MetrO2 RGP – Cantor Barnard

MetrO2 is a custom RGP contact lens design developed by Cantor & Nissel. The lens uses a computer-calculated design featuring:

Constant Axial Edge Lift

combined with a:

Spherical Central Optic Zone

and:

Aspheric Periphery

The aim is to maintain a balanced peripheral lens relationship as the Base Curve and overall lens diameter change.

Delivery Time

The lenses are supplied within a maximum period of:

30 to 60 days

from the date the order is confirmed.

Progressive Base Curve and Diameter Relationship

A key feature of the MetrO2 design is that the overall Diameter changes progressively according to the selected Base Curve.

Published technical information begins at:

BOZR 7.00 mm with Diameter 8.80 mm

and extends to:

BOZR 8.70 mm with Diameter 10.50 mm

This means that the design does not use one fixed Diameter across all Base Curves.

Instead, it uses a progressive relationship between:

• BOZR
• Overall Diameter
• Peripheral geometry

to help maintain consistent peripheral lens characteristics.

Lens Material

The original MetrO2 Practitioner Guide describes the material family as:

Fluoro-silicone Acrylate RGP Material

An independent clinical study also used MetrO2 lenses manufactured by Cantor & Nissel in:

FluoroPerm 30 – Fluorosilicone Acrylate – Dk 30

However, this represents the material used in that specific study and does not confirm that FluoroPerm 30 is the only standard or currently available material.

For a current product listing, the safer wording is:

Material: RGP material – according to material availability from Cantor Barnard at the time of order.

Key Features

• Computer-designed RGP contact lens
• Constant Axial Edge Lift
• Spherical central optic zone
• Aspheric periphery
• Progressive relationship between Base Curve and Diameter
• Historically broad Base Curve range
• Overall Diameter changes with lens curvature
• Custom-made according to prescription and corneal measurements
• Designed for professional fluorescein-based fitting
• Daily Wear
• Reusable rigid contact lens
• Manufactured in the United Kingdom

Published Design Specifications

Material Information

The original MetrO2 practitioner information identifies the material family as:

Fluoro-silicone Acrylate RGP Material

A separate clinical study using Cantor & Nissel MetrO2 lenses reported:

FluoroPerm 30

with:

• Material Type: Fluorosilicone Acrylate
• Dk: 30

For a current store listing, recommended wording is:

Material: RGP material – subject to the material currently available from Cantor Barnard when ordered.

MetrO2 Fitting Guidance

Published professional fitting guidance for MetrO2 provides different starting approaches depending on the amount of corneal astigmatism.

Corneal Astigmatism up to Approximately 1.00D

The practitioner may begin with a trial lens approximately:

On Flat K or slightly steeper

Corneal Astigmatism Greater than Approximately 1.00D

A suggested initial approach is to select a:

BOZR approximately 0.10–0.15 mm steeper than K

as a starting point.

These are professional fitting guidelines and are not parameters that should be selected independently by the customer.

Fitting Objective

The fitting objective is to achieve:

• Good lens centration
• Approximately 1–1.5 mm movement with blinking
• A balanced central fluorescein pattern
• Appropriate progressive peripheral clearance

The final fit should always be assessed clinically by the eye care professional.

Suitable Applications

Current Cantor Barnard information places MetrO2 within its RGP lens family used for correction or management of conditions including:

• Myopia
• Hyperopia
• Astigmatism
• Keratoconus
• Presbyopia, when incorporated into an appropriate RGP design

A clinical study has also used MetrO2 in patients with:

Keratoconus

However, MetrO2 should not necessarily be presented as a dedicated Keratoconus-specific lens without confirmation from Cantor Barnard.

Cantor Barnard currently presents Nissel KII as a specifically designated Keratoconus product.

Wearing Schedule

MetrO2 falls under Cantor Barnard’s current RGP care and use instructions.

The lenses are classified as:

Daily Wear

The eye care professional determines:

• Daily wearing time
• Replacement schedule
• Follow-up frequency

Cantor Barnard’s general RGP guidance states that the total defined life of an RGP lens may be:

Up to two years including storage and use

while the actual period of wear after starting use should not exceed:

One year

Lens Care Instructions

• Wash hands thoroughly with soap and water and dry them before handling the lens
• Keep fingernails short and smooth
• Use cleaning and disinfecting products intended specifically for RGP lenses
• Rub the lens using the appropriate cleaning solution after removal
• Rinse with contact lens solution rather than tap water
• Use fresh disinfecting solution each time
• Do not reuse old storage solution
• Do not top up old solution with fresh solution
• Do not use saliva to wet the lens
• Do not sterilize RGP lenses using an Autoclave
• Store the lens in a clean case with appropriate solution
• Replace the lens case regularly
• Cantor Barnard instructions indicate approximately every 1–2 months, while current care guidance recommends replacement at least monthly
• If the lens has not been used for 28 days, disinfect it again for the full recommended disinfection period and use a new storage case
• Do not wear the lens if it is scratched, cracked, distorted, or cannot be adequately cleaned

What Should Be Avoided?

Cantor Barnard advises against:

• Sleeping in the lenses unless specifically permitted by the eye care professional
• Swimming while wearing the lenses
• Showering while wearing the lenses
• Using a hot tub while wearing the lenses
• Exposing the lens or storage case to tap water
• Sharing the lens with another person
• Continuing to wear the lens if pain, redness, or blurred vision occurs

Because MetrO2 is classified as an RGP lens for:

Daily Wear

it should not be presented as a routine overnight-wear lens.

Important Warnings

MetrO2 is a specialized medical RGP contact lens that should be manufactured and fitted according to the prescription and corneal measurements of the individual eye. It should only be supplied under the supervision of an eye care professional.

The lens is intended for:

Daily Wear

Remove the lens and consult an eye care professional if you experience:

• Eye pain
• Redness
• Swelling
• Blurred vision
• Unusual changes in vision

Do not use water or saliva to clean or wet the lens.

Do not wear a lens that is:

• Damaged
• Scratched
• Cracked
• Distorted

Improper lens use or care may be associated with complications including:

• Microbial Keratitis
• Acanthamoeba Keratitis
• Corneal Ulcer
• Corneal Abrasion