Transcript Dry Eye
2. Ocular Surface Disorders Conjuctivitis: inflammation of bulbar conjunctiva Viral conjunctivitis Allergic conjunctivitis Bacterial conjunctivitis Usually self-limiting, with symptoms resolving 1-3 weeks Viral conjunctivitis Pinkeye The most common conjunctivitis Causes: recent cold, sore throat, exposure to someone with pink eye (acute contagious conjunctivitis) Symptoms: “pink-eye” with copious amounts of watery discharge; ocular discomfort; mild to moderate foreign body sensation; occasionally blurred vision; low grade fever, swollen lymph nodes Treatment: relief major symptoms using artificial tears & ocular decongestants. Certain forms are extremely contagious: wash hands, do not share towels, properly dispose of tissues used to blot the eye Allergic conjunctivitis Caused by many antigens (Ag): pollen grains, animal dander & topical eye preparations Symptoms: red eye with watery discharge Hallmark symptom: itching Afflicted people often report seasonal allergic rhinitis Ask patient about recent exposure to Ag Treatment: removal of cause (best); ocular decongestants and antihistamines; oral antihistamines; cold compresses Bacterial conjuctivitis Staphylococcus epidermidis, Staphylococcus aureus, Heamophilus influenza & Streptococcus pneumoniae Symptoms: red eye with purulent discharge Key symptom: eyelids sticking together on awakening Self-limiting within 2 weeks, but topical antibiotics may clear the symptoms more quickly Corneal Oedema Oedematous area of cornea: epithelium Causes: over-wearing of contact lens, surgical damage to cornea, inherited cornea dystrophies Hallmark symptom: halos or starbursts around lights, with or without reduced vision because: accumulation of fluid distorts optical properties of cornea Treatment: apply hypertonic saline solution or ointment (2-5%) to dehydrate cornea Corneal Edema Dry Eye Contrary to what the name suggests Very common eye disorder Symptoms: white or mildly red eye, sandy or gritty feeling & excess tearing Any abnormality in tear layers less lubrication to ocular surface leads to production of more inadequate tears “vicious cycle” What are the causes of dry eye? Dry Eye Causes: Aging Lid defects Sjögren’s Syndrome: a syndrome characterised by dry mouth, defective lacrimation and rheumatoid arthritis Bell’s palsy: peripheral paralysis of the facial nerve Medication: any with anticholinergic properties e.g. antihistamines, antidepressants, diuretics The goal in treating dry eye is to alleviate and control dryness of the ocular surface, so as to relief the symptoms and prevent possible damage Non pharmacologic: warm compresses, avoid atmosphere that causes evaporation of tear film Dry Eye Treatment: OTC lubricants and artificial tears (drops or ointments) Vitamin A: greatest benefit in treatment of severe dry eye associated with glandular tissue destruction Ocular inserts or Na If very severe dry eye: hyaluronate Occlusion of lacrimal drainage system to increase available tear pool How does artificial tears work? Compromised Tear Film For dry eye sufferers, dry spots on the surface of the eye cause irriation, and may create the potential for more serious damage to the surface of the eye. Artificial Tears drop of artificial tears The artificial tear solution is quickly absorbed and key ingredients rapidly work to help restore the tear film. All layers of the normal tear film is restored Lubricants solutions ointments solutions/ointments that help to alleviate dryness of ocular surface Viscosity according to the severity of the condition MOA: increase viscosity of existing tears, retard drainage and increase retention time. However, although viscous agents enhance the ocular retention time of tear substitutes, high viscosity itself does not provide relief for all dry eye conditions (Pharmaceutical Journal; 264 (7082):212-218; 2000) A. - - Artificial Tear Solutions (Demulcents) water-soluble polymers, preservative, electrolytes to control pH and tonicity Administered 3-4 times daily 1. Cellulose ethers: - - - - HPMC (hypromellose) ; HPC, HEC, methylcellulose, carboxymethylcellulose Colourless and vary in viscosity Methylcellulose 0.2-1.0%, if >2% ointment HEC & HPC solutions: are less viscous but have greater emollient (cohesive, film-making) properties than methylcellulose The most important property of cellulose ethers: stabilize tear film (surface active properties) and prevent evaporation Lack toxicity & irritation Other less viscous hydrophilic substances, such as polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (povidone or PVP), have been included as the polymeric ingredients of many artificial tear formulations. The tears of patients with dry eyes due to aqueous deficiency have been shown to have a higher osmolarity than normal subjects, a factor which may be responsible for the ocular surface disease in this condition. In such patients, hypotonic solutions such as polyvinyl alcohol 1 per cent with an osmolarity of 150 mOsm/L have been shown to be superior to an isotonic solution of 300 mOsm/L in providing symptom relief. 2. Polyvinyl Alcohol Important: avoid using PVA with ophthalmic products that contain: NaHCO3, Na-Borate, Na/K/Zn sulphate….. Cause: it will react and form a thick gel e.g. PVA-containing contact lens wetting solution & irrigants containing Na-Borate 3. Povidone (polyvinyl pyrrolidone; PVP) Exerts surface active properties similar to those of cellulose ethers forms hydrophilic layer on corneal surface, mimicking conjunctival mucin promotes wetting of ocular surface Patients with mild dry eye may benefit from instillation of one of these artificial tear drops up to four times a day. However, in moderate to severe cases, these preparations need to be instilled more frequently. To overcome this problem, preparations containing a longer-acting polymer, polyacrylic acid, also known as carbomer 940, have been introduced. Such preparations have a much longer retention time in the eye and symptom relief is obtained with significantly fewer instillations. In Jordan: 4. Retinol Solution An alcohol form of vitamin A Retinol palmitate aqueous ophthalmic solution is used for the treatment of dry eye failing to respond to the conventional therapy with artificial tears; The benefits of vitamin A in treatment of dry eye are speculative (lack controlled trials) Note: (Benzalkonium Cl) Benzalkonium chloride (BAK) is a poor choice preservative for artificial tear solution, because it has toxic effects on tear film & corneal endothelium* A single drop BAK can break the lipid superficial layer of tear film into numerous oil droplets Alternative preservatives: chlorhexidine, chlorbutanol, EDTA * Reference: Lemp MA, Zimmerman LE. Toxic endothelial degeneration in ocular surface disease treated with topical medications containing benzalkonium chloride. Am J Ophthalmol 1988;105:670-3. 5. Preservative-Free Formulations For patients who are sensitive to preservatives like benzalkonium chloride (BAK) & thimerosal* Formed as unit-dose dispensers More expensive than products with preservative. Requires strictly hygienic procedure: easy to get contaminated Discard any unused solution after 12 hours * Reference: Lee-Wong M, Resnick D, Chong K.A generalized reaction to thimerosal from an influenza vaccine. Ann Allergy Asthma Immunol. 2005 Jan;94(1):90-4. However,…… It is unlikely that patients purchasing dry eye products OTC would wish to bear the cost of unit dose preparations unless they fall into the category of patients in whom preserved eye-drops are contraindicated. WHO ARE THEY?? 1. patients allergic to, or intolerant of, preservative and 2. patients who wear soft contact lenses. B. non-medicated ointments (Emollients) 1. 2. Main advantage: melt at the temperature of the ocular tissue and are retained longer than other ophthalmic vehicles enhance integrity of tear film Preferably instilled at bedtime: To keep eyes moist during sleep & improve morning symptoms of dry eye Because they cause blurred vision e.g. white soft paraffin, lanolin and liquid paraffin. Decision Making Algorithm RED EYE Clinical presentation Management With pain With blurred vision With photophobia (light sensitivity) With history of trauma With contact lens wear (??) IMMEDIATE REFERRAL Decision Making Algorithm RED EYE Clinical presentation Management With history of pink eye exposure, cold, flu, and watery discharge Self-treatment and mucous discharge Referral Decision Making Algorithm RED EYE Clinical presentation With known allergies and itching, watery discharge and mucous discharge Management Self-treatment Referral Decision Making Algorithm RED EYE Clinical presentation Management With foreign body sensation and possible contamination Immediate Referral OTC ophthalmic products Lubricants: 1. Artificial tear solutions (demulcents); 2. Non-medicated ointments (emollients) Decongestants Antihistamines Irrigants Hyperosmotics Antiseptics Eyelid scrubs Multivitamins Decongestants Phenylphrine & Imidazoles (naphazoline, tetrahydrozoline & oxymetazoline) -adrenoceptor agonists vasoconstriction of conjuctival vessels If instilled to irritant/damaged cornea: dilate pupil may precipitate angle-closure glaucoma Systemic S.E: very rare at OTC dose Caution in patients with CVD, HTN or DM Decongestants Most common S.E if chronic use: rebound congestion “hyperameia” Rebound congestion is less with (naphazoline, tetrahydrozoline) than with phenylephrine and oxymetazoline In some patients “Xerosis” (abnormal dryness) with prolonged topical instillation of local decongestants Decongestants Napahzoline (0.02%): - The ocular decongestant of choice: higher efficacy and relative lack of S.E - in addition to constricting conjuctival vessels, it reduces pain & tearing associated with ocular inflammation - Patients with lightly pigmented irides (blue or green eyes) are more sensitive to the mydriatic effects of naphazoline Antihistamines Pheniramine maleate & Antazoline phosphate Indication: rapid relief of symptoms associated with seasonal allergic conjunctivitis Almost always used along with naphazoline: much more effective than if used individually Dose: 1-2 drops applied to each eye 3-4 times daily May cause mydriasis, because of anticholinergic C/I: sensitivity to one of the components or known risk to angle-closure glaucoma Irrigants Cleanse ocular tissues while maintaining their moisture Must be physiologically balanced: pH & osmolality Uses: (1) after certain clinical procedures to wash away mucus & debris from eye (2) to clean eyes in between changes of ocular dressings (3) wash out eyes after wearing contact lens (4) initial ocular lavage after chemical injuries to eye before seeing doctor Irrigants Should not be applied while contact lens is in place: because irrigants reduce mucin component of tear film discomfort absorption of BAK by soft contact lens deleterious effect on corneal epithelium Commercial irrigants that use an eye cup should be avoided difficult to clean risk of bacterial/fungal contamination Examples: normal saline, water, sodium borate Hyperosmotics Promote movement of fluid from cornea NaCl: solution and ointment (2-5%) 5% is more effective, but causes stinging, burning but 2% is preferable for long term use 1-2 drops instilled 3-4 times daily Several instillations in the 1st few waking hours are helpful as vision associated with corneal edema is worse on awakening Non toxic and very rarely to cause allergy Hyperosmotics C/I: in traumatised corneal epithelium Because: this will increase the permeability of the hyperosmotic solution and thus, reduces its local osmotic effect Management of such compromised cornea is usually with prescription rather than OTC medication refer to doctor if patient has a history of damaged epithelium Antiseptics To reduce bacterial population on ocular surface including eyelid margins May be recommended for patients with minor conjuctival or eyelid inflammation that is possibly associated with infectious organisms Examples: silver protein, Boric acid & zinc sulphate, distilled witch hazel Silver protein: A colloidal preparation of silver oxide and protein, usually gelatin or albumin, used as an antibacterial agent. Treatment of ocular infections and preoperative use in ocular surgery At low doses: antimicrobial activity against gram +ve and gram –ve bacteria Preoperative: 2-3 drops instilled then rinse with sterile irrigating solution In mild infections: several drops instilled every 3-4 hours for several days Avoid frequent topical application for prolonged periods of time may cause permanent discoloration of eyelid skin or conjunctiva “argyria” Boric acid Treatment of irritated, inflamed eyelids Applied in small quantity on the inner surface of the lower eyelid once or twice daily Zn sulphate Mild astringent for temporary relief of minor ocular irritation Also effective in infections cause by moraxella (uncommon gram –ve bacteria, member of the URT normal flora, occasionally cause infections) Eyelid scrubs Best treatment for blepharitis is maintain eyelid hygiene This is best done by hot compresses 15-20 minutes 2-4 times daily followed by eye lid scrubs using baby shampoo with cotton pad or a gauze Application Technique Procedure for eyelid scrubs 1. 2. 3. 4. 5. 6. Wash hands thoroughly Apply 3-4 drops of baby shampoo to cotton-tipped applicator or gauze pad Close one eye and clean the upper eyelid & eyelashes using side-to-side strokes, being careful not to touch the eye ball with applicator or fingers Open eye, look up and clean lower eye lid and eyelashes using side-to-side strokes Repeat procedure on other eye using a clean applicator or gauze pad Rinse eyelids and eyelashes with clean, warm water Multivitamins Deficiencies of vitamin A and zinc have been associated with certain ocular conditions Vitamin A, C, E and zinc have antioxidant free radical-scavenging effect that help in prophylaxis and treatment of degenerative ophthalmic conditions 6. Prosthesis Lubricant/Cleanser A sterile, buffered isotonic solution of 0.25% tyloxapol and 0.02% BAK, for cleaning and lubricating artificial eyes Tyloxapol: detergent surfactant, liquefies solid matter on artificial eye BAK: a quaternary surfactant, aids in wetting artificial eyes Apply while artificial eye in place, 1-2 drops 3-4 times daily for lubricant effect To clean & remove oily or mucous deposits: by rubbing artificial eye between fingers & rinse with water before insertion Ophthalmic antibiotic agents are used to treat superficial ocular bacterial and fungal infections. conjunctivitis, blepharitis, and corneal ulcers. Acute conjunctivitis is the most common disorder of the eye seen by the primary care physician, and the term encompasses a broad group of conditions presenting as inflammation of the conjunctiva. The most common pathogen of viral or bacterial infections varies with age. In children, that pathogen is H. influenzae and S. pneumoniae, and the pathogens in adults range from Staphylococcus to Pseudomonas, usually introduced as a contagious manifestation The topical agents used to treat ocular infections are grouped into various classes such as aminoglycosides (gentamicin, neomycin, and tobramycin), macrolides (erythromycin), fluoroquinolones (ciprofloxacin, levofloxacin, ofloxacin, gatifloxacin, and moxifloxacin), and others including chloramphenicol and natamycin (should be reserved for fungal eye infections).