Ophthalmic Surgery Practice Questions

Q: A patient developed a complication after cataract surgery. On slit lamp examination, the following finding was observed. What is the diagnosis?

Lens subluxation. ***Lens subluxation*** - This occurs due to **zonular dehiscence** or weakness, leading to partial displacement of the lens from its normal position. - On slit-lamp examination, this typically manifests as **phacodonesis** (tremulousness of the lens) or an asymmetric anterior chamber depth. *Aphakia* - Refers to the complete absence of the crystalline lens from the eye, often resulting from surgical extraction without an **intraocular lens (IOL) implantation**. - Slit-lamp biomicroscopy would reveal an **absent lens** and often an **iridodonesis** (tremulousness of the iris) due to the lack of lens support. *Posterior capsular opacification* - This is the most common long-term complication of cataract surgery, often termed **after-cataract**. - It presents as a clouding of the posterior capsule caused by the **migration of lens epithelial cells** across the posterior capsule surface, significantly reducing visual acuity. *Endophthalmitis* - A devastating **intraocular inflammation** involving both the anterior and posterior segments, usually caused by a **bacterial or fungal infection**. - Clinical features include severe **pain, decreased vision, hypopyon, and vitreous haze**, rather than simple lens displacement.

Q: Triple surgery in glaucoma includes all of the following except?

Insertion of drainage device. **Explanation:** The term **"Triple Procedure"** in ophthalmology refers to a combined surgical approach performed in a single sitting to manage patients who have both a significant cataract and glaucoma. The primary goal is to restore vision while simultaneously controlling intraocular pressure (IOP). **Why Option C is the correct answer:** A "Triple Procedure" specifically consists of three distinct steps: **Cataract extraction + Intraocular lens (IOL) implantation + Trabeculectomy.** The insertion of a glaucoma drainage device (like an Ahmed Glaucoma Valve) is a separate surgical intervention used for refractory glaucoma and is not considered a component of the standard "triple surgery" definition. **Analysis of Incorrect Options:** * **Option A (Trabeculectomy):** This is the filtering component of the triple procedure, providing a new drainage pathway for aqueous humor to lower IOP. * **Option B (PCIOL implantation):** Posterior Chamber Intraocular Lens (PCIOL) implantation is the refractive component, replacing the natural lens to restore clear vision. * **Option D (Extra capsular cataract extraction):** This is the cataract removal component. While modern surgeons often use Phacoemulsification (Phaco-triple), the classic definition includes any form of extracapsular extraction (ECCE). **High-Yield Clinical Pearls for NEET-PG:** * **Phaco-triple:** The most common modern variation involving Phacoemulsification + PCIOL + Trabeculectomy. * **Indications:** Indicated when a patient has a clinically significant cataract and glaucoma that is poorly controlled on maximal medical therapy. * **Advantage:** Reduces the risk of postoperative IOP spikes that often occur after standalone cataract surgery in glaucoma patients. * **Site:** Often performed through two separate incisions (superior for trabeculectomy and temporal for phacoemulsification) to improve the success rate of the bleb.

Q: A 60-year-old woman presents 4 days after cataract surgery with pain and decreased vision after an initial improvement. What is the most likely diagnosis?

Endophthalmitis. **Explanation:** The clinical presentation of sudden onset pain and decreased vision following a "lucid interval" (initial improvement) after cataract surgery is a classic hallmark of **Acute Postoperative Endophthalmitis**. **1. Why Endophthalmitis is correct:** Acute endophthalmitis typically occurs within **2–7 days** post-surgery. It is a severe intraocular inflammation resulting from bacterial infection (most commonly *Staphylococcus epidermidis* or *Staphylococcus aureus*). The key diagnostic features are a rapid decline in vision, ocular pain, conjunctival congestion, and the presence of **hypopyon** (pus in the anterior chamber) or vitritis. **2. Why the other options are incorrect:** * **After-cataract (Posterior Capsular Opacification):** This presents as a **gradual, painless** decrease in vision months or years after surgery, not acutely with pain. * **Iris prolapse:** This usually occurs in the immediate postoperative period (within 24 hours) due to wound leak or trauma. While it causes pain and distortion of the pupil, it does not typically present with the severe inflammatory picture of endophthalmitis. * **Posterior capsular rupture:** This is an **intraoperative** complication, not a delayed postoperative event. It occurs during the surgery itself, leading to vitreous loss. **Clinical Pearls for NEET-PG:** * **Most common source of infection:** Patient’s own lid margin and conjunctival flora. * **Most common organism:** *Staphylococcus epidermidis*. * **Most common organism for "Fulminant" cases:** *Pseudomonas*. * **Prophylaxis:** Povidone-iodine (5%) application to the conjunctival sac pre-operatively is the most effective proven method to reduce risk. * **Management:** Immediate vitreous tap for culture and intravitreal antibiotics (Vancomycin + Ceftazidime).

Q: Which of the following is NOT a common complication of intraocular lens (IOL) implantation?

Corneal dystrophy. **Explanation:** The correct answer is **A. Corneal dystrophy**. **1. Why Corneal Dystrophy is the correct answer:** Corneal dystrophies are a group of **genetic, bilateral, and progressive** disorders (e.g., Fuchs' endothelial dystrophy) that are determined at birth, though they may manifest later in life. They are not caused by external factors like surgery. In contrast, surgical trauma to the corneal endothelium during IOL implantation can lead to **Pseudophakic Bullous Keratopathy (PBK)** or corneal edema, but this is an acquired condition, not a "dystrophy." **2. Why the other options are common complications:** * **Glaucoma (B):** Post-operative intraocular pressure (IOP) spikes can occur due to retained viscoelastic material, inflammatory debris (uveitis), or pupillary block. Chronic secondary glaucoma can also occur. * **Anisocoria (C):** Unequal pupil size is common post-surgery due to mechanical trauma to the iris sphincter, the use of miotics/mydriatics, or iris incarceration in the wound. * **Macular Edema (D):** Specifically known as **Irvine-Gass Syndrome**, this is a well-known complication of cataract surgery occurring due to inflammatory mediators reaching the posterior segment, typically 4–6 weeks post-op. **High-Yield Clinical Pearls for NEET-PG:** * **Most common complication of IOL surgery:** Posterior Capsular Opacification (PCO), also known as "After Cataract." * **Treatment for PCO:** Nd:YAG Laser Capsulotomy. * **Irvine-Gass Syndrome:** Diagnosed via Fundus Fluorescein Angiography (FFA), showing a characteristic **"Flower-petal appearance"** due to leakage in the Henle’s layer. * **Toxic Anterior Segment Syndrome (TASS):** An acute sterile postoperative inflammation occurring within 12–24 hours, often due to contaminated instruments or solutions.

Q: Capsulotomy after phacoemulsification is done using which one of the following methods?

Nd - YAG laser. **Explanation:** The correct answer is **Nd:YAG laser (Neodymium-doped Yttrium Aluminum Garnet)**. **1. Why Nd:YAG Laser is Correct:** After phacoemulsification, the most common late complication is **Posterior Capsular Opacification (PCO)**, also known as "After Cataract." This occurs due to the proliferation and migration of residual lens epithelial cells across the posterior capsule. The Nd:YAG laser is a **solid-state, photodisruptive laser** (wavelength 1064 nm). It works via **optical breakdown**, creating a plasma that generates a shockwave to mechanically cut the opacified tissue without requiring a surgical incision. This procedure is called **Nd:YAG Laser Capsulotomy**. **2. Why Other Options are Incorrect:** * **Argon Laser:** This is a gas laser used for **photocoagulation**. It is absorbed by pigment (melanin/hemoglobin) and is primarily used for retinal procedures (e.g., PRP for diabetic retinopathy) or trabeculoplasty. It cannot "cut" transparent tissue like the lens capsule. * **CO2 Laser:** This is a long-wavelength infrared laser used for **photovaporization**. It is used in oculoplastics (e.g., blepharoplasty) but is not used intraocularly due to high thermal damage. * **Krypton Laser:** Similar to Argon, it is used for retinal photocoagulation, particularly when treating through thin hemorrhages or in the macula. **3. High-Yield Clinical Pearls for NEET-PG:** * **Laser Type:** Nd:YAG is a **Q-switched** laser (delivers high energy in short bursts). * **Complications of YAG Capsulotomy:** Transient rise in Intraocular Pressure (IOP) – most common; Cystoid Macular Edema (CME); Retinal Detachment; and IOL pitting (damage to the lens). * **Timing:** Usually performed at least 3–6 months post-surgery to allow the eye to quieten. * **PCO Types:** Elschnig’s pearls (most common) and Fibrotic PCO.

Q: Vitrectomy approach is most commonly via which anatomical location?

Pars plana. **Explanation:** **Pars Plana Vitrectomy (PPV)** is the gold standard approach for posterior segment surgeries. The **pars plana** is a part of the ciliary body located approximately 3.5 mm to 4 mm posterior to the limbus. It is considered the "surgical gateway" to the vitreous cavity because it is **relatively avascular** and, most importantly, it is located behind the lens and anterior to the functional retina (ora serrata). Entering through this zone minimizes the risk of causing a retinal detachment or damaging the crystalline lens. **Analysis of Options:** * **Cornea (Option B):** The corneal approach is used for anterior segment surgeries (e.g., cataract surgery or keratoplasty). While an "anterior vitrectomy" can be performed via a limbal incision during complicated cataract surgery, it is not the standard approach for a formal vitrectomy. * **Equator of the eye (Option C):** The equator is located much further posterior (approximately 12-14 mm from the limbus). Attempting to enter here would result in immediate **retinal perforation and hemorrhage**, as the functional sensory retina is firmly attached at this location. **High-Yield Clinical Pearls for NEET-PG:** * **Anatomical Landmarks:** In phakic eyes (natural lens present), the incision is made **4 mm** from the limbus. In aphakic/pseudophakic eyes, it is made **3.5 mm** from the limbus. * **Indications for PPV:** Retinal detachment, vitreous hemorrhage (most common cause: Diabetic Retinopathy), endophthalmitis, and dropped lens fragments. * **Infusion Port:** During PPV, a constant infusion of fluid is required to maintain intraocular pressure; this port is always placed first.

Q: Late onset endophthalmitis after cataract surgery is most often caused by which organism?

Propionibacterium Acnes. **Explanation:** Postoperative endophthalmitis is categorized based on the timing of presentation, which dictates the likely causative organism. **1. Why Propionibacterium acnes is correct:** **Late-onset (Chronic) Endophthalmitis** typically occurs 6 weeks to several months after cataract surgery. It is characterized by a low-grade, indolent inflammatory course. **Propionibacterium acnes** (now often referred to as *Cutibacterium acnes*), a Gram-positive anaerobic rod found in the normal skin flora, is the most common cause. It often presents with a characteristic **white plaque** on the posterior lens capsule or the intraocular lens (IOL). **2. Why the other options are incorrect:** * **Staphylococcus epidermidis:** This is the most common cause of **Acute Postoperative Endophthalmitis** (presenting within 1–7 days). While it is the most common cause of endophthalmitis overall, it is not the primary cause of the late-onset variant. * **Pseudomonas:** This is a common cause of hyperacute, fulminant endophthalmitis characterized by rapid progression and corneal melting. * **Streptococcus pyogenes:** This typically causes a very aggressive acute endophthalmitis with severe visual loss and significant fibrin formation. **Clinical Pearls for NEET-PG:** * **Acute Endophthalmitis ( 6 weeks):** Most common is *P. acnes*; second most common is *Candida albicans*. * **Post-Traumatic Endophthalmitis:** Most common organism is *Bacillus cereus* (highly virulent). * **Management:** The gold standard for diagnosis is a vitreous tap for culture. Treatment involves intravitreal antibiotics (Vancomycin + Ceftazidime). In chronic cases due to *P. acnes*, partial or total capsulectomy may be required.

Q: What is the safe size of a corneal graft with the least chances of failure?

7.5 mm. In Penetrating Keratoplasty (PKP), the size of the donor corneal graft is critical for visual recovery and graft survival. **Why 7.5 mm is the Correct Answer:** The standard "safe" range for a corneal graft is **7.0 mm to 8.5 mm**, with **7.5 mm** being the most common and ideal size. * **Optical Zone:** A graft of this size is large enough to cover the pupillary area, ensuring a clear visual axis and minimizing postoperative astigmatism. * **Immunological Safety:** It remains far enough from the **limbus** (the peripheral vascularized zone). The limbus contains blood vessels and lymphatics; the closer a graft is to the limbus, the higher the risk of graft rejection due to increased exposure to the host’s immune system. **Explanation of Incorrect Options:** * **6.5 mm (Option B):** While sometimes used in specific pediatric cases, a 6.5 mm graft is generally considered too small. It often results in significant **high irregular astigmatism** and may not sufficiently cover the optical zone if the graft decenters slightly. * **5.5 mm and 4.5 mm (Options C & D):** These are far too small for standard keratoplasty. Very small grafts lead to severe optical distortion and "taco-shelling" of the cornea. Furthermore, they provide an insufficient number of healthy donor endothelial cells to maintain long-term corneal clarity. **NEET-PG High-Yield Pearls:** * **The "Oversizing" Rule:** The donor button is typically cut **0.25 mm to 0.50 mm larger** than the host bed (e.g., a 7.5 mm host bed receives a 7.75 mm donor graft) to ensure a watertight closure and reduce postoperative flattening/glaucoma. * **Large Grafts (>8.5 mm):** These are associated with a very high risk of vascularization, rejection, and secondary glaucoma (due to peripheral anterior synechiae). * **Small Grafts (<7.0 mm):** These are associated with high astigmatism and poor optical quality.

Question 1

A patient developed a complication after cataract surgery. On slit lamp examination, the following finding was observed. What is the diagnosis?

Accepted Answer

Lens subluxation

Answer

Aphakia

Answer

Posterior capsular opacification

Answer

Endophthalmitis

Question 2

Triple surgery in glaucoma includes all of the following except?

Accepted Answer

Insertion of drainage device

Answer

Trabeculectomy

Answer

PCIOL implantation

Answer

Extra capsular cataract extraction

Question 3

A 60-year-old woman presents 4 days after cataract surgery with pain and decreased vision after an initial improvement. What is the most likely diagnosis?

Accepted Answer

Endophthalmitis

Answer

After-cataract (e.g., Elschnig pearls or Soemmerring ring)

Answer

Iris prolapse

Answer

Posterior capsular rupture

Question 4

Which of the following is NOT a common complication of intraocular lens (IOL) implantation?

Accepted Answer

Corneal dystrophy

Answer

Glaucoma

Answer

Anisocoria

Answer

Macular edema

Question 5

Capsulotomy after phacoemulsification is done using which one of the following methods?

Accepted Answer

Nd - YAG laser

Answer

Argon laser

Answer

CO2 laser

Answer

Krypton laser

Question 6

Vitrectomy approach is most commonly via which anatomical location?

Accepted Answer

Pars plana

Answer

Cornea

Answer

Equator of the eye

Answer

None of the above

Question 7

Late onset endophthalmitis after cataract surgery is most often caused by which organism?

Accepted Answer

Propionibacterium Acnes

Answer

Staphylococcus Epidermidis

Answer

Pseudomonas

Answer

Streptococcus Pyogenes

Question 8

What is the safe size of a corneal graft with the least chances of failure?

Accepted Answer

7.5 mm

Answer

6.5 mm

Answer

5.5 mm

Answer

4.5 mm

Question 9

What is the standard incision size for sutureless cataract surgery performed with phacoemulsification and foldable IOL?

Accepted Answer

3-3.5mm

Answer

1-1.5mm

Answer

2-2.5mm

Answer

3.5-4.5mm

Question 10

A 60-year-old man who underwent phacoemulsification surgery and placement of a foldable intraocular lens in his left eye a year ago now presents with complaints of hazy vision in that eye. There is no associated redness, pain, or watering of the eye. What is the most common cause?

Accepted Answer

Posterior capsular opacification

Answer

Cystoid macular edema

Answer

Neovascular glaucoma

Answer

Chorioretinitis

Ophthalmic Surgery — MCQs

Ophthalmic Surgery — MCQs

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