position. This "anti-elevation" effect makes it the most potent weakening procedure for severe IO overaction and dissociated vertical deviation (DVD). **Analysis of Incorrect Options:** * **Disinsertion:** Simply detaching the muscle from its insertion and allowing it to retract. It is unpredictable and often results in the muscle reattaching itself (re-adherence), leading to recurrence. * **Recession:** Moving the insertion closer to the origin along its natural path. While effective for mild to moderate overaction, it only reduces the muscle's pull without changing its functional action (elevation). * **Myotomy/Myectomy:** Cutting the muscle or removing a segment. While more effective than disinsertion, these do not provide the powerful "anti-elevation" force created by anteriorization. **Clinical Pearls for NEET-PG:** * **Primary Action of IO:** Elevation in adduction (also extorsion and abduction). * **Nerve Supply:** Inferior division of the Oculomotor nerve (CN III). Note: The nerve to the IO enters the muscle where it crosses the inferior rectus; this serves as a landmark in surgery. * **V-Pattern Strabismus:** Often associated with IO overaction; weakening the IO helps collapse the "V" pattern. * **Complication:** The "J-deformity" can occur if the new insertion is placed too far anteriorly or asymmetrically.

Question 35: What technique of cataract extraction is used in the care of a subluxated lens?

A. Extracapsular Cataract extraction
B. Intracapsular Cataract extraction (Correct Answer)
C. Phacoemulsification
D. Small incision Cataract surgery

Explanation: **Explanation:** The management of a subluxated lens depends on the degree of zonular instability. In cases of significant subluxation where the zonules are extensively damaged or broken, **Intracapsular Cataract Extraction (ICCE)** is the preferred traditional technique. **Why ICCE is the correct answer:** In a subluxated lens, the zonular support is compromised, making it difficult to perform procedures that rely on an intact capsular bag. ICCE involves removing the **entire lens along with its intact capsule**. Since the zonules are already weak or broken, the lens can be delivered as a single unit (often using a cryoprobe), avoiding the risk of the lens or its fragments falling into the vitreous during more complex maneuvers. **Why the other options are incorrect:** * **Extracapsular Cataract Extraction (ECCE):** This requires an intact posterior capsule and stable zonules to support the lens expression. In subluxation, the pressure applied to express the nucleus can cause further zonular dialysis and vitreous loss. * **Phacoemulsification:** This is generally contraindicated in significant subluxation because the ultrasonic energy and fluidics (irrigation/aspiration) require a stable capsular bag. Attempting phacoemulsification on a "floppy" lens can lead to posterior capsule rupture and dropped nucleus. * **Small Incision Cataract Surgery (SICS):** Similar to ECCE, SICS involves manual nucleus delivery from within the capsule. Without stable zonular support, this maneuver is risky and can lead to total zonular loss. **High-Yield Clinical Pearls for NEET-PG:** * **Definition:** Subluxation is partial displacement of the lens; Luxation (Dislocation) is complete displacement. * **Modern Alternative:** While ICCE is the classic answer for exams, modern surgeons may use Phacoemulsification with **Capsular Tension Rings (CTR)** if the subluxation is less than 180 degrees. * **Common Causes:** Trauma (most common), Marfan syndrome (upward subluxation), and Homocystinuria (downward subluxation). * **Indications for Surgery:** Visual impairment, lens-induced glaucoma, or lens-induced uveitis.

Question 36: Which method is used to visualize the periphery of the retina?

A. Indirect ophthalmoscopy (Correct Answer)
B. Direct ophthalmoscopy
C. Goniocopy
D. Contact lens

Explanation: **Explanation:** The visualization of the retina depends on the field of view and the magnification provided by the instrument. **1. Why Indirect Ophthalmoscopy is Correct:** Indirect ophthalmoscopy is the gold standard for examining the **peripheral retina** (up to the *ora serrata*). It utilizes a condensing lens (typically +20D) to create a real, inverted, and reversed image. Its primary advantages for peripheral viewing include: * **Wide Field of View:** It offers a wide field (about 37°–45°), allowing for a panoramic view. * **Scleral Indentation:** It can be combined with scleral depression, which brings the extreme periphery into view. * **High Illumination:** The intense light source can penetrate hazy media (like mild cataracts or vitreous hemorrhage). **2. Why the Other Options are Incorrect:** * **Direct Ophthalmoscopy:** Provides high magnification (15x) but a very narrow field of view (about 10°). It can only visualize the retina up to the post-equatorial region and cannot see the periphery. * **Gonioscopy:** This technique is used to visualize the **angle of the anterior chamber** (e.g., trabecular meshwork, Schwalbe’s line) to differentiate between open-angle and angle-closure glaucoma. It is not used for retinal examination. * **Contact Lens:** While certain contact lenses (like the Goldmann 3-mirror lens) can see the periphery, "Contact lens" as a general term is non-specific. In the context of standard examination tools, Indirect Ophthalmoscopy is the definitive method for peripheral screening. **High-Yield Clinical Pearls for NEET-PG:** * **Image in Indirect:** Real, Inverted, and Magnified (approx. 3x with a +20D lens). * **Image in Direct:** Virtual, Erect, and Highly Magnified (15x). * **Principle of Indirect:** Based on the principle of **Convex lens optics**, where the patient's retina and the examiner's eye are at conjugate foci. * **Lens Power:** Higher power lenses (e.g., +30D) provide a wider field but less magnification; lower power lenses (e.g., +14D) provide higher magnification but a narrower field.

Question 37: Inverse hypopyon is seen in which of the following conditions?

A. Fungal endophthalmitis
B. Bacterial endophthalmitis
C. Post vitreoretinal surgery with silicone oil (Correct Answer)
D. Anterior uveitis

Explanation: **Explanation:** **Correct Answer: C. Post vitreoretinal surgery with silicone oil** **Mechanism:** A standard hypopyon consists of inflammatory cells (pus) that settle at the **bottom** of the anterior chamber due to gravity, as these cells are heavier than aqueous humor. In contrast, **Inverse Hypopyon** (also known as "Reverse Hypopyon") occurs when emulsified **silicone oil** bubbles migrate from the vitreous cavity into the anterior chamber. Because silicone oil has a lower specific gravity than aqueous humor, it **floats**, collecting at the **top (superior aspect)** of the anterior chamber, mimicking an upside-down hypopyon. **Analysis of Incorrect Options:** * **A & B (Fungal and Bacterial Endophthalmitis):** These are severe intraocular infections. They result in a true hypopyon where exudates and white blood cells settle inferiorly due to gravity. * **D (Anterior Uveitis):** This is characterized by a breakdown of the blood-aqueous barrier. The resulting inflammatory cells settle at the 6 o'clock position (inferiorly), forming a standard hypopyon. **High-Yield Clinical Pearls for NEET-PG:** * **Silicone Oil Specific Gravity:** It is <1.0 (approx. 0.97), which is why it floats. * **Emulsification:** This is a late complication of silicone oil injection. Risk factors include long-term retention and the use of low-viscosity oil (1000 centistokes). * **Management:** If silicone oil causes secondary glaucoma or inverse hypopyon, it usually necessitates surgical removal (Silicone Oil Removal - SORP). * **Other "Inverse" signs:** Remember **Inverse Argyl Robertson Pupil** is seen in Adie’s tonic pupil (near-light dissociation where the reaction to light is better than to accommodation, though this is rare).

Question 38: A patient developed pain and severe vision loss 2 days after cataract surgery. On examination, a particular finding was noted. Which of the following statements about the given condition is INCORRECT?

A. It involves inflammation of all layers of the eyeball. (Correct Answer)
B. Systemic antibiotics are not useful.
C. Instillation of 5% povidone-iodine into conjunctival fornices is a good prophylactic treatment.
D. The incidence is 0.2-0.5%.

Explanation: ***It involves inflammation of all layers of the eyeball.*** - **Endophthalmitis** affects only the **intraocular contents** (vitreous and aqueous humor), not all layers of the eyeball. - **Panophthalmitis** involves inflammation of all layers including the **sclera** and **orbital tissues**, which is different from endophthalmitis. *Systemic antibiotics are not useful.* - The **Endophthalmitis Vitrectomy Study (EVS)** demonstrated that **systemic antibiotics do not improve outcomes** in acute post-operative endophthalmitis. - **Intravitreal antibiotics** remain the gold standard treatment, with **vancomycin** and **ceftazidime** being commonly used. *Instillation of 5% povidone-iodine into conjunctival fornices is a good prophylactic treatment.* - **Povidone-iodine 5%** is highly effective in reducing **bacterial load** on the conjunctiva and lid margins before surgery. - It significantly **reduces the risk** of post-operative endophthalmitis when used as pre-operative antisepsis. *The incidence is 0.2-0.5%.* - The incidence of **acute post-operative endophthalmitis** after cataract surgery is indeed **0.2-0.5%** in most studies. - This represents a **rare but serious complication** that can lead to permanent vision loss if not treated promptly.

Question 39: Which of the following is not true regarding the treatment for chalazion?

A. Vertical incision
B. Incision and curettage
C. Biopsy in recurrent cases
D. Cryotherapy (Correct Answer)

Explanation: **Explanation:** A **chalazion** is a chronic, non-infectious granulomatous inflammation of the Meibomian glands caused by the blockage of gland ducts and the stagnation of sebaceous secretions. **Why Cryotherapy is the Correct Answer:** Cryotherapy is **not** a treatment for chalazion. It is primarily used in ophthalmology for treating trichiasis (destruction of hair follicles), retinal cryopexy, or certain ocular surface malignancies. Using extreme cold on a chalazion would be ineffective for removing the lipogranulomatous material and could cause unnecessary damage to the eyelid margin and skin. **Analysis of Other Options:** * **A. Vertical Incision:** This is the standard technique. The incision is made on the palpebral conjunctival surface **vertically** (perpendicular to the lid margin) to avoid cutting across adjacent Meibomian glands, which prevents further ductal damage and scarring. * **B. Incision and Curettage (I&C):** This is the definitive surgical treatment. After a vertical incision is made using a chalazion clamp, a curette is used to thoroughly scrape out the jelly-like granulomatous material and the pseudocapsule. * **C. Biopsy in Recurrent Cases:** This is a critical clinical step. Recurrent chalazia in the same location, especially in elderly patients, can mimic **Sebaceous Cell Carcinoma**. Histopathological examination is mandatory to rule out malignancy. **High-Yield Clinical Pearls for NEET-PG:** * **Initial Treatment:** Conservative management (warm compresses and lid hygiene) works in about 50% of cases. * **Incision Site:** Always from the conjunctival side (vertical) unless the chalazion is pointing through the skin, in which case a horizontal incision is made to follow the skin creases (Langer’s lines). * **Steroid Injection:** Intralesional triamcinolone acetonide is an alternative for chalazia near the lacrimal punctum where surgery might risk canalicular damage.

Question 40: What is the treatment of choice for acute dacryocystitis?

A. Massage over the lacrimal sac
B. Syringing and probing
C. Systemic antibiotics and analgesics (Correct Answer)
D. Dacryocystorhinostomy

Explanation: **Explanation:** **Acute Dacryocystitis** is a medical emergency characterized by an acute suppurative inflammation of the lacrimal sac, typically presenting with pain, redness, and swelling over the inner canthus. **Why Option C is Correct:** The primary goal in the acute phase is to control the infection and alleviate pain. Since the lacrimal sac is an enclosed space, inflammation leads to significant pressure and potential abscess formation. **Systemic antibiotics** (to cover Gram-positive organisms like *Staph. aureus* and *Streptococcus*) and **analgesics** (to manage pain) are the first-line treatments. Warm compresses are also used to encourage localization of the infection. **Why Other Options are Incorrect:** * **Option A (Massage):** Crigler’s massage is the treatment of choice for *Congenital Nasolacrimal Duct Obstruction (CNLDO)*, not acute infection. Massaging an acutely infected sac can lead to the spread of infection and orbital cellulitis. * **Option B (Syringing and Probing):** These are strictly **contraindicated** in the acute stage. Forcing fluid or a probe through an infected sac can cause trauma and disseminate the infection into the surrounding orbital tissues. * **Option D (Dacryocystorhinostomy - DCR):** While DCR is the definitive treatment for chronic dacryocystitis or the underlying NLD obstruction, it is **never** performed during the acute phase. Surgery is delayed until the infection has completely subsided (usually 4–6 weeks later). **High-Yield Clinical Pearls for NEET-PG:** * **Causative Organisms:** Most common is *Staphylococcus aureus*. * **Complication:** If left untreated, it can lead to **Lacrimal Abscess**, which may rupture to form a **Lacrimal Fistula**. * **Surgical Management:** If an abscess forms, it requires **Incision and Drainage (I&D)**. * **Definitive Treatment:** Once the acute episode resolves, **DCR** is the procedure of choice to prevent recurrence.

Practice by Chapter

Surgical Anatomy of Eye

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Asepsis and Sterilization in Eye Surgery

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Anesthesia in Ophthalmic Surgery

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Cataract Surgery Techniques

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Corneal Surgeries

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Glaucoma Surgeries

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Oculoplastic Surgeries

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Vitreoretinal Surgeries

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Strabismus Surgery

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Refractive Surgery

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Ocular Oncology Surgeries

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Management of Surgical Complications

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