DOI: 10.14457/tu.the.2022.130
title: Biomedical image processing techniques for screening of glaucoma with cup-to-disc ratio, inferior, superior, nasal, temporal rule and evaluating the visibility of glistening in IOL for the quality of vision

description: Cataract and glaucoma are two leading causes of blindness. This research studies the problems of human eyes and solves them from the biomedical image processing approach. For the cataract patients, the ophthalmologist suggested changing the intraocular lens to restore vision. But, visual performance is degraded by the cause of glistening and subsurface nanoglistening (whitening) after intraocular lens (IOL) implantation into human eyes. Glistening is micro-sized vacuoles and, Whitening is caused by nano-sized vacuoles in IOLs, which cause light scattering and affect vision quality. Investigation of glistening and light scattering in IOL mainly depends on the characteristics of glistenings which are size, shape, refractive index and number of glistenings. In fact, glistening occurrence in IOL relates to several conditions. In addition, vision quality can vary depending upon these facts. Since the number of glistening is increasing progressively with time, medicine and treatment are not able to stop it. The best treatment is replacing new IOL and thus, the impact of glistening on vision quality is important to assess. Therefore, we approach the light scattering problem from time and cost-effective way which evaluates the visibility of IOL. Many research investigated glistenings from the point of ophthalmology and examined the consequence of glistening in visual function by clinical tests, for example, visual acuity, contrast sensitivity, and glare testing or wavefront measurements of the human eyes. This kind of research is demanded many patients to participate and assessed light scattering through IOL by means of clinical devices, for example, C-Quant, Scheimpflug photography, spectrometer and thus, it is complicated, laborious and expensive to examine. Furthermore, the previous studies presented the light scattering from single sphere particle but multiple particle scattering for IOL are not studied. The real issue in IOL is light transmittance to the retina which can interfere by glistenings is not light scattering from single particle and thus, multi-scattering from grouped glistenings are also important to evaluate. Lastly, there is no report to evaluate the visibility of IOL with glistenings to solve each of the above problems. This study presents an optical model to investigate glistenings in IOLs using the T-matrix approach to assess visibility from multiple light scattering. However, our optical model takes into account key details in order to address real-world issues that have yet to be addressed by earlier research. Light scatter will be encountered inside the lens as glistening numbers increase, reducing vision quality. As a result, the properties of glistenings are used to evaluate the visibility function in the optical model. Despite the fact that light scattering can be studied in a variety of ways, no research has been done on how the consequences of light scattering vary based on human activities. Then, the problems of glare and contrast sensitivity in the vision system is considered and the visual function of IOLs with glistening is evaluated by the optical model. As a result, the quality of the lens degradation is assessed by evaluating the reduction of contrast due to glistenings for visual functions. Overall, this study uses a microscopic image analysis based on a light scattering model to describe the visibility evaluation of intracoular lenses with glistenings.For glaucoma, this study proposes an automatic glaucoma screening algorithm. Glaucoma is a dangerous eye condition that can result in irreversible blindness. Glaucoma is defined by damage to the optic nerve head (ONH) caused by high intraocular pressure. Many glaucoma screening algorithms use the size of the optic cup to detect the presence of glaucoma. On the other hand, myopia and a genetically large optic cup are not distinguished by this clinical indicator since their optic nerve heads are larger than others. Hence, two clinical indicators are being investigated to use in this proposed screening algorithm: cup-to-disc ratio and ISNT rule. In addition, a support vector machine is employed to conduct an automatic screening algorithm. The proposed screening algorithm can appropriately classify, according to the findings of this investigation. Consequently, this screening algorithm can be used for optic nerve heads with normal or high optic cup sizes.