OPHTALMOLOGIC CONDITIONS
VISUAL LOSS
History and Exam:
-ask about onset of loss, duration and progression of symptoms
-measure the visual acuity with and without a pinhole
-examine the cornea and pupil
-dilate the pupil and examine the optic disc and retina with an ophthalmoscope
Differential:
-Refractive errors include:
-myopia: short sightedness causing poor distance vision; will correct with pinhole
-hypermetropia: long-sightedness giving difficulty with near vision in young pts
-astigmatism: die to a different refraction in 2 axes of the eye
-aphakia: refractive error due to absence of the lens
-pesbyopia: poor accomidation giving difficulty in reading, usually after age 40
-Cataracts: most common cause of bilateral blindness worldwide. They cause gradual and progressive decrease in visual acuity. They may appear as a grey-white to white opacity in the pupil. Fundoscopic exam will show an opacity of the red reflex with obscuration f the fundal detail. Pupil reaction to light is normal in an uncomplicated cataract. They are treated surgically under local anesthesia.
-Corneal Opacity: May follow a corneal ulcer, injury, or due to a specific eye disease such as vit A deficiency, trachoma, or leprosy. It will appear as a white opacity on the cornea which usually obscures a clear view of the pupil. Treatment options are limited but if both eyes are affected than a corneal transplant or optical iridectomy may be considered.
-Glaucoma: Responsible for 10-20% of all causes of blindness. May be acute with a red painful eye or chronic with gradual progressive loss of vision due to nerve damage. Early diagnosis is difficult without proper equipment; late glaucoma will manifest in fundoscopic exam with pathological cupping of the optic disc and poor pupil reaction to light. Mgt consists of decreasing intraocular pressure with life-long eye drops or filtration surgery. Tx does not restore sight but is given in effort to preserve remaining vision.
RED EYE
History and Exam:
-ask about any known cause, particularly any injury
-measure visual acuity
-carefully examine the eyelids, conjunctiva, cornea, and pupil
Differential:
if h/o trauma, consider
-Corneal or conjunctival foreign bodies: if FB still present, use local anesthetic drop to conjunctiva and remove FB gently with corner of thick paper. Gove antibiotic eye ointment and eye pad for 1 day
-Corneal abrasions: this occurs when something scratches the cornea and removes some of the epithelial cells. It will manifest as sudden severe pain and photophobia. Dx can be confirmed by applying florescein to stain the cornea where there the epithelium has been scraped off. Treat with antibiotic ointment and eye pad until pain resolves and epithelium has healed
-Hyphaema: severe blunt injury may cause bleeding to occur in the eye. A level of blood (hyphaema) may be visible between the cornea and iris. This will usually resolve over several days with rest. Avoid anticoagulants such as ASA or NSAIDS. If the eye is painful give acetazolamide 250mg qds for 3-7 days to lower the IOP.
if no h/o trauma, consider
-Conjunctivitis: conjunctivitis can be infective (either bacterial or viral) or allergic. If you suspect infective conjunctivitis you can prescribe an antibiotic eye ointment for 5-7 days. Treatment of chlamydial conjunctivitis (trachoma) will be specifically discussed below.
-Corneal ulcers: these may occur spontaneously or follow minor trauma. There is usually severe pain and blurred vision. PE will reveal redness around the eye and an opacity on the cornea which usually stains with florescein. In severe cases there may be a fluid level of pus inside the eye (hypopyon). Treatment is based on the cause. Herpes simplex is treated with acyclovir ointment. A bacterial infection needs to be treated with intensive topical or sub-conjunctival antibiotics. Fungal infections are treated with antifungals. Vit A deficiency is txd with vit A 200,000 iu x 3. Exposure ulcers (ie from leprosy causing eyelids to stay open) are txd with antibiotics and by taping the affected eye closed.
-Uveitis: anterior uveitis is termed iritis while posterior uveitis is termed choroiditis. There are many causes including leprosy, onchocerciasis, toxo, TB and syphilis. Iritis presents with mild to severe pain and is usually associated with blurring of vision and photophobia. PE will reveal dilated blood vessels around the margin of the cornea and irregular pupil margins. Mgt consists of dilating the pupil and topical anti-inflamatory agents. Choroiditis presents with painless visual loss although a severe attack may cause some discomfort. A white inflammatory lesion may be seen in the retina. Mgt requires treatment of the cause.
-Acute glaucoma: If the IOP increases suddenly over hours or days then the eye becomes red and very painful with severe loss of vision. This is an uncommon condition in people under the age of 50. It may occur spontaneously or as a complication of an old cataract. The cornea appears hazy and the pupil is semi-dilated and fixed to light. Pts should be given acetazolamide 500mg stat and then 250 qds. Surgical treatment is often also required.
OTHER EYE CONDITIONS
-Trachoma: chronic conjunctivitis caused by repeated infection with Chlamydia trachomatis. Inflammation from active scarring leads to conjunctival scarring causing the eyelashes to turn in and cause corneal ulceration, scarring and blindness. PE will reveal trichiasis (inturned eyelashes or previously removed eyelashes), evidence of corneal opacities, conjunctival inflammation and scarring. Treat with either azithromycin 20mg/kg po as a single dose or tetracycline 1% topical ointment bd x 6 weeks.
-Vit A deficiency: can lead to xerophthalmia (dry eyes) which can lead to corneal ulcerations and blindness. See lecture on nutritional deficiencies for more details.
-Onchocerciasis: Infection of the eye and skin due to the filarial worm Onchocerca valvulus. Inflammation lead to keratitis and corneal scar, iritis, chorioretinitis, night blindness, and optic neuritis and secondary optic atrophy.
-HIV infection: the ocular manifestations of HIV include herpes zoster ophtalmicus (treat with oral acyclovir), squamous cell carcinoma of the conjunctiva (treat with surgical excision if possible), and CMV retinopathy (treat with gancyclovir or foscarnet). CMV retinopathy is the most common OI of the eye and the major cause of blindness in AIDS patients. It is bilateral in 50% of cases. Appearance is one of red hemorrhages and yellow necrotic tissue. It is progressive and can destroy the whole retina, unfortunately treatment is expensive and has severe side effects.
OPHTO CASES
Case 1
A 62 yo M with diabetes and HTN presents with a chief complaint of blurry vision.
1. What questions do you want to ask the patient?
2. What do you want to look for in physical exam?
The patient states that his vision loss is bilateral. He first became aware of it about 6 months ago and it has been progressively been getting worse. He has no pain or photophobia, no ocular discharge. He does not recall any trauma. There is a grey-white opacity in the pupils. Pupils are minimally reactive to light. Conjunctiva appear normal.
3. What is your differential diagnosis?
4. What is your management at this point?
Case 2
A 29 yo M presents c/o severe left eye pain. He states that the pain began about 3 days ago and is associated with blurry vision. He denies trauma or foreign body. PE reveals erythema around the eye and an opacity on the cornea which stains with florescein.
5. What do you think is the cause of the patient’s symptoms?
6. What are some causes of corneal ulcers? What are their treatments?
7. If the patient were HIV positive how might it change your differential diagnosis and management?
Answers
- Ask about onset, progression of symptoms. Any pain, photophobia, or ocular discharge? Any recent trauma? Does blurry vision fluctuate or is it constant? Is the patient’s diabetes & HTN well-controlled?
- Examine acuity & peripheral vision. Examine cornea to look for cataracts or corneal abrasions. Check pupillary reflex. Perform fundoscopic exam to look examine optic disk, retinal vessels & perform red-reflex.
- DDx: cataracts, glaucoma, diabetic/hypertensive retinopathy
- Refer patient to ophthalmologist for possible corneal transplant.
- Corneal abrasion/ulcer.
- Corneal ulcers are caused by: vit A deficiency, trachoma, leprosy, or onchoceriasis. Treat vitamin A deficiency with vit A supplementation. Treat trachoma with azithromycin 20mg/kg po as a single dose or tetracycline 1% topical ointment bd x 6 weeks. Treat leprosy with anti-TB medications. Treat onchoceriasis with ivermectin 150mcg/kg in one time oral dose.
- In HIV patients, consider CMV retinopathy, herpes zoster ophtalmicus, squamous cell carcinoma of the conjunctiva. CMV is treated with gancyclovir or foscarnet. HSV can be treated with oral acyclovir. Squamous cell carcinoma is treated with surgical exision.
