Benefits and Disadvantages of Scleral Lenses Over RGPs
- January 23, 2023
If you wear rigid gas permeable (RGP) contact lenses, perhaps you have heard about scleral contact lenses. Are scleral contact lenses right for you? Learn six advantages of scleral lenses and two potential disadvantages over RGP lenses.
Why Wear RGPs?
RGP contact lenses have existed since 1978. RGPs are also referred to as corneal gas permeable (GP) lenses or “hard” contact lenses even though the true “hard” lenses existed prior to 1978. If you wear RGPs, there probably is a good reason why your doctor did not prescribe you soft disposable contacts. Many that wear RGPs need them to get the best possible vision. This is often because the cornea – or front clear dome of the eye – is not smooth. If you wear RGPs, it is likely that you have high astigmatism, corneal scarring, keratoconus, or complications from either radial keratotomy (RK) or LASIK. In these uncommon cases, soft contact lenses do not afford stable nor sufficient vision. This is because soft lenses conform to the distorted surface of the eye whereas RGPs provide a new smooth surface to clearly bend light.
Common problems with RGP lenses include discomfort, lenses decentering or ejecting, irritation in dusty environments, dryness symptoms, the need for prescription glasses over contacts to obtain optimized vision, and vision drifting after lens removal. This is where scleral lenses can help!
Six Scleral Lens Advantages Over RGPs
Most of our patients that are prescribed scleral lenses from RGPs say that wish they wish they did it sooner. Here are six reasons why:
- The hallmark of scleral contact lenses is comfort, at least when they are prescribed appropriately. Many patients describe that scleral lenses are as comfortable as soft contact lenses. RGP contacts touch the cornea, the most sensitive part of the human body. By comparison, scleral lenses are designed to avoid touching the cornea and instead rest on the insensitive conjunctiva and scleral, the white part of the eye.
- Once on the eye, you can expect that scleral lenses will not decenter or eject. Scleral lenses are great for sports, whereas RGPs have a greater risk of popping out during competition. A side benefit of the stability and centration of scleral lenses is that patients often have more consistent vision since they are not looking through the edge of the RGP as it moves during blinking. Scleral lenses remain centered even while gazing in different directions and blinking.
- Scleral contact lenses minimize the likelihood of environmental irritants ranging from dust, smoke, and chemicals, from getting underneath the lens. RGP contact lens wearers will often relate to how uncomfortable it is when they get a speck of dust underneath their contact lens. By comparison, once a scleral lens is applied onto the eye, it is unlikely for an outside irritant to get underneath. Our scleral lens wearers comment that scleral lenses are helpful for chopping onions. Our scleral lens wearers working in law enforcement comment that scleral lenses help protect their eyes from irritation when working close to tear gas and pepper spray.
- Moisture. For patients with exposure dry eye where the eye surface physically dries out, often due to incomplete blinking or inability to close the eye, scleral lenses can help. Scleral lenses trap non-preserved fluid against the sensitive cornea, keeping the eye surface moist all day long. RGP lenses do not have this effect since they do not provide enough surface area of coverage over the eye.
- Enhanced Vision. Many RGP wearers still benefit from prescription glasses worn over them to provide the best vision. This is due to left-over or residual astigmatism. The advantage of scleral lenses is that that they readily correct residual astigmatism because of the stability of these lenses on the eye, unlike RGPs. In other words, scleral lenses can often absolve the need for prescription glasses worn over RGPs.
- Vision Stability After Removal. Most RGP wearers notice that their vision drifts in the ensuing hours to days after taking out their lenses. This can make prescription eyeglasses for wear after taking out RGPs a moving target based on the time elapsed from RGP removal. This effect is due to RGP lenses interacting and unintentionally molding the corneal surface. By comparison, scleral contact lens wearers do not experience this visual drift because scleral lenses are not supposed to mechanically interact with the corneal surface.
Two Scleral Lens Disadvantages over RGPs
- Initial handling difficulty. The majority of scleral lens wearers quickly learn to apply and remove these lenses, but a minority of RGP wearers have persisting difficulties. The patients with scleral lens application difficulty tend to already have problems handling their RGP lenses with extreme eyelid spasm and uncontrollable blinking as anything approaching their eye. The good news is that it is rare for patients not to gain facility with scleral lens handling, particularly with appropriate in-person training and guidance.
- Greater cost. For patients paying out-of-pocket, scleral lenses are significantly more expensive than RGPs. That said, the majority of our scleral lens wearers say that the advantages are well worth the cost premium. Many of our scleral lens wearers with eye disease will qualify for medically necessary contact lens authorizations through major vision plans, which significantly offsets the out-of-pocket costs of the lenses are professional care.
Not everyone is a suitable candidate for scleral contact lenses. To find out your candidacy status, schedule a comprehensive eye examination at ReVision Optometry.
ReVision Optometry is a referral-based practice in San Diego providing scleral contact lens services for patients with keratoconus and other complex eye conditions. To schedule, request your examination online or call our office at 619.299.6064.