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Ophthalmic diseases

  1. By Bahaa Halwany Department of Ophthalmology Medicals international
  2. A. In Accessory structure 1. Dry eyes 2. Conjunctivitis B. In Fibrous Tunic 1. Keratoconus 2. Refractive errors C. In Vascular tunic 1. Uveitis D. In Nervous Tunic 1. Color blindness 1. Retinal detachment 2. Diabetic retinopathy 3. Age-related Macular Degeneration E. In interior of Eyeball 1. Glaucoma 2. Cataract 3. Floaters
  3. Dry eyes either do not produce enough tears or have poor tear quality Any deficiency within the tear layers will cause dry eyes keratoconjunctivitis sicca (KCS) its due to an inadequate amount of the water layer in tears.
  4. Age Gender Medications Medical conditions Environmental conditions Other factors
  5. Artificial tear solution Blocking the tear ducts with tiny silicone or gel-like plugs that can be removed.
  6. Infection of the conjunctiva. Common in children and is very contagious. Symptoms include:  Red eyes  Swelling of conjunctiva  Watering of the eyes  Itching  Sensitivity to light There are four types of Conjunctivitis.
  7. Types Symptoms /Description Treatment Bacterial • Large amount of discharge that is green to yellow in color •Usually lasts 3 to 5 days Requires antibiotics eye drops to help remove the infection Viral • Caused by viruses • The discharge is clear and watery • Symptoms of cold may be present Will not respond to antibiotics Topical antiviral agents Allergic • Caused by allergens such as pollen, perfumes, cosmetics, smoke, dust… Can respond to allergy treatment or disappear on its own. Chemical • Caused by chemicals irritants such as air pollution, smoke, or noxious fumes. Usually, no treatment is needed
  8. Keratoconus is a degenerative disorder Structural changes within the cornea cause it to thin and change to a more conical shape
  9. Symptoms • Distorted vision with multiple images • Progressive nearsightedness • Irregular astigmatism to develop • sensitivity to light Causes • Imbalance of enzymes within the cornea; becoming more susceptible to oxidative damage by free- radicals • Hereditary predisposition • Exposure to UV light • Excessive eye rubbing • Poorly fitted contact • Chronic eye irritation Treatment • Rigid gas permeable (RGP ) lenses • Hybrid lens • Intrastromal corneal ring segments(Intacs) • Corneal collagen cross-linking • Corneal transplantation
  10. Type of Errors Reason Effects Correction Myopia (Nearsightedness) • Lens is thickened • The eyeball is too long • The cornea has too much curvature Image focused in front of the retina Concave lenses Hypermetropia (Farsightedness) • Thin lens •The cornea is not curved enough •Shortened eyeball Image is focused behind the retina Convex lenses Presbyopia Aging, lens looses elasticity Decline of accommodation, close objects difficult to see Reading glasses (convex lenses)
  11. Type of Errors Reason Effects Correction Astigmatism • Difference in degree of curvature refraction of the two different meridians •The inability of the optics of the eye to focus a point object into a sharp focused image on the retina. •Vision is blurred Cylindrical lenses are used to correct vision Types of astigmatism Description Regular astigmatism – principal meridians are perpendicular • With-the-rule astigmatism – the vertical meridian is steepest • Against-the-rule astigmatism – the horizontal meridian is steepest • Oblique astigmatism – the steepest curve lies in between 120 and 150 degrees and 30 and 60 degrees. Irregular astigmatism – principal meridians are not perpendicular. •Caused by a corneal scar or scattering in the crystalline lens, and cannot be corrected by standard spectacle lenses, but can be corrected by contact lenses.
  12. Inflammation of the uvea Caused by Foreign organisms, injury, inflammatory diseases Symptoms • Eye redness • Blurred vision • Increased sensitivity to light • Floating spots before the eyes. Treatment • Steroid eye drops • Antibiotic • If untreated glaucoma, cataracts, abnormal growth of blood vessels will develop
  13. Iritis: • Inflammation of the iris • Associated with autoimmune disorders such as rheumatoid arthritis. • May develop suddenly • May last up to 8 weeks even with treatment. Cyclitis • Inflammation of the ciliary body. • Develops suddenly and may last several month Choroiditis • An inflammation of the choroid, the layer beneath the retina. • Can be caused by an autoimmune disease such as lupus.
  14. Absence or deficiency of one of the three cone photopigments. Color blindness is an inherited condition and cannot be treated. Other color vision problems are caused by: Aging Disease Injury to the eye Optic nerve problems
  15. A disorder of the eye in which the retina peels away from its underlying layer of support tissue. Initial detachment may be localized, or broad but without rapid treatment the entire retina may detach, leading to vision loss and blindness.
  16. Retinal Detachments Description Rhegmatogenous retinal Detachment • Is a retinal break, hole or tear. • Liquid from the vitreous gel passes through the tear • Accumulates behind the retina • Flashing lights, floaters, or a veil drawn over the field of vision may be the initial symptoms. Exudative retinal detachment • Is a breakdown in the normal inner or outer blood-retinal barrier • Allowing build-up of fluid beneath the retina. Traction retinal detachment • Scar tissue or other abnormal tissue grows on the surface of the retina, • Pulling the retina away from the layer beneath it.
  17. Identification of the hole through microscopic headlight. Sealed with diathermy, cryoprobe, or laser Sclera buckle made of (silicone, plastic or sponge) compresses the eye Surgeon drains fluid from behind the retina through a small slit in the sclera Air bubbles are placed into the vitreous cavity keeping the hole in proper position
  18. • Injection of gas bubble into the eye, after which laser or freezing treatment is applied to the hole. • Seals the hole allowing the retinal pigment epithelium back into place. • It’s simpler and less costly than scleral buckle. If unsuccessful scleral buckle still can be performed.
  19. 1. Incision through the pars plana with continuous irrigation 2. Insert of fiber optic light source through a 2nd incision 3. Insert of cutter through a 3rd incision 4. Removal of central vitreous and replaced with BSS 5. Vacuum values are lowered when approaching the retina 6. High speed cutting extracting the remaining vitreous 7. Air is switched on and BSS is evacuated using a cutter or a flute needle 8. Laser or cryo is used for retinal detachment 9. Injection of silicon oil 10. Silicon-gas extraction occurs after 2weeks to 4 months.
  20. Is caused by the blood vessels of the retina not receiving enough oxygen If untreated it may lead to blindness All people with diabetes are at risk
  21. Types or Diabetic Retinopathy Description Nonproliferative retinopathy: • Hemorrhages (bleeding) in the retina • Leakage of blood causing a “wet retina” • Diminishing vision. Proliferative retinopathy: • New abnormal fragile vessels develop on the surface of the retina • May grow toward the center of the eye. • These vessels frequently bleed into the vitreous causing severe visual problems.
  22. Stages Description Mild non proliferative retinopathy Micro-aneurysms occur( swelling in the blood vessels) Moderate non proliferative retinopathy Some blood vessels that nourish retina are blocked Vision may be diminished Severe non proliferative retinopathy More blocking of blood vessels. Retina send signals to the body to grow new blood vessels for nourishment Proliferative retinopathy New growth of abnormal and fragile vessels along the retina and surface of the clear vitreous gel. Bleed into vitreous causing severe visual problems To prevent progression of Diabetic retinopathy People with diabetes should control their levels of blood sugar, blood pressure, and blood cholesterol.
  23. Proliferative retinopathy: treated with Scatter laser treatment  Shrinking the abnormal blood vessels If the bleeding is severe a vitrectomy is needed Macular edema: Macular edema is treated with laser surgery focal laser treatment.
  24. AMD destroys the macula, impairing central vision. It rarely causes blindness because only the center of vision is affected.
  25. Wet AMD, abnormal blood vessels behind the retina start to grow under the macula and leak blood and fluid, causing loss of central vision
  26. Laser Surgery Photodynamic therapy Anti-VEGF injection
  27. Dry AMD, is a gradual breakdown of the light-sensitive cells in the macula  Treatment: High dose of antioxidants and zinc significantly reduces risk of advanced AMD Stages Description/Symptoms Early AMD  Small or medium sized dursen.  No symptoms or vision loss Intermediate AMD  Many medium-sized or one or more large sized dursen.  Blurred spot in the center of the vision  more light may be needed for reading and other tasking Advanced AMD  Drusen with breakdown of light sensitive cells and supporting tissue in the central retinal area  Blurred spot in the center of vision which may get bigger and darker with time taking more of central vision.
  28. Increase in fluid pressure inside the eye leads to: Increase in IOL pressure Optic nerve damage and loss of vision
  29. Open-angle glaucoma: The structure of the eye is normal but drainage of the aqueous humor thru the trabecular meshwork is faced with resistance due to narrowed openings of the latter.
  30. Angle-closure glaucoma: This happens when the drainage canals get blocked or covered over. the iris is not as wide and open as it should be. The outer edge of the iris bunches up over the drainage canals, when the pupil enlarges too much
  31. Eye drops Iridotomy Trabeculoplasty Cyclophotocoagulation Microsurgery (trabeculectomy)
  32. A cataract is a clouding of the lens inside the eye which leads to a decrease in vision. Two major types of cataract: Congenital and Acquired cataract
  33. Opacification of the lens obstructs light from passing and being focused onto the retina May be caused by injury, exposure to ultraviolet rays, certain medication such as steroids or complications of other diseases such as diabetes.
  34. Phacoemulsification is the most common procedure to remove the opacified lens 1. Making a small incision and Paracentesis in some cases 2. Injecting a viscoelastic solution into the anterior chamber reducing shock into the intraocular tissues 3. Performing Capsulorhexis 4. Hydrodissection/hydrolineation 5. Sculpting the opacified nucleus and cortex by U/S 6. Irrigation/aspiration 7. Injecting viscoelastic again 8. Implanting IOL 9. Irrigation/aspiration 10. Suturing
  35. Floaters are deposits of various size and shapes within the eye’s vitreous humor. Floaters are visible because of the shadows they cast on the retina or their refraction of the light that passes through them.
  36. Floaters are due to degenerative changes of the vitreous humor. This gel-like substance consists of 99% water and 1% solid elements. The solid depolymerization of collagen makes the hyaluronic acid release its trapped water, thereby liquefying the gel. The collagen breaks down into fibrils, which are the floaters.
  37. No treatment is usually recommended. However, vitrectomy and laser vitreolysis may be useful in severe cases.

Hinweis der Redaktion

  1. Age: symptoms are experienced at age 65+ Gender: women develop dry eyes due to hormonal changes caused by pregnancy, the use of oral contraceptives (birth control) and menopause. Medications: certain medicines can reduce tear production (antihistamines, decongestant, antidepressants and blood pressure medications) Medical conditions: such as rheumatoid arthritis, diabetes, and thyroid problems. Or inflammation of the eyelids or surface of the eye Environmental conditions: exposure to smoke, wind and dry climates. Failure to blink regularly ( i.e.: when looking at a pc screen) Other factors: long term use of contact lenses. Refractive eye surgeries, such as LASIK.
  2. Laser Surgery: It involves aiming an intense "hot" laser at the abnormal blood vessels in your eyes to destroy them. Photodynamic therapy: This technique involves laser treatment of select areas of the retina, verteporfin is injected into a vein, The drug is absorbed by new, growing blood vessels. Once activated, the drug closes off the new blood vessels, slows their growth, and slows the rate of vision loss.
  3. Drusen are made up of lipids, a fatty protein
  4. Eye drops: either to reduce formation of fluid or to increase its outflow. iridotomy, in which a tiny whole is made in the iris, allowing the fluid to flow more freely. trabeculoplasty, in which a laser is used to pull open the trabecular meshwork drainage area cyclophotocoagulation, in which a laser beam treats areas of the ciliary body, reducing the production of fluid. Microsurgery: in a trabeculectomy, a new channel is created to drain the fluid, thereby reducing intraocular pressure that causes glaucoma