Experimental measurement of corneal haze after excimer laser keratectomy

We developed a model of corneal haze following photorefractive keratectomy (PRK) in Iber Braun hens and studied optical properties. The animals underw ent PRK for -9.0 diopters of myopia and were divided into groups based on t reatment with different wound-healing modulators. At different time points postoperatively, we evaluated haze by slit-lamp microscopy. An experimental device was developed to measure transmittance spatial maps and forward sca ttering of He-Ne laser light in the excised corneas. Subjective and objecti ve haze measures were compared for each group at the different times. Kerat ocyte densities were determined by optical microscopy and keratocyte sizes by electron microscopy. The agreement between experimental results and a si mple numerical model of scattering suggests that increases in stromal kerat ocyte density after PRK might explain the degree of corneal haze. (C) 2001 Optical Society of America.