Regarding a positive relative afferent pupillary defect (RAPD), all of the following statements are true EXCEPT:
Answer: C: Testing for an afferent pupillary defect is important and should be performed consistently during examination of the eye in the ED. This is done with the swinging flashlight test. A positive RAPD means there is a disturbance in the anterior afferent visual pathway that carries the light perception to the central nervous system. The disturbance or the defect may be present at any level along the pathway including:
RAPD should not be assumed to be caused by a cataract because light can still penetrate the lens with a cataract.
It should be noted that prior to testing with the swinging flashlight test, the pupillary defect will not be apparent and the pupil of the affected side will be the same size as on the normal side. This is because of the normal consensual light response on the affected side. During the swinging flashlight test when the light is moved from the normal side to the affected side, that pupil will dilate paradoxically, therefore producing a positive RAPD.
References:
Regarding childhood conjunctivitis, which ONE of the following statements is FALSE?
Answer: A: Bacterial conjunctivitis is more common in children than viral conjunctivitis although viral syndromes affect children more commonly. Streptococcus pneumoniae, Staphylococcus aureus and non-typeable Haemophilus influenzae are the most commonly implicated bacterial organisms, whereas adenovirus conjunctivitis is the most common viral conjunctivitis. The patient may present with a conjunctivitis as part of a viral syndrome or it can be an isolated conjunctivitis. The presence of preauricular lymphadenopathy in viral conjunctivitis is one of the differentiating factors. A more severe and highly contagious form of adenovirus infection is epidemic keratoconjunctivitis. Slit lamp examination shows a diffuse superficial keratitis without corneal ulceration.
Slit lamp examination is important during examination of the eye; the cornea should be viewed with fluoresceine staining to exclude dendritic ulcers caused by herpes simplex virus (HSV). However, this is a challenging but necessary examination in children. The diagnoses of conjunctivitis is clinical and appropriate swabs for bacterial culture and viral studies should only be performed in severe cases and in patients who have not responded adequately to initial therapy.
Reference:
Regarding orbital cellulitis and periorbital cellulitis in children, which ONE of the following statements is TRUE?
Answer: D: These infections are more common in children, and differentiating between the two conditions is important because disposition, treatment and sequelae associated with the conditions vary. Orbital (post-septal) and periorbital (preseptal) cellulitis are described in relation to the location of the soft tissue infection relative to the orbital septum. The orbital septum extends from the periosteum into the upper and lower eyelids. Subsequently, it is unlikely that the infection will spread from one area to the other. However, because of the location of the paranasal sinuses in relation to the orbit, infection in these sinuses can cause osteitis, periosteal abscesses, orbital abscesses and orbital cellulitis. This infection does not spread to the periorbital area. In this area, the main source of infection is the skin secondary to conditions such as insect bites, impetigo, hordeolum, chalazion and dacrocystitis.
Differentiating the two entities clinically may be difficult at times; however, a contrast CT scan is able to differentiate between the two conditions. MRI is useful as well:
The organisms involved in orbital cellulitis are respiratory pathogens (S. pneumoniae, H. influenzae in non-immunized patients), S. aureus and anaerobes spreading from the paranasal sinuses. Periorbital cellulitis is more commonly caused by gram-positive skin flora, mainly S. aureus, Staphylococcus epidermidis and Streptococcal species. It can also be associated with upper respiratory tract infections, especially paranasal sinusitis. Other causes include insect bites, periorbital trauma and spread from eyelid infections (e.g. hordeolum and chalazion).
In differentiating acute anterior uveitis from other causes of acute red eye, which ONE of the following clinical features of anterior uveitis is MOST useful?
Answer: C: Anterior uveitis is the inflammation of the anterior portion of the uveal tract, especially the iris and ciliary body, hence it is referred to as iridocyclitis. The causes could be due to systemic diseases (e.g. juvenile rheumatoid arthritis or ulcerative colitis), infections, malignancies and trauma. This is not a true ocular emergency but needs discussion and follow-up with ophthalmology. The symptoms and examination findings include:
Regarding the diagnosis of acute angle closure glaucoma (AACG) in the ED, which ONE of the following statements is TRUE?
Answer: B: In AACG there is a blockage of the outflow of aqueous humor caused by a number of mechanisms. There is usually an abrupt onset of symptoms and severe pain and redness in the eye are prominent features. Headache on the affected side, as well as nausea and vomiting, tearing, blurred vision and ‘halos around lights’, are usually present. The eye examination shows:
The eyeball may feel hard on palpation. If the pupil reacts, the AACG diagnosis is generally incorrect and an alternative diagnosis should be considered. Normal intraocular pressure (IOP) is 10–20 mmHg. In AACG the IOP is above this level and in severe disease may be as high as 60–80 mmHg. If the IOP is >30 mmHg emergent treatment is indicated to prevent visual loss.
In contrast, primary open angle glaucoma (POAG) is a chronic and progressive condition causing visual field loss. In POAG, pain is not a prominent feature. There is a familial predilection in first-degree relatives. In one in three, IOP may be normal (normal tension glaucoma) and examination of the optic disc is much more important in the diagnosis. These patients generally present to their general practitioners rather than to the ED.
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