Ophthalmology Quiz: Eye Conditions and Treatments

Sensory Challenges - Study Notes

• Sensory Challenges (Chapters 60 & 61, 4th Ed.)
• This material covers assessment and management of sensory challenges related to the eyes and vision disorders, hearing and balance disorders.
• The provided material is adapted from the textbook "Brunner & Suddarth's Canadian Textbook of Medical-Surgical Nursing".

External Structures of the Eye

• The eye has several external structures including the brow, upper and lower lids, inner and outer canthi, caruncle, lacrimal sac, naso-lacrimal duct, conjunctiva, sclera, limbus, and iris.
• The image provides a visual representation of these structures.

Cross-Section of the Eye

• This image details the internal structures including the retina, choroid, sclera, optic nerve, central retinal artery and vein, macular area, vitreous body, lens, iris, ciliary body, and rectus muscles.

Assessment and Evaluation of Vision

• Ocular History: Detailed medical history of the eye is significant.
• Visual Acuity: A Snellen eye chart is used. 20/20 indicates normal vision where a person can read a 20-foot line from 20 feet away.
• The chart also indicates that "finger count" and "hand motion" are used to describe visual impairment.

Examination of External Structures

• The examination needs to evaluate any signs of inflammation, irritation, discharge or other eye conditions.
• Eyelids and sclera to be assessed for any abnormalities
• Pupils and pupillary response are checked in a darkened room.
• Gaze and position of eyes should be noted (eye alignment)
• Extraocular movements should be evaluated

Diagnostic Evaluation

• Ophthalmoscopy: Direct or indirect examination of the cornea, lens, and retina
• Slit-Lamp Examination: Used to assess cataracts
• Fluoroscein angiography: Records blood flow in the retina to detect any neovascularization (new blood vessels).
• Colour Vision Testing: Include use of Amsler grid to evaluate for macular degeneration
• Ultrasonography: Used to assess for tumours or retinal detachment
• Optical Coherence Tomography: High-resolution imaging of the eye's structures to measure tissue thickness.
• Colour Fundus Photography: Image of the interior surfaces of the eye, used to identify colour variations and/or abnormalities.
• Laser Scanning: Used to provide images of the eye's surfaces. Indocyanine green angiography, tonometry (intraocular pressure), and gonioscopy (examination of the angle between the iris and cornea) are also part of the diagnostic procedures.
• Perimetry Testing: Measures the visual field (detects blind areas/scotomas).

Impaired Vision

• Refractive Errors: These arise from irregularities in the eye's shape that affect the focusing of light on the retina- they can be corrected with glasses. Types include emmetropia (normal vision), myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (distorted vision).

• Low Vision and Blindness: This section discusses the different levels of impaired/reduced vision, from "low vision", where corrective lenses and assistive technologies are needed, to "blindness”, where vision is significantly impaired. Legal blindness thresholds (BCVA—best corrected visual acuity) and field of vision thresholds are discussed.

Assessment of Low Vision

• History: Detailed history of visual impairment is crucial.
• Examination: Examination of distance and near visual acuity, visual field, contrast sensitivity, glare sensitivity, color perception, and refraction.
• Special Charts: Special charts aid the evaluation for low vision
• Nursing Assessment: Assessment of functional ability and coping mechanisms is important.

Management

• Coping Strategies: Strategies for adaptation to environmental changes and acceptance of visual loss
• Environmental Adaptations: Placement of items in the room, "clock method" for trays.
• Communication Strategies: Communication strategies are also detailed, to cater to different forms of needs (see Chart 60-3). Collaboration with low vision specialists, occupational therapists, and other resources is vital.
• Assistive Technologies: Alternative learning and communication such as Braille or assistive service animals are also mentioned.

Glaucoma

• Definition: A group of ocular conditions where optic nerve damage occurs due to increased intraocular pressure (IOP) caused by congestion of the aqueous humour.

• Causes: One of the leading causes of blindness in adults; incidence of glaucoma increases with age. Several risk factors are noted (see Chart 60-5).

• Pathophysiology: Aqueous humour production and drainage are not balanced, leading to intraocular pressure increase. Increased IOP causes irreversible damage to the eye.

• Types: Open-angle and closed-angle glaucoma (including acute, subacute, and chronic forms) are described.

• Clinical Manifestations: Glaucoma is often referred to as the "silent thief" because initial symptoms are often subtle and unnoticeable. Vision loss (peripheral), blurring, halos, and difficulty adjusting to lighting are indicators of the disease.

• Diagnostic Findings: Tonometry (measuring IOP), gonioscopy (visualizing the angle between iris and cornea), and perimetry (assessing the visual field) are key diagnostic tools.

• Treatment: Aim is to prevent further optic nerve damage by maintaining IOP (intraocular pressure) in a suitable range. Pharmacologic therapy (see Table 60-5) and surgical interventions are used (laser trabeculoplasty, laser iridotomy, filtering procedures, trabeculectomy, drainage implants/shunts).

Cataracts

• An opacity or cloudiness of the lens, which can lead to vision impairment. Cataracts are a leading cause of visual problems in older adults in Canada. Surgery is highly common to treat such conditions.

• Risk Factors: Age, toxic exposures, diabetes, nutrition, renal issues, and traumatic events. These factors are mentioned to be found in Chart 60-8 in the provided notes.

• Clinical Manifestations: Painless, blurry vision, sensitivity to glare, reduced visual acuity, myopic shift, astigmatism, diplopia (double vision), colour shifts (brunescens), opacity of the lens. This can be diagnosed using slit-lamps, ophthalmoscopes for inspection and other visual acuity tests, as mentioned in the notes.

• Surgical Management: Elective procedure, mostly performed outpatient with local anaesthesia.

• Types of Surgery: Intracapsular cataract extraction (ICCE), Extracapsular cataract extraction (ECCE), Phacoemulsification, and Lens replacement. These are the different types of surgical options available for patient care, as described in the notes.

• Nursing Management: Pre-operative instructions will include the monitoring of any eye drops, as ordered. Post-operative instructions will include detailed guidance on home care checkups.

• The patient should be educated/advised to immediately report any change in vision, continuous flashing lights, pain increase, increased drainage or any other unusual/concerning symptoms.

Corneal Disorders

• Treatment: Treatments for diseases/disorders of the corneal tissue, such as, Phototherapeutic keratectomy (PTK), Keratoplasty, Use of donor tissue, Follow-up and support, Potential graft failure, Refractive surgery. Counselling is essential for patients about the risks, benefits, and likely complications as part of patient care.

Retinal Disorders

• Retinal detachment: Separation between sensory retina and retinal pigment epithelium. Manifestations include sensation of shade or curtain, bright flashes of lights, and sudden floaters. Diagnostic findings require assessing visual acuity, retinal observation with indirect ophthalmoscopy, slit-lamp biomicroscopy, stereo fundus photography, fluorescence angiography and tomography and ultrasounds.
• Retinal vascular disorders: These include central retinal vein occlusion, branch retinal vein occlusion, central retinal artery occlusion and macular degeneration.
• Age-related macular degeneration (AMD) is a notable condition, that affects the central vision. There's both dry (nonexudative) and wet (exudative) types. Dry type is more common and characterized by slow breakdown of retina layers, and the appearance of macular drusen. Wet type may have sudden onset with growth of abnormal blood vessels under retina- called neovascularization (CNV).

Retinal Detachment Treatment

• Surgical Treatment: Scleral buckle, Pars plana vitrectomy for vitreous removal, Pneumatic retinopexy (using gas, liquid, or oil to push the retina against the RPE layer.).

Nursing Management for Retinal Detachment and Other Retinal conditions

• Includes teaching patients about signs and symptoms (increased IOP, infection), promoting comfort (special positions with pneumatic retinopexy), and offering patient teaching regarding the procedure, complications and other relevant information about the eye condition.

Retinal Vein or Artery Occlusion

• Occlusion arises from atherosclerosis, cardiac valvular disease, venous stasis, hypertension, and increased blood viscosity. Risk factors include diabetes mellitus, glaucoma, and aging.
• Patients often report decreased visual acuity or sudden loss of vision.

Age-Related Macular Degeneration (AMD)

• AMD is the leading cause of severe vision loss in older adults.
• Includes both dry (nonexudative) and wet (exudative) types.

Vision Loss Associated with Macular Degeneration

• Visual field distortions/deficits are possible, likely to be apparent upon assessment.

Nursing Management of AMD

• Patient teaching/supportive care, safety recommendations (improving lighting/magnification devices/referral to vision centre).

Ophthalmic Medications

• Absorption limitations: Eye absorption is limited by conjunctival sacs,corneal membranes, ocular barriers, drainage, tears, blinking etc.
• Medication types: Topical medications (eye drops/ointments) are most common due to low invasiveness, fewer side effects and self-administration options.
• Medications for Glaucoma: Increase aqueous outflow or decrease production, potentially causing pupil constriction which may affect vision.
• Anti-inflammatories/steroids: Topical steroids can have side effects like glaucoma, cataracts, and increased infection risk.
• Guidelines for instillation: Specific instructions are given for instilling eye medications (e.g., shaking suspensions, cleaning hands, adequate lighting, position, and avoiding contamination.) and other important factors like waiting duration.

Safety Measures and Teaching

• Patient teaching: Vital for eye/vision disorders, also for prevention of injuries and safety strategies for low-vision patients within hospital settings and especially at home conditions.
• Potential Complications: Loss of binocular vision, patches, vision impairment, potential use of eye patches/shields.

Hearing and Balance Disorders (Chapter 61)

• Anatomy: Includes auricle, the external auditory canal, tympanic membrane, ossicles, cochlea, semicircular canals, the organ of Corti, and related nerves. A visual description of the ear anatomy is provided.

• Assessment: Examination of the external ear with otoscope, evaluating gross auditory acuity, whisper test, Weber and Rinne test procedures are detailed. This section also discusses the technique for using an otoscope.

• Diagnostic Evaluation: Procedures including audiometry, tympanogram, auditory brain stem response (ABR), electronystagmography, platform posturography, sinusoidal harmonic acceleration, and middle ear endoscopy.

• Hearing Loss: Factors and types include conductive loss (external/middle ear), sensorineural loss (inner ear structures damage), mixed, and functional/psychogenic loss, age-related hearing loss (presbycusis).

• Manifestations: Early symptoms include tinnitus (perception of sound), difficulty hearing in groups, turning up the volume of audio devices, gradual deterioration in hearing may occur over time causing social and communication issues.

• Communication guidelines: Guidelines for communicating with hearing impaired patients, including using a low-tone normal voice, speaking slowly and clearly, minimizing background noise and distractions, facing the individual and speaking into the better ear (if applicable). Strategies for additional resources such as sign language translators or written communication might also be necessary.

Review Questions

• A series of questions are provided, covering various topics related to eye and vision, and hearing and balance disorders to assess understanding.

Test your knowledge on ophthalmology with this quiz focusing on aqueous outflow, intraocular pressure, and common eye conditions. Explore questions about medications and diagnostic techniques like fluorescein angiography. Challenge yourself and enhance your understanding of eye health.