Eagleview Eye Clinic

Tag Eyecare

STERILE BURR

A sterile burr is a small, drill-like ophthalmic instrument used to remove rust rings or embedded foreign bodies from the cornea. It’s typically single-use, precision-engineered, and comes pre-sterilized to prevent infection.

Here’s the step-by-step usage:

  1. Numb the eye with topical anesthetic drops.
  2. Position the patient comfortably under a slit lamp for magnification.
  3. Stabilize the eye using a lid speculum or gentle pressure.
  4. Activate the burr (usually battery-powered) and gently apply it to the rust ring or foreign body.
  5. Rotate lightly to scrape away the material without pressing too deep.
  6. Irrigate the eye to flush out debris.
  7. Apply antibiotic ointment and possibly a patch for comfort.
  8. Advise on aftercare — typically antibiotic drops, no rubbing, and follow-up if pain or vision changes persist.
P50 and N95

P50 and N95 are key waves in pattern ERG (PERG), reflecting retinal ganglion cell (RGC) function:

  • P50: Early positive wave, mainly from RGCs and inner retinal layers. Reduced amplitude or delayed timing suggests ganglion cell dysfunction, common in early glaucoma or optic neuropathies.
  • N95: Later negative wave, more specific to optic nerve health. A drop in N95 amplitude often signals optic nerve damage or axonal loss.

Both waves together help gauge severity and progression of optic nerve diseases. For example, in glaucoma, P50 might reduce first, then N95 drops as damage worsens.

PATTERN ERG

Pattern ERG (PERG) measures electrical activity from retinal ganglion cells in response to a reversing checkerboard pattern. It’s great for spotting optic nerve issues like glaucoma and macular problems.

  • How it’s done: Electrodes on the eye, patient looks at a screen with a checkerboard pattern that flips contrast.
  • What it records: P50 wave (early positive) reflects ganglion cell function; N95 wave (negative) relates to optic nerve health.
  • Key use: Detects ganglion cell loss early, even before visual field defects show up.
  • Difference from full-field ERG: PERG focuses on central retina and optic nerve, not whole retinal response.
FULL ERG

Full-field ERG tests the entire retina’s electrical response to light. You get electrodes on the cornea or skin, dark-adapt for ~20 mins, then flashes of light stimulate rods and cones. It records a-waves (photoreceptor activity) and b-waves (inner retinal response). Used to diagnose widespread retinal diseases like retinitis pigmentosa or Leber congenital amaurosis. Results show overall retinal function, not localized areas.

ELECTRORETINOGRAPHY

Electroretinography (ERG) is a test that measures the electrical response of the retina’s light-sensitive cells (rods and cones) to light stimuli. It helps diagnose retinal diseases like retinitis pigmentosa, macular degeneration, and Leber congenital amaurosis.

  • How it works: Electrodes placed on the cornea or skin around the eye record electrical activity while the eye is exposed to flashes of light.
  • What it shows: Waves (a-waves, b-waves) reflecting function of photoreceptors and inner retinal layers.
  • Types: Full-field ERG (tests whole retina), multifocal ERG (tests small areas), and pattern ERG (tests ganglion cells).
  • Use: Detects retinal dysfunction even before vision loss is noticeable.

CONDITIONS THAT CAN OCCUR FROM CONTACT LENS USE

😊 Contact lens misuse can lead to various eye issues, including:

  • Infections: Bacterial (e.g., bacterial keratitis), fungal, or viral (e.g., adenovirus).
  • Irritation and allergies: Giant papillary conjunctivitis (GPC), allergic reactions to lens solutions.
  • Corneal issues: Abrasions, ulcers, neovascularization, or dellen.
  • Hypoxia-related problems: Corneal edema, neovascularization.
  • Other: Dry eye, discomfort, or lens-related complications.

AIR PUFF TONOMETER

👓 The air puff tonometer is a non-contact device that measures intraocular pressure (IOP) by blowing a quick puff of air onto the cornea.

  • How it works: The device measures the corneal deformation caused by the air puff.
  • Advantages: No direct contact with the eye, reducing infection risk.
  • Common use: Often used for glaucoma screening and routine eye exams.
  • Considerations: Can be less accurate than contact tonometers (e.g., Goldmann).

MONOFOCAL IOL

A monofocal IOL 👀 is a type of intraocular lens that focuses at one distance (near, intermediate, or far).

Key things

  • Single focus point: Usually set for distance vision (you’d use glasses for near tasks like reading).
  • Less dependence on glasses if monovision approach is used (e.g., one eye for distance, one for near).
  • Common and reliable: Predictable outcomes, often covered by insurance.

Pros

  • Sharp vision at chosen distance.
  • Lower risk of visual side effects (e.g., halos, glare) vs multifocal IOLs.

Cons

  • Glasses needed for other distances (unless monovision).
  • Less flexibility compared to multifocal/accommodating IOLs.

INTRAOCULAR LENS

An intraocular lens (IOL) 👓 is an artificial lens implanted in the eye to replace the natural lens, usually during cataract surgery or refractive lens exchange.

Types

  • Monofocal IOLs: Focus at one distance (near, intermediate, or far).
  • Multifocal IOLs: Allow focus at multiple distances (e.g., near and far).
  • Accommodating IOLs: Move with eye muscles to focus.
  • Toric IOLs: Correct astigmatism.

Benefits

  • Vision restoration: Improves clarity after cataract removal.
  • Reduced dependence on glasses: Depending on IOL type.
  • Customizable: Chosen based on lifestyle and needs.

MIRROR TEST

The mirror test 🪞 is a sneaky way to check if someone’s faking vision loss in one eye (malingering).

How it works

  1. Patient claims blindness in one eye.
  2. Place a mirror in front of them, angled to show their “blind” eye.
  3. Ask them to look straight ahead.
  4. Check if they react to their own reflection (e.g., blink, move, etc.).

What it shows

  • If they react to their reflection, it suggests the “blind” eye can see.
  • If they don’t react, could be malingering… or really blind 😅.

Tips

  • Casual setup: Make it seem like a normal exam step.
  • Distract them: Talk about something else while doing the test.
  • Combine with other tests for stronger evidence.