Scleral Lens Care and Handling
BY MELISSA BARNETT, OD & MINDY TOABE, OD
It is well established that scleral lenses are advantageous for protecting the ocular surface and improving visual acuity in cases of irregular astigmatism. As awareness of scleral lenses becomes widespread, the use of scleral lenses continue to grow. However, because the handling and care of large-diameter scleral lens designs is different compared with corneal gas permeable lenses or soft contact lenses, scleral lenses pose some unique challenges, including minimal tear exchange and the potential for fogging in the post lens fluid reservoir. In fact, difficulty with scleral lens handling is the primary reason for dropout. Scleral lens dropout rates vary in the literature, but range from about 25% to 49%.1,2 Therefore, proper care and handling of scleral lenses is critical to success.
INSERTION OF SCLERAL LENSES
Prior to handling scleral lenses, it is important to wash hands with a mild soap, rinse thoroughly, and dry with a lint-free towel. Avoid oils, lotions, hand sanitizers, and soaps with perfumes. Hand cream, makeup, and hair spray may be used after lens application to avoid a residue on the lens.
Insertion of a scleral lens can be challenging due to the large size of the lens compared with the palpebral fissure; it may be difficult to balance the lens on the fingers with manual insertion. A rubber device called a plunger, or scleral cup, is sometimes used to stabilize and prepare the lens for application. There are a few commercially available plungers in ventilated and non-ventilated designs to aid with insertion and removal of scleral lenses. Although both plunger designs can be used, some practitioners prefer one over the other. A vented plunger allows the lens to balance in the cup without inducing suction. The lens could tip or be displaced if the lens is bumped during the application process due to the lack of suction. A non-ventilated plunger maintains lens stability; but gentle squeezing of the plunger is needed when applying the lens. Pinching the plunger at the junction between the cup and the handle will remove the plunger from the scleral lens in the event that the plunger remains on the scleral lens upon insertion.
Figure 1. Scleral lenses utilize a post-lens fluid-filled reservoir that allows the cornea to be submerged in an artificial pool of preservative-free saline solution. Shown, a scleral lens prior to insertion on a large plunger filled with saline and sodium fluorescein.
Figure 2. Removal of scleral lens with small plunger on the periphery of the lens.
There are two methods for scleral lens application. The first is the three-finger approach, or the plunger (also known as inserter) method. To begin, have the patient sit or stand and place a clean towel on a flat table. A mirror lying flat on the table is helpful when applying the lens. With the three-finger method, the thumb, index, and middle fingers are used to create a tripod stand for scleral lens application. The lens is filled with sterile, nonpreserved saline solution, the eyelids are held open, and the scleral lens is placed on the eye.
For the second method, the large plunger method, the ventilated and non-ventilated plungers are prepared by wetting the plunger’s surface with one to two drops of sterile, preservative-free saline solution. Next, have the patient squeeze the non-ventilated plunger and hold the outside edge of the lens and place it on the plunger. When released, the lens is tightly secured to the non-ventilated plunger. With the ventilated plunger version, have the patient hold the outside edge of the lens and place it on the plunger. Next, have the patient overfill the bowl of the lens with sterile, preservative-free saline so the saline appears as a convex or round surface above the lens. The lens is held with the dominant hand. Have the patient lean forward, sitting with the chin toward the chest and eyes facing the mirror on the table with the head parallel to the ground. Holding the eyelids wide open with the index finger on the upper eyelid and middle finger or thumb on the lower eyelid of the non-dominant hand, have the patient steadily move the lens closer to the eye.
Instruct the patient to look straight down toward the mirror on the table, and then at the plunger or the hole of the plunger while inserting the lens. To visualize the hole, the patient may close the opposite eye, which may impede application. The goal of lens placement is to be perfectly centered over the cornea. If the lens is placed in the lower cul de sac, the lens should be moved superiorly to center the lens. As the solution touches the eye, the lens is inserted gently. Here again, patients may squeeze their eyes and pull back once they feel the fluid sensation when the lens approaches the eye. The eyelids are released when the lens is on the eye. If using the ventilated plunger, the plunger is removed from the lens gently; if using the non-ventilated plunger, the plunger is gently squeezed to release suction and the lens. The plunger should be cleaned with alcohol or peroxide after each use and allowed to air dry.
After insertion, the patient should use the mirror to inspect the eye for air bubbles that can cause discomfort and decrease vision if the air bubble is in front of the pupil. An air bubble creates a dry area underneath the lens and can cause corneal desiccation through time. Air bubbles may appear upon insertion if the is head pulled back and is not parallel to the ground, causing the lens to tilt upon insertion and allowing air to be trapped between the solution and the eyeball. If an air bubble is present, the lens should be removed and reinserted. To avoid air bubbles, use one to two drops of a thicker, more viscous non-preserved artificial tear, such as carboxymethylcellulose sodium solution, combined with a preservative-free saline solution to fill the bowl of the scleral lens.
SCLERAL LENS REMOVAL
Plungers can also be helpful for lens removal. Generally speaking, large plungers are used for insertion and small plungers are used for removal.
A drop of preservative-free saline or artificial tears is instilled in the eye to loosen the lens prior to removal. With the manual two-finger method, the patient first looks up, and pressure is applied to the middle of the lower eyelid below the lashes. The eyelid is manipulated underneath the inferior edge of the lens. Pressure is then applied to the globe, and the lens is lifted. Then, the lower eyelid and finger are used together to nudge the lower edge of the lens off the eye, and the lens is removed. Have the patient stabilize and anchor the upper edge of the lens with the upper lid.
With the small plunger method, have the patient sit in a chair or stand up and place a clean towel on a flat table. Again, placing a mirror on the table can be helpful during lens removal. Have the patient wet the plunger’s surface with one to two drops of sterile, preservative-free saline solution. Next, have the patient look into the mirror. While holding the eye open, the patient should apply the plunger to the lens in the peripheral inferior or superior quadrant by the limbus. The lens is then removed by releasing suction of the lens on the eye with the plunger.
Using the eyelid, press into the globe adjacent to the lens edge where the plunger will be applied to the lens. This pressure may be needed to break the seal of the lens and allow for a bubble under the lens to loosen the lens prior to removal. As the lens is being removed, patients should be cautious not to scrape the edge of the lens across the cornea to avoid causing a corneal abrasion. If the plunger is on the center of the lens, pinch the base of the plunger to remove it from the lens and re-apply the plunger in the peripheral location of the lens. The patient should hold the outside edge of the lens while squeezing the base of the plunger to remove it from the lens. After removal, disinfect and store the lenses. After each use, the plunger should be cleaned with alcohol or peroxide and allowed to air dry.
Cleaning the plunger is critical, as an old plunger can become cracked, may leave residue on the lens surface, and may not provide good suction on the scleral lens. It is beneficial for the patient to have plungers in multiple locations (home, work, school, and so on). Plungers should be replaced every 3 to 6 months, or sooner if the edges become rough, uneven, or if suction is insufficient. Plungers are not readily obtainable at the local pharmacy and should be stocked in-office. Online resources for plungers include dryeyeshop.com, myeyesupply.com, and Amazon.com, among others.
The Scleral Lens Education Society website is a great resource for practitioners and patients. In addition to a how-to video and a downloadable slide presentations, the site provides useful information on how to properly insert and remove scleral lenses, as well as other tips and tricks.
ADDITIONAL TIPS FOR SCLERAL LENS HANDLING
Some patients may face unique challenges with handling. For example, older patients, aphakic patients, patients with high refractive error or rheumatoid arthritis, or patients who have dexterity issues as a result of arthritis or missing digits may need extra assistance. If a patient is struggling with application and removal, a family member or friend can be trained to insert and remove the lenses.
Additional tools may be used to increase success with scleral lens handling. For example, inserters with accompanying stands are available to help hold the plunger and lens in place prior to application. This is helpful for patients who have unsteady hands, missing digits, or for those who need both hands to hold their eyelids open.
Another helpful tool is a lens insertion ring, which is placed on the finger like a ring and has a base for scleral lens application. This design provides stability, allowing patients to apply scleral devices with one finger.
Other options are a sterile orthodonic ring or a #8 O-ring from a hardware store. O-ring dimensions are 3/8” x 9/16” x 3/32”. The scleral lens rests on the O-ring on a patient’s finger, which can allow for stable application.
A LESSON WORTH REPEATING
Proper care and handling of scleral lenses should not be a one-time discussion. At every visit, care and handling should be reviewed. In addition, patients should be given contact information in case of an after-hours emergency. No matter how well a scleral lens is fit, patients need to understand proper application and removal to help ensure a successful scleral lens experience. •
For references, please visit www.clspectrum.com/references and click on document #SCLERAL2016.