Browsing by Author "Rampersad, Nishanee."

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A clinical description of anterior segment variables measured using optical coherence tomography in a healthy South African young adult population: the development of normal reference intervals.
(2018) Rampersad, Nishanee.; Hansraj Singh, Rekha.
Background: Assessment of anterior segment variables is important to screen, diagnose and monitor ocular anomalies. Previous studies, which have focused exclusively on Caucasian and Asian sub-populations with limited attention to South African sub-populations, suggest that anterior segment variable (corneal and anterior chamber angle) measurements vary with demographic and/or ocular factors. This study investigated anterior segment variables, measured using optical coherence tomography, in a healthy South African young adult population and develop a clinical biometric guideline with normal reference intervals. Methods: A quantitative cross-sectional research design was used. Multistage random sampling was used to select 700 participants from a university population. Anterior segment variables were measured using the Fourier-domain iVue100 Optical Coherence Tomographer. The Oculus Keratograph, Goldmann applanation tonometer and Nidek US-500 ultrasonographer were used to measure corneal topography, intraocular pressure (IOP) and axial biometry respectively. Data were analysed by descriptive and inferential statistics. The reference intervals were computed using the non-parametric method recommended by the Clinical and Laboratory Standards Institute. Results: The mean age of the sample, which consisted of 350 males and 350 females, was 20.4 ± 1.8 years. The anterior segment variable measurements of the right and left eyes showed high levels of interocular symmetry with intraclass correlation coefficients greater than 0.933 and marginal mean interocular differences. Accordingly, data from only the right eyes were analysed because of the high levels of interocular symmetry. The mean central corneal thickness (CCT) was 501.91 ± 33.74 μm and significantly thinner than the mean corneal thickness in each quadrant of the paracentral and peripheral cornea (p < 0.001). The mean minimum corneal thickness was 495.73 ± 33.89 μm and 1.23% thinner than the mean CCT measurement (p < 0.001). The thinnest point on the cornea was central for 94% of participants (n = 659). The anterior chamber angle (ACA) width variables, which included the angle-opening distance taken at 500 μm (AOD500) and trabecular-iris angle (TIA), were ~553 μm and ~37° respectively. The majority of participants showed ACA width variable measurements associated with open non-occludable ACAs. The temporal ACA had slightly higher variable measurements than the nasal ACA. The corneal thickness measurements in the different zones were normally distributed (p ≥ 0.095) whereas the ACA width variable measurements were asymmetrically distributed (p < 0.001). Black participants had significantly thinner mean corneal thickness measurements than Indian participants (range between 29.10 μm between 36.38 μm) for all zones (p < 0.001). For both the nasal and temporal ACAs, Black participants had 10 μm to 22 μm lower median AOD500 measurements (p ≥ 0.031) and slightly higher (less than 1°) median TIA measurements (p ≥ 0.068). The mean corneal thickness in males were 0.35 μm to 3.93 μm thicker compared with females (p ≥ 0.137). Female participants had higher median ACA width variable measurements than male participants for both the nasal and temporal ACAs (p ≥ 0.029). Emmetropes and hyperopes had the lowest corneal thickness and ACA width variable measurements respectively. The anterior segment variables were inversely correlated with spherical equivalent refraction (p ≤ 0.003) although the correlation coefficients were relatively weak (range between 0.111 and 0.222). The CCT was the most important anterior segment variable, with a cut-off value of 527 μm, to influence IOP in the unpruned and pruned regression tree models. The other important variables included the average peripheral corneal thickness, axial anterior chamber depth and average paracentral corneal thickness. The clinical biometric guideline presents the normal reference intervals as well as the associated 95% confidence intervals for the corneal thickness and ACA width variables in a healthy South African young adult population. The normal reference interval for the CCT measurement ranged from 434 μm to 566 μm. In the present study, the mean, range and normal reference interval for the CCT measurement differed when compared with the measurements reported in other studies involving healthy African samples living within the African continent. Conclusion: This study demonstrated that anterior segment variable measurements in a South African young adult population differ when compared with studies involving Caucasian, Asian and other African sub-populations globally. Consequently, the clinical biometric guideline with normal reference intervals therein should be used by eye care personnel when examining South African individuals. Moreover, the possible influences of demographic and/or ocular factors should be considered when evaluating anterior segment variable measurements.
Graduates' perceptions of an undergraduate optometry program at a tertiary institution : a qualitative study.
(2010) Rampersad, Nishanee.; O'Brien, Frances Yvonne.
The aim of this study is to explore the views of recent optometry graduates, from the University of KwaZulu-Natal, towards the professional education and training program they had experienced. The optometry program aims to produce graduates who are equipped with the necessary knowledge and clinical skills to contribute to the health care needs of society within the field of eye care (Discipline of optometry, 2005). Within this program, individual modules are evaluated biannually by registered students. Thus far, there has been no attempt to explore the views of graduates once they have entered professional practice. Previous studies involving optometry students and graduates focused more on expectations and perceptions of the profession with little emphasis on perceptions of their education and training experiences in preparing them for professional practice. This study is an attempt to find out the relevance of the educational program in preparing graduates for professional practice. In addition, graduates are asked to make recommendations for ways in which the educational program can be strengthened to assist novice professionals to meet the demands of professional practice. This study involved the graduating class of 2009 presently working in professional practice. Of all participants who were willing to participate in the study, 8 were selected using purposive sampling. Semi-structured interviews are used to explore graduates‟ perceptions of their undergraduate educational experiences as preparation for professional practice and their recommendations for strengthening the program to provide for the needs of novice professionals. These interviews are conducted individually and last between 35 and 72 minutes. They are analysed qualitatively using the conceptual framework of communities of practice (Wenger, 1998) in which learning is considered as a four-fold concept: learning as (1) engaging in practice, (2) belonging to a community, (3) interrogating the meanings of experiences, (4) becoming and thus creating an identity. The findings reveal that in general graduates find the content of their professional education and training program to be relevant to their preparation for professional practice and were able to make suggestions for improvement. They were particularly satisfied with their clinical experiences as it allows them to engage with, gain exposure and develop professional identities. Additionally participants value these experiences for the development of other work related skills such as communication, time management, team work and problem solving. Recommendations for strengthening the optometry program are made in light of the proposed program restructuring.
Visual function and quality of life in adolescents with visual impairment: a case study of the Arthur Blaxall School in Pietermaritzburg.
(2018) Naipal, Shivani.; Rampersad, Nishanee.
Background: Visual impairment (VI) may affect the lives of children, adolescents and adults although the effects of VI on the former two groups may be taken for granted as they account for less than half the population affected by VI. Affected children and adolescents may endure a lifetime of vision related difficulties that may affect their education, social interactions and possible future employment. Aim: To investigate visual function and quality of life (QoL) in adolescents with VI at the Arthur Blaxall School in Pietermaritzburg. Methods: This study followed a descriptive case study research design. Students registered at Arthur Blaxall School aged 10 years to 19 years were recruited using convenience sampling. Visual function was quantified by distance visual acuity (VA) and refractive error, contrast sensitivity, colour vision and central visual field. The QoL was assessed with the Cardiff Visual Ability Questionnaire for Children (CVAQC). Data were analysed using differential and inferential statistics. Results: The sample consisted of 70 participants with a mean age of 13.83 ± 2.28 years. The most common cause of VI was oculocutaneous albinism (OCA) followed by posterior segment disorders. The mean best-corrected VA ranged from 0.79 ± 0.16 logMAR to 0.91 ± 0.22 logMAR in the right, left and both eyes. Only 16 participants presented with spectacles and an additional 18 participants required spectacles following refraction. More than 40% of participants had moderate loss of contrast sensitivity in each eye. The majority of participants did not have any colour vision or central visual field defects. The mean visual ability score was −0.27 ± 0.74 log units, and the most difficult tasks were reading smallest print in textbooks and the board in the classroom for near and distance respectively. Participants with OCA had the best monocular best-corrected VA and contrast sensitivity. The most common colour vision defects among participants with anterior and posterior segment disorders were tritan and deutan colour vision defects respectively. Participants with anterior segment disorders had the poorest QoL while those with OCA had the best QoL. Conclusion: The results of this study showed that visual function varied among adolescents with VI. Furthermore, both visual function and QoL differed between each of the main causes of VI.