Fluorescein Patterns

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Table of Contents

ONLY USE SALINE WITH FLUORESCEIN
ALIGNMENT OF CENTRAL ZONE (BOZR) TO CORNEA
ALWAYS ALIGN LENS IN CENTER OF CORNEA FOR EVALUATION
EVALUATION AREAS

ONLY USE SALINE WITH FLUORESCEIN #

Only use saline when using fluorescein, as most modern lubricating drops has some form of additive that helps attract fluid onto surfaces. Adding a lubricant with fluorescein, it tends to adhere to the front surface of the lens and you will get false patterning during the evaluation- so always only use saline.

ALIGNMENT OF CENTRAL ZONE (BOZR) TO CORNEA #

A contact lens doesn’t really bare on the cornea directly. It floats on top of the tear layer. You have to design your lens to get a thin compressed tear layer between the lens surface and the corneal surface. Too little tears and the lens will not float and it will sink down and start rubbing on the cornea, resulting in staining. Too much fluid- a capillary suction force is create and the lens will suck onto the eye resulting in staining and long term problems. The Central Zone is a key part to getting a thin and even tear layer across the cornea, by matching up the surface of the cornea with the surface of the lens.

ALWAYS ALIGN LENS IN CENTER OF CORNEA FOR EVALUATION #

The lens should align to the center of the apex of the cornea. Correct positioning of the lens is the key to accurate fitting practice. Gently use the patient’s bottom lid to manipulate the lens if not centered. Failure to do this will result in misinterpretation of the Fluorescein patterns.

A classic error occurs when a flat lens is allowed to drop so that the central zone of the lens is sitting on a peripheral part of the cornea. In most patients, the peripheral cornea is rather flatter, and the result will be a pooling of NaFl under the lens. This lens can then wrongly be interpreted as steep.¹

Remember, as soon as you place the lens and solution in the eye, there will be a tear reflex. Give the lens a minute or two to settle before you evaluate the fit.