comunity ophthalmology - 2.pptx
- 6. Refractive Errors In states of refractive error rays of light cannot be focused on the retina and the image appears blurred. The main types of refractive errors are
- 8. 1. Myopia (short sightedness) In myopic eye the refractive power is so high that parallel rays of light focused in front of the retina. Symptom -Poor distant vision Treatment - Spectacle- concave or negative lens
- 14. 2. Hypermetropia (long sightedness) In hypermetropia rays of light are focused behind the retina because the power of the optical system is too low for the length of the eye. Symptoms -Complain about near vision tasks -In advanced state they will have poor distant vision Treatment - Convex lens or positive lens
- 20. 3-Astigmatism In astigmatism the rays of light coming to the eye are focused differently in different meridians or has two focal points. Symptom -Distortion of image -Poor vision at any distance Treatment -Spectacle with cylindrical lens
- 25. 4- Presbyobia This is the result of the natural aging process of the lens where it becomes harder and less elastic. Accommodation will be ineffective and the person fails to do near work like reading. There is no difficulty of distant vision. Treatment-convex lens
- 26. 5- Surgical Aphakia This is an eye with lens removed surgically. Treatment-spectacle with high positive lens
- 27. STRABISMUS
- 28. STRABISMUS Definition- misalignment of eyes Symptom -Deviation of the eye - Could have Diplopia - Poor vision
- 29. STRABISMUS Sign -V/A may be normal or reduced - Deviated eye Types of strabismus Medial deviation (esotropia) Lateral deviation (exotropia),see color plate17 Upward (hyper tropic) Down ward (hypotropic) Treatment Early detection and referral for - Ambylopia treatment - For spectacle and/or surgery
- 31. Ambylopia (lazy eye) Definition: a reduction of vision of one or both eyes despite normal ocular finding. Causes -certain types of refractive error - Strabismus -sensory e.g. cataract, Ptosis Treatment - Early referral to better center
- 33. Vitamin A Deficiency Disorder (VADD) Defn :It is change in the eye and other systems from vitamin A deficiency. 1. Dietary sources of retinol Animal foods -contain the active vitamin retinol -liver is the best source which stores retinol -milk products are also very rich in retinol
- 34. Dietary sources of retinol Plant foods -are particularly important because they are the staple diet for poor people -Contain carotene pigment which is converted into retinol -The best source is red palm oil others carrots, mangoes, papaya -poor sources rice, cassava, yams, and white maize which are staple diet of the poor
- 36. Function of vitamin A .main function is maintenance of healthy epithelium .formation of visual purple
- 37. Clinical signs and symptoms 1. XN -Night blindness -poor dark adaptation and poor night vision (nyctalopia) -is the earliest symptom of vitamin A deficiency 2. X1A- conjunctival xerosis - Dryness of the conjunctiva causes to lose its normal shiny luster and look like wax or paint instead - With treatment it is reversible 3. X1B -Bitots spot with conjunctival xerosis - Bitots spot is a foamy plaque on the temporal aspect of bulbar conjunctiva
- 38. Clinical signs and symptoms 4. X2 -corneal xerosis - Corneal surface looks rough, dull and irregular 5. X3A-corneal ulceration with xerosis - The ulcers are bilateral and central 6. X3B-keratomalecia liquefaction of part of cornea 7. XS-Xerophthalmia scar -Bilateral, central or lower part of cornea-It is the last and severe sign with melting of the cornea 8. XF-Xerophthalmia fundus -A pale yellow spot appear near the course of retinal vessels and also in the retinal periphery..
- 39. Treatment Indications All children with any active corneal ulceration. All children with signs of Xerophthalmia All children with measles since they are prone to develop Xerophthalmia All severely ill or malnourished children from areas where Xerophthalmia occurs, even if there is no clinical evidence of Xerophthalmia.
- 40. Mg IU Day 1 110 200,000 Day 2 110 200,000 Day 7 110 200,000 Table 5.2. Recommended dose of vitamin A for age > one year or weight > 8 Kgm
- 41. Mg IU Day 1 55 100,000 Day 2 55 100,000 Day 7 55 100,000
- 42. Preventive treatment in the community - Children under one year old 55 mg or 100,000 IU, repeat every 4-6 months - Children over one year old 110mg or 200,000 IU, repeat every 4-6 months. - Children at birth 27.5mg or 50,000 IU - Mothers just after giving birth 165mg or 300,000 IU - Pregnant and lactating mother 5.5mg or 10,000 IU daily for two weeks.
- 43. Prevention of blindness from Xerophthalmia -Distribution of massive dose capsule -Fortification of food; identify pertinent food and process with Vitamin A. -Horticulture and agriculture to grow and eat the right sort of food. -Nutrition and health education -Immunization especially measles
- 45. Congenital cataract Definition Cataract noticed at birth. Etiology -congenital infection (TORCH) - Trauma or anoxia at birth - Genetic disorders
- 46. Congenital cataract Clinical features - whitish Pupillary reflex - increased eye movement(nystagmus) Treatment - Early referral for surgical management. It is due to a fear of ambylopia.
- 48. Congenital glaucoma Cause: mal development of trabeculum including iridocorneal junction Symptoms Triad of - Epiphora - Photophobia - Blepharospasm
- 49. Congenital glaucoma Signs Triad of- - Megalocornea (buphthalmos) - Haabs striae (descemenet membrane break) - IOP > 20mm Hg Treatment Early referral for surgical management
- 50. GLAUCOMA
- 51. GLAUCOMA Defn: It is commonly defined as a condition in which the intra ocular pressure is sufficiently high to cause optic nerve damage followed by visual field changes. Glaucoma is broadly classified as 1. Open angle glaucoma 2 closed angle glaucoma.
- 53. PRIMARY OPEN ANGLE GLAUCOMA It is characterized by - Adult onset of age above 40 years - Repeated IOP > 21mmHg - Bilateral but severe in one eye Symptoms - Usually asymptomatic - In advanced cases, there will be constriction of visual fields
- 54. PRIMARY OPEN ANGLE GLAUCOMA Signs - V/A is reduced in advanced case - IOP is raised - Visual field constriction - Optic disc cupping Treatment Urgent referral for medical and surgical treatment.