Eye disorders Flashcards
ENT
What is inflammation of the eyelid margin, resulting in irritation, eye redness, a foreign-body sensation, and flaking and crusting of the eyelids and eyelashes?
Blepharitis
Blepharitis refers to the inflammation of the eyelid margin resulting in irritation, hyperemia, and flaking and crusting of the eyelids and eyelashes. It is a common condition that affects individuals of all ages, ethnicity, and sex equally. Infection and inflammation can cause blepharitis, including infestation by the Demodex mite. In addition to the discomfort of the eyes, individuals can experience light sensitivity, blurred vision, and a foreign body sensation. Diagnosis is largely clinical and based on a history and review of systems but slit lamp exam and tear break-up time testing can be used for confirmation. Blepharitis treatment involves eyelid hygiene, massage, and washing with gentle cleansers, such as baby shampoo. Blepharitis is often a chronic condition that can be prevented with daily hygiene and the elimination of triggers.
What causes blepharitis?
The cause of blepharitis is multifactorial; however, infection and inflammation have been identified as the primary contributors. Some examples include infection by Staphylococcal bacteria, viral infection by herpes simplex and varicella zoster, or infestation by a microscopic mite called Demodex. Additionally, allergic reactions and skin conditions (e.g., seborrhea and rosacea) have been thought to be associated with the development of blepharitis. Lastly, meibomian gland dysfunction, in which the oil glands lining the eyelids posterior to the lash margin become clogged and engorged, can cause blepharitis.
What are the signs and symptoms of blepharitis?
The signs and symptoms of blepharitis include discomfort and irritation of the bilateral eyelids. Individuals may experience itching, burning, and crusting of the eyelids. Associated symptoms can include light sensitivity, blurred vision, tearing, and foreign body sensation. Generally, symptoms are worse in the morning upon waking due to an accumulation of crust along the eyelid margins. Scaling can be seen at the base of the eyelashes forming “collarettes,” which are waxy buildup and debris wrapping around the lashes. Also, loss of lashes (i.e., madarosis), depigmentation of lashes (i.e., poliosis), and misdirection of lashes (i.e. trichiasis) may be seen. If the meibomian glands are obstructed, thick secretions and scarring of the lid may be seen in the area surrounding the glands. Symptoms of blepharitis are often intermittent; however, it can be a chronic, lifelong condition. Blepharitis is rarely sight-threatening, but if left untreated, it can result in complications, including chronic conjunctivitis (i.e., inflammation of the membrane that covers the white of the eye), scarring of the eyelids, keratitis (i.e., inflammation of the cornea), corneal ulcers, and vision loss.
How is blepharitis diagnosed?
Blepharitis is a clinical diagnosis made based on exam findings of irritation of the lid margins with crusting and flaking of the lashes. A history, including the individual’s symptoms, medical history, and current medications, can provide a more complete clinical picture. No specific diagnostic testing beyond the history and physical exam is required; however, they can be helpful in confirming the diagnosis. For example, a slit lamp exam of an individual with blepharitis may reveal erythema and edema of the eyelid margin, telangiectasias (i.e., dilated blood vessels) at the outer portions, and the presence of Demodex mites.
Additionally, a test measuring the tear break up time can be performed. Fluorescein dye is placed in the eye, the individual is asked to blink, then keep their eye open for 10 seconds. The tear film is then examined for breaks or dry spots under cobalt blue light. If the individual has blepharitis, the tear film may show signs of rapid evaporation and the tear break up time will be less than 10 seconds, which is abnormal. Contact illumination infrared meibography (i.e,. specialized imaging to look at the morphology of meibomian glands) may also be used, which can show gland abnormality (e.g., distortion, shortening) in those with blepharitis. Individuals who fail treatment for chronic blepharitis may undergo a biopsy of the eyelid to exclude carcinoma, especially when there is eyelash loss.
How is blepharitis treated?
Blepharitis is treated primarily by preventing the condition with eyelid hygiene and eliminating potential triggers, including eye makeup. During acute stages of blepharitis, wet and warm compresses can be applied to the eyes for 5 to 10 minutes to soften the eyelid secretions and dilate the meibomian glands. Following the compress, individuals can gently massage the closed eyelid in small circular patterns to express oils from the meibomian glands, then wash the eyelids with a cotton swab soaked in warm water and baby shampoo. This can be repeated two to four times a day during an acute flare. Since there is no definitive cure, those with chronic, recurrent blepharitis may need to continue their lid hygiene regimen daily even when they are not experiencing an acute flare. Artificial tears may be used to reduce redness, swelling, and dryness.
Pharmacologic options include topical antibiotic eye drops (e.g., bacitracin, erythromycin), which can be applied to the lid margin, and oral tetracycline or macrolide antibiotics (e.g., erythromycin, clarithromycin, azithromycin). If the disease is refractory to conservative measures, steroid eye drops or topical cyclosporine may be used. If the blepharitis is caused by Demodex, tea tree oil has been used with efficacy.
How does Dacryocystitis present?
persistent tearing and discharge and swelling in the medial portion of the eye
Acute or chronic infection resulting in inflammation of the lacrimal sac is caused by …
Dacryocystitis can be either an acute or chronic stasis of tears leading to infection resulting in inflammation of the lacrimal sac
S. aureus and streptococcus are commonly associated with acute Dacryocystitis
Pneumococcus, H. influenza and Pseudomonas are commonly associated with chronic Dacryocystitis.
Besides infectious, what is another cause for Dacryocystitis?
congenital
How is congenital dacryocystitis managed?
The diagnosis is clinical but can be supported with syringing or probing
The treatment starts with massage, followed by stenting, then dacryocystorhinostomy.
How does acute Dacryocystitis present?
Erythema, edema, warmth, and significant pain below the medial canthus of the eye
Pressure on the swelling causes pain and purulent discharge from the punctum.
Epiphora
Fever (may be present)
How is acute Dacryocystitis managed?
Diagnosis is clinical but can be supported with a pus culture. Blood cultures may be indicated in patients with systemic symptoms (fever).
Treatment is symptomatic, using warm compresses, NSAIDs. If necessary, systemic antibiotics such as Oral clindamycin, IV or oral amoxicillin + clavulanic acid, or IV vancomycin can be used empirically. Culture-specific antibiotics are used once the report is ready. Incision and drainage if lacrimal sac abscess occurs. Dacryocystorhinostomy (treatment of the NLD obstruction): after treating the infection
How does chronic Dacryocystitis present?
Persistent epiphora
Mucopurulent discharge from the punctum
No signs of acute inflammation; no fever
How is chronic Dacryocystitis managed?
Antibiotics (culture-specific)
DCR (to prevent recurrence)
Children < 12 months old with chronic dacryocystitis: Nasolacrimal duct probing
When would advanced diagnostics be indicated for Dacryocystitis?
A Dacryocystography (DCG) can be used in advanced diagnostics where a contrast imaging of the lacrimal sac and NLD but is mainly performed in patients with dacryostenosis secondary to trauma (altered anatomy) or suspected tumors (to locate the tumor).
What is a major complication of Dacryocystitis?
Preseptal cellulitis
localized, tender, erythematous, pus-filled nodules at the distal lid margin
Hordeolum (Stye)
A common acute inflammation of the tear gland or eyelash follicles (Zeis or meibomian glands), most commonly due to S. aureus. Presents as a painful, erythematous, and tender pus-filled nodule on the eyelid.
A patient describes seeing this, what are the likely causes?
Age-related macular degeneration
Optic neuritis
Open-angle glaucoma: Peripheral vision loss, disc cupping on fundoscopy.
Central retinal artery occlusion: Acute painless vision loss, cherry-red macula.
Retinal detachment: Acute vision loss with a “curtain falling” sensation.
Cataracts: Gradual vision dimming with glare and opacified red reflex.
What are the two major forms of macular degeneration, and what is their prevalence?
“Dry” and “Wet”
Dry AMD (nonexudative or atrophic): ~90%.
Wet AMD (exudative or neovascular): ~10%.
What is the pathophysiology of Dry AMD?
Deposition of drusen (lipid and protein deposits) under the retinal pigment epithelium (RPE) and Bruch’s membrane, leading to slow progressive atrophy of the retina.
What is the pathophysiology of Wet AMD?
Choroidal neovascularization between the RPE and Bruch’s membrane, resulting in leakage of fluid and blood, leading to rapid vision loss and potential retinal detachment.
What findings on fundoscopy are diagnostic of Dry AMD?
Drusen: Yellow-white deposits under the retina.
RPE atrophy and mottling.
