Eagleview Eye Clinic

Tag Eyecare

MIOTIC DRUGS

👨‍⚕️ Miotic drugs constrict the pupil (miosis) and reduce intraocular pressure (IOP). Used for glaucoma, post-surgery, or counteracting mydriasis.

Common examples:

  1. Pilocarpine (cholinergic)
    • Effect: 1–2 hours, lasts 4–8h.
    • Use: Open-angle glaucoma, miosis.
    • Side effects: Headache, dim vision, brow ache.
  2. Carbachol (cholinergic)
    • Effect: Strong, longer-lasting.
    • Use: Glaucoma, post-op care.
    • Risk: Retinal detachment risk.
  3. Acetylcholine (direct-acting)
    • Use: Intraocular surgery (short-acting).
  4. Echothiophate (anticholinesterase)
    • Use: Chronic glaucoma.
    • Risk: Cysts, systemic toxicity.

Precautions:

  • Night vision issues: Avoid driving in low light.
  • Retinal risk: Check for detachment symptoms.
  • Asthma/COPD: Caution (bronchospasm).
  • Tapering: Avoid sudden stop.

MYDRIATIC DRUGS

👁️ Mydriatic drugs dilate the pupil (mydriasis) by relaxing the iris sphincter muscle. Used for exams, surgery, or treating inflammation.

Common examples:

  1. Phenylephrine (α-1 agonist)
    • Effect: Fast (30–60 min), short (3–6h).
    • Use: Diagnostic exams.
    • Risk: Hypertension, arrhythmia.
  2. Tropicamide (anticholinergic)
    • Effect: 30–45 min, lasts 4–6h.
    • Use: Routine dilation.
    • Risk: Blurred vision, photophobia.
  3. Atropine (strong, long-acting)
    • Effect: 1–2 weeks.
    • Use: Uveitis, amblyopia.
    • Risk: Prolonged blur, dry mouth.
  4. Cyclopentolate
    • Effect: 24–48h.
    • Use: Pediatric exams.
    • Risk: Behavioral changes in kids.

Precautions:

  • Avoid driving until pupils return to normal.
  • Glaucoma risk: Check IOP.
  • Monitor elderly/kids.
  • Side effects: Headache, stinging, dry eyes.

MACULA

The macula is a specialized region at the back of the eye, responsible for central vision and fine detail.

Key functions:

  1. Central vision
  2. Color vision
  3. Fine detail vision

Location:

The macula is located at the center of the retina, including the fovea.

Krimsky test

The Krimsky test is used to measure strabismus (misaligned eyes) in patients who can’t fixate or have poor fixation.

What it’s for:

The Krimsky test is used to:

  1. Measure strabismus in patients with poor fixation
  2. Assess ocular alignment

How it’s done:

  1. A light is shone into the patient’s eyes.
  2. Prisms are placed in front of the deviated eye.
  3. The prism is adjusted until the corneal reflections are symmetrical.

What it shows:

The test measures the amount of strabismus, helping diagnose and manage eye alignment issues.

VAN HERRICK TEST

The Van Herrick test is a method used to estimate the depth of the anterior chamber angle in the eye.

What it’s for:

The Van Herrick test is used to:

  1. Assess the risk of angle-closure glaucoma
  2. Evaluate the anterior chamber angle width

How it’s done:

  1. A narrow slit beam is shone onto the peripheral cornea.
  2. The examiner observes the angle between the cornea and iris.
  3. The width of the angle is estimated and graded.

Grading:

The Van Herrick test grades the angle as:

  1. Grade 4: Wide open angle
  2. Grade 3: Moderate angle
  3. Grade 2: Narrow angle
  4. Grade 1: Extremely narrow angle
  5. Grade 0: Closed angle

What it shows:

The test helps identify patients at risk of angle-closure glaucoma, allowing for further evaluation and treatment if necessary.

HORIZONTAL COINCIDENCE TEST

The horizontal coincidence test, also known as the cover-uncover test or Hirschberg’s test, assesses binocular alignment and detects strabismus (misaligned eyes).

How it’s done:

  1. Patient fixates: The patient looks at a target, usually a light or object.
  2. Covering one eye: One eye is covered, and the movement of the uncovered eye is observed.
  3. Uncovering the eye: The covered eye is uncovered, and the movement of both eyes is observed.

Purpose:

The test helps detect:

  1. Strabismus: Misalignment of the eyes (esotropia, exotropia, hypertropia, etc.).
  2. Binocular vision problems: Issues with how the eyes work together.

The test provides valuable information about binocular alignment and helps diagnose and manage strabismus and other binocular vision problems.

THE BJERRUM TANGENT SCREEN

The Bjerrum tangent screen is a device used in ophthalmology to assess the visual field, particularly the central and paracentral areas. It’s a flat surface with a tangent curve marked on it, used to map out the field of vision.

How it’s used:

  1. Patient fixation: The patient fixates on a central point.
  2. Stimulus presentation: A stimulus (e.g., a small object or light) is moved along the tangent screen.
  3. Visual field mapping: The patient indicates when they see the stimulus, allowing the examiner to map out the visual field.

Purpose:

The Bjerrum tangent screen is used to:

  1. Detect visual field defects: Identify defects in the central and paracentral visual field.
  2. Monitor glaucoma: Track changes in the visual field associated with glaucoma.
  3. Assess optic nerve function: Evaluate the function of the optic nerve.

The Bjerrum tangent screen is a useful tool for assessing and monitoring visual field defects, particularly in glaucoma patients.

TITMUS FLY TEST

The Titmus fly test, also known as the Titmus stereo test or Titmus test, is a widely used assessment tool for evaluating stereopsis, which is the ability to perceive depth and 3D vision.

How it works:

  1. Polarized glasses: The patient wears polarized glasses.
  2. Image presentation: The patient views a series of images, including a fly or other objects, through the polarized glasses.
  3. Depth perception: The images are designed to create a sense of depth, and the patient is asked to identify the objects or shapes that appear to be raised or recessed.

Purpose:

The Titmus test is used to:

  1. Assess stereopsis: Evaluate the patient’s ability to perceive depth and 3D vision.
  2. Detect binocular vision problems: Identify issues with binocular vision, such as strabismus or amblyopia.
  3. Monitor treatment progress: Track changes in stereopsis during treatment or therapy.

Common applications:

  1. Pediatric vision screening: Often used in children’s vision screenings to assess depth perception.
  2. Vision therapy: Used to evaluate and improve binocular vision and stereopsis.
  3. Occupational vision assessments: May be used in certain occupations that require depth perception.

The Titmus fly test is a valuable tool for assessing stereopsis and binocular vision, helping practitioners diagnose and manage vision problems.

MADDOX ROD

The Maddox rod is a cylindrical lens with parallel rods that convert a point source of light into a streak or line. It’s used in ophthalmology and optometry to assess and measure strabismus (misaligned eyes) and heterophoria (latent strabismus).

How it works:

  1. Light source: A point source of light is shone through the Maddox rod.
  2. Streak formation: The rods convert the light into a streak or line, which is perceived by the patient.
  3. Alignment assessment: The orientation and position of the streak relative to the other eye help diagnose and quantify deviations in eye alignment.

Types of Maddox rods:

  1. Single Maddox rod: Used to assess horizontal or vertical deviations.
  2. Double Maddox rod: Used to assess torsional deviations.

Clinical applications:

  1. Strabismus diagnosis: Helps diagnose and quantify esotropia, exotropia, hypertropia, and other types of strabismus.
  2. Heterophoria diagnosis: Detects latent strabismus, which can cause eye strain or other symptoms.
  3. Treatment planning: Guides treatment decisions, such as prism correction or strabismus surgery.

The Maddox rod is a valuable tool in ophthalmology and optometry, enabling practitioners to accurately diagnose and manage strabismus and heterophoria.

WORTH 4 DOT TEST

The Worth 4-Dot test is a clinical test used in ophthalmology and orthoptics to assess binocular vision and detect suppression or anomalies in binocular vision.

Key Features:

  1. Four dots: The test involves four dots or lights, typically arranged in a square or diamond pattern.
  2. Color filters: The patient wears red-green glasses or filters, with one eye seeing two dots (or lights) and the other eye seeing the other two.
  3. Binocular fusion: The test assesses the patient’s ability to fuse the images from both eyes.

Purpose:

The Worth 4-Dot test is used to:

  1. Assess binocular vision: Evaluate the patient’s ability to combine images from both eyes.
  2. Detect suppression: Identify suppression or anomalies in binocular vision, which can indicate conditions like strabismus or amblyopia.
  3. Monitor treatment: Track changes in binocular vision during treatment or therapy.

How it works:

  1. Patient views the dots: The patient looks at the four dots or lights through the red-green glasses.
  2. Response evaluation: The practitioner evaluates the patient’s response, noting whether they see four dots (indicating binocular fusion), two dots (indicating suppression), or some other pattern.

The Worth 4-Dot test provides valuable information about binocular vision and can help diagnose and manage various vision disorders.