Eye diseases
The term xerophthalmia covers all the ocular manifestations of vitamin A deficiency. Xerophthalmia can progress to irreversible blindness if left untreated.
In endemic areas, vitamin A deficiency and xerophthalmia affect mainly children buy Azelaic Acid Online (particularly those suffering from malnutrition or measles) and pregnant women.
Disorders due to vitamin A deficiency can be prevented by the routine administration of retinol.
Clinical features
The first sign is hemeralopia (crepuscular blindness): the child cannot see in dim light, may bump into objects and/or show decreased mobility.
Then, other signs appear gradually:
Conjunctival xerosis: bulbar conjunctiva buy ivermectin for dogs appears dry, dull, thick, wrinkled and insensitive
Bitot's spots: greyish foamy patches on the bulbar conjunctiva, usually in both eyes (specific sign, however not always present).
Corneal xerosis: cornea appears dry and dull
Corneal ulcerations
Keratomalacia (the last and most severe sign of xerophthalmia): softening of the cornea, followed by perforation of the eyeball and blindness (extreme care must be taken during ophthalmic examination due to risk of rupturing cornea).
Treatment
It is essential to recognise and treat early symptoms to avoid the development of severe complications. Vision can be saved provided that ulcerations affect less than a third of the cornea and the pupil is spared. Even if deficiency has already led to keratomalacia purchase mebendazole and irreversible loss of sight, it is imperative to administer treatment, in order to save the other eye and the life of the patient.
Retinol (vitamin A) PO
Regardless of the clinical stage:
Children from 6 to 12 months (or under 8 kg): 100 000 IU once daily on D1, D2 and D8 Children over 1 year (or over 8 kg): 200 000 IU once daily on D1, D2 and D8
Adults (except pregnant women): 200 000 IU once daily on D1, D2 and D8
Vitamin A deficiency is rare in breast fed infants under 6 months, if needed: 50 000 IU once daily on D1, D2 and D8.
In pregnant women, treatment varies according to the stage of illness:
Hemeralopia or Bitot's spots: 10 000 IU once daily or 25 000 IU once weekly for at least 4 weeks. Do not exceed indicated doses (risk of foetal malformations).
If the cornea is affected, risk of blindness outweighs teratogenic risk. Administer 200 000 IU once daily on D1, D2 and D8.
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Xerophthalmia
Corneal lesions are a medical emergency. In addition to the immediate administration of retinol, treat or prevent secondary bacterial infections: apply 1% tetracycline eye ointment twice daily (do not apply eye drops containing corticosteroids) and protect the eye with an eyepad after each application.
Prevention
Systematically administer retinol PO to children suffering from measles (one dose on D1 and D2).
In areas where vitamin A deficiency is common, routine supplementation of retinol PO: Children under 6 months: 50 000 IU as a single dose
Children from 6 to 12 months: 100 000 IU as a single dose every 4 to 6 months Children from 1 to 5 years: 200 000 IU as a single dose every 4 to 6 months Mothers after giving birth: 200 000 IU as a single dose immediately after delivery or within 8 weeks of delivery
Note: to avoid excessive dosage, record any doses administered on the health/ immunisation card and do not exceed indicated doses. Vitamin A overdose may cause raised intracranial pressure (bulging fontanelle in infants; headache, nausea, vomiting) and, in severe cases, impaired consciousness and convulsions. These adverse effects are transient; they require medical surveillance and buy ampicillin 250mg symptomatic treatment if needed.
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5. Eye diseases
Conjunctivitis
Conjunctivitis is an acute inflammation of the conjunctiva due to a bacterial or viral infection, allergy, or irritation. Endemic or epidemic, conjunctivitis may be associated with measles or rhinopharyngitis in children. In the absence of hygiene and effective treatment, secondary bacterial infections may develop, affecting the cornea (keratitis) and leading to blindness.
Clinical features
Clinical signs of all conjuctivites include: redness of the eye and irritation. Visual acuity is not affected.
Depending on the cause:
abundant and purulent secretions, eyelids stuck together on waking, unilateral infection at onset: bacterial conjunctivitis
watery (serous) secretions, no itching: viral conjunctivitis
excessive lacrimation, eyelid oedema, intense itching: allergic conjunctivitis
In endemic areas, turn both upper eyelids up to check for signs of trachoma (see Trachoma, page 126).
Suspect keratitis if patient reports intense pain (more than is usually associated with conjunctivitis) and photophobia. Instill one drop of 0.5% fluorescein to check for possible ulcerations.
Always check for foreign bodies (subconjunctival or corneal) and remove after administering 0.4% oxybuprocaine anaesthetic eye drops. Never give bottle of eye drops to the patient.
Treatment
Bacterial conjunctivitis
Clean eyes 4 to 6 times/day with boiled water or 0.9% sodium chloride.
Apply 1% tetracycline eye ointment 2 times/day into both eyes for 7 days.
Never use corticosteroid drops or ointment.
Viral conjunctivitis
Clean eyes 4 to 6 times/day with boiled water or 0.9% sodium chloride.
Apply local antibiotics if there is a (risk of) secondary bacterial infection (see above).
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Conjunctivitis
Allergic conjunctivitis
Local treatment as for viral conjunctivitis.
Antihistamines for one to 3 days (promethazine PO or chlorphenamine PO, see page 117).
Note: in the event of a foreign body, check tetanus immunisation status.
Neonatal conjunctivitis
Conjunctivitis due to Neisseria gonorrhoeae and/or Chlamydia trachomatis in children born to infected mothers.
Clinical features
Purulent conjunctivitis within the first 28 days of life.
Gonococcal conjunctivitis usually occurs 2 to 7 days after birth. The infection is bilateral in 50% of cases, highly contagious and may rapidly lead to severe corneal lesions and blindness.
Chlamydial conjunctivitis usually occurs 5 to 14 days after birth. The infection is often unilateral.
Prevention
Immediately at birth:
Clean eyelids with sterile 0.9% sodium chloride.
Then, apply 1% tetracycline eye ointment once into both eyes.
Note:
In case of maternal herpes simplex virus infection purchase azithromycin at delivery: clean eyelids with sterile 0.9% sodium chloride then, apply 3% aciclovir eye ointment once into both eyes, then wait 12 hours and apply tetracycline.
Treatment
At dispensary level
Treatment is urgent and the child should be referred. When immediate hospitalisation is not possible, clean and apply 1% tetracycline eye ointment into both eyes every hour, until systemic treatment is available.
At hospital level
If possible isolate the newborn for 24 to 48 hours.
Treatment of choice is ceftriaxone IM: 50 mg/kg as a single dose (without exceeding 125 mg) if only the eyes are infected.
Failing the above, use spectinomycin IM: 25 mg/kg as a single dose (without exceeding 75 mg).
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5. Eye diseases
Clean eyes with an isotonic sterile solution (0.9% sodium chloride or Ringer Lactate) to prevent secretions from adhering, and apply 1 % tetracycline eye ointment
4 times/day.
If systemic treatment is not immediately available, apply 1% tetracycline eye ointment into both eyes every hour until the treatment is available.
Treat mother and partner (see Genital infections, page 229)
If treatment with ceftriaxone fails, treat for chlamydia: erythromycin PO: 50 mg/kg/day in 2 or 3 divided doses for 14 days
Viral epidemic keratoconjunctivitis
(corneal and conjunctival lesions)
Treat as viral conjunctivitis. If possible, refer to an ophthalmologist.
Protect the eye with a compress as long as photophobia lasts. Remove as soon as possible.
If necessary, administer a preventive dose of vitamin A (see page 122).
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Trachoma
Trachoma
Trachoma is a highly contagious buy Linezolid keratoconjunctivitis due to Chlamydia trachomatis. The disease is endemic in the poorest rural areas of Africa, Asia, Central and South America and the Middle East.
Infection is usually first contracted early in childhood by direct or indirect contact (dirty hands, contaminated towels, flies). In the absence of hygiene and effective treatment, the inflammation intensifies with successive infections, causing scars and deformities on the upper tarsal conjunctiva. The resulting ingrowing eyelashes (trichiasis) cause corneal lesions followed by permanent blindness, usually in adulthood.
The WHO classifies trachoma into 5 stages. Early diagnosis and treatment of first stages is essential to avoid the development of trichiasis and associated complications.
Clinical features
Several stages can occur simultaneously:
Stage I: trachomatous inflammation follicular (TF)
Presence of five or more follicles in the upper tarsal conjunctiva. Follicles are whitish, grey or yellow elevations, paler than the surrounding conjunctiva.
Stage II: trachomatous inflammation intense (TI)
The upper tarsal conjunctiva is red, rough and thickened. The blood vessels, normally visible, are masked by a diffuse inflammatory infiltration or follicles.
Stage III: trachomatous scarring (TS)
Follicles disappear, leaving scars: scars are white lines, bands or patches in the tarsal conjunctiva.
Stage IV: trachomatous trichiasis (TT)
Due to multiple scars, the margin of the eyelid turns inwards (entropion); the eyelashes rub the cornea and cause ulcerations and chronic inflammation.
Stage V: corneal opacity (CO)
Cornea gradually loses its transparency, leading to visual impairment and blindness.
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5. Eye diseases
T reatment
Stages I and II:
Clean eyes and face several times per day.
Antibiotic therapy:
The treatment of choice is azithromycin PO:
Children over 6 months or over 6 kg: 20 mg/kg as a single dose Adults: 1 g as a single dose
Failing the above, apply 1% tetracycline eye ointment: 2 times/ day for 6 weeks In children under 6 months or 6 kg: erythromycin PO (40 mg/kg/day in 2 divided doses for 14 days)
Stage III: no treatment
Stage IV: surgical treatment
While waiting for surgery, if regular patient followup is possible, taping eyelashes to the eyelid is a palliative measure that can help protect the cornea. In certain cases, this may lead to permanent correction of the trichiasis within a few months.
The method consists in sticking the ingrowing eyelashes to the external eyelid with thin strip of stickingplaster, making sure that the eyelid can open and close perfectly. Replace the plaster when it starts to peel off (usually once a week); continue treatment for 3 months.
Note: epilation of ingrowing eyelashes is not recommended since it offers only temporary relief and regrowing eyelashes are more abrasive to the cornea.
Stage V: no treatment
Prevention
Cleaning of the eyes, face and hands with clean water reduces direct transmission and the development of secondary bacterial infections.
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Other pathologies
Other pathologies
Onchocerciasis (river blindness)
Ocular lesions result from the invasion of the eye by microfilariae. They generally develop in adults and progress to blindness in the absence of early treatment.
Clinical features and treatment
Ocular lesions are always associated with onchocercal skin lesions (see page 157).
Pruritus, hemeralopia (crepuscular blindness), decrease in visual acuity, narrowing of the visual field, awareness of microfilariae in the visual field (the patient sees "little wiggling worms before his eyes").
Lesions of the cornea (punctuate, then sclerosing, keratitis), iris (iridocyclitis) or posterior segment (chorioretinopathy and optic atrophy); microfilariae within the anterior chamber or vitreous humor (slit lamp).
For treatment, see Onchocerciasis, page 157. Ivermectin treatment may improve anterior segment lesions (sclerosing keratitis, iridocyclitis) and visual acuity. Severe lesions (chorioretinal lesions, optic atrophy) continue to progress despite treatment.
Loiasis
Clinical features and treatment
Migration of an adult worm under the palpebral or bulbar conjunctiva (white, filiform worm, measuring 4 to 7 cm in length, mobile) and ocular pruritus, lacrimation, photophobia or eyelid oedema.
For treatment, see Loiais, page 159. The migration of the worm is often of very brief duration. Do not attempt to extract it, or administer anaesthetic drops; simply reassure the patient, the event is harmless. Surgical removal is likewise futile if the worm is dead/calcified.
Pterygium
A whitish, triangular growth of fibrovascular tissue extending slowly from the conjunctiva to the cornea. It occurs most frequently in patients who are exposed to wind, dust, or arid climates and never disappears spontaneously.
Clinical features and treatment
Two stages:
Benign pterygium develops slowly, does not reach the pupil: no treatment.
Progressive vascularized pterygium: red and inflamed growth covers the pupil and may impair vision:
Clean eye with sterile water or 0.9% sodium chloride.
Surgical removal if facilities are available.