Updates on Managements for Keratoconus

Abstract

Purpose: Keratoconus is a progressive disease of the cornea which can lead to blindness as irregular astigmatism increases. Currently, a variety of methods are available for the treatment of keratoconus, and in certain cases, it may be difficult to choose the most appropriate option. This article reviews available treatment modalities for keratoconus to provide the practitioner with practical and useful information for selecting the most suitable option for each individual patient.

Methods: To review treatment methods for different stages of keratoconus, PubMed (United States National Library of Medicine) and Scopus (Elsevier BV) databases were searched using the keywords "keratoconus", "contact lens", "cross-linking", "Intacs", "keratoplasty", "gene therapy", and "irregular astigmatism", and related articles were reviewed based on disease assessment parameters and treatment methods.

Results: Various methods are available for the treatment of keratoconus: eyeglasses and contact lenses in the early stages, cross-linking for stabilizing disease progression, intrastromal corneal ring segments (ICRS) for reducing refractive errors or flattening the cornea, and penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK), conductive keratoplasty, gene therapy and more recently, bowman layer transplantation (BL transplantation) in advanced stages of the disease. To achieve optimum results, it is essential to choose the best option for each individual patient.

Conclusions: A commonality of the reviewed papers was the advancement of novel diagnostic and treatment methods in ophthalmology, which can delay the need for corneal grafting. A better understanding of keratoconus treatment options can help enhance visual rehabilitation and prevent blindness in keratoconus patients.

Keywords: Bowman layer transplantation; Contact lens; Cross-linking; Gene therapy; Intacs; Keraflex; Keratoconus; Keratoplasty.

Fig. 1

Surgical algorithm for management of keratoconus. *Age<25 years should be considered as progressive keratoconus. ** Rigid gas permeable (RGP) lenses should be considered in any case if tolerant. *** Photorefractive keratectomy (PRK) is only recommended for age>25 years and in conjunction with corneal cross-linking (CXL). BCVA: Best corrected visual acuity, CCT: Central corneal thickness, RSB: Residual stromal bed, KR: Keratometry reading, D: Diopter, CXL: Cross-linking, PRK: Photorefractive keratectomy, DALK: Deep anterior lamellar keratoplasty, PK: Penetrating keratoplasty.

Fig. 2

Slit-lamp image of a keratoconus eye implanted with MyoRing.

Fig. 3

MyoRing combined with cross-linking done in a keratoconus patient. A) Preoperative: −6.00/-5.50–170, Visual acuity: 20/50; B) 12 month postoperative: −1.00/-3.00–165, Visual acuity: 20/30.

Fig. 4

Patient with superior steepening and high myopia, preoperative: −6.00/-2.25–20, Visual acuity: 20/30; A phakic intraocular lens was implanted for correction.