GP Lens Case Grand Rounds Troubleshooting Guide

Vascularized Limbal Keratitis (VLK): Robert M. Grohe, OD, FAAO

Background

JE is a previous ten year daily wear PMMA wearer and current continuous (seven days) corneal GP lens wearer. The specific GP material worn is unknown and the information is unavailable. In the last week JE has become symptomatic with pain, photophobia, discharge and a white bump noticed by friends on his right eye. He thinks it also occurred previously in the left eye.

Test Procedures/Fitting & Refitting, Lens Designs & Ordering

Visual Acuity (with Corneal GP Lenses):

OD: 20/25 (moderate photophobia)
OS: 20/20 -2 (mild photophobia)

Slit Lamp Examination:

The right lens/cornea demonstrates slightly inferior decentration with < ½ mm movement with blink. The fluorescein pattern shows moderate central pooling, wide mid-peripheral bearing and low edge clearance. There is also a compression-indentation ring imprint remaining on the cornea when the lens is manually dislodged. The left contact lens shows a central position with 1-2mm movement and a mild central pooling, mild mid-peripheral bearing and a low edge clearance.

After Lens Removal:

OD: temporally, there is a whitish elevated limbal mass with a leash of vascularization surrounding and entering the mass. There are trace diffuse corneal and mild overlying superficial punctate keratitis (SPK), moderate arc-like SPK from the edge rubbing against the inner rim of the mass and a 1+ flare in the anterior chamber.

OS: there is mild SPK at 2:00 to 5:00 o’clock and 7:00 to 10:00 o’clock. There is no evidence of either vascularization or anterior chamber reaction.

Treatment:

Contact lens wear was discontinued for two weeks to allow for treatment and healing. JE was prescribed Tobrex topical antibiotic drops used one drop, OU, QID for one week then subsequently placed on Zylet combination drops used one drop, OU, bid for one week to regress the limbal mass. Artificial tears at bedtime were recommended.

Ordering of New Lenses:

Subsequent corneal GP lenses ordered were Dk 100 material fit with a base curve 0.75 flatter than “K” as measured after two weeks of recovery. A moderate edge lift was designed to allow for uninterrupted peripheral clearance and to minimize tissue drag in the peripheral cornea.

Patient Consultation and Education

The key factor for the patient in avoiding a rebound VLK is to discard all previously worn PMMA or GP lenses as patients will revert to them if a new high Dk corneal GP lens is broken or lost. The key factor for the practitioner is to redesign the new GP lenses with a hyper Dk lens material that incorporates a mild apical bearing lens-to-cornea fitting relationship and a moderate edge lift.

Follow-Up Care/Final Outcome

After initially wearing the new corneal GP lenses for two weeks as daily wear without any appearance of adhesion, VLK or photophobia , JE was able to successfully resume six day continuous wear. Visual acuity was 20/20 -1 with the right lens, 20/20+ with the left lens and 20/20+ OU. To reduce any rebound dryness, JE was asked to use rewetting drops each night before bed and throughout the day as needed.

Discussion, Alternative Management Options

VLK is a multi-factorial condition most frequently associated with corneal GP continuous wear, chronic dryness, retro lens debris and tight central and peripheral fitting lens designs. After refitting with a high Dk material using an alignment-to-mild apical bearing lens to cornea relationship and moderate edge lift, patients can in most instances return to successful continuous GP wear. To achieve a safe lens-to-cornea fitting relationship, it is important to maintain a superior to central lens position with 1-2mm of lens movement upon blinking.

Before refitting, it is critical to therapeutically treat the cornea with a topical antibiotic and subsequent steroid combination to eliminate any infection and reduce the inflamed limbal mass. Just as important is the need to discard all previously worn lenses as rebound VLK will quickly occur if the same tight fitting lenses are reused.

Alternative options include the nightly use of rewetting drops, reduced continuous wear to 1-3 days or restricting to daily wear only (best option). When daily wear is chosen, it is important for the patient to instill non-preserved eye-drops at bedtime to help maintain corneal and limbal tissue moisture to avoid overnight desiccation. Also, you can recommend regular use of enzyme treatment to minimize hydrophobic lysozyme film buildup.

Practitioners and patients must remain vigilant for any return of VLK as this will occur if subsequent lens-to-cornea relationships become imbalanced toward a tight fitting lens. In cases of persistent inferiorly decentered lenses that promote desiccation, it may be necessary to increase the lens diameter and to select a GP material of lighter specific gravity to encourage a more superior positioning of the lenses.