Name of the Procedure:

Ophthalmic Biometry by Ultrasound Echography, A-Scan; with Intraocular Lens Power Calculation
Common name(s): A-Scan Biometry; Ultrasound Biometry for IOL Calculation

Summary

Ophthalmic biometry by ultrasound echography, A-scan, with intraocular lens power calculation is a diagnostic procedure used to measure the eye’s dimensions to determine the correct power of an intraocular lens (IOL) needed for cataract surgery.

Purpose

This procedure addresses vision issues caused by cataracts, where the eye's natural lens becomes cloudy. The goal is to accurately measure the eye’s axial length and other parameters to ensure the correct lens power is selected, leading to optimal vision post-surgery.

Indications

• Presence of cataracts causing significant vision impairment.
• Patients scheduled for cataract surgery.
• Patients needing precise measurement of eye structures due to various ocular conditions.

Preparation

• No specific fasting required.
• Temporary discontinuation of certain medications as advised by the healthcare provider.
• Pre-procedure assessments include a comprehensive eye exam and review of patient’s medical history.

Procedure Description

1. The patient is seated in a comfortable position.
2. The procedure begins by applying a drop of anesthetic to numb the eye.
3. An ultrasound probe (transducer) is gently placed against the cornea or the eyelid.
4. The device sends sound waves into the eye and measurements such as axial length, anterior chamber depth, and lens thickness are recorded.
5. These measurements are then used to calculate the appropriate power for the intraocular lens (IOL).
6. The procedure is generally painless and lasts only a few minutes.

Duration

The procedure typically takes about 10-15 minutes.

Setting

This procedure is performed in an ophthalmologist’s office, an outpatient clinic, or a specialized eye center.

Personnel

• Ophthalmologist or trained technician
• Supportive nursing staff may be present

Risks and Complications

• Minimal risk of infection
• Possible discomfort or mild irritation
• Rare complications may include corneal abrasion which is generally minor and temporary

Benefits

• Accurate IOL power calculation leading to better visual outcomes post-cataract surgery.
• Non-invasive and quick procedure with immediate results.
• Facilitates tailored cataract surgery providing optimal vision correction.

Recovery

• No specific recovery time needed as the procedure is non-invasive.
• Patients can resume normal activities immediately after.
• Follow-up required during pre-surgery assessment and planning.

Alternatives

• Optical biometry (using light instead of ultrasound for measurements).
• Pros: Optical biometry can be more accurate and doesn’t require corneal contact.
• Cons: Less effective for cases of dense cataracts compared to ultrasound biometry.

Patient Experience

• Patients may feel a slight pressure but no pain due to the anesthetic drops used.
• Post-procedure, there might be mild, brief blurred vision which resolves quickly.
• Comfort measures include ensuring the patient is relaxed and informed about each step.

This procedure is crucial for the successful outcome of cataract surgery, helping to restore vision impaired by cloudy lenses with precision-tailored intraocular lenses.