Last updated on June 6th, 2017 at 11:00 am
If you’ve been told in the past that you can not use contact lenses because of an irregular cornea or other issues, you may wish to get a consultation and ask your eye doctor about scleral contact lenses.
Scleral contacts are large-diameter gas permeable contact lenses specifically developed to rise over the whole corneal surface and rest on the “white” of the eye (sclera). In doing so, scleral lenses functionally replace the irregular cornea with a perfectly smooth optical surface to fix vision problems triggered by keratoconus and other corneal abnormalities.
Likewise, the area between the cornea and the back surface of a scleral lens acts as a fluid reservoir to supply comfort for individuals with severe dry eyes who otherwise could not tolerate contact lens wear.
Types Of Scleral Contact Lenses
Scleral contacts are visibly bigger than standard gas permeable (GP) contacts and have a size equivalent to or higher than that of soft contact lenses. The smallest sclerals are around 14.5 mm in size, and the biggest can be as much as 24 mm.
Generally, lenses that are 18 mm or smaller are subcategorized as mini-sclerals.
The typical human cornea is roughly 11.8 millimeters in size, so even the smallest scleral contacts are developed to cover the whole corneal surface area.
In contrast, a lot of standard GP contact lenses are 9.0 to 9.5 mm in size and cover just 75 to 80 percent of the cornea.
Another category of gas permeable lenses bridges the size gap in between conventional GP lenses and mini-sclerals. These lenses, called corneo-scleral lenses, typically are approximately 13 to 15 mm in diameter.
Corneo-scleral lenses often are a great option for individuals who require larger-than-normal GP lenses for greater convenience. They likewise are regularly used when contact lenses are needed after LASIK or other corneal refractive surgery to correct irregular astigmatism.
The size of lens used often is determined by the degree of intricacy of the condition. Milder types of keratoconus and irregular astigmatism from corneal grafts and refractive surgery frequently are easily handled with scleral lenses at the smaller end of the spectrum.
Smaller sized scleral and mini-scleral contacts can be easier to apply, can be less expensive and need fewer care items.
More intricate conditions, including advanced keratoconus, pathologically dry eyes or severe ocular surface area disease that might require a large tear reservoir, often are fitted with bigger scleral lenses, as they have more capacity to hold fluid or bridge large changes in corneal curvature.
During your contact lens exam and fitting, your eye care expert will figure out the best scleral lens type and size for your specific requirements.
Scleral Contact Lenses For Keratoconus
Numerous eye doctors and eye doctors advise scleral contact lenses for a range of hard-to-fit eyes, including eyes with keratoconus.
In cases of early keratoconus, a basic GP lens might be used. However, if the lens does not center properly on the eye or relocations exceedingly with blinks and causes pain, switching to a large-diameter scleral contact lens may solve the problem.
Since scleral lenses are developed to vault the corneal surface area and rest on the less delicate surface area of the sclera, these lenses often are more comfy for a person with keratoconus. Also, scleral lenses are designed to fit with little or no lens movement during blinks, making them more steady on the eye, compared to conventional corneal gas permeable lenses.
Scleral Contact Lenses For Other Eye Problems
In addition to keratoconus, scleral contact lenses can be used for eyes that have actually gone through a cornea transplant, and for people with severe dry eyes caused by conditions such as Sjogren’s syndrome, graft-versus-host disease (GVHD) and Stevens-Johnson syndrome.
Advances in lens design technology are permitting producers to design scleral lenses that can fix more conditions than ever before, including bifocal sclerals for the correction of presbyopia.
Special-Effect Scleral Contacts
In some cases the term “scleral lenses” (or “sclera lenses”) also is used to describe special-effect contact lenses that considerably modify the look of the wearer’s eyes.
Nevertheless, these costume contact lenses (likewise called theatrical contact lenses, Halloween contacts or gothic lenses) typically are soft lenses that bear little similarity to scleral gas permeable contacts — aside from their big diameter to fully mask the cornea. Likewise, soft theatrical contacts generally are created for cosmetic purposes only and not for vision correction.
Scleral Contact Lens Cost
Scleral contact lenses are personalized for each user, so fitting scleral contacts needs higher know-how and more time than fitting standard soft or GP contact lenses.
Often, computerized maps of the curvature of the entire cornea are created to facilitate the lens fitting, and several trial lenses of different sizes and curvatures may be used to the eye during the fitting process.
Also, depending upon the complexity of the problem and how the individual eye tolerates the scleral lens, changes of lens parameters may be required, which will require extra lenses to be made and exchanged. The whole scleral lens fitting process can take several visits to figure out the optimal lens for each eye.
While lots of people who use scleral lenses have worn soft or corneal GP lenses in the past, the procedure for applying and getting rid of scleral lenses may take some practice. The additional time needed to master this, due to the bigger size of the lenses and the fluid reservoir under the lenses, needs to be taken into consideration during the fitting procedure.
For these and other factors, scleral contact lenses can cost significantly more than basic contacts; in fact, it is not unusual for scleral contacts to cost 3 or four times more. While not normal, in cases when a complex, extremely customized scleral lens is needed, cost can be as high as $4,000 per eye or more.
The majority of insurance coverage programs do not immediately cover the complete cost of scleral contact lenses. In many cases, vision insurance may lower the cost of your lenses and/or fitting charge. In other instances, calling your medical insurance company and inquiring what actions are required to acquire coverage can be useful. Ask your eye doctor’s workplace for details.
Likewise, some eye care practitioners offer funding choices for scleral contacts.