8ConceptionThe ocular surface is a complex biological continuum responsible for the maintenance of corneal clarity, elaboration of a stable tear film for clear vision, as well as protection of the eye against microbial and mechanical insults.Comprising a variety of disorders on cornea, eyelid, conjunctiva, lacrimal apparatus and tear film.
9Classification Corneal, conjunctival lesion Tear film disorders Squamous epithelization typeLimbal stem cell deficiency typeTear film disordersAqueous tear deficiencyLipid tear deficiencyMucoprotein deficiencyKinetic disorders of lacrimal fluid
10Treatment Reconstruction Epithelium, limbal stem cells Lacrimal secretion, tear filmInnervation (nerve restore)Structure and function of eyelidSurgical operationTo re-establish conjunctiva, cornea, tear film and eyelid.
12ConceptionDry eye (known by doctors as keratoconjunctivitis sicca) is a chronic lack of sufficient lubrication and moisture in the eye.Its consequences range from subtle but constant irritation to ocular inflammation of the anterior (front) tissues of the eye.
13Tear Secretion Lacrimal gland Producing the watery part of the tear film called the aqueous.Meibomian glandsProducing lipids which keep the tear film from evaporating.Goblet cells of the conjunctivaProducing mucin which allows the wetting of the ocular surface as well as stabilizes the tear film.
15Clinical Manifestation Dry eye symptomsasthenopiairritation, grittinessdrynessburningophthalmalgialight sensitivitypink-eyeDo you regularly experience one or several symptoms above?Some diseases and conditions (like rheumatoid arthritis, lupus and Sjögren’s Syndrome) also cause chronic Dry Eye in many patients.On the other hand, activities like reading, Wearing contact lenses or working at the computer may cause Dry Eye.
16Diagnostic Tests for Dry Eye Dry Eye questionnaireLacrimal river widthSchirmer test – uses paper strips under eyelid to measure the wetness that collects over a specific period of time.Break-up time of tear film (BUT)Staining – uses special dyes to highlight areas of possible damage to the eye surface.Tear ferning testLactoferrin contentsTear penetration pressure testCorneal tonographic mapImpression cytology
17Diagnosing Schirmer test, BUT, Staining Foundation Symptom Instability of tear filmDamage on epitheliumTear penetration pressure increasing
19Treatment According to the clinical category For tear deficiency: Maintain moisture in the eyes; reducing the evaporation; increasing the secretion; controlling inflammation & immunoreaction.For over-evaporation: Therapy the Meibomian gland dysfunction; controlling inflammation; cleaning eyelid; decreasing the evaporation; lipid replacement.According to the eye conditionsFor intermittent symptoms: Artificial tears add volume to the tear film as long as they remain in contact with the surface of the eye.For midrange dry eye: Artificial tears and punctal occlusion.For Severe dry eye: Appending cyclosporin, surgery.
20Summary Eliminating the etiological factors Tears replacement therapy Maintain moisture in the eyesIncreasing the tear secretionImmune inhibition therapyRe-establish the tear filmOther supporting treatment
22Etiological Factor Failure of the glands to produce or secrete lipids. Wax ester declining and cholesterol increasing make the symptoms worse .Lack of tears and tear penetration pressure increasing.Lupus, brandy nose etc.
23Clinical Manifestation Common in aged people and who lived in cold region.No specific symptoms.Lid-margin mostly thickening; abnormal secretionwhile pressurizing.Disorder in Meibomiangland, eyelid, conjunctiva.Figure: Notching of the lid caused by loss of meibomian glands.
24DiagnosingAbsence of Meibomian gland.The gland orifices are often compromised due to stenosis or closure.A declining quality and quantity of lipid secretion.Anyone of the physical signs can make the diagnosis of Meibomian gland dysfunction if the patient has clinical symptoms.Figure: No visible meibomian gland orifices: Eversion of the lower lids in both eyes showed atresic meibomian glands.
25Treatment Clearing Hot fomentation on eyelids for 5~10mins. Massaging the eyelids.Swabbing the lid-margin with mild cleaning solution.