Internal ACD Measurement Tools in Ophthalmology

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Questions and Answers

How should you pre-treat the eye before taking measurements with the Digital Caliper?

With anesthetic drops

At what position should the patient be when taking the measurement with the Digital Caliper?

Supine position

Where should the Digital Caliper measurement be taken from and to in the eye?

Middle of the limbus to middle of the limbus

What should be used to validate the caliper measurement of the w-to-w?

ORBScan Signup and view all the answers

What should be done if there is a discrepancy in the w-to-w measurement between eyes?

Cross check multiple times with different instruments Signup and view all the answers

How should you read the caliper measure when using the Digital Caliper?

On a ruler Signup and view all the answers

What is one method to measure the W-to-W and vault of PC-PHAKIC IOL?

Anterior segment OCT accurately and by Slit Lamp manually Signup and view all the answers

What issue can high vault post-operatively cause?

Pupillary block and increased risk of angle closure glaucoma Signup and view all the answers

What complication may arise from low vault post-operatively?

Risk of anterior sub-capsular opacification Signup and view all the answers

What management approach can be taken for high vault exceeding 1000 microns?

Changing orientation from horizontal to vertical, Exchange with a smaller sized P-IOL Signup and view all the answers

What is the regular limit for low vault measurement?

250 microns Signup and view all the answers

How can a low vault be managed if there is peripheral touch despite a central vault of 100 or 150 microns?

Dilate and do an AS-OCT or UBM to assess the peripheral touch Signup and view all the answers

What is the recommended minimum internal ACD measurement to avoid errors when using the EYECRYL™ PHAKIC IOL?

2.8 mm Signup and view all the answers

Name some of the tools that can be used to measure ACD for proper evaluation before using the EYECRYL™ PHAKIC IOL.

Orbscan® ll, Pentacam® HR, SIRIUS, IOL Master® 500 & 700, LENSTAR®, Ultrasound Biometer (A-Scan) Signup and view all the answers

Why is the measurement of Intra-Ocular Pressure (IOP) important when considering the use of PC Phakic IOL like EYECRYL™?

To detect rise in IOP due to pigment dispersion and vaulting issue Signup and view all the answers

What screening tests should be performed to evaluate the risk of Glaucoma before using the EYECRYL™ PHAKIC IOL?

Non-contact Tonometry (NCT), Goldman Applanation Tonometry (GAT), Gonioscopy Signup and view all the answers

Why is it important to evaluate dry eye condition before considering the EYECRYL™ PHAKIC IOL?

Dry ocular surface may significantly affect keratometric values Signup and view all the answers

What is the recommended timeframe for discontinuing soft contact lenses and RGP contact lenses before corneal topography when planning to use EYECRYL™ PHAKIC IOL?

Soft contact lenses for 5 days, RGP contact lenses for 3 weeks Signup and view all the answers

Study Notes

Preparing for Measurements with Digital Caliper

The eye should be pre-treated before taking measurements with the Digital Caliper.
The patient should be in a seated position when taking the measurement with the Digital Caliper.
The Digital Caliper measurement should be taken from the white-to-white (w-to-w) of the eye.

Validating Caliper Measurements

The caliper measurement of the w-to-w should be validated using a keratometer or IOLMaster.
If there is a discrepancy in the w-to-w measurement between eyes, the measurement should be re-taken and re-validated.

Reading Caliper Measurements

When using the Digital Caliper, the caliper measure should be read in a way that is perpendicular to the eye.

Measuring W-to-W and Vault of PC-PHAKIC IOL

One method to measure the W-to-W and vault of PC-PHAKIC IOL is by using a digital caliper.

Complications of High and Low Vault

High vault post-operatively can cause glare and halos.
Low vault post-operatively may cause peripheral touch.
If high vault exceeds 1000 microns, a management approach can be taken to reduce the vault.
The regular limit for low vault measurement is 100-150 microns.

Managing Low Vault

If there is peripheral touch despite a central vault of 100 or 150 microns, a low vault can be managed by adjusting the vault height.

Measuring Internal ACD for EYECRYL™ PHAKIC IOL

The recommended minimum internal ACD measurement to avoid errors when using the EYECRYL™ PHAKIC IOL is 12.5 mm.
Tools that can be used to measure ACD for proper evaluation before using the EYECRYL™ PHAKIC IOL include the IOLMaster and ultrasound.

Importance of Measuring IOP and Screening for Glaucoma

Measuring Intra-Ocular Pressure (IOP) is important when considering the use of PC Phakic IOL like EYECRYL™ to avoid complications.
Screening tests should be performed to evaluate the risk of Glaucoma before using the EYECRYL™ PHAKIC IOL.

Evaluating Dry Eye Condition

It is important to evaluate dry eye condition before considering the EYECRYL™ PHAKIC IOL to avoid complications.

Discontinuing Contact Lenses before Corneal Topography

Soft contact lenses should be discontinued for 7 days and RGP contact lenses for 30 days before corneal topography when planning to use EYECRYL™ PHAKIC IOL.

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Description

This quiz covers the equipment and tools used for measuring internal anterior chamber depth (ACD) in ophthalmology, with a focus on ensuring ACD from the endothelium is not less than 2.8 mm. Learn about devices such as Orbscan® ll, Pentacam® HR, and IOL Master® 500 & 700 commonly used for this purpose.