Abstract

CORRELATION OF FUNDUS CHANGES IN RELATION TO REFRACTIVE ERROR IN PATIENTS WITH MYOPIA- A CLINICAL PROSPECTIVE STUDY

Author(s): Balasubramanian M. Manickavelu, Ajeetha T. Thamarai Kannan

BACKGROUND Retina is unique among the complex element of the central nervous system and the special senses. It may be readily viewed during life and it is sufficiently transparent, so that alterations within and adjacent to it may be observed in vivo. The peripheral retina owing to its thinness comparing to that of the central part, poorly-developed retinal cells, absence of large blood vessels, relatively insensitive to light, less resistance to traction, forms a seat for various lesions, which are potentially dangerous for the vision. It is in myopia that we meet the most frequent and the most obvious anomalies in the fundus changes, which bear some relation to the degree of myopia and appeal to be concerned with it either as a cause or effect or perhaps both. The aim of our study is to correlate fundus changes in relation to refractive error in patients with myopia. MATERIALS AND METHODS In our study, 100 cases of myopic (<--6D:50 cases; >-6D:50 cases) patients were selected. Detailed evaluation done. History of refractive error includes duration, age at which spectacles were worn for the first time. Time of last change of spectacles, family history of myopia, history of other symptoms like progressive loss of vision, defective vision related to day or night, sudden loss of vision, flashes and floaters. Anterior segment was examined followed by the recording of initial visual acuity and the best corrected visual acuity was noted. IOP was measured for all the cases using Schiotz tonometry. Axial length was measured in all the cases. Fundus examined with direct ophthalmoscope, indirect ophthalmoscope, 3 mirror and 90D lens. B-scan was done in few cases. The media, disc, vessels, macula and the surrounding retina were examined. The periphery was examined with indentation method. The various fundus features and pathological lesions in different degrees of myopia were noted. RESULTS Females were comparatively more affected. Highest incidence was seen in the younger age group. 73 patients showed various fundus changes. Most commonly seen were tessellated fundus (41%). 36% of cases showed vitreous floaters. Commonly, temporal crescents were seen. Few cases showed stippled appearance of the macula. Axial length is comparatively increased in higher degrees of myopia. Peripheral retinal degenerative changes are common in moderate to higher degrees of myopia. Early onset vitreous degeneration was seen in myopes. Though the peripheral degeneration changes was comparatively higher in >-6D cases, some of the degenerative changes like lattice, chorioretinal atrophic changes, white with pressure and white without pressure, retinal detachment, posterior staphyloma and retinal hole were also seen in <-6D cases. CONCLUSION Degenerative changes were seen in all degrees of myopia though comparatively lower in lesser degrees of myopia. All cases, myopia must be examined meticulously with indirect ophthalmoscope to rule out any peripheral degenerative changes. Early diagnosis and prompt treatment of retinal degeneration could prevent disabling visual loss due to myopia.