The treatment of keratoconus can be implemented by the use of spectacle lenses, contact lenses of various kinds, and surgery. In this article, we deal with the procedures of contact lens fitting in patients diagnosed with keratoconus. The different types of specific contact lenses and the methodology of fitting these contact lenses for keratoconus are described. To select a contact lens for the individual patient depends upon the severity of keratoconus and the amount of corneal ectasia. Pending these criteria, a contact lens is chosen, which will give the best visual acuity and tolerance. At present, many designs of special contact lenses exist in oxygen-permeable materials; in addition, other systems, such as piggy-back, SoftPerm, semi-scleral, and scleral contact lens types are used. Contact lens fitting on a conical cornea will smooth out the highly irregular optical surface of the cornea and improve visual acuity considerably. Contact lenses are one of the better solutions to correct refractive errors induced by pathology, and they should be prescribed as soon as the keratoconus is detected to avoid development of amblyopia. The quality and quantity of vision is far better than with spectacle lens correction.
"The quality and quantity of vision is far better than with spectacle lens correction . Success in the contact lens usage in the keratoconus patients may increase the visual acuity and vision related quality of life. "
[Show abstract][Hide abstract] ABSTRACT: Purpose. The purpose of this study is to evaluate the vision related quality of life in patients with keratoconus by using the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25). Methods. Thirty patients presented with keratoconus (keratoconus group) and 30 healthy patients (control group) were included in this study. Twenty patients were using rigid gas permeable and 10 patients were not using contact lenses in keratoconus group. High and low contrast visual acuity and mean K values of the patients were recorded. Each subject completed the 25-item NEI-VFQ-25. Results. All subscales of NEI-VFQ-25 were lower in the keratoconus patients. The difference was more evident in the subscales of general vision, ocular pain, near vision, vision-specific mental health, vision-specific role difficulties, and peripheral vision . Overall composite score was 75.2 +/- 17.2 in the keratoconus group and 93.2 +/- 5.6 in the control group . Contact lens wearers had higher best corrected visual acuity in comparison with noncontact lens wearers . Patients with low visual acuity (logMAR > 0.4) in the better eye had lower distance vision, social functioning, mental health, and role difficulties. Meanwhile, patients with low visual acuity (logMAR > 0.4) in the worse eye had lower general health scores . Conclusions. Vision related quality of life was worse in keratoconus patients. Success in the contact lens usage and maintaining higher visual acuity may improve vision related quality of life.
Journal of Ophthalmology 04/2014; 2014(4). DOI:10.1155/2014/694542 · 1.43 Impact Factor
"The optical features of soft and rigid contact lenses, including correction at the corneal plane and elimination of surface irregularities, offer advantages in corneal ectasia, thus contact lenses are the next step in treatment. As the cornea becomes more irregular and conical, difficulties in achieving satisfactory contact lens fit present  . "
[Show abstract][Hide abstract] ABSTRACT: Prosthetic replacement of the ocular surface ecosystem (PROSE) uses custom designed and fabricated prosthetic devices in a treatment that restores vision, supports healing, reduces symptoms and improves quality of life in patients with complex corneal disease. We report the success rate for PROSE treatment of corneal ectasia.
Records of 59 patients with corneal ectasia seen in consultation over 6months were reviewed. Candidacy for treatment, topographic indices, change in visual acuity, achievement of satisfactory fit, device wear status and change in visual function at 6months were recorded.
Sixteen eyes were non-candidates because conventional correction was adequate. Trial devices were inserted but not dispensed for 13 eyes. No eyes were excluded for severity of ectasia. In the remaining 89 eyes, satisfactory fit was achieved and a device was dispensed. Twenty-one eyes (15 patients) had undergone penetrating keratoplasty. Device wear at 6months was documented in 78/89 eyes (88%). NEI VFQ-25 score improved 27.6 points (p<0.001) on a 100 point scale in patients wearing a device at 6months.
All candidate eyes with corneal ectasia could be fitted with a PROSE device. PROSE treatment has a high success rate when measured by ability to achieve satisfactory fit, impact on visual acuity and 6month data on both rate of continued wear and impact on visual function. PROSE treatment is an alternative to penetrating keratoplasty for patients with corneal ectasia who are contact lens intolerant.
Contact lens & anterior eye: the journal of the British Contact Lens Association 05/2012; 35(5):222-7. DOI:10.1016/j.clae.2012.04.003 · 1.37 Impact Factor
"This congenital, noninfl ammatory, usually bilateral disease manifests as a progressing stromal instability, leading to a reduction in corneal rigidity (Andreassen et al 1980) and may affect visual acuity to such an extent as to require penetrating keratoplasy in up to 20% of patients (Pramanik et al 2006). Treatment options include conservative approaches, aimed at maintaining visual acuity, such as rigid contact lenses placed to straighten corneal aberrations (Garcia-Lledo et al 2006). Alternatively, more invasive methods are applied using intrastromal corneal implants (Ertan and Colin 2007), performing anterior lamellar keratoplasty, and penetrating keratoplasty in extreme cases (Pramanik et al 2006; Tan and Por 2007). "
[Show abstract][Hide abstract] ABSTRACT: Corneal ectasia, a weakening of corneal integrity, occurs both due to acquired and congenital conditions such as keratoconus. It is a progressing condition that affects both visual acuity, and corneal stability. Various methods exist for correcting this impairment, however none address the inherit pathology, an increase laxity of the corneal stroma. Collagen cross-linking, a new, minimally invasive method, aims to strengthen the stroma by inducing cross links between neighboring collagen fibers. This method results in an increase in corneal tensile strength, with no medium term adverse effects on its normal architecture. Clinically, treated patients display improvement in both visual acuity and keratometric readings. This method may provide clinicians with easily accessible tools to stop the progression, and even correct visual deterioration due to corneal ectasia. Here we review the current information regarding this new method, as well as discuss its potential benefits and downfalls.
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