1. Identify household toxins that cause most eye injuries and describe the appropriate treatment for each type of toxin.

2. Utilize the classification system (based on location, stage, and degree of vascular dilation) for ROP.

3. Recognize risk factors for development of ROP and take into account optimal timing for referral and treatment of infants at risk for ROP.

4. Evaluate available data on the role of nutritional supplementation in the management of AMD.

5. Choose among surgical and pharmacologic treatments for AMD and summarize therapeutic approaches currently in research and clinical trials.

Ocular Injuries From Household Toxins
Devin Gattey, MD, Assistant Professor of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland

Background: data from toxic exposure surveillance system of American Association of Poison Control Centers; >85,000 ocular exposures reported from 2002 to 2005; exposures categorized as minor (signs and symptoms resolve rapidly), moderate (symptoms prolonged, treatment required, but no permanent injury) or major (significant residual disability)

Toxins: most eye injuries caused by bleach, alkalis, hydrocarbons (eg, gasoline, diesel, brake fluid), detergents, acids, alcohols, cyanoacrylates, insecticides, herbicides, lachrymators, and chemiluminescent glow sticks; most injurious toxins (cause moderate and major injuries) include cyanoacrylates, alkalis, acids, detergents, and bleaches; alkalis cause greatest number of major injuries (of 148 major injuries, >38 caused by alkalis); major injuries caused most often by alkalis, acids, bleach, detergent, and hydrocarbons

Chemiluminescent glow sticks: injuries probably caused by release of hydrogen peroxide when sticks break; of 1000 reported injuries, 21 moderate and none major; effects include mild conjunctivitis; treat with routine irrigation

Lachrymators: usually contain chloroacetophenone (CN; mace) or pepper spray; ocular injuries usually temporary, but injury also possible from propellant; effects include severe pain, blepharospasm, lachrymation, epithelial erosion, decreased corneal sensation, total loss of corneal epithelium (from high doses), and death from asthma attacks; treat by irrigation (capsaicin not soluble in water); effects usually resolve in 30 to 60 min

Insecticides and herbicides: most insecticides have N,N-diethyl-3-methylbenzamide (DEET); of 3000 reported injuries from insecticides and herbicides, 180 moderate and only 4 major; with permethrin (tick repellant), no reports of ocular injuries; organophosphates have cholinergic side effects and may cause Saku disease; many exposures to glyphosate (Roundup) reported, but no major injuries; effects include burning sensation, conjunctival injection, lachrymation, miosis, and accommodative spasm from chemicals or surfactants and alcohols; treat by irrigation; add atropine for acute poisoning by organophosphates

Cyanoacrylates (glue): containers often mistaken for eye drops; glue hardens and sticks to conjunctiva; 3000 injuries reported (>500 moderate); effects include eyelashes and eyelids stuck together, foreign bodies in conjunctival sack, corneal abrasion, chemical conjunctivitis from short-chain forms, plugs of glue in anterior chamber, iridolenticular adhesions, and blocked pupil; mechanical separation (eg, prying apart, cutting with scissors) or acetone (also toxic) can separate stuck lashes; unclear whether foreign bodies should be removed or left to work out over weeks; however, foreign body in anterior chamber should be removed immediately

Alcohols: only one major injury reported; isopropanol and ethanol common in antiseptics and cosmetics; found in solutions to clean tips of tonometers; 20% to 40% ethanol used to remove corneal epithelium during surgery and also present in hand cleaners; methanol found in windshield wiper fluid; splash injuries with alcohols usually well tolerated; effects include burning, hyperemia, and corneal abrasion

Acids: 10 major and 560 moderate injuries reported; hydrochloric acid used in industrial cleaners; hydrofluoric acid (HF)—used in detailing cars (eg, wheel cleaners); fluoride ion penetrates skin, and can cause severe injuries, fatalities, and metabolic disorders; speaker recommends involving poison control specialist or possibly endocrinologist in cases of exposure to HF; sulfuric acid found in batteries; if pH of any solution <2.5, injury more likely severe; treat by copious irrigation to achieve pH >7; when HF exposure occurs, calcium gluconate gels beneficial if applied directly to skin, but not for use in eye

Detergents and surfactants: categorized as anionic, cationic, nonionic, and zwitterionic; cationic detergents, eg, benzalkonium chloride (BAK), most toxic to cornea; alkaline gel packs for dishwashers can injure children; effects generally mild, including burning, conjunctival hyperemia, and punctate keratitis; treat by routine irrigation unless injury from alkali suspected

Hydrocarbons: gasoline—major injuries probably result from pressure or heat, rather than from chemicals; treat by irrigation; inhalation of leaded gasoline can cause hallucinations and abnormal visual evoked response

Alkalis: cause most of major injuties; lye (sodium or potassium hydroxide) used in drain cleaners, and manufacturing of soap, glass, and biodiesel; lime (calcium oxide); slaked lime (calcium hydroxide) found in cement, and injury may result from hardened product stuck to conjunctiva or superior cul-de-sac that leaches alkali; ammonia—used in fertilizer, methamphetamine, and glass cleaners (10% solution); penetrates eye more rapidly than any other chemical; anhydrous ammonia (gaseous form) can cause severe injuries; splash-injuries from glass cleaner typically mild; magnesium hydroxide (primary ingredient in fireworks) can cause injury from alkali in addition to heat; if pH >11, injury more likely to be serious; effects include symblepharon, glaucoma, iritis, and cataract; treat by copious irrigation (minimum of 2 intravenous [IV] bags of normal saline); reduce pH to <8; look for foreign bodies if injury involves cement; for exposure to large doses of ammonia, 2 hr of irrigation recommended or washout of anterior chamber; oral treatment with 3 to 4 g vitamin C possibly beneficial

Bleach (hypochlorous acid [HOCl]): present in household cleaners, water systems, and swimming pools; few household exposures to chlorine gas reported; bleach releases chlorine when in contact with water; bleach pH 11, so injuries involve alkali component; chlorine used in swimming pools combines with urea and produces chloramines that irritate eyes; avoid drying containers after using bleach to clean tips of tonometers (bleach crystals can cause mechanical and chemical injuries); swimming pool conjunctivitis includes punctate erosions and corneal edema that resolve quickly; exposure to chlorine gas causes severe pulmonary injury when bleach mixed with acid; treatment similar to that for alkaline injury (ie, copious irrigation)

Retinopathy of Prematurity: Current Surveillance Guidelines
James B. Ruben, MD, Clinical Professor, University of California, Davis, School of Medicine, and Department of Pediatric Ophthalmology and Adult Strabismus, The Permanente Medical Group, Sacramento, CA

Background: retinopathy of prematurity (ROP) causes 3% to 10% of blindness in children; partially preventable; ≈600 children blinded per year (30,000 life-years of blindness) and ≈2100 infants per year have cicatricial sequelae; results in many malpractice lawsuits

Pathology: retina differentiates under very low level of oxygen in utero; premature exposure to atmospheric levels of oxygen arrests development of vessels; retina (most metabolically active tissue in body) continues to differentiate with increasing demand for oxygen, resulting in neovascularization (as in diabetes)

Classification: by location; by stage; by degree of vascular dilatation (probably most important)

Stage 1: line of demarcation between avascular and vascular retina

Stage 2: similar but 3-dimensional line (with height)

Stage 3: characterized by shunting, elevation, and neovascularization; presence of dilated tortuous blood vessels poor sign

Stages 4A and 4B: retinal detachment; 4A represents foveal sparing detachment; in 4B, fovea detached

Stage 5: funnel detachment

Degree of vascular dilatation: defines plus disease and indicates arteriovenous shunting and neovascularization

Risk factors: gestational age (GA); sex; levels of oxygenation; ethnicity

Age: among infants 23 wk GA, >50% die; most of those >27 wk to 28 wk GA survive; no infants >32 wk GA have ROP; few children >28 wk GA require retinal surgery; screening older infants for ROP subjects them to unnecessary trauma

Sex: likelihood of developing significant ROP that requires surgery almost twice as high in male infants as in female infants

Ethnicity: black girls least likely to develop ROP, but difference between sexes not as great as in white infants; no differences in risk between white and Southeast Asian or Hispanic infants; study showed genetic factors caused 70% of variance in ROP

Oxygen: large fluctuations in levels of oxygenation in infants correlate strongly with adverse outcome; study showed tight control of oxygenation level decreased risk for severe ROP (from 12.5% to 4.5%), with no laser surgeries required during 1 yr; optimal level for prevention—younger infants given lower oxygenation did better; lowering threshold levels for saturation alarm decreased incidence from 17% to 5.6%

Guidelines for referral: American Academy of Pediatrics (AAP), American Academy of Ophthalmology (AAO), and American Association for Pediatric Ophthalmology and Strabismus (APOS) recommend referral for infants with birth weight <1500 g or GA ≤30 wk (original guidelines [2006] erroneously stated ≤32 wk as cutoff for referral); guidelines recommend seeing infants with 22-wk GA at 9-wk chronologic age, and infants with 32-wk GA at 4-wk chronologic age to achieve 99% confidence for detecting significant ROP; adverse effects of screening (cycloplegia) include ileus (many infants have cloudy corneas); timing of treatment critical; important elements include good communication between neonatal intensive care unit (NICU) and ophthalmologist, effective tracking system, and accurate calculation of appropriate date for screening

Treatment options

Increased oxygen: Supplemental Therapeutic Oxygen for Prethreshold Retinopathy of Prematurity (STOP-ROP) study showed increasing oxygen levels ineffective after disease has developed

Ablative laser surgery: current standard; preferred over cryotherapy since 1990s; large prospective studies show better outcomes with laser

When to treat: in past, <13% of patients who received treatment on basis of cumulative or contiguous clock-hour had >20/40 vision; trial showed that immediate treatment provided best outcome for 1) patients with zone 1 ROP and any stage with plus disease, 2) zone 1 ROP and stage 3, with or without plus disease, or 3) zone 2 ROP and stage 2 or 3 with plus disease; delay causes accumulation of vascular endothelial growth factor (VEGF) in vitreous and possible blindness despite treatment

New developments for screening: RetCam device provides photographs of peripheral fundus and allows quantitation of plus disease; provides permanent record

Future treatment: injection of anti-VEGF compounds similar to those used for macular degeneration

Age-related Macular Degeneration: New Trends
Johnny Tang, MD, Assistant Professor, Department of Ophthalmology and Visual Sciences, Division of Vitreoretinal Surgery and Medicine, Case Western Reserve University School of Medicine, and University Hospitals Case Medical Center, Cleveland, OH

Risk factors: female sex, light color of iris, family history (presence of AMD in both parents suggests probability of developing AMD), smoking, exposure to sun

Environmental factors: 3 epidemiologic studies show that patients with AMD generally have poor health; 9.3% of patients with intermediate disease and 17.7% of those with advanced disease died within 6.5 yr of diagnosis; conclusion—AMD systemic issue

Clinical trials: Age-Related Eye Disease Study (AREDS) has shown nutritional supplementation can reduce susceptibility to advanced AMD; AREDS 2 trial currently evaluating supplementation with long-chain polyunsaturated fatty acids (FAs) and demonstrating additional benefit; supplementation with zinc shown to increase effects of vitamin therapy; lower dose of zinc recommended if gastrointestinal upset develops; concern about beta-carotene because of increased risk for lung cancer in smokers

Prognosis: AREDS developed 4-point scale (2 points per eye) for classifying risk of developing neovascular AMD; per eye, 1 point assigned for mottling of retinal pigment epithelium (RPE), 1 point for large drusen, one-half point for smaller-sized drusen, and 2 points for signs of neovascularization or atrophy; patients with 4 total points have 50% risk of developing catastrophic end-stage AMD, neovascularization, and atrophy over 5 yr; for patients with 3 points, risk 25%

Surgery: conflicting reports on whether surgery for cataracts affects progression of AMD; patients with problems absorbing nutrients (eg, after bariatric surgery) may have accelerated development of AMD

Treatments for neovascular AMD: previous therapies (eg, thermodynamic therapy [TDT], photodynamic therapy [PDT]) worked poorly; injected anti-VEGF—trial showed that frequent injections maintained or improved vision

Encapsulated cell technology for treatment of dry AMD: early treatment may prevent end-stage complications (eg, neovascularization, disciform scarring); device encapsulates live genetically modified RPE cells; cells live indefinitely and secrete neurotrophic factors; when implanted into eye, nutrients from aqueous and vitreous humor can permeate capsules, but white blood cells cannot

Clinical trials: phase 1 trial enrolled patients with retinitis pigmentosa (RP); phase 2 trial includes those with dry AMD and earlier stages of RP; found treatment improved vision from hand motion and flat electroretinography (ERG) to ability to read 3 lines on Early Treatment Diabetic Retinopathy Study (ETDRS)

Device: uses 23-gauge injector, 1 mm in size; implantation possible in office; device remains free in vitreous