Name of the Procedure:

Tonography with Interpretation and Report (Indentation Tonometer Method or Perilimbal Suction Method)

Summary

Tonography is a diagnostic procedure that involves measuring the outflow of aqueous humor from the eye, helping to assess intraocular pressure (IOP). This test can be done using either the indentation tonometer method or the perilimbal suction method.

Purpose

Tonography is primarily used to diagnose and manage glaucoma, a condition characterized by elevated intraocular pressure, which can lead to optic nerve damage and vision loss. By evaluating the rate of aqueous humor outflow, physicians can determine the effectiveness of treatments aimed at lowering IOP or make decisions about initiating therapy.

Indications

• Elevated intraocular pressure (IOP) detected during routine eye exams
• Suspected or diagnosed glaucoma
• Monitoring the effectiveness of glaucoma treatment
• Unexplained vision loss or optic nerve damage

Preparation

• Patients may need to avoid certain medications that could affect eye pressure.
• It is important to follow any specific instructions provided by your ophthalmologist.
• An initial eye examination and history will be taken to determine baseline IOP.

Procedure Description

1. The patient will be seated in an examination chair and asked to stay still.
2. Eye drops may be administered to numb the eye.
3. Depending on the method:
   • Indentation Tonometer Method: An indentation tonometer is placed on the cornea and a controlled weight is applied to measure the indentation of the cornea and calculate the rate of aqueous outflow.
   • Perilimbal Suction Method: A suction cup is placed over the perilimbal region of the eye. The suction device gently raises the pressure and a manometer measures the resultant outflow of aqueous humor.
4. Data is recorded and interpreted by the physician to provide an accurate assessment of the outflow facility.

Duration

The entire procedure typically takes about 15-30 minutes.

Setting

Tonography is usually performed in an outpatient ophthalmology clinic or eye care center.

Personnel

• Ophthalmologist or optometrist
• Trained ophthalmic technicians

Risks and Complications

• Mild discomfort or irritation of the eye
• Rare complications include corneal abrasions or infections
• Temporary blurring of vision due to the numbing drops

Benefits

• Accurate assessment and monitoring of intraocular pressure and aqueous outflow.
• Helps in early diagnosis and management of glaucoma, preventing vision loss.
• Non-invasive and relatively quick procedure.

Recovery

• Minimal to no recovery time; patients can typically resume normal activities immediately after.
• Follow-up appointments may be scheduled to monitor IOP and treatment efficacy.

Alternatives

• Other tonometry methods such as Goldmann applanation tonometry or non-contact tonometry.
• Comprehensive eye examinations and imaging tests.
• Pros: Some alternative methods are quicker or less invasive.
• Cons: Alternatives may not provide as detailed an assessment of aqueous humor outflow.

Patient Experience

• Patients might feel slight pressure on the eye during the procedure.
• The numbing eye drops may cause temporary blurriness.
• Generally, the procedure is well-tolerated with minor discomfort.
• Pain management is typically not necessary, but comfort measures include reassurance and short procedural time.