Name of the Procedure:

Ophthalmic biometry by ultrasound echography, A-scan (also known as A-scan ultrasonography)

Summary

Ophthalmic biometry by ultrasound echography, A-scan is a diagnostic procedure used to measure the internal structures of the eye. This non-invasive technique uses sound waves to create detailed images, allowing eye care specialists to assess eye structures accurately and determine appropriate treatments.

Purpose

This procedure is primarily used to measure the eye's axial length, which is crucial for determining the correct power of intraocular lenses (IOLs) to be implanted during cataract surgery. It also helps in diagnosing other eye conditions like high myopia or eye abnormalities.

Indications

• Patients requiring cataract surgery.
• Individuals with high degrees of nearsightedness (myopia) or farsightedness (hyperopia).
• Patients with suspected eye abnormalities or intraocular tumors.
• Other specific eye conditions requiring precise measurement of the eye's length.

Preparation

• No fasting or special diet is required.
• Continue regular medications unless instructed otherwise.
• Inform the doctor of any recent eye infections or other relevant medical history.
• In some cases, a comprehensive eye exam may be conducted beforehand.

Procedure Description

1. The patient is seated comfortably, and an eye drop may be used to numb the eye.
2. A probe (transducer) is gently placed on the eye or the front of the eye.
3. The device emits high-frequency sound waves, which bounce off the eye structures.
4. The echoes are collected and translated into measurements displayed on a screen.
5. Multiple measurements are taken to ensure accuracy.

No anesthesia or sedation is typically required aside from the numbing drops.

Duration

The procedure generally takes about 10 to 20 minutes.

Setting

Typically performed in an ophthalmologist's office or an outpatient clinic with specialized equipment.

Personnel

• Ophthalmologist or optometrist
• Trained medical technician

Risks and Complications

• Minor discomfort or pressure sensation during the procedure.
• Rarely, a temporary increase in eye pressure.
• No significant long-term risks associated with the procedure.

Benefits

• Accurate measurement of the eye's axial length.
• Essential for planning successful cataract surgery and selecting proper IOLs.
• Non-invasive and quick, with immediate results.

Recovery

• No downtime or recovery period required.
• Patients can resume normal activities immediately after the procedure.
• Follow-up appointments may be necessary to discuss the results and plan treatment.

Alternatives

• Optical biometry (another non-invasive method using light waves to measure eye structures).
  • Pros: Generally quicker and does not require contact with the eye.
  • Cons: May be less accurate in patients with dense cataracts or other eye conditions.

Patient Experience

• The patient may feel slight pressure from the probe.
• Numbing drops may cause temporary mild discomfort.
• Overall, the procedure is painless and well-tolerated by most patients.