Preventive Ophthalmology: Background and Current Trends

1. Preventive Ophthalmology:Background and Current Trends Ophthalmology Clerkship Rotation Quirino Memorial Medical Center July 28 2011 Matthew David Parco and Jaesser Tan

2. Outline • Prevention of Injuries to the Eye • Prevention of Acquired Ocular Infections • Prevention of Iatrogenic Ocular Infections • Prevention of Ocular Damage from Congenital Ocular Infections • Prevention of Genetic Diseases with Ocular Components • Early Detection of Treatable Ocular Diseases • Prevention of Amblyopia Development • Prevention of Ocular Damage from Systemic Diseases • Prevention of Visual Loss due to Medications

3. Introduction • Vision is a vital factor influencing the quality of life. • Eye care in the practice of medicine is essential. • According to WHO: • 1 person goes blind every 6 seconds. • 1 child goes blind every minute. • 75% of cases are PREVENTABLE! • Preventive medicine • Success factors: LICE • Law mandating safety for workers. • Identification of groups at-risk. • Cooperation of all parties involved. • Effectivity and acceptability of preventive measures.

4. Prevention of Ocular Injuries • Occupational and Non-occupational • Occupational • Trauma • Chemical • Thermal/Radiation • Occupational Injuries • Majority of these injuries result from small particles or objects striking or abrading the eye. • Large objects causing blunt force trauma to the eyeball or eye socket.

5. Chemical Burns • Chemical Burns • ONE OF THE TWO “TRUE” OCULAR EMERGENCIES! • Chemical burns to one or both eyes from splashes of industrial chemicals or cleaning products are common. • Acid vs Alkali • Radiation Burns • UV radiation burns (welder’s flash) routinely damage workers’ eyes and surrounding tissue, leading to epithelial keratitis. Radiation Burns

6. Current Trends in Management of Chemical Ocular Burns (Chau, Lee, Lo, 2011) • Patients who underwent irrigation with tap water immediately following alkali burns had significantly better outcomes. • Irrigation with diphoterine resulted in better outcomes following grade 1 and 2 ocular burns. • With regard to duration of eye irrigation, patients with ocular chemical burns treated with prolonged irrigation reported shorter duration of treatment at hospital.

7. Who are at risk? • Patients who work in physically-demanding jobs, including factory workers, manufacturers, welders, carpenters, and construction workers. • PREVENTIVE TIPS: • Proper training and education of workers in the use of machinery and goggles, as well as the public. • Early recognition & urgent assessment of ocular injuries are essential. • Proper labeling and storage

8. Nonoccupational injuries • Windshield injuries • Decreased incidence of ocular trauma due to fireworks ban • Sports related injuries • Home based ocular injuries • Ultraviolet radiation exposure • Associated with pterygium, basal cell carcinoma and melanoma of the eyelids • Substantial evidence linking UV exposure with development of cataract. • Solar retinitis (Eclipse retinopathy) • Result of direct observation of the sun during eclipses without adequate filter. • Prevention: Use of adequate filters.

9. Prevention of Acquired Ocular Infections • Preventive measures are based on maintenance of the integrity of the normal barrier to infection. • Examples of disruption include penetrating trauma and intraocular surgery. • High risk • Corneal injuries or defects • Corneal exposure (e.g., exophthalmos and dry eyes) • Abnormal eyelid function. • Contact lens wear • Associated with suppurative keratitis due to high load of organisms and minor trauma to the cornea, or to toxic reactions to preservatives in CL solutions. • Prevention: Good hygiene for contact lens users. Corneal abrasion Corneal ulceration Suppurative keratitis

10. Giant papillary conjunctivitis • Usually occurs in soft contact lens wearers • Condition that produces a chronic irritant stimulus • Common history: wearing of contact lens and through the years, they become intolerant to the pain. • Neonatal conjunctivitis • Etiologic agent: Neisseria gonorrhea, Chlamydia, Herpes simplex, Staphylococcus aureus, Haemophilus, Streptococcus pneumoniae. • Exposure: Passage through birth canal. • Prevention: Prior treatment of the mother before delivery; ocular prophylaxis of neonates (silver nitrate erythromycin) Giant papillary conjunctivitis Neonatal conjunctivitis Chlamydial conjunctivitis

11. Current Trends in Pediatric Ocular Infections (Wong, Lai, Chi, Lam, 2011) • Contact lens wear and blepharitis were the major risk factors. The positive culture rate was 60.9%, of which 65.5% were Gram-positive organisms. Coagulase-negative staphylococci were the most common organisms (23.2%), followed by Pseudomonas aeruginosa (9.4%) and Staphylococcus aureus (8.0%). • With increasing contact lens wear in the pediatric and adolescent populations and the common occurrence of blepharokeratoconjunctivitis and staphylococcal ocular surface infections, parents and children should be highly vigilant with eyelid hygiene and contact lens practice.

12. Prevention of Iatrogenic Ocular Infection • Epidemic keratoconjunctivitis • Traced to the contamination of ophthalmologist’s office • Organisms transmitted via the ophthalmologist’s hand, tonometer, or solutions contaminated by droppers • Preventive: ApplanationTonometer tips can be adequately sterilized by wiping with 70% isopropyl alcohol swabs Epidemic keratoconjunctivitis

13. Prevention of Ocular Damage Due to Congenital Infections Rubella • Immunization with Rubella vaccine confers lifelong immunity, and is indicated for would-be mothers. Susceptibility is by assessing antibody titers. • If Rubella strikes during early pregnancy, the mother must be informed of the likelihood of ocular abnormalities in her offspring. Cytomegalovirus • No protective immunization. Hence, strive to practice good personal hygiene, including hand washing with soap and water • Refrain from sharing food and utensils with anyone and have yourself tested for CMV antibodies to determine infection. • However, breastfeeding benefits outweigh the minimal risk of transmitting CMV. Rubella Cytomegalovirus

14. Congenital rubella: Ophthalmologic Manifestations (Merdassi, Limaiem, Turki, Chaker, et.al, 2011) • The eye complaints are often congenital cataract, congenital glaucoma, microphthalmia, and oculomotor disorders. • Given patient’s complaints of loss of visual acuity in the right eye, the patient was operated on with a phacoaspiration implant in the capsular bag. The postoperative course was uneventful. The prevention of congenital rubella is based on routine vaccination of children.

15. Toxoplasmosis • Chorioretinitis • CNS abnormalities, such as: • Cerebral or cerebellar calcification. • Hydrocephalus. • Activated when the mother is immunocompromised. • Prevention: • By eating only well-cooked meat and washing vegetables and fruits. • By wearing gloves when disposing of cat litter or working in the garden so to prevent contact with viable oocysts and tissue cysts. Toxoplasmosis: Various Retinal Manifestations

16. Physiologic Aging of the Eye • Thickening of the cornea, adding to extra light scatter already inside the aging eye. • Less flexibility in the lens, making it unable to focus on detailed objects at close range, as well as yellowing of the lens, resulting to opacity. • The pupil gets smaller in diameter. • The vitreous humor eventually turns into a water-like consistency. Also pockets of liquid vitreous develop, creating “floaters”. This can cause posterior vitreous detachment, characterized with light flashes, distorted images, and floaters. • The retinal pigment epithelium is also rendered less able to filter excess light and to control light scatter, due to the cells becoming irregular.

17. Visual Effects as a result of the Physiologic Aging of the Eye • Older persons experience lower light levels due to 1) Decreased pupil diameter and 2) More yellow and opaque lens. • Glare resulting from interaction between different types of lighting PLUS anatomical changes. • Veiling glare: when stray light hits the retina uniformly. • Scotomatic glare: when overloaded light results to afterimage. • Dazzling glare: when overloaded with very bright light. • Inability to discriminate colors due to: 1) An older lens acting as filter for shorter wavelengths (e.g., purple and blue) and 2) Cell loss in fovea. • Poor contrast sensitivity. • Decreased acuity, from: 1) Cell loss in the fovea, 2) Decreased transparency of the vitreous, and 3) Increased light scatter and glare within the eye. Veiling glare Scotomatic glare Dazzling glare

18. Preventive Ophthalmology in the Elderly (Wormald, Wright, Courtney, Beaumont, & Haines, 1992). • The prevalence of blindness was 1% by WHO criteria. • The prevalence of visual impairment was 7.7%. • Cataract accounted for 75% of cases of visual impairment. • The journal’s conclusion: There seems to be a considerable amount of undetected ocular disease in elderly people in the community.

19. Preventing Development of Cataracts (and Visual Impairment) among the Elderly • Regular and continuous monitoring of their blood sugar levels and HB1Ac and blood pressure levels. These are linked to development of cataracts. • Make sure that proper filters such as sunglasses are used to keep out increased light exposure. • High levels of antioxidant intake (Vitamins C and E and Carotenoids through food intake of tablets) may be protective. • Reduce or eliminate caffeine, soda intake, wine intake, and tobacco smoking. • Ensure periodic check-ups with the ophthalmologist to halt development of Cataract.

20. Prevention of Genetic Disease with Ocular Components • Prevention of genetic diseases received little attention • History of DM, retinitis pigmentosa, retinoblastoma, consanguineous mating, neurofibromatosis, etcneeds counseling to prevent disaster to the offsprings. • Genetic centers of counseling centers available at St. Lukes and The Medical City. • Genetic workup consists of constructing a pedigree and PGD(Pre-implantation genetic diagnosis) • Prenatal diagnosis can be made through amniotic fluid exam(amniocentesis).

21. Pre-implantation Genetic Diagnosis

22. Retinitis Pigmentosa

23. Early Detection of Treatable Ocular Diseases • A number of primary ocular diseases are treatable only during their early stages or are more effectively treated at that time. • Early detection is crucial • Age-Related Macular Degeneration • PrimaryOpen-Angle Glaucoma

24. Age-Related Macular Degeneration • Leading cause of permanent visual loss in the elderly in industrialized countries • Incidence increased with each decade over age 50

25. Age-Related Macular Degeneration 2 major forms: • Atrophic ("dry") Degeneration • progressive degeneration of the outer retina, retinal pigment epithelium, Bruch's membrane, and choriocapillaris • No treatment • Low vision aids • Exudative ("wet") Degeneration • sudden onset of visual loss due to leakage of serous fluid or blood into the retina followed by new vessel formation under the retinal pigment epithelium (subretinalneovascular membrane).

26. Age-Related Macular Degeneration Prevention: • Laser photocoagulation of subretinalneovascular membranes and photodynamic therapy following IV verteporfin • delay the onset of central visual loss but only when the membrane is far enough away from the fovea to permit treatment • Translocation of the macula • radical surgical approach • may benefit a few patients • Intravitreal Vascular Endothelial Growth Factor Inhibitors • most promising • Ex. Ranibizumab (Lucentis) and Bevacizumab (Avastin) • Both must be given by repeated intravitreal injection

27. Age-Related Macular Degeneration Prophylactic Therapy • Treatment with oral vitamins and antioxidants, comprising vitamin C (500 g), vitamin E (400 IU), betacarotene (15 mg), and zinc (80 mg) and copper (2 mg) daily reduce the 5-year risk of progression to late age-related macular degeneration from 28% to 20% • Smoking is a proven risk factor for development of all forms of macular degeneration. Cessation of smoking is thought to reduce the rate of progression, although further trials are required to establish the extent of its effect. • Smokers taking betacarotene have been shown to have an increased risk of development of lung cancer. Therefore, smokers and ex-smokers are advised to omit the betacarotene.

28. Age-Related Macular Degeneration • Elderly patients developing sudden visual loss, paracentral distortion or scotoma, with preservation of central acuity • urgent ophthalmic assessment • Fluorescein Angiography • to determine their suitability for treatment • No effective treatment for the atrophic form of macular degeneration except for the provision of low vision aids.

29. Low Vision • When conventional spectacles can no longer help and surgery or medical treatment is not appropriate. • Classifying low vision(better eye with best possible glasses correction) • 20/30 to 20/60 : is considered mild vision loss, or near-normal vision • 20/70 to 20/160 : is considered moderate visual impairment, or moderate low vision • Legalblind • 20/200 to 20/400 : is considered severe visual impairment, or severe low vision • 20/500 to 20/1,000 : is considered profound visual impairment, or profound low vision • More Than 20/1,000 : is considered near-total visual impairment, or near total blindness • No Light Perception : is considered total visual impairment, or total blindness

30. Low Vision Aids

31. Primary Open-Angle Glaucoma • Major cause of preventable blindness worldwide • African or Caribbean race • About 2 million Americans have the disease • Half are undiagnosed • Prevalence increases from 0.1% for those aged 40-49 • 3% for those >70 • Symptoms do not usually occur until there is advanced visual field loss

32. Primary Open-Angle Glaucoma

33. Primary Open-Angle Glaucoma Prevention: • Early detection • Specific Screening Programs • Ocular Hypertension • 10 times more common than primary open-angle glaucoma • high frequency of normal intraocular pressure on a single reading in untreated open-angle glaucoma • complexities of screening for optic disk or visual field abnormalities. • Tonometry and Direct Ophthalmoscopy of the Optic Disk on all adult patients every 3 years • Best screening • relevant abnormalities • first-degree relatives of affected individuals – q1 year.

34. Prevention of Amblyopia Development • Amblyopia or “lazy eye," is the loss of one eye's ability to see details in the absence of organic eye disease. • Central vision develops from 6-7 yo, if visions has not developed by then, there will be no chance for it to develop later. • Two abnormalities that will prevent a child from acquiring binocular vision are: Strabismus(eyes not aligned) and anisometropia (in the absence of eye disease)

35. Strabismus • Esotropia or exotropiain a young child causes double vision • The child quickly learns to suppress the image in the deviating eye and learns to see normally with one eye • Vision does not develop in the unused eye • Child will grow up with one perfectly normal eye that is essentially blind, since it has never developed a functional connection with the visual centers of the brain • More likely to occur with esotropia than with exotropia • Good eye should be patched forcing the child to use the deviating eye • Correction either by surgery or eye glasses should be advised.

36. Strabismus

37. Anisometropia • Condition in which the two eyes have unequal refractive power • Young children are more concerned with perception of near object than with distant ones. • If one eye is nearsighted and the other is farsighted, the child will favor nearsighted eye, the farsignted eye will be “lazy: and will eventually become blind though it is straightly aligned. • best way to prevent amblyopia is to test the eye or visual acuity of pre-school children. • Ambylopia can be corrected using pharmacologically, eye patches, combination eyeglasses and prisms, vision therapy or surgery.

38. Amblyopia - Early Diagnosis Ambylopia can be corrected using pharmacologically(Atropine), eye patches, combination eyeglasses and prisms, vision therapy or surgery. Visual Acuity Test • Best • All preschool children (3-5 years old) • After this, it is usually too late for occlusion therapy • Parents can perform the test at home with the illiterate "E" chart. This is sometimes known as the "Home Eye Test< 4y/o Photorefraction • useful in screening for anisometropia, ametropia, astigmatism, and strabismus in preschool children • Any child observed to have strabismus after the age of 3 months should be seen by an ophthalmologist

39. Prevention of Ocular Damage from Systemic Diseases • Diabetic retinopathy • most common cause of blindness developing between ages 20 and 64. • Treatment is available to prevent such blindness, but for best effect it must be administered before visual loss has occurred, ie, • All diabetics must undergo regular fundal examination and be referred whenever treatment is indicated. • The major abnormalities that must be recognized are new vessel formation on the optic disk and exudates around the macula. • Any diabetic developing visual loss should also be referred for ophthalmic assessment.

40. Diabetic Retinopathy Screening • Early detection and treatment of diabetic retinopathy is essential. Readily detectable changes occur before vision is affected. • Screening for diabetic retinopathy should be performed within 3 years from diagnosis of diabetes, and annually thereafter in both types. • Digital fundal photography proven to be an effective and sensitive method for screening. • Seven-field photography is the gold standard, but two 45-degree fields, one centered on the macula and the other centered on the disc, are becoming the method of choice in most screening programs. • Diabetic retinopathy can progress rapidly during pregnancy. Every pregnant diabetic woman should be examined by an ophthalmologist or digital fundal photography in the first trimester and at least every 3 months until delivery.

41. Diabetic Retinopathy • Begin having eye examinations as follows: • Children older than 10 years who have had diabetes for 3 - 5 years or more • Adults and adolescents with type 2 diabetes soon after diagnosis • Adolescents and adults with type 1 diabetes within 5 years of diagnosis • After the first exam, most patients should have a yearly eye exam.

42. Prevention of Ocular Damage from Systemic Diseases • xerophthalmiastill occur, and in the underdeveloped areas the world over, where nutrition is often poor, it is still common. Vitamin A deficiency disease, in which the eye changes (xerophthalmia and keratomalacia) are the most damaging and often cause blindness, • Usually due to deficient diet associated with poverty. • May also be associated with chronic alcoholism, weight-reducing diets, dietary management of food allergy, or poor absorption from the gastrointestinal tract due to the use of mineral oil or gastrointestinal disease such as chronic diarrhea.

43. Prevention of Ocular Damage from Systemic Diseases • In vitamin A deficient children, measles may result in severe corneal disease. Because of the eye signs (ie, night blindness, Bitot's spots, or a lackluster corneal epithelium), • Ophthalmologist may be the first to recognize vitamin A deficiency. • Early recognition and treatment can prevent loss of vision or blindness due to secondary infection and corneal perforation. • Treatment of the acute condition may require large intramuscular doses of vitamin A followed by corrective diet and careful analysis of all possible causes.

44. Prevention of Visual Loss Due to Drugs Ophthalmic drugs • Packaged and labeled • Color-labeling • Patient should bring along any previously prescribed medications in order to avoid duplication and possible overdosage • Special monitoring and special warnings to the patient

45. Prevention of Visual Loss Due to Drugs Atropine (use to dilate pupils) • may precipitate glaucoma • prolonged use may lead to conjunctivitis, allergic eczema of eyelids Anti-glaucoma drugs • stenosis of puncta • shrinkage of conjunctiva

46. Prevention of Visual Loss Due to Drugs • Preservatives in eye drops (benzalkoniumchloride (BAK)) • Commonly the cause of allergic reactions • Prolonged use - cicatrizing conjunctivitis similar to cicatricialpemphigoid • Topical anesthetics • Prolonged use - severe corneal ulceration and scarring

47. Prevention of Visual Loss Due to Drugs Prolonged used of Corticosteroids • Drop or ointment forms • Depress the local defense mechanisms and precipitate corneal infection • worsen herpetic keratitis and other corneal infection • Lead to open-angle glaucoma and posterior subcapsular cataract • HSV and VZV corneal infections • fungal endoppthalmitis after cataract surgery • Exact pathophysiology unknown but steroid-induced IOP elevation is secondary to increased resistance to aqueous outflow. • increased accumulation of glycosaminoglycans or increased production of trabecular meshwork-inducible glucocorticoid response (TIGR) proteincouldmechanically obstruct outflow. • corticosteroid-induced cytoskeletal changes that could inhibit pinocytosis of aqueous humor or inhibit the clearing of glycosaminoglycans, resulting in the accumulation of this substance.

48. Prevention of Visual Loss Due to Drugs Ethambutol(EMB or simply E) • Ethambutol hydrochloride is a bacteriostatic antimycobacterial • Can cause optic neuritis leading to decreased visual acuity, irreversible blindness, scotoma, color blindness, and/or visual defect • Advise patient to discontinue EMB and promptly consult their physician • Visual acuity performed before beginning Ethambutol therapy and periodically during drug administration, monthly basis when dosage of more than 15 mg per kilogram per day. • Snellen eye charts are recommended for testing of visual acuity. Studies have shown that there are definite fluctuations of one or two lines of the Snellen chart in the visual acuity of many tuberculous patients not receiving Ethambutol.

49. Prevention of Visual Loss Due to Drugs Ethambutol(EMB or simply E) • Some patients received Ethambutolwithout visual problems • Recovery of visual acuity generally occurs over a period of weeks to months after the drug has been discontinued but still remains controversial. • Reported incidence of ethambutol-related retrobulbar neuritis varies between 18% in patients receiving more than 35 mg/kg per day, 5% to 6% with 25 mg/kg per day, and less than 1% with 15 mg/kg per day for more than 2 months. • No ‘safe dose’ of ethambutol has been reported with toxicity observed as low as 12.3 mg/kg per day.

50. When should an eye exam be scheduled? • The American Optometric Association recommends regular eye examinations to detect vision deficiencies and disease. How often you see the eye doctor depends on your age and stage in life. • Initial visit at 6 months of age • At age 3 • At age 5, or just before entering school • Every two years throughout school ages • Every two to three years, from age 19 to 40 • Every one to two years, from age 41 to 60 • Every year after reaching age 60