PHD theses : Optics
Permanent URI for this collectionhttps://repository.neelain.edu.sd/handle/123456789/12111
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Item The Impact of Use of Hydrogel Contact Lenses on the Visual Functions among University Students(Neelain University, 2016) El-Bashir El-Saeed El-Bashir Gar El-NabiABSTRACT This study is composed of three phases, the first, second and three. In the first and second phases the study is a longitudinal (prospective) clinical hospital-based study, carried in October 2011 to June 2014 in the Faculty of Optometry and Visual Science (eye hospital), AL-Neelain University, Khartoum, Sudan. The first phase of the study aimed to determine the effects of long- term soft contact lens daily wear on visual functions in young adult Sudanese subjects, and the second phase aimed to investigate and assess patient’s visual response, comfort, symptoms, complications and overall satisfaction. A total 63 (12 males, 51 females) young adults Sudanese neophyte (who never worn contact lens before), were recruited to be involved in the study. Their ages ranged between 18 to 38 years of ages. Routine eye examination was carried and all subjects were fitted with clear hydrogel lenses (CLEVIO) (water content 38%) POTEC Co. LTD for one year. Testing of vision, contrast sensitivity, stereoscopic vision, central visual field, and color vision were examined on each follow up visits. Follow up visits for examination was at 2 weeks, 1, 3,6,12 months. In our study hydrogel contact lens wearers showed a significantly drop in contrast sensitivity and stereoscopic vision. Whoever, there were no changes in colour vision and central visual fields. The second phase aimed to assess the patient’s visual response, comfort, symptoms, complications and overall satisfaction of patients wearing corrective hydrogel contact lenses. It concluded that the visual and comfort response during all follow up visits revealed that the majority of participants had excellent visual and comfort response and only one patient showed poor visual and comfort response. In the early aftercare visits most of subjects were found to be free from signs and symptom due to contact lens and few subjects complained of burning, foreign body sensation, itching, dryness, tearing, photophobia, scratchiness, and redness, at late aftercare visits. There was no serious complications occurred during examinations except 7 subjects who had corneal staining, edema, ulcer, injections and lens deposits at late stages of follow up visits. All participants were extremely satisfied and only one had low level of satisfaction. The third phase aimed to assess awareness of contact lens wear among students of Al-Neelain University, Khartoum, Sudan. A total of 450 students were enrolled in this study. In this phase the level of understanding about contact lenses was found to be high among most of participants, the main source of their information they reported were televisions, followed by internet, friends and relatives, radio, magazines and newspapers. Most of students knew therapeutic and cosmetics contact lenses and few of them heard about corrective contact lenses. Most of the participant who wore contact lenses before reported they used it without prescription and few of them had prescription. About their opinions and considerations about contact lenses we concluded the following: Most of respondents reported they get contact lenses from optical centers, pharmacies and few of them reported beauty centers. 50.4% of students reported that the contact lenses could hurt their eyes and vision, while 46.4% assumed that it’s safe and comfortable. Most of participants prefer spectacle over contact lenses to correct their refractive errors. Regarding the alternative method to correct their errors most of them reported contact lenses were the best alternative for glasses other reported they preferred LASIK method. Knowledge about contact lenses have an expiration date most of them reported yes while few of them assumed that they are not expired. The study showed that most of respondents do not shared their contact lenses with others and few of them believed that they can do; most of them thought they do not sleep with lenses. 58.4% of participants reported that there was special solution should be used to care for lenses, followed by 22.2% of them thought they should use tap water , 15.8% believed they should use distilled water and 0.4% thought it could be licked by their mouth to keep lenses clean and sterile. Most of them reported that contact lenses should be cleaned before and after use and they thought that there were no special hours per day to wear the contact lenses. Most of participants believed that the main reasons for restricted use of contact lenses were due to environmental condition, lack of knowledge, when not advised by specialists and economic status of participants. The findings indicate that the best method to increase awareness and understanding of contact lenses wear among Sudanese population by the use of bulletin and programs, training and promotion. Key words: hydrogel lenses, visual acuity, contrast sensitivity, stereo acuity, central visual field, color vision, daily wear, optometrists, complications, increase awareness of contact lens.