Eye Exam

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History

• Ocular symptoms: degree of pain, redness, discharge, blurred vision, photophobia, duration of symptoms, circumstances surrounding the onset of symptoms
• Contact lens history: wearing schedule, overnight wear, type of contact lens, contact lens solution, contact lens hygiene protocol, tap-water rinse of contact lenses, swimming, using a hot tub or showering while wearing contact lenses
• Review of other ocular history, including risk factors such as previous HSV keratitis
• Review of other medical problems and systemic medications
• Current and recently used ocular medications
• Medication allergies

Examination

The physical examination includes measurement of visual acuity, external examination, and slit- lamp biomicroscopy.

Visual Acuity

Patient discomfort, photophobia, and tearing may compromise determination of visual acuity. It is important, however, to document baseline visual acuity and to ascertain that it is consistent with the anterior segment examination.

Visual fields

	Unilateral anopia – complete loss of vision in one eyeUnilateral optic nerve lesion or ocular pathology
	Bitemporal hemianopia – loss of lateral vision in both eyesOptic chiasmal compression
	Homonymous hemianopia – loss of left or right field in both eyesContralateral optic tract lesion
	Homonymous inferior quadrantanopia – loss of the left or right lower quarters of vision in both eyesContralateral lower optic radiation lesion
	Homonymous superior quadrantanopia– loss of the left or right upper quarters of vision in both eyesContralateral upper optic radiation lesion
	Homonymous hemianopia with macular sparingContralateral occipital lobe lesion

External Examination

An external examination should be performed with particular attention to the following:

• General appearance of the patient, including skin conditions
• Facial examination
• Preauricular adenopathy
• Globe position
• Eyelids and eyelid closure
• Conjunctival discharge
• Nasolacrimal discharge
• Corneal sensation

Slit-Lamp 

should include evaluation of the following:

Eyelid margins:

• Inflammation
• Ulceration
• Eyelash abnormalities, including trichiasis/distichiasis
• Lacrimal punctal anomalies
• Ectropion/entropion

Conjunctiva:

• Normal – translucent, flat, sclera visible beneath
• Abnormal – Injected – bloodshot – Chemosis (oedema) – Discharge – Subconjunctival haemorrhage – Lacerations – Lesions

Sclera:

• Inflammation
• Ulceration
• Scar/thinning
• Nodule
• Ischemia

Cornea:

• Epithelium, including defects and their pattern (punctate, dendritic, geographic), edema
• Stroma, including scar, ulceration, thinning, perforation, and infiltrate (location [central, peripheral, perineural, surgical, or traumatic wound], density, size, shape [ring], number [satellite], depth, character of infiltrate margin [suppurative, necrotic, feathery, soft, crystalline], color), edema
• Endothelium, including presence of keratic precipitates, guttae
• Foreign body, including sutures
• Signs of corneal dystrophy (bilaterality)
• Previous corneal inflammation (thinning, scarring, or neovascularization)
• Signs of previous corneal or refractive surgery

Anterior Chamber 

• Space between posterior cornea and iris filled with aqueous fluid
• Normal- clear, bright & deep
• Abnormal- – flat, shallow – hyphaema – hypopyon –Anterior chamber Intraocular Lens (IOL)

Pupil Iris 

• Normal – may be variable sizes but should be equal – react to light – central – round
• Abnormal – unequal – dilated or constricted – not reacting to light – irregular (eg tear drop) – not central

Iris

• Normal – similar appearance between eyes – Be aware of coloured contact lenses 
• Abnormal – lesions – tears, lacerations – prolapse

Fluorescein 

• staining helps identify a corneal epithelial defect.
• reveal or confirm the presence of dendrites, pseudodendrites, loose or exposed sutures, foreign body, and any epithelial defect and its morphology

Snellen Chart

1. Design: The chart features 11 lines of uppercase letters, progressively smaller from top to bottom. The top letter, usually an “E”, is the largest.
2. Distance: The patient stands 6 meters away from the chart. This distance can be halved to 3 meters in smaller spaces by using a modified version of the chart.
3. Reading the Chart: The patient reads from the top line downwards until the letters become too difficult to distinguish. The smallest line they can read clearly determines their visual acuity.
4. Scoring: The visual acuity is expressed as a fraction:
   • Numerator: Indicates the testing distance (6 meters) – (top number)
   • Denominator: Indicates the distance at which a person with normal vision can read the same line. (bottom number) For example, if a person reads the line labeled as “6/9”, it means they can see at 6 meters what a person with normal vision can see at 9 meters.

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Ishihara Test

is a widely used diagnostic tool designed to identify color vision deficiencies, commonly referred to as color blindness. This test was created by Dr. Shinobu Ishihara, a Japanese ophthalmologist, in 1917 and remains one of the most effective methods for detecting red-green color blindness.

1. Test Plates: The Ishihara Test consists of a series of circular plates (also called Ishihara plates), each containing a mosaic of dots of various sizes and colors. The dots are arranged to form numbers or patterns.
2. Color Variations: The colors used in the dots are specifically selected so that they appear different to individuals with and without color vision deficiencies. The test primarily uses shades that may be difficult to distinguish for those with red-green color blindness, the most common form of color blindness.
3. Identifying Numbers or Patterns: During the test, the person being tested is asked to identify a number or a pattern formed by the dots within each plate. The numbers or shapes are designed to be visible only if the viewer has normal color vision.
4. Results Interpretation:
   • If a person can correctly identify the numbers or patterns on most plates, their color vision is likely normal.
   • If they struggle to see some or all the numbers or shapes, it suggests some degree of color blindness.
   • The specific plates missed can help determine the type and severity of color vision deficiency.

Types of Plates in the Ishihara Test:

• Vanishing Design: Contains numbers or shapes that are visible to those with normal color vision but disappear for those with certain types of color blindness.
• Transformation Design: Displays numbers or shapes that appear different depending on the viewer’s color vision ability.
• Hidden Digit Design: Designed so that only those with color deficiencies can see the number, while those with normal color vision cannot.

Testing for Color Blindness:

The Ishihara Test specifically tests for red-green color blindness, which includes conditions such as:

• Protanopia and Protanomaly: Where there is a deficiency or absence of red cones in the eye.
• Deuteranopia and Deuteranomaly: Where there is a deficiency or absence of green cones in the eye.

Usage:

The Ishihara Test is commonly used in routine eye exams, especially in settings where quick screening is necessary, like in schools or driver’s license renewals. However, it’s important to note that the test is not effective for detecting blue-yellow color blindness or total color blindness (achromatopsia). For more comprehensive testing, other methods like the Anomaloscope or more advanced computer-based tests may be recommended.

The simplicity and effectiveness of the Ishihara Test make it a fundamental tool in assessing color vision deficiencies, helping in early identification and management of color blindness.

Ishihara_Tests Download