Abstract | Keratokonus je poremećaj rožnice oka u kojem ona progresivno mijenja svoju zakrivljenost, fokalno se stanjuje te u krajnjoj fazi poremećaja zadobiva stožast oblik. Opisane promjene rožnice rezultiraju padom vidne oštrine najčešće po tipu progresivne kratkovidnosti i/ili iregularnog astigmatizma. Procjenjuje se kako prevalencija keratokonusa u općoj populaciji iznosi između 50 i 230 na 100 000 stanovnika. Keratokonus počinje tipično u pubertetu, napreduje kroz 10 do 20 godina i u srednjoj životnoj dobi progresija obično prestaje. Iako je specifičan uzrok keratokonusa još uvijek nepoznat, pretpostavlja se kako su promjene strome rožnice najzaslužnije za razvoj poremećaja. Danas postoji velik broj metoda u liječenju keratokonusa. Izbor metode ovisi o stadiju poremećaja i njegovim karakteristikama. Glavni ciljevi liječenja su spriječiti progresiju poremećaja i poboljšati vidnu oštrinu. Prva metoda koja je pokazala učinkovitost u zaustavljanju progresije keratokonusa je tzv. križno umrežavanje kolagena rožnice (CXL). Uporaba naočala i mekih kontaktnih leća u svrhu korekcije vidne oštrine kod keratokonusa je veoma ograničena i moguća samo u ranim stadijima. Zlatni standard u korekciji kod umjerenih i uznapredovalih stadija keratokonusa su tradicionalne RGP i posebne, keratokonusno dizajnirane, Rose K, piggyback i hibridne kontaktne leće. Kada korekcija kontaktnim lećama više nije moguća, primjenjuju se kirurške metode kao što su PRK i ugradnja intrakornealnih prstenova. Osim ispravljanja patološke zakrivljenosti rožnice i korekcije vidne oštrine, ove metode omogućuju bolje prilagođavanje (fitting) i ponovnu uporabu kontaktnih leća. U krajnje uznapredovalim stadijima poremećaja često je jedina opcija transplantacija rožnice. Iako je penetrantna keratoplastika dosad smatrana zlatnim standardom, u zadnje vrijeme sve je više zamjenjuje prednja duboka lamelarna keratoplastika. |
Abstract (english) | Keratoconus is a progressive, bilateral, non-inflammatory eye disorder in which the cornea of the eye alters in shape and thickness, eventually forming a cone-like shape. The cornea affected by the disease changes its curve and tends to be thinner than the normal cornea, causing progressive impairment of visual acuity, usually in terms of progressive nearsightedness and/or irregular astigmatism. The prevalence of keratoconus is usually estimated between 50 and 230 per 100 000. The process typically starts around puberty and continues over a period of 10-20 years until it gradually stops. The etiopathogenesis of keratoconus is yet to be discovered. However, the weakening of the stroma is probably the most important factor in keratoconus development. Management of keratoconus varies significantly depending on the stage of the disease. Control of progression and visual acuity correction are its main goals. Over the past 10 years, great effort has been put into research of corneal cross-linking, which has already shown stable long-term results in the control of keratoconus progression. In terms of correcting visual acuity, spectacle correction is limited and used in early stages only. Traditional RGP contacts, as well as special, keratoconic designs like Rose K, piggybacks or hybrid contact lenses are the mainstay method in correcting moderate to advanced keratoconus. In cases of contact lens intolerance, photorefractive keratectomy and intracorneal ring segment insertion are considered. Except from visual acuity correction, these surgical methods provide better postoperative contact lens fitting. In cases of very advanced keratoconus, corneal transplantation is often the only treatment option. Even though penetrating keratoplasty has traditionally been the surgery of choice, lamellar keratoplasty is recently becoming more popular, especially for patients with mild to moderate disease. |