Eagleview Eye Clinic

Tag ey diseases

CYCLOPLEGIC DRUGS

👨‍⚕️ Cycloplegic drugs paralyze the ciliary muscle, blocking accommodation (focusing) and dilating the pupil. Used in eye exams, treating uveitis, or managing amblyopia.

Common examples:

  1. Atropine (long-acting, 1–2 weeks)
    • Use: Amblyopia, uveitis.
    • Side effect: Dry mouth, blurred vision.
  2. Cyclopentolate (shorter, 24–48h)
    • Use: Pediatric exams, refraction.
    • Risk: Hallucinations in kids.
  3. Tropicamide (fast, 4–6h)
    • Use: Routine dilation.
    • Mildest side effects.
  4. Homatropine (moderate duration)
    • Use: Uveitis, post-surgery.

Precautions:

  • Avoid driving post-use.
  • Monitor IOP (glaucoma risk).
  • Children/elderly: Adjust doses.
  • Contraindicated: Narrow-angle glaucoma.

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.

SEGMENT HEIGHT

Segment height refers to the vertical measurement of a bifocal or progressive lens segment.

What it’s for:

Segment height is used to:

  1. Position the lens segment correctly
  2. Ensure optimal vision through the segment

Measurement:

Segment height is typically measured from the lower eyelid margin to the top of the segment.

LASH EPILATION

Lash epilation refers to the removal of eyelashes, typically performed for medical or cosmetic reasons. Methods include:

  • Plucking: Removing individual lashes with tweezers.
  • Waxing: Applying wax to remove multiple lashes at once.
  • Threading: Using a thread to remove lashes.

Lash epilation can be used to:

  • Treat trichiasis: A condition where lashes grow inward, causing irritation.
  • Prepare for surgery: In some cases, lash removal may be necessary before eye surgery.
  • Cosmetic purposes: Some individuals may choose lash epilation for aesthetic reasons.

It’s essential to have lash epilation performed by a trained professional to minimize risks and ensure proper aftercare.

ANTERIOR CHAMBER ANGLE

The anterior chamber angle is a critical area in the eye. Key features:

  1. Location: The angle formed by the junction of the iris and cornea in the anterior chamber.
  2. Importance:
    • Contains the trabecular meshwork, which drains aqueous humor
    • Plays a key role in regulating intraocular pressure
  3. Clinical significance: Narrowing or closure of the anterior chamber angle can lead to angle-closure glaucoma.

The anatomy of the anterior chamber angle is important for understanding glaucoma and other ocular conditions.

RETINAL GANGLION CELLS

Retinal ganglion cells (RGCs) are a type of neuron in the retina. Key features:

  1. Signal transmission: RGCs receive visual information from bipolar cells and transmit it to the brain via the optic nerve.
  2. Visual processing: RGCs play a crucial role in processing visual information, including:
    • Detecting light intensity and patterns
    • Processing color and contrast
    • Detecting motion and direction
  3. Types: There are several types of RGCs, each responding to different visual stimuli.

RGCs are essential for transmitting visual information from the eye to the brain, enabling us to perceive and interpret visual stimuli.

ORA SERRATA

The ora serrata is the serrated, anterior (front) edge of the retina, marking the transition from the non-photosensitive area of the eye to the photosensitive area. It is located near the junction of the ciliary body and the retina.

Key features:

  1. Anatomical location: The ora serrata is situated at the boundary between the retina and the ciliary body.
  2. Serrated appearance: It has a distinctive serrated or jagged edge.
  3. Transition zone: The ora serrata marks the transition from the non-photosensitive ciliary body to the photosensitive retina.

The ora serrata is an important anatomical landmark in the eye, and its location is relevant in various ophthalmic procedures and diagnoses.

LAYERS OF THE CHOROID

The choroid is a vascular layer in the eye between the sclera and retina. It consists of several layers:

1. Suprachoroid Lamina (or Suprachoroid Layer)

  • The outermost layer of the choroid, adjacent to the sclera.
  • Composed of loose connective tissue and melanocytes.

2. Choriocapillaris

  • A layer of capillaries that supplies oxygen and nutrients to the outer retina.
  • Fenestrated capillaries allow for the exchange of substances.

3. Bruch’s Membrane

  • A thin, acellular layer separating the choroid from the retinal pigment epithelium (RPE).
  • Composed of collagen and elastin fibers.

These layers work together to provide nourishment to the retina and support its function. The choroid plays a crucial role in maintaining the health and function of the retina.

PUPIL

The pupil is the circular opening in the center of the iris, the colored part of the eye. It plays a crucial role in regulating the amount of light that enters the eye.

Key characteristics:

  1. Location: The pupil is located in the center of the iris.
  2. Function: The pupil:
    • Regulates light entry into the eye
    • Adjusts size to control light intensity
    • Helps maintain optimal vision
  3. Size adjustment: The pupil:
    • Constricts (gets smaller) in response to:
      • Bright light
      • Near vision
      • Certain medications
    • Dilates (gets larger) in response to:
      • Low light
      • Emotional arousal
      • Certain medications or substances
  4. Control: The pupil’s size is controlled by the autonomic nervous system, specifically the:
    • Parasympathetic nervous system (constriction)
    • Sympathetic nervous system (dilation)

Importance: The pupil’s ability to regulate light entry is essential for maintaining optimal vision, protecting the retina, and responding to changes in lighting conditions.

CORNEA

The cornea is the transparent, avascular (without blood vessels), dome-shaped surface at the front of the eye. It plays a crucial role in refracting (bending) light and protecting the eye.

Key characteristics:

  1. Transparency: The cornea is clear and transparent, allowing light to pass through.
  2. Structure: It consists of five layers:
    • Epithelium (outermost layer)
    • Bowman’s layer
    • Stroma (thickest layer)
    • Descemet’s membrane
    • Endothelium (innermost layer)
  3. Function: The cornea:
    • Refracts light, accounting for most of the eye’s focusing power
    • Protects the eye from external damage
    • Maintains the shape of the eye
  4. Sensitivity: The cornea is highly sensitive to touch, temperature, and chemicals.
  5. Nourishment: The cornea receives nutrients and oxygen from tears and the aqueous humor.

Importance: The cornea is essential for clear vision, and any damage, disease, or irregularity can significantly impact visual acuity.