STANDARDISATION OF OPTOTYPES
Autori:
Zdenko Bujger, Jasenka Pičman, Andreja Lukenda, Igor Petriček
Sažetak
Sažetak. Optotipi su znakovi različite veličine, sustavno poredani na tabli za ispitivanje vidne oštrine. Ljudsko oko posjeduje prostornu rezoluciju od 1’ (Snellen). Sve su table izrađene tako da se optotipi osnovnog reda vide iz daljine ispitivanja pod kutom od 5’, a njihov detalj pod kutom od 1’. Nedostatak klasičnih tabli je nepravilna promjena veličine optotipa susjednih redova. To je 1976. riješeno logMAR (Bailey-Lovie) tablom. Na njoj postoji stupnjevita promjena veličine optotipa s konstantnim omjerom promjene 1:1,2589. Ta je tabla postala standard za ispitivanje oštrine vida. Preporučena je od sljedećih tijela: Svjetski oftalmološki zbor (International Council of Ophthalmology – ICO) 1984. i 2002.; Svjetska zdravstvena organizacija (WHO) 2003.; Međunarodna organizacija za standardizaciju (International Organisation for Standardisation – ISO) 1996. i Hrvatski zavod za norme (HZN) homologirao je ISO standard kao nHRN EN ISO 8596:1996. U školskoj medicini, medicini rada i oftalmologiji treba prijeći na upotrebu logMAR-tabli iz normativnih, medicinskih i praktičnih razloga.
Summary
Summary. Optotypes are signs of different sizes, systematically placed on the visual acuity chart. The human eye has a spatial resolution of 1’ of arc (Snellen). Optotypes in the basic row on all charts subtend 5’ of arc and their detail 1’ of arc, from the testing distance. The disadvantage of all classical charts is the irregular progresssion of optotype sizes in adjacent rows. This was solved by logMAR (Bailey-Lovie) chart in 1976. The chart was made with optotype sizes in steps with a constant ratio 1: 1.2589 (geometric progression). This chart has become the standard for visual acuity testing worldwide. It has been recommended by the following bodies: International Council of Ophthalmology (ICO), 1984 and 2002; World Health Organisation (WHO), 2003; International Organisation for Standardisation (ISO) 1996, and Croatian Standard Insitute homologised the ISO standard as nHRN EN ISO 8596:1996. For normative, medical and practical reasons it is advised that all school medicine, occupational health and ophthalmology departments adopt the logMAR charts system.
