Term | Definition |
What happens to the lens as we age? | Lens hardens and become too large for the eye muscles |
Snellen’s test | test for visual acuity. |
Amsler’s chart | chart used to detect defects of the macular area of the retina. |
Exophthalmometry | equipment used to measure the degree of forward placement of the eye. |
Slit-lamp | equipment used to examine the conjunctiva, lens, vitreous humor, iris, and cornea. |
Tonometry | equipment used to measure intraocular pressure to detect tumors and glaucoma; intraocular pressure can be measured by using a Schiotz tonometer, but most accurate reading are obtained by applanation tonometry. |
Schirmer’s tear test | study measures tear volume produced throughout fixed time period. |
Ophthalmoscopy | - evaluation of the underlying structure of the eye; routine screening; using mydriatic drops to dilate the pupil. |
Retinoscopy | refraction through retinoscope or sample lens that measures visual acuity to determine nearsightedness, farsightedness, presbyopia (inability to focus on close objects) and astigmatism (blurred vision). |
Total blindness | no light perception and no usable vision. |
Functional Blindness is present when | the patient has some light perception but no usable vision. |
Legally blind | refers to individuals with a maximum visual acuity of 20/200 with corrective eyewear and/or visual field sight capacity reduced by 20 degrees. |
Etiology of blindness | (1) Congenital from defects.
(2) Results from diabetes retinopathy, glaucoma, cataracts, retinal degeneration, and acute trauma. |
Etiology of astigmatism | may be hereditary or a muscular deficit. Blurring of vision. Eye discomfort, blurred vision, difficulty focusing. |
Etiology of strabismus | neurological or muscular dysfunction. Only one eye can fix on an object because axes do not focus simultaneously. Eyeball position is not symmetrical. difficulty following objects; objective- only one eye focuses. |
Etiology of Myopia | elongation of the eyeball, refractory error focuses light in front of the retina. Difficulty seeing at a distance. difficulty seeing faraway; objective- note ability to read road
signs or describe an object in the distance, Snellen’s test. |
Etiology of Hyperopia | refractory error where rays of light entering the eye are brought into focus behind the retina. Difficulty |
Hordeolum (stye) | infection of eyelid margins or sebaceous glands of the eyelashes. (Staphylococcus organism). Abscess at base of eyelashes, edema of lid. : tenderness; pain with edema. raised, red area, pustule with exudate. |
Blepharitis | inflammation of eyelid margins. Pruritis, erythema of eyelid, eye pain, photophobia. Tearing may occur in nonulcerative type. pruritis of the eye, lids adhere together during sleep. erythema, patient rubs eyes, light sensitivity, tear spillage. |
Ulcerative Blepharitis | bacterial infection; usually staphylococcal organisms. |
Non-ulcerative Blepharitis | caused by psoriasis, seborrhea or allergic reaction. |
Chalazion | inflammatory cyst on the meibomian gland at the eyelid margin. Visual disturbances. c/o pressure felt as eyelid closes over cornea, visual changes. Cyst formation; eyelid edema. |
Conjunctivitis (Pink Eye) | inflammation of the conjunctiva caused by bacterial
or viral infection, allergy or environmental factors. |
Conjunctivitis: Major causative agents include | Pneumococcal, staphylococcal, streptococcal, gonococcal and chlamydial organisms. |
Keratitis | Inflammation of the cornea resulting from injury; irritants; allergies; viral infections; congenital syphilis, or smallpox; dirty contact lens. |
Sulamyd | Sulfacetamide sodium |
Sulamyd (Sulfacetamide sodium) Use: | treatment of ocular infections |
Garamycin | Gentamycin sulfate |
Garamycin (Gentamycin sulfate) Use | ocular inflammation |
Keratoconjunctivitis sicca | caused by a lacrimal gland disorder from an autoimmune disorder. |
Sjogren’s syndrome. | Keratoconjunctivitis sicca associated with dry mouth |
Keratoconjunctivitis sicca Assessment | Subjective: minimal tearing complains of sandy/gritty sensation. |
Keratoconjunctivitis sicca Dx test | Schirmer's test - measures tear volume |
Keratoconjunctivitis sicca Medical Management | Nonprescription products ex: Artificial tears.
Punctual plugs to close tear ducts.
HRT for menopausal women.
Limit medications that may cause dry eyes as a side effect.
Use of filtering machine to reduce environmental irritants; surgery. |
Artificial tears | Liquifilm Forte Polyvinyl |
Ectropion | outward turning of the eyelid margins. (c) Paralytic Ectropion occurs when the orbicularis oculi muscle are disturbed as in Bell’s Palsy. |
Entropion | inward turning of the eyelid. atrophy of the eyelid tissue, scarring of the tarsal plate - congenital or trauma. |
Cataracts | non-infectious opacity or clouding of the lens. |
Cataracts Etiology | Congenital.
Systemic diseases.
Trauma.
Toxins.
UV light.
Corticosteroids.
Aging.
Intraocular inflammation.
Patients who have diabetes develop cataracts at an earlier age.
Smoking is linked. |
Cataracts Clinical Manifestations | Blurred vision.
Diplopia.
Photosensitivity.
Glare.
Difficulty driving at night.
No pain.
Visual distortions. |
Cataracts Dx Tests | Ophthalmoscope or slit-lamp microscopic examination. |
Cataracts Medical Management | surgical intervention either intracapsular (removal of lens with its capsule) or extra capsular (removal of the lens leaving posterior portion of its capsule) is the preferred method. Usually a same day surgery procedure. |
Diabetic retinopathy | disorder of retinal blood vessels characterized by a series of capillary microaneurysms, hemorrhages, exudates, and the creation of new blood vessels and connective tissue. |
Diabetic retinopathy Etiology | after about 15 years with DM nearly all patients with Type 1 have some degree of retinopathy. |
Diabetic retinopathy Clinical Manifestations | initially identified through ophthalmoscope examination, later by the evidence of “floaters”. |
Photocoagulation | laser beam seals leaking blood vessels; destroys new ones. coagulates tissue protein of the retina. |
Vitrectomy | removal of excess vitreous fluid caused by a hemorrhage and replacement with normal saline, and removal of scar tissue. Used when Photocoagulation is not possible. |
Cryotherapy | a procedure in which a topical anesthetic is used so that a cryoprobe can be placed directly on the surface of the eye. |
Macular degeneration | condition of aging retina with slow loss of central and near vision. |
Wet type or neovascular degeneration | new vessel growth in the macular region; macula is displaced, and scarred. Scarred cells cannot register light. Blindness occurs in 10% of cases. Tx photocoagulation. |
Dry type or nonexudative or nonneovascular degeneration | Outer layers of the retina break down.
Lipid deposits are followed by slow atrophy of the macular region.
Characteristic small yellowish hyaline deposits (drusen) form within the macula resulting in blurred vision.
No known treatment. |
Macular degeneration Clinical Manifestations | Gradual loss of bilateral central vision, color perception is affected. |
Macular degeneration assessment | Subjective: loss of ability to see objects clearly, distorted vision, gradual loss of clear color vision, dark/empty center of vision.
Objective: note degree to which the patient can centrally view objects. |
Macular degeneration Dx Tests | Indirect ophthalmoscopy. Amsler grid test may help define
involved area. |
Macular degeneration Medical Management | telescopic and microscopic special lenses. |
Retinal detachment | separation of the retina from the choroid. |
Retinal detachment Etiology | usually from a hole in the retina that allows vitreous humor to leak between the choroid and the retina.
Immediate cause; trauma to the eye.
May also occur in severe physical exertion.
Most common cause-age related changes. |
Retinal detachment Clinical Manifestation | sudden or gradual development of flashes of light, floating spots, loss of specific field of vision. |
Retinal detachment Assessment | Complaints of "flashes/floaters".
"Curtain drawn over the eye".
Observation of ability to perform ADLs. |
Retinal detachment Dx Tests | Direct and indirect ophthalmoscopy.
Slit lamp examination.
Ultrasound examination. |
Retinal detachment Medical Management | Photocoagulation.
Cryosurgery is used to freeze the borders of a retinal hole.
Diathermy is used to burn a retina break using ultrasonic probe.
Scleral buckling. |
Glaucoma | An abnormal condition of elevated pressure within the eye because of the obstruction of the outflow of aqueous humor; associated with progressive loss of peripheral vision. |
Glaucoma occurs | when there is an obstruction of aqueous humor drainage that increases
intraocular pressure, and causes damage to the optic nerve. |
Open-angle glaucoma | progressive and results in degenerative changes and may be bilateral. |
Closed-angle glaucoma | occurs when there is an abrupt angle change of the iris. |
Open-angle glaucoma Clinical Manifestations | no s/sx in early stages; later stages: tunnel vision, eye pain, halos, inability to detect color and high intraocular pressure. |
Closed-angle glaucoma Clinical Manifestations | severe pain, immediate vision, nausea and vomiting; high intraocular pressure and optic disc cupping. |
Closed-angle glaucoma Dx Tests | Schiotz tonometry or Applanation tonometry. |
Open-angle glaucoma Medical Management | 1) Treat with medication: beta-blockers, mitotic, carbonic anhydrase inhibitors.
2) Surgical intervention: trabeculectomy, which removes the corneoscleral tissue, canal of Schlemm and trabecular meshwork. |
Closed-angle glaucoma Medical Management | 1) Treat with osmotic diuretics. |
Glaucoma Surgical Interventions | (a) Iridectomy, which removes part of the iris.
(b) Iridotomy, which is an incision in the iris of the eye to create an opening for
the aqueous flow. |
Incidence of glaucoma directly related to age so ophthalmologic examination. | Every 2 to 4 years between 40-64 years.
Every 1 to 2 years age 65. |
Glaucoma Medications: Beta Adrenergic (Reduces the formation of aqueous humor.) | Used for open-angle glaucoma.
Betopic (Betaxolol hydrochloride).
Timoptic (Timolol maleate). |
Glaucoma Medications: Carbonic Anhydrase Inhibitor (lowers intraocular pressure). | Used for open-angle glaucoma.
Diamox (Acetazolamide) |
Glaucoma Medications: Mitotics (Reduces intraocular pressure). | Used for open-angle glaucoma.
Pilocar (Pilocarpine hydrochloride) |
Glaucoma Medications: Anticholinergic | Used for Dx purposes only.
Cyclogyl (Cyclopentolate hydrochoride) |
Glaucoma Medications: Osmotic Diuretic | Used for glaucomas.
Mannitol (Osmitrol) |
Corneal injuries | injuries to the corneal layers of the eye. |
Enucleation | surgical removal of the eyeball, followed by surgical implantation of a cornea from another donor; highly successful if transplant area is small. |
Keratoplasty | excision of the corneal tissue, followed by surgical implantation from another human donor; if implantation is small, high success rate; if large, high donor rejection rate. |