[Medline]. Arch Ophthalmol. The disease was first described in detail more than 150 years ago by Dr John Nottingham, but the understanding of the disease and its management have undergone significant changes over the last few decades. 1-8 Today, we have a broad and ever-increasing number of viable options including larger-diameter intralimbal corneal GPs, scleral lenses, hybrid lenses, and custom soft lenses. Eye (Lond). [Medline]. [Medline]. [Medline]. [Medline]. Although not often fully successful, they are an option for patients who (1) are intolerant to contact lenses, (2) have clear central corneas, (3) have corneas with a thickness of at least 400 µm, and (4) retain penetrating keratoplasty as a remaining option. The term CXL Plus pertains to treatment with CXL combined with an additional refractive treatment. 2005 Nov. 24 (8):941-6. , Long-term studies are still needed to determine the success and adverse effects of UV-CXL, as well as the long-term biomechanical effect. Deep anterior lamellar keratoplasty (DALK) is becoming the preferred surgical option for keratoconic eyes without hydrops because of the avoidance of endothelial rejection, quicker heal time, and increased wound strength. The preferred treatment for progressive KC has shown a paradigm shift from contact lens fitting for as long as tolerated, followed by Penetrating Keratoplasty (PK) or Deep anterior lamellar keratoplasty (DALK), to Ultraviolet-A (UV-A) induced collagen cross-linking (CXL) to stabilize corneal ectasia in the long term. New algorithms using computerized videokeratopgraphy have been devised which now allow the detection of forme fruste, subclinical or suspected keratoconus. 121 (4):812-21.  particularly if corneal steepening has made the current rigid contact lens fit flat. 2013 Dec. 131 (12):1583-90. Graefes Arch Clin Exp Ophthalmol 2007; 245:869-75. Alió JL, Shabayek MH. . [Medline]. 52-58. Sharma A, Nottage JM, Mirchia K, Sharma R, Mohan K, Nirankari VS. Nonsurgical options such as spectacles and contact lenses (soft, rigid or scleral) in children are not always tolerated and often insufficient to obtain a satisfactory visual acuity. 2008 May. More studies are also needed to identify high-risk patients perhaps related to their age, diagnosis, corneal shape, and/or stages of ectasia. The most sensitive and specific indicator of KC is the fragmentation of Bowman layer – an insult that critically destabilizes the surrounding cornea, predisposing it to ongoing ectasia. Acar BT, Utine CA, Ozturk V, Acar S, Ciftci F. Can the effect of transepithelial corneal collagen cross-linking be improved by increasing the duration of topical riboflavin application? The management of Keratoconus can be a struggle. Barry A Weissman, OD, PhD, FAAO Professor of Optometry, Southern California College of Optometry; Professor Emeritus of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles, David Geffen School of Medicine Topography-guided conductive keratoplasty (CK) is a procedure that uses a hand-held tool to deliver energy from radio waves to specific points in the periphery of the cornea to reshape the eye's front surface. [Medline]. Moschos MM, Nitoda E, Georgoudis P, Balidis M, Karageorgiadis E, Kozeis N. Contact Lenses for Keratoconus- Current Practice. Complications of UV-CXL have included corneal haze, Farjadnia M, Naderan M. Corneal cross-linking treatment of keratoconus. Invest Ophthalmol Vis Sci. Accessed: December 7, 2013. A 48-year clinical and epidemiologic study of keratoconus. Genetics in Keratoconus: where are we?. 32(2):211-7. [Medline]. Superoxide dismutase isoenzymes in the normal and diseased human cornea. For many people, the cornea will become stable after a few years.  to improve the corneal integrity prior to surgery on keratoconic eyes. Classically, keratoconus is defined as a bilateral but typically asymmetric, non‐inflammatory corneal ectasia that is characterised by progressive thinning of the axial stroma. Surv Ophthalmol. 2015 May. 1994 Nov. 35(12):4008-14. 2008 May. Does lamellar surgery for keratoconus experience the popularity it deserves?. 2005 Apr. To do the opposite (UV-CXL, then later ICRS) limits the flattening effect of the segments since the cornea has been already fixed into a sub-optimal configuration. By means of this article, we aim to provide a summary of these recent trends in therapeutic options for the optimal management of keratoconus. Am J Ophthalmol. Outcomes of penetrating keratoplasty in keratoconus. Modified automated lamellar therapeutic keratoplasty for keratoconus: a new technique. Hashemian H, Jabbarvand M, Khodaparast M, Ameli K. Evaluation of corneal changes after conventional versus accelerated corneal cross-linking: a randomized controlled trial. [Medline]. Duddell in 1729, described a … Keratoconus (KC) is a disorder of the eye which results in progressive thinning of the cornea. Management of keratoconus: current scenario. Ferrari G, Iuliano L, Viganò M, Rama P. Impending corneal perforation after collagen cross-linking for herpetic keratitis. 2016 Nov. 35 (11):1416-1420. Changes in collagen orientation and distribution in keratoconus corneas. [Medline]. 115(5):845-50. [Medline]. Semisoft or RGP or Rose K contact lens, can help in cases with mild to moderate keratoconus. Mandathara PS(1), Stapleton FJ, Willcox MDP. J Cataract Refract Surg. Kosaki R, Maeda N, Bessho K, Hori Y, Nishida K, Suzaki A. One-Year Results of Simultaneous Topography-Guided Photorefractive Keratectomy and Corneal Collagen Cross-Linking in Keratoconus Utilizing a Modern Ablation Software. Patients may still require contact lenses after surgical correction. Kymionis GD, Portaliou DM, Diakonis VF, Kounis GA, Panagopoulou SI, Grentzelos MA. Int Ophthalmol Clin. Does ethnic origin influence the incidence or severity of keratoconus?. Share cases and questions with Physicians on Medscape consult. Br J Ophthalmol 2011; 95:1044. Eye (Lond). Choi JA, Lee MA, Kim MS. The genetics of keratoconus. Christopher J Rapuano, MD Professor, Department of Ophthalmology, Sidney Kimmel Medical College of Thomas Jefferson University; Director of the Cornea Service, Wills Eye Hospital Am J Ophthalmol. Keeping Eyes Safe From COVID-19: What Works? 33(3):112-8. Keratoconus diagnosis include a comprehensive eye exam and tests to determine your corneal shape. Busin M, Scorcia V, Zambianchi L, Ponzin D. Outcomes from a modified microkeratome-assisted lamellar keratoplasty for keratoconus. Cont Lens Anterior Eye. [Medline]. 2014 Apr. J Refract Surg 2012; 28:787-93. Ku JY, Niederer RL, Patel DV, Sherwin T, McGhee CN. Clinical outcomes of posterior chamber toric phakic intraocular lens implantation for the correction of high myopic astigmatism in eyes with keratoconus: 6-month follow-up. Inflammatory response to contact lenses in patients with keratoconus compared with myopic subjects. 2009 May. 2013 Aug. 61 (8):410-5. 93 (3):e199-207. Shallower than 60%, the effect may be lessened and the likelihood of a variety of ocular surface complications increased. 129(6):691-7. Both Photrexa and Photrexa Viscous (in 20% dextran) topical ophthalmic solutions are used during various stages of the procedure with the electronic device (KXL System), which irradiates the solutions with ultraviolet A light after they have been applied to the debrided cornea. Eye Vis (Lond). [Medline]. Riboflavin 5´-phosphate topical ophthalmic (Photrexa, Photrexa Viscous) was approved by the US Food and Drug Administration (FDA) in April 2016 for use in corneal collagen cross-linking (CXL) in combination with the KXL System for the treatment of progressive keratoconus. Int Ophthalmol 2014; 34:49-58. In the year 2000, Colin and associates15 first published an article about their preliminary results regarding the management of keratoconus with Intacs. Weissman B, Chun MW, Barnhart LA. Refractive and topographic results of benzalkonium chloride-assisted transepithelial crosslinking. Keratoconus Management What is Keratoconus? Complications include significant pigment dispersion and risk of endothelial cell loss with anterior chamber IOLs and development of anterior subcapsular cataract, glaucoma and rotation of toric ICL in cases of posterior chamber IOLs. J Refract Surg 2012; 28:341-5. But facing Keratoconus with other conditions like: Diabetes, Cataracts, Hypertension, or even arthritis can be even more of a challenge. 7 (3):517-21. Curr Opin Ophthalmol. The characteristics of the most popular ICRS implants have been described in (Table 1). Invest Ophthalmol Vis Sci 2010; 51:129-38. [Medline]. 3:16. This website also contains material copyrighted by 3rd parties. It is known that eyes with KC have significant aberrations that affect visual quality, with higher levels of vertical coma, primary coma and coma-like aberrations as compared to normal eyes. 1997 May. [Medline]. J Refract Surg 2011; 27:915–8. The cascade hypothesis of keratoconus. Zadnik K, Barr JT, Edrington TB, et al. The short-term safety and efficacy of intracorneal ring segment (ICRS) implantation in keratoconus eyes of children are investigated in this study. 11 (2):93-108. 31(6):595-9. Am J Ophthalmol 2003; 135:620-7. Other investigators have also reported on combining a customized partial refraction surface ablation and CXL in the management of keratoconus and ectasia.16–19. 3:2. Measurements of corneal stiffness using surface wave elastometry in ex vivo porcine eyes suggested that ‘flash-linking’ and conventional CXL may have a comparable effect. J Refract Surg 2009; 25:S812-8. Keratoconus and related noninflammatory corneal thinning disorders. However, it is not recommended for ablations larger than 50µm. Simultaneous topography-guided photorefractive keratectomy followed by corneal collagen cross-linking for keratoconus. Even in the absence of signs or symptoms of complications, contact lens care should be provided at 4-month to 6-month intervals to promptly address changes in fit or optics, as well as detecting asymptomatic complications and early intolerance. Indian J Ophthalmol 2013; 61:425-7. Keraflex (KXS) is a new procedure that aims to cause significant flattening using thermal heat below the corneal surface. Rocha KM, Ramos-Esteban JC, Qian Y, Herekar S, Krueger RR. 2012 Sep. 90(6):e482-6. Alió JL, Shabayek MH. A comparison of lamellar and penetrating keratoplasty outcomes: a registry study. An in vivo confocal microscopy study. Contact lens management of keratoconus. [Medline]. [Medline]. Bowman layer transplantationto reduce and stabilize progressive, end stage, keratoconus. J Cataract Refract Surg. ICRS consist of two tiny, clear, cresecnt shaped pieces of PMMA which can be inserted into the cornea. [Medline]. 108(4):534-8. [Medline]. [Medline]. [Medline]. Vogt striae and some scarring can also be seen centrally; superiorly, a small (brown) section of the Fleischer ring is noted. Contemporary advances in contact lens designs and materials have significantly expanded the available fitting options for patients with corneal ectasia. Surgical care is differentiated among (1) treating the progression of keratoconus with ultraviolet corneal collagen cross-linking (UV-CXL), (2) removing corneal scars to improve contact lens tolerance, and (3) improving keratoconus-induced poor vision keratoconus with intrastromal corneal rings and corneal transplants. The current technique involves the use of riboflavin (vitamin B2), which is exposed to a measured dose of longer wavelength UV-A radiation (370nm) at 3 mW/cm2 (5.4 J/cm2). 12-JUN-2015, Published Online:
Compañ V, Aguilella-Arzo M, Edrington TB, Weissman BA. 2007 Dec. 33 (12):2135-7. Clinical indications and results. [Medline]. Mannis MJ, Ling JJ, Kyrillos R, Barnett M. Keratoconus and Personality-A Review. Karseras AG, Ruben M. Aetiology of keratoconus. With the potential to alter the natural history of KC and possibly even halt disease progression using methods like CXL and BL Transplantation and with the newly developed procedures to provide best possible optical outcomes to these patients, need for corneal transplant in KC may become a thing of the past. Examine the upper eyelids via lid eversion in all contact lens wearers. Surgical care is recommended when the best corrected visual acuity achieved with contact lenses is worse than 20/40 vision or when contact lenses and scleral lenses are no longer tolerated. Disadvantages: Unlike corneal-based treatments that aim to normalise the shape of the keratoconic cornea, IOLs can correct only spherical and cylindrical error. Keratoconus: I. Biochemical studies. 15(2):139-46. [Medline]. Therapies Corneal collagen cross-linking. 2003 Sep. 26(3):139-46. Am J Ophthalmol. Surgically removing central nodular scars by shaving the corneal surface (superficial keratectomy with a blade or excimer laser phototherapeutic keratectomy) may improve contact lens tolerance, decrease the rate of associated corneal abrasions, and preclude the need for corneal transplant. Ophthalmology. Cornea.  and UV-CXL corneal epithelium intact (epi-on) or removed (epi-off) techniques. [Medline]. [54, 55, 56] Most patients will require spectacles and/or contact lenses following surgery. . For myopia, ICRS work by flattening the cornea to re-focus light rays and improve vision; while in KC patients, ICRS flatten the steep part of the cone and reduce vision distortions. Varying techniques have been used to promote riboflavin absorption into the stroma keeping an intact epithelium. J Refract Surg 2014; 30:837-42. ICRS implantation in children keratoconus eyes allows a reduction of corneal astigmatism, irregularity, and aberrations, leading to a significant visual improvement. 2006 Jun. 2006 Aug. 17(4):349-55. Määttä M, Väisänen T, Väisänen MR, Pihlajaniemi T, Tervo T. Altered expression of type XIII collagen in keratoconus and scarred human cornea: Increased expression in scarred cornea is associated with myofibroblast transformation. This paper provides a comprehensive review of the range of contact lens modalities, including soft lenses, hybrid designs, rigid lenses, piggyback configurations, corneo‐scleral, mini‐scleral and scleral lenses that are currently available for the optical management of keratoconus. Invest Ophthalmol Vis Sci. Indian J Ophthalmol. Gondhowiardjo TD, van Haeringen NJ. Ophthalmol Clin North Am. Cornea 2007; 26:385-9. Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus. Piñero DP, Nieto JC, Lopez-Miguel A. Woodward MA, Blachley TS, Stein JD. Spadea L, Gizzi R, Evangelista Conocchia N, Urbano S. Optical pachymetry-guided custom excimer laser-assisted lamellar keratoplasty for the surgical treatment of keratoconus. [30, 31] UV-CXL has also been combined with same-day photorefractive keratectomy (PRK), An optic section of a keratoconic cornea shows corneal thinning. [Medline]. J Ophthalmol. A retrospective interventional case series study including a total of 33 keratoconus eyes (age 8 to 17 years) that had undergone ICRS (Keraring segments, Mediphacos) implantation was conducted. Hafezi F, Mrochen M, Iseli HP, Seiler T. Collagen crosslinking with ultraviolet-A and hypoosmolar riboflavin solution in thin corneas. Available from: http://www.djo.org.in/articles/26/1/management-of-keratoconus.html. Changes in keratoconic corneas after intracorneal ring segment explantation and reimplantation. With mean follow-up of 11.3 months, intracorneal ring segments implantation improved UCVA and BCVA in the majority of the keratoconus patients. Mathew JH, Goosey JD, Söderberg PG, Bergmanson JP. Midstromal transplantation of Bowman layer (also known as anterior limiting lamina [ALL]) is a newer procedure used to flatten and strengthen advanced keratoconic corneas that may be too thin for UV-CXL. Lema I, Durán JA. Surv Ophthalmol. Reinhart WJ, Musch DC, Jacobs DS, Lee WB, Kaufman SC, Shtein RM. 2017. In the future, surely new treatment techniques will have scientific foundations in molecular mechanisms which can halt the initial onset of ectasia. Intrastromal corneal ring segments implantation in patients with keratoconus: 10-year follow-up. Contemporary advances in contact lens designs and materials have significantly expanded the available fitting options for patients with corneal ectasia. Treatment of KC needs to be individualized. These segments may be implanted symmetrically if the keratoconic cone is located centrally, or asymmetrically if the cone is decentred. [Medline]. Furthermore, imaging technology, such as corneal topography …. Update on the keratoconus genetics. In Keratoconus there is progressive thinning of the cornea and as a result the cornea develops a cone-like bulge and becomes distorted. Keratoconus is a disease of the cornea (the curved, clear front surface of the eye) that is often visually debilitating. Br J Ophthalmol. Extended long-term outcomes of penetrating keratoplasty for keratoconus. 42 Online:e22-5. Posterior chamber phakic IOLs are placed between the iris and crystalline lens. Management of progressive keratoconus with partial topography-guided PRK combined with refractive, customized CXL – a novel technique: the enhanced Athens protocol Anastasios John Kanellopoulos 1, 2 Ophthalmology. Arch Ophthalmol. 2015 Jun 30. Comparison of sequential vs same-day simultaneous collagen cross-linking and topography-guided PRK for treatment of keratoconus. A randomized, controlled trial of corneal collagen cross-linking in progressive keratoconus: three-year results. 2002 Mar. 2005 Mar. Alnawaiseh M, Rosentreter A, Eveslage M, Eter N, Zumhagen L. Changes in Corneal Transparency After Cross-linking for Progressive Keratoconus: Long-term Follow-up. Invest Ophthalmol Vis Sci.  endothelial cell density loss, Kymionis GD, Kontadakis GA, Kounis GA, Portaliou DM, Karavitaki AE, et al. Nattis A, Donnenfeld ED, Rosenberg E, Perry HD. Intrastromal corneal rings (ICRS) are polymethyl methacrylate segments implanted into the corneal stroma to reduce corneal distortion by flattening the steep areas of the keratoconic eye. Iovieno A, Légaré ME, Rootman DB, Yeung SN, Kim P, Rootman DS. Br J Ophthalmol. Gas-permeable scleral lenses should be made of the highest oxygen-transmissible (Dk) material, and the tear layer should not be excessive to minimize hypoxia. When keratoconus develops, the cornea becomes thin and begins to bulge like a cone.  Bowman layer transplantation usually improves 1-2 lines of visual acuity. These bridge the amino groups of collagen fibrils, increasing the rigidity of corneal tissue.