Clinical evaluation of different types of contact lenses in keratoconus management

How to Improve Visual Acuity in Keratoconic Cornea?

“…Keratoconus patients tend to be complicated to treat because they are forced to leave their glasses frequently due to oscillations in their refraction because their measurements are unstable and must continually adapt to new glasses or other types of devices to achieve an optimal visual acuity [5]. The visual correction of the keratoconus will depend on the stage in which it is found; in the early stages astigmatism can be corrected with glasses; however, when it is moderate to severe, contact lenses become the most appropriate option before placement of intrastromal rings or corneal transplantation [6].…”

“…Contact lenses for the treatment of keratoconus were induced by Adolf Fick in 1888 [6]. The corneoscleral contact lens (CScL) are rigid oxygen-permeable gas lenses and are composed of fluorosilicone acrylate; these rest partially on the cornea and conjunctival tissue and are used to improve vision in patients with high or irregular astigmatism either secondary to keratoconus, marginal pellucid degeneration, keratoglobus, or posttransplant astigmatism, as well as other pathologies such as Steven-Johnson syndrome, scar pemphigoid, or graft versus host disease may require its use, and also for patients who do not tolerate conventional gas-permeable rigid lenses [7,8].…”

“…There are several types of contact lenses that can be used for the correction of visual acuity, astigmatism, and high-order aberrations in patients with keratoconus such as the corneoscleral contact lenses mentioned above, the mini-scleral contact lens (MSCL), the piggyback contact lens, and the rigid gas-permeable contact lens (RGPCL), being the hybrid contact lens (HCLs), soft toric lenses (STCLs), and corneoscleral contact lens (CScL) the most used for the correction of refractive error reporting excellent comfort and better vision with the corneoscleral contact lenses since the latter tends to be more accessible to use than conventional [5,6,9].…”

“…DOI: http://dx.doi.org /10.5772/intechopen.90478 The advantages of these lenses are that they are less mobile, focus better on the cornea, and have no contact with it so it does not cause irritation discomfort since they settle on the conjunctiva and the sclera; the ideal measures are between 15 and 17 mm of diameter or more. One of the advantages of this type of contact lenses is that they create a new ocular surface to compensate for the optical system so they must be filled with liquid before being placed and can be used for a longer time than conventional ones as long as the height of the vault is larger, so it is usually comfortable for some patients given the extended hours of use without complications [5][6][7]10].…”

“…The disadvantage of soft, silicone hydrogel and permeable gas lenses concerning scleral lenses is that they cannot neutralize irregular astigmatism, so they do not provide visual acuity as suitable as corneoscleral contact lenses [5,6].…”