Mixed Deck — All ABO Topics Flashcards

What is the most important first step in managing an alkali chemical injury to the eye?

Answer: Immediate copious irrigation until the pH is neutral

Immediate, prolonged irrigation to reach a neutral pH of about 7 limits the stromal penetration of alkali and the damage to limbal stem cells.

Which feature best distinguishes Vogt-Koyanagi-Harada disease from sympathetic ophthalmia?

Answer: Absence of a history of penetrating ocular trauma or surgery

Both diseases share similar clinical and histologic findings, but VKH requires no prior penetrating injury or intraocular surgery.

An infant with sporadic aniridia should undergo which screening?

Answer: Serial renal ultrasound for Wilms tumor

Sporadic aniridia may involve 11p13 deletions including WT1 (WAGR), warranting Wilms tumor surveillance.

What was the primary finding of the Steroids for Corneal Ulcers Trial (SCUT) for bacterial keratitis?

Answer: Adjunctive topical steroids did not significantly change 3-month best-corrected visual acuity overall

SCUT found no significant overall difference in 3-month BSCVA with adjunctive topical prednisolone, and no rise in adverse events.

Which topical regimen is first-line for Acanthamoeba keratitis?

Answer: Biguanides such as PHMB or chlorhexidine

Biguanides like PHMB and chlorhexidine are active against both trophozoites and cysts, often combined with a diamidine such as propamidine.

Which condition presents with a white pupillary reflex in a child?

Answer: Retinoblastoma

Retinoblastoma is the most common primary intraocular malignancy in children, and its classic presenting sign is leukocoria, or a white pupillary reflex. This 'cat's eye reflex' occurs when light reflects off the tumor mass within the eye. Early detection is critical for successful treatment and preservation of vision and life.

According to the Pediatric Eye Disease Investigator Group (PEDIG) Amblyopia Treatment Studies, which of the following is true regarding the treatment of moderate amblyopia (20/40 to 20/80) in children aged 3 to <7 years?

Answer: Patching for 2 hours daily was found to be as effective as patching for 6 hours daily.

A landmark PEDIG study (ATS1) demonstrated that for children aged 3 to <7 years with moderate amblyopia (visual acuity 20/40 to 20/80), patching the sound eye for 2 hours per day was as effective as patching for 6 hours per day. This finding changed clinical practice, allowing for reduced treatment burden with similar efficacy. Subsequent studies showed atropine to be a comparable alternative to patching, not superior. Other studies have also shown that a significant number of children improve with optical correction alone, which should be tried first.

Without any lens at a 67 cm working distance, the retinoscopic reflex shows 'with' motion. The patient could be:

Answer: Hyperopic, emmetropic, or myopic less than 1.50 D

With motion means the far point is behind the examiner, which includes hyperopia, emmetropia, and low myopia under the working distance value.

In primary congenital glaucoma, what is the typical orientation of Haab striae, compared with birth-trauma Descemet breaks?

Answer: Horizontal or curvilinear, parallel to the limbus

Haab striae are horizontal or concentric to the limbus, whereas forceps injury usually causes vertical or oblique breaks.

On orbital CT, enlargement of an extraocular muscle that includes the tendon insertion is most characteristic of which condition?

Answer: Idiopathic orbital myositis

Orbital myositis typically involves the tendon, whereas thyroid eye disease classically spares it.

A 10-year-old boy has bilateral spoke-wheel foveal schisis and an electronegative ERG. Which gene is most likely mutated?

Answer: RS1

X-linked juvenile retinoschisis is caused by RS1 mutations and classically shows foveal schisis with a reduced b-wave (negative ERG).

Intraoperative floppy iris syndrome is most strongly associated with which systemic medication?

Answer: Tamsulosin

Tamsulosin selectively blocks alpha-1A receptors in the iris dilator, which causes iris billowing, prolapse, and progressive miosis during cataract surgery.

What is the most common cause of amblyopia in children?

Answer: Strabismus

Amblyopia, or 'lazy eye,' is reduced vision in an eye that did not develop normal sight during childhood. Strabismus, a misalignment of the eyes, is the most common cause because the brain suppresses the image from the misaligned eye to avoid double vision, leading to a lack of visual stimulation and development in that eye. Early detection and treatment are crucial for improving visual outcomes.

Why is brimonidine contraindicated in infants and children under 2 years old?

Answer: It crosses the blood-brain barrier and can cause CNS depression, hypotension, and apnea

Brimonidine's lipophilicity allows CNS penetration in infants, risking somnolence, bradycardia, and apnea.

A patient's prescription is -2.00 -1.00 x 180. What is the total power of this lens in the 90-degree meridian?

Answer: -3.00 D

The power in the principal meridians of a spherocylindrical lens can be determined by analyzing the prescription. The sphere power (-2.00 D) is present in all meridians. The cylinder power (-1.00 D) is at its maximum at 90 degrees away from its axis. The axis is 180, so 90 degrees away is the 90-degree meridian. Therefore, the total power in the 90th meridian is the sum of the sphere and cylinder powers: -2.00 D + (-1.00 D) = -3.00 D.

Which feature distinguishes dissociated vertical deviation (DVD) from a true hypertropia?

Answer: The covered eye drifts up without a corresponding hypotropia of the fellow eye on refixation

DVD violates Hering's law: either eye drifts upward when covered without the fellow eye moving downward.

A patient with a known pituitary adenoma develops sudden severe headache, bilateral vision loss, and ophthalmoplegia. What is the most likely diagnosis?

Answer: Pituitary apoplexy

Hemorrhage or infarction of an adenoma causes acute chiasmal and cavernous sinus compression and needs urgent steroids and neurosurgical review.

During gonioscopy, what is the most posterior structure visible in a normal, open angle?

Answer: Ciliary body band

The structures of the angle from posterior to anterior are: Ciliary body band, Scleral spur, Trabecular meshwork, and Schwalbe's line. Therefore, the ciliary body band is the most posterior structure.

Which cycloplegic agent has the longest duration of action?

Answer: Atropine

Atropine's mydriatic and cycloplegic effects can last 7 to 14 days.

Which feature of Stickler syndrome type 1 vitreous distinguishes it on slit-lamp examination?

Answer: Membranous (vestigial gel) vitreous anomaly

COL2A1-related Stickler type 1 shows a membranous retrolental vitreous, whereas COL11A1 type 2 shows a beaded pattern.