Ophthalmic Surgery — MCQs

A 60-year-old diabetic patient underwent uneventful phacoemulsification with IOL implantation. On the third postoperative day, the patient presented with pain, diminished vision, redness, watering, and a grayish-yellow pupillary reflex. Examination revealed circumcorneal congestion, 4+ aqueous cells, hypopyon in the anterior chamber, and posterior synechiae. What is the most likely diagnosis?

Q75Medium

Which of the following is NOT a feature of basal cell carcinoma of the eyelid?

Q76Easy

Which investigation is used to predict the visual outcome after phacosurgery?

Q77Easy

What is the treatment for chronic dacryocystitis?

Q78Easy

What is the wavelength of the laser used in Femto Laser assisted cataract removal?

Q79Easy

Which laser is used for cutting out the cataract capsule?

Q80Easy

Which instrument is used to visualize the periphery of the retina?

Ophthalmic Surgery Indian Medical PG Practice Questions and MCQs

Question 71: Peribulbar injection is given in which space?

A. Subtenon space
B. Outside the muscle cone (Correct Answer)
C. Periorbital space
D. Subperiorbital space

Explanation: **Explanation:** The correct answer is **B. Outside the muscle cone.** **Concept:** Local anesthesia in ophthalmology is categorized based on the anatomical space where the anesthetic agent is deposited. The orbit is divided into two main compartments by the four recti muscles and their intermuscular septa: the **intraconal space** (inside the muscle cone) and the **extraconal space** (outside the muscle cone). * **Retrobulbar blocks** involve injecting anesthesia directly into the **intraconal space**. * **Peribulbar blocks** involve injecting anesthesia into the **extraconal space** (outside the muscle cone). The anesthetic then diffuses through the intermuscular septa into the muscle cone to achieve akinesia and anesthesia. **Analysis of Incorrect Options:** * **A. Subtenon space:** This refers to the space between the Tenon’s capsule and the sclera. A Sub-Tenon block involves a blunt cannula injection and is distinct from the peribulbar technique. * **C & D. Periorbital/Subperiorbital space:** The periorbita is the periosteum of the orbit. Injecting here would be sub-periosteal, which is not the target for routine ocular regional anesthesia. **High-Yield Clinical Pearls for NEET-PG:** * **Safety:** Peribulbar anesthesia is considered **safer** than retrobulbar anesthesia because the needle stays further from the optic nerve and major vessels, reducing the risk of globe perforation and retrobulbar hemorrhage. * **Volume:** Peribulbar blocks require a **larger volume** of anesthetic (6–10 ml) compared to retrobulbar blocks (2–4 ml). * **Onset:** Peribulbar anesthesia has a **slower onset** of action because it relies on diffusion across the muscle septa. * **Nerve Involvement:** Both blocks aim to anesthetize the ciliary nerves, but peribulbar is less likely to cause "brainstem anesthesia" (a rare complication of retrobulbar blocks).

Question 72: Which of the following is NOT true regarding vitreous wick syndrome?

A. More commonly seen in ICCE or ECCE
B. Vitreous comes in anterior chamber
C. Can cause secondary glaucoma
D. Seen in phacomorphic glaucoma (Correct Answer)

Explanation: **Vitreous Wick Syndrome** is a postoperative complication where a strand of vitreous prolapses through a wound dehiscence or a needle track, creating a "wick" between the inner eye and the external surface. ### Why Option D is the Correct Answer **Phacomorphic glaucoma** is a type of secondary angle-closure glaucoma caused by an intumescent (swollen), cataractous lens pushing the iris forward. It is a **pre-operative** lens-induced condition. In contrast, Vitreous Wick Syndrome is strictly a **post-operative** complication related to surgical wound integrity. Therefore, it is not associated with phacomorphic glaucoma. ### Explanation of Incorrect Options * **Option A:** It is more common in **ICCE** (Intracapsular Cataract Extraction) because the posterior capsule is entirely removed, allowing vitreous to move forward easily. It can also occur in **ECCE** or Phacoemulsification if there is a posterior capsular rupture (PCR). * **Option B:** For a "wick" to form, the vitreous must first prolapse into the **anterior chamber** and then exit through the surgical incision. * **Option C:** The vitreous strand can cause **secondary glaucoma** via two mechanisms: mechanical blockage of the trabecular meshwork or by causing chronic low-grade inflammation (uveitis) that leads to synechiae. ### Clinical Pearls for NEET-PG * **Classic Presentation:** A patient presents post-cataract surgery with a peaked/distorted pupil (pointing toward the wound) and a microscopic "wick" of vitreous at the incision site. * **Major Risk:** The most serious complication is **Endophthalmitis**, as the vitreous strand acts as a conduit for bacteria to enter the eye. * **Cystoid Macular Edema (CME):** Chronic vitreous incarceration can lead to Irvine-Gass Syndrome. * **Management:** Surgical repair involves performing an anterior vitrectomy to remove the strand and resuturing the wound to ensure it is watertight.

Question 73: Inward rolling of the eyelid margin is known as:

A. Entropion (Correct Answer)
B. Ectropion
C. Trichiasis
D. Ankyloblepharon

Explanation: **Explanation:** **1. Why Entropion is Correct:** **Entropion** is defined as the inward turning (inversion) of the eyelid margin toward the globe. This condition causes the eyelashes and the outer skin of the lid to rub against the cornea and conjunctiva, leading to irritation, corneal abrasions, and potential scarring. It is most commonly classified into four types: Involutional (age-related, most common), Cicatricial (due to scarring), Congenital, and Spastic. **2. Why Other Options are Incorrect:** * **Ectropion:** This is the exact opposite of entropion; it refers to the **outward turning** (eversion) of the eyelid margin, exposing the palpebral conjunctiva. * **Trichiasis:** This refers to the **misdirection of eyelashes** toward the globe in the presence of a normal eyelid position. In entropion, the lid margin itself is malpositioned; in trichiasis, only the lashes are at fault. * **Ankyloblepharon:** This is a condition where the upper and lower eyelid margins are **fused together** by tags of skin, narrowing the palpebral fissure. **3. High-Yield Clinical Pearls for NEET-PG:** * **Involutional Entropion:** The primary cause is the horizontal laxity of the eyelid and the overriding of the preseptal orbicularis oculi over the pretarsal muscle. * **Jones Procedure:** A common surgical repair for involutional entropion involving the tightening of the lower lid retractors. * **Cicatricial Entropion:** Frequently caused by **Trachoma** (the leading infectious cause of blindness) or Stevens-Johnson Syndrome. * **Complication:** The most serious complication of untreated entropion is **corneal ulceration** due to constant mechanical trauma.

Question 74: A 60-year-old diabetic patient underwent uneventful phacoemulsification with IOL implantation. On the third postoperative day, the patient presented with pain, diminished vision, redness, watering, and a grayish-yellow pupillary reflex. Examination revealed circumcorneal congestion, 4+ aqueous cells, hypopyon in the anterior chamber, and posterior synechiae. What is the most likely diagnosis?

A. Postoperative endophthalmitis (Correct Answer)
B. Postoperative glaucoma
C. Postoperative keratitis
D. Postoperative cystitis

Explanation: ### Explanation **Correct Option: A. Postoperative endophthalmitis** The clinical presentation is a classic textbook case of **Acute Postoperative Endophthalmitis**. It typically occurs within 1–7 days after intraocular surgery (most commonly phacoemulsification). * **Key Diagnostic Features:** The presence of a **grayish-yellow pupillary reflex** (indicating vitritis/exudates), **hypopyon** (pus in the anterior chamber), and severe inflammatory signs (4+ cells, circumcorneal congestion) in a patient with sudden vision loss and pain post-surgery are pathognomonic. * **Risk Factors:** Diabetes mellitus (as seen in this patient) increases the risk due to a compromised immune response. **Why Incorrect Options are Wrong:** * **B. Postoperative glaucoma:** While it causes pain and redness, it would present with corneal edema and high intraocular pressure, not a yellow pupillary reflex or hypopyon. * **C. Postoperative keratitis:** This involves the cornea (ulcers/infiltrates). While it can cause hypopyon, the primary pathology here is intraocular (behind the cornea), indicated by the pupillary reflex. * **D. Postoperative cystitis:** This is an inflammation of the urinary bladder and is irrelevant to ophthalmic surgery. **High-Yield Clinical Pearls for NEET-PG:** * **Most common causative organism:** *Staphylococcus epidermidis* (coagulase-negative Staph). * **Most virulent/severe organism:** *Pseudomonas* or *Bacillus cereus*. * **Source of infection:** Most commonly the patient’s own conjunctival and eyelid flora. * **Management:** Immediate vitreous tap for culture and intravitreal antibiotics (Vancomycin + Ceftazidime). * **Differential Diagnosis:** TASS (Toxic Anterior Segment Syndrome) – occurs within 12–24 hours, is sterile, and responds to steroids.

Question 75: Which of the following is NOT a feature of basal cell carcinoma of the eyelid?

A. Occurs on the lower lid
B. Referred to as Rodent Ulcer
C. Liver metastases are common (Correct Answer)
D. Treated with surgical excision

Explanation: **Explanation:** Basal Cell Carcinoma (BCC) is the most common malignant tumor of the eyelids (accounting for approximately 90% of cases). The hallmark of BCC is that it is **locally invasive but rarely metastasizes.** **Why Option C is the correct answer:** Metastasis in BCC is extremely rare (less than 0.1%). It spreads by local infiltration and tissue destruction rather than through the lymphatic or hematogenous routes. Therefore, the statement that "liver metastases are common" is incorrect. In contrast, Sebaceous Gland Carcinoma and Melanoma are much more likely to metastasize to regional lymph nodes and distant organs like the liver. **Analysis of other options:** * **Option A (Lower lid):** This is a classic feature. BCC most commonly affects the **lower eyelid (50-60%)**, followed by the medial canthus, upper lid, and lateral canthus. * **Option B (Rodent Ulcer):** The nodulo-ulcerative type of BCC is frequently called a "Rodent Ulcer." It features a central ulcerated area with characteristic "pearly" rolled edges and telangiectasia. * **Option D (Surgical excision):** Wide surgical excision with clear margins (often using **Mohs Micrographic Surgery**) is the gold standard treatment to ensure complete removal while preserving as much healthy eyelid tissue as possible. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factor:** Chronic exposure to UV-B radiation is the primary trigger. * **Medial Canthus Warning:** BCC in the medial canthus is more dangerous as it can invade the orbit and paranasal sinuses deeply. * **Histopathology:** Shows "peripheral palisading" of nuclei and retraction artifacts. * **Most common eyelid malignancy:** BCC. * **Most common eyelid malignancy to metastasize:** Sebaceous Gland Carcinoma (often mimics chalazion—"Masquerade syndrome").

Question 76: Which investigation is used to predict the visual outcome after phacosurgery?

A. Pachymeter
B. Potential Acuity Meter (Correct Answer)
C. Lensometer
D. Topometer

Explanation: **Explanation:** The primary goal of cataract surgery (phacosurgery) is to restore vision. However, if a patient has co-existing retinal or optic nerve pathology (e.g., macular degeneration or optic atrophy), removing the cataract will not result in significant visual improvement. **Potential Acuity Meter (PAM)** is a specialized diagnostic tool used to estimate the "potential" visual acuity a patient might achieve after the lens opacity is removed. It works by projecting a miniaturized Snellen eye chart via a narrow beam of light through the less dense areas (windows) of the cataract directly onto the retina. If the patient can read the chart despite the cataract, it indicates that the macular function is intact and the post-operative prognosis is good. **Analysis of Incorrect Options:** * **Pachymeter:** Used to measure **corneal thickness**. It is essential for screening glaucoma (CCT) and pre-refractive surgery (LASIK) but does not predict visual potential. * **Lensometer:** An instrument used to determine the **dioptric power** of an existing pair of spectacles or hard contact lenses. * **Topometer (Keratometer/Topography):** Used to map the **curvature of the cornea**. While vital for calculating IOL power (biometry), it does not assess retinal function or visual outcome. **Clinical Pearls for NEET-PG:** * **Laser Interferometry:** Another method to predict post-op vision by projecting interference fringes onto the retina. * **In Mature/Dense Cataracts:** When the media is too opaque for PAM, **Projection of Light (PR) and Perception of Light (PL)** are used as basic clinical indicators of retinal function. * **B-Scan Ultrasonography:** Mandatory in mature cataracts to rule out retinal detachment or posterior segment tumors before surgery.

Question 77: What is the treatment for chronic dacryocystitis?

A. Dacryocystorhinostomy (Correct Answer)
B. Dacryocystectomy
C. Massaging
D. Syringing

Explanation: **Explanation:** Chronic dacryocystitis is most commonly caused by a **Nasolacrimal Duct Obstruction (NLDO)**, leading to stasis of tears and secondary infection within the lacrimal sac. **1. Why Dacryocystorhinostomy (DCR) is the Correct Answer:** DCR is the **treatment of choice** for chronic dacryocystitis. The procedure involves creating an anastomosis between the lacrimal sac and the middle meatus of the nasal cavity by bypassing the obstructed nasolacrimal duct. This restores drainage and eliminates the reservoir for infection. **2. Why the Other Options are Incorrect:** * **Dacryocystectomy (DCT):** This involves the complete surgical removal of the lacrimal sac. It is indicated only when DCR is contraindicated (e.g., elderly patients, lacrimal sac tumors, or tuberculosis of the sac). It results in persistent epiphora (watering). * **Massaging (Crigler Maneuver):** This is the treatment for **Congenital Nasolacrimal Duct Obstruction (CNLDO)** in infants, not for chronic dacryocystitis in adults. * **Syringing:** This is a **diagnostic tool** used to confirm the patency or site of obstruction in the lacrimal apparatus. It is not a definitive treatment for chronic infection. **Clinical Pearls for NEET-PG:** * **Gold Standard:** External DCR remains the gold standard (success rate >90%). * **Cardinal Sign:** The most characteristic clinical sign of chronic dacryocystitis is a **positive Regurgitation Test** (pressure over the sac causes mucoid/purulent discharge from the puncta). * **Pre-requisite:** Always perform a syringing test before any cataract surgery to rule out dacryocystitis, as it is a major risk factor for **endophthalmitis**. * **Most common organism:** *Staphylococcus aureus* (Acute) and *Streptococcus pneumoniae* (Chronic).

Question 78: What is the wavelength of the laser used in Femto Laser assisted cataract removal?

A. 1064 nm
B. 1053 nm (Correct Answer)
C. 532 nm
D. 193 nm

Explanation: **Explanation:** **Correct Option: B (1053 nm)** Femtosecond lasers used in cataract surgery (FLACS) utilize an **Infrared** wavelength, typically **1053 nm**. The underlying mechanism is **photodisruption**. The laser delivers ultra-short pulses (one quadrillionth of a second), which create micro-explosions of tissue known as laser-induced optical breakdown. This process generates expanding bubbles of gas and plasma that precisely separate tissue layers (e.g., for capsulotomy or lens fragmentation) with minimal collateral thermal damage. **Analysis of Incorrect Options:** * **A. 1064 nm:** This is the wavelength of the **Nd:YAG laser**. While also an infrared laser used for photodisruption, it operates in the nanosecond range. It is primarily used for Posterior Capsulotomy and Peripheral Iridotomy. * **C. 532 nm:** This is the wavelength of the **Frequency-doubled Nd:YAG (Green) laser**. It is used for **photocoagulation** in conditions like Diabetic Retinopathy (Pan-retinal photocoagulation). * **D. 193 nm:** This is the wavelength of the **Argon-Fluoride Excimer laser**. It is a Far-Ultraviolet laser used for **photoablation** in refractive surgeries like LASIK and PRK to reshape the cornea. **High-Yield Clinical Pearls for NEET-PG:** * **FLACS Utility:** It is used for three main steps: Clear corneal incisions, Circular Capsulotomy, and Lens fragmentation. * **Precision:** The primary advantage of Femto-laser over manual technique is the creation of a perfectly centered and sized capsulorhexis, which improves IOL stability. * **Safety:** It reduces the total "Phaco time" and energy required, thereby protecting the corneal endothelium.

Question 79: Which laser is used for cutting out the cataract capsule?

A. Nd: YAG laser (Correct Answer)
B. Argon laser
C. Dye laser
D. Diode laser

Explanation: **Explanation:** The correct answer is **Nd: YAG laser** (Neodymium-doped Yttrium Aluminum Garnet). **1. Why Nd: YAG Laser is Correct:** The Nd: YAG laser (1064 nm) operates on the principle of **photodisruption**. It is a "cold" laser that creates a plasma expansion, resulting in a mechanical shockwave that cuts through ocular tissues regardless of pigmentation. In cataract surgery, it is the gold standard for **Posterior Capsulotomy** to treat Posterior Capsular Opacification (PCO) and is also used for Peripheral Iridotomy in angle-closure glaucoma. **2. Why Other Options are Incorrect:** * **Argon Laser:** Operates on the principle of **photocoagulation**. It is absorbed by pigment (melanin/hemoglobin) and produces heat. It is used for retinal photocoagulation (DR, BRVO) and trabeculoplasty, but it cannot "cut" a clear or mildly opaque capsule. * **Dye Laser:** These are tunable lasers used primarily in photodynamic therapy (PDT) or specific vascular lesions; they lack the disruptive power required for capsulotomy. * **Diode Laser:** Primarily used for photocoagulation or cyclophotocoagulation (destroying ciliary processes in refractory glaucoma). Like Argon, it relies on thermal effects rather than disruption. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism of Nd:YAG:** Photodisruption (Ionization/Plasma formation). * **Common Complication:** Transient rise in Intraocular Pressure (IOP) is the most common side effect post-YAG capsulotomy. Cystoid Macular Edema (CME) and Retinal Detachment are rare but serious risks. * **Femtosecond Laser:** While Nd:YAG is used *post-operatively* for the capsule, the **Femtosecond laser** is used *intra-operatively* for "Laser-Assisted Cataract Surgery" (LACS) to perform the anterior capsulorhexis. * **Excimer Laser:** Used in LASIK for **photoablation** (corneal reshaping).

Question 80: Which instrument is used to visualize the periphery of the retina?

A. Indirect binocular ophthalmoscopy (Correct Answer)
B. Direct ophthalmoscopy
C. Contact lens
D. All of the above

Explanation: **Explanation:** The visualization of the retinal periphery requires a wide field of view and the ability to perform **scleral indentation**, making **Indirect Binocular Ophthalmoscopy (IBO)** the gold standard. 1. **Why Indirect Binocular Ophthalmoscopy is Correct:** * **Field of View:** IBO provides a wide field of view (approx. 37°), which is significantly larger than direct ophthalmoscopy. * **Scleral Indentation:** It allows the surgeon to use a scleral depressor to bring the extreme periphery (ora serrata and pars plana) into view. * **Stereopsis:** Being binocular, it provides excellent depth perception, essential for detecting retinal breaks or elevations. * **Illumination:** The high-intensity light source can penetrate hazy media (like mild cataracts or vitreous hemorrhage) better than other methods. 2. **Why Other Options are Incorrect:** * **Direct Ophthalmoscopy:** While it provides high magnification (15x), it has a very narrow field of view (about 10°) and cannot visualize beyond the equator. It lacks stereopsis and cannot be used with scleral indentation. * **Contact Lens (Slit-lamp Biomicroscopy):** While lenses like the Goldmann 3-mirror can see the periphery, the term "Contact lens" alone is non-specific. In a standard clinical setting, IBO is the primary instrument designed specifically for comprehensive peripheral screening. **High-Yield Clinical Pearls for NEET-PG:** * **Image in IBO:** Real, inverted, and magnified (magnification depends on the lens power; a 20D lens provides ~3x magnification). * **Image in Direct Ophthalmoscopy:** Virtual, erect, and highly magnified (15x). * **The 20D Lens:** The most commonly used lens in IBO; it strikes a balance between magnification and field of view. * **Indication:** IBO is mandatory for evaluating patients with flashes and floaters to rule out peripheral retinal tears or detachment.

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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