Search

Background: The coronavirus disease 2019 (COVID-19) outbreak poses serious threats to the physical and mental health of individuals worldwide. The lockdown strategy and social distancing regulations adopted in South Africa have disrupted the day-to-day life activities of all people including students. Aim: To explore the impact of COVID-19 on the mental health of optometry students at a higher education institution. Setting: The study population included optometry students currently registered at the University of KwaZulu-Natal, in Durban, South Africa. Methods: The study adopted a case study research design and used an online questionnaire and follow-up interviews to collect data. The Depression Anxiety Stress Scale (DASS-21) questionnaire that assesses depression, anxiety and stress subscales was used. Data were analysed using descriptive and inferential statistics. The interview data were analysed using thematic content analysis. Results: A total of 147 participants responded to the online questionnaire and consisted of majority black people ( n = 98), female ( n = 114) and second year ( n = 58) students. The majority of the participants had normal scores for depression ( n = 97), anxiety ( n = 79) and stress ( n = 107). Only a few participants had scores indicating severe or extremely severe depression ( n = 13), anxiety ( n = 23) and stress ( n = 5). Follow-up interviews were conducted with 10 participants and of these, seven reported that COVID-19 had a negative impact on their ability to concentrate and they felt anxious about examining patients. Factors such as stigma and judgment were perceived as hindrances to seeking mental health help. Conclusion: Most participants had normal scores for depression, anxiety and stress; however, some participants presented with abnormal scores. The impact of the COVID-19 pandemic on mental health should be highlighted and higher education authorities should plan and provide appropriate services to improve the quality of life of affected students.

Background: Information on the visual health of school children can assist in developing strategies to reduce preventable causes of visual impairment (VI) and maintain good vision. Aim: This study aimed to determine the magnitude and causes of VI amongst basic school children aged 6–16 years in the Bono Region of Ghana. Setting: The study site included five basic schools in 12 administrative districts of the Bono Region of Ghana. Methods: A multistage random sampling technique was used to enrol 645 participants from five selected public schools. Results: Overall, 1.4% of the sample had some form of VI that was worse than mild or no VI, and ocular conditions were present amongst 45.1% of the participants. Uncorrected refractive error (URE) was found amongst 9.8% of the study participants ( n = 63) and was an important cause of VI. Other ocular conditions detected in the sample included allergic conjunctivitis ( n = 174), cataract ( n = 2) and keratoconus ( n = 2). Overall, 632 (98.0%) participants recorded a visual acuity (VA) of 20/20 – 20/60, 11 (1.7%) participants had a VA of < 20/60 – 20/200, 1 (0.15%) participant had a VA of < 20/200 – 10/200 and 1 (0.15%) participant had a VA of < 10/200. Conclusion: The presence of ocular conditions was high amongst the study participants (45.1%). However, the prevalence of VI was found to be low (1.4%) with URE being the most common cause. This study supports the need to intensify awareness of ocular conditions and/or VI in basic schools through regular vision health screening and education.

Background: Climate change is a global challenge requiring mitigation from all economic sectors. Although the consequences of climate change are well documented, there are limited studies regarding greenhouse gas emissions generated by the optometric industry. Aim: This study explored the greenhouse gas emissions created from the freight-related distribution of spectacle and contact lenses to South Africa (SA) in 2019. Setting: Spectacle and contact lens distributors in SA and an optometric courier service in KwaZulu-Natal. Methods: Data from a survey completed by lens suppliers and a courier service provider in SA were used in a standardised emissions calculations tool. Results: The results indicate significant greenhouse gas emissions generated from the distribution of lenses in SA, which is of concern for climate change alleviation goals. Conclusion: It is recommended that practitioners in the optometric industry, and other healthcare service providers, calculate their emissions data, modify practices to support climate change mitigation and be cognisant of the effect of their practices on the environment.

Background: Patients with keratoconus, which is a common corneal ectasia, often present to specialised clinics for management. Understanding the clinical characteristics of keratoconus patients can help improve knowledge of the presentation and management of this corneal ectasia and predict the needs of the clinic providing care for affected individuals. Aim: To describe the clinical characteristics of keratoconus patients attending the University of KwaZulu-Natal (UKZN) eye clinic. Setting: University of KwaZulu-Natal eye clinic. Methods: The study used a retrospective research design by reviewing the clinical record cards of patients attending the UKZN contact lens eye clinic over a 4-year period (January 2014 to December 2017). Data related to age, clinical characteristics and method of management of the keratoconus patients were extracted and analysed using descriptive statistics. Results: Just less than one-quarter of all patients ( n = 1210) attending the UKZN contact lens eye clinic had keratoconus that was most often bilateral. The mean age at presentation was 25.2 ± 9.6 years with 74% of the sample being younger than 30 years. More than 90% ( n = 419) of the sample reported refractive reasons as the primary reason for presenting to the clinic. The majority of the sample had severe keratoconus ( n = 257) and rigid contact lenses were most commonly used for management of keratoconus patients. Conclusion: Keratoconus presents at an early age with a more severe grade and it is most commonly managed using rigid contact lenses. These findings should be considered for keratoconus screening, diagnosis and treatment programmes in KwaZulu-Natal.

Background: Blindness and visual impairment have been shown to reduce vision-related quality of life (VRQoL), general health and social status and increase mortality. Understanding the influence of different cataract surgery techniques on VRQoL can enhance the understanding of which technique may be most suitable to achieve the best outcomes from a patient’s perspective. Previous studies have focused exclusively on the phacoemulsification technique, with limited attention on other techniques that are common in developing countries, such as the extracapsular cataract extraction (ECCE) and manual small-incision cataract surgery (MSICS) techniques. Aim: To evaluate the impact of cataract surgery on VRQoL for the ECCE and MSICS techniques. Setting: The study was conducted at the Themba Hospital in the Mpumalanga province. Methods: A case study research design was used at the Themba Hospital. Participants underwent either the ECCE or the MSICS technique and were followed for a period of 6-weeks post-surgery. The VRQoL was assessed using the 33-item Indian Vision Functioning Questionnaire (IND-VFQ-33). Data were presented using frequencies, percentages and means ± standard deviations. Results: The sample included 101 participants, with a mean age of ~66 years. Following cataract surgery, there was an increase in the frequency of the ‘not at all’ response for the majority of the questions in the IND-VQ-33 questionnaire in all three domains. There were statistically significant differences ( p < 0.05) between the pre-surgery and post-surgery mean scores for all the questions, with the exceptions being those related to problems experienced when seeing outside in bright sunlight, bright light hurting the eyes and closing the eyes because of light from vehicles. Conclusion: Individuals who underwent both the ECCE and MSICS techniques showed improvement in VRQoL in terms of general functioning, psychosocial impact and vision symptoms domains.

Background: Stereopsis is the accurate awareness of relative depth necessary for efficient hand–eye coordination and navigation. A popular brand of sunglasses claims to enhance depth perception. Aim: This study set out to investigate the effect of tinted lenses on distance stereoacuity under varying retinal illumination. Setting: This study was set at the Discipline of Optometry, University of KwaZulu-Natal. Methods: A pretest–post-test research design was used. Forty participants were recruited using convenience sampling. The Howard–Dolman apparatus was used to measure distance stereoacuity with different tints of a popular sporting brand under varying retinal illumination. The tinted lenses and their respective transmission values used included persimmon (61%), light grey (38%), G30 (30%) and black iridium (10%). The placebo comprised of a white lens (100% transmission). Habitual distance stereoacuity was measured with no lens as the control. Retinal illumination was varied with neutral density filters to simulate mesopic and scotopic conditions. The Friedman and paired t -tests were used to analyse the data. Results: The mean stereoacuity for each lens was significantly different across the three retinal illumination levels ( p < 0.05). A statistically significant difference ( p = 0.012) was found with only the light grey tint under scotopic conditions when compared to the habitual stereoacuity. However, clinically significant differences were noted with the persimmon, light grey and black iridium tints. Overall, poorer stereoacuity was noted in mesopic and scotopic conditions compared to photopic for all five lenses. Conclusion: Tinted lenses used had no statistically significant effect on distance stereoacuity but clinically significant changes were noted. However, the change in retinal illumination adversely affected distance stereoacuity.

Background: Corneal thickness measurements have various diagnostic and therapeutic applications. Studies have reported on the distribution of corneal thickness measurements in Caucasian and Asian subpopulations with limited focus on African subpopulations. Aim: The goal of this study was to examine the distribution of corneal thickness measured using optical coherence tomography in a South African young adult population. Setting: The study was conducted at the eye clinic at the University of KwaZulu-Natal. Methods: The study used a quantitative cross-sectional research design and participants were recruited using two-stage random sampling. Seven hundred participants consisting of 50% South African blacks and 50% South African Indians aged between 17 and 30 years were included. The sample included an equal distribution of male ( n = 350) and female ( n = 350) participants. Corneal thickness was measured using the Fourier-domain Optovue iVue100 optical coherence tomographer. As the data from the right and left eyes showed high levels of interocular symmetry, data from only the right eyes were analysed using descriptive and inferential statistics. Results: The mean age of the sample was 20.42 ± 1.80 years. Corneal thickness measurements resembled Gaussian curves ( p ≥ 0.095) and the mean central corneal thickness (CCT) was 501.91 µ m. Corneal thickness at the thinnest point was 495.73 µ m and 1.23% thinner than the mean CCT measurement ( p < 0.001). Males had slightly higher corneal thickness measurements than females but these differences (0.35 µ m – 3.93 µ m) were not significant ( p ≥ 0.137). Corneal thickness varied significantly with refractive error and was lowest in emmetropes followed by myopes and then hyperopes. Conclusion: Corneal thickness measurements are normally distributed in South African young adults. The mean CCT is different from that reported in other populations and lower than the calibrated CCT measurement for Goldmann applanation tonometry. Eye care personnel should consider the characteristics of corneal thickness measurements and its implications on intraocular pressure measurements when examining South African individuals.

Background: The reliability of an instrument is dependent on its accuracy and repeatability. The iVue-100 optical coherence tomographer (OCT) is a spectral domain device that has the advantage of being able to measure both the anterior and posterior segments of the eye. But its repeatability for macular thickness measurements has not been assessed and this was the primary purpose of this study. Aim: To determine the repeatability of the iVue-100 OCT for macular thickness measurements. Settings: This study was conducted at the University of KwaZulu-Natal. Methods: Repeatability (intra-observer, inter-observer and inter-session) of the iVue-100 OCT was assessed on 50 participants selected using convenience sampling. Data were statistically analysed using Bland–Altman analysis, the intra-class correlation coefficient (ICC), coefficient of variation and the paired t -test. Results: The mean age and standard deviation for the 50 participants were 23.88 ± 6.93 years (range 18–51 years). The ICCs for intra-observer repeatability ranged between 0.940 and 0.989, whereas the coefficients of variation ranged between 0.040 and 0.084. For both inter-observer and inter-session repeatability, the t -test showed no statistically significant differences ( p > 0.05), and Bland–Altman analysis found the majority of the measurements to be within the 95% limits of agreement. Conclusion: Irrespective of whether repeated measurements are being taken consecutively by the same examiner, by a different observer or at a different time, the iVue-100 OCT is highly reliable in terms of repeatability which is of paramount importance in any clinical or research setting.

Background: Keratoconus, a corneal ectasia, is associated with corneal thinning and altered optical media. Consequently, assessment of the visual field, optic nerve head and intraocular pressure measurements may be challenging in patients with keratoconus. Few studies have investigated posterior segment variables including the retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC) thickness in patients with keratoconus. Aim: To investigate RNFL and GCC thickness in patients with keratoconus. Methods: A comparative quantitative research design was used. The sample consisted of 56 participants (28 with mild, moderate or severe keratoconus, and 28 controls) who accessed the optometry clinic at the University of KwaZulu-Natal. There was an equal distribution of male ( n = 14) and female ( n = 14) participants in the keratoconus and control groups. Most participants were black ( n = 34) or Indian ( n = 18). Corneal power and refractive error were assessed with the Oculus Keratograph and subjective refraction respectively. The iVue-100 optical coherence topography device was used to measure RNFL and GCC thickness. Data were analysed by descriptive and inferential statistics. Results: The mean global RNFL thickness was slightly higher in the control group than the keratoconus group for the right (106 µm vs. 99 µm) and left (103 µm vs. 98 µm) eyes but these differences were not significant ( p ≥ 0.057). For all RNFL quadrants, slightly lower mean RNFL measurements were found in the keratoconus group. The mean GCC thicknesses were marginally higher (3 µm – 6 µm) in the control group. Conclusion: The RNFL and GCC thickness differences between patients with keratoconus and controls are not clinically significant. Therefore, abnormally reduced RNFL and GCC thickness measurements in patients with keratoconus warrant further investigation for other pathologies specifically glaucoma.

Visual impairment (VI), a global concern that is likely to escalate with prolonged life expectancies, has gained increasing attention in the realm of eye care. The purpose of this article is to highlight the different aspects of VI, including its definition and characteristics, prevalence, causes and implications. The importance of rehabilitation in individuals with VI is also discussed.

Aim: Spectacle wearers often prefer tintedlenses to clear or non-tinted lenses for their protection against harmful radiation, improved cos-mesis, enhancement of visual performance and effects on colour vision. Among the available tinted lenses on the market blue, brown and grey tinted spectacle lenses are popular with varying gradesranging from A to D. Due to reduced transmission of light through such lenses, the optical system of the eyes and the environmental vision may be temporarily altered. Colour vision (CV) and con-trast sensitivity (CS) are important aspects of this altered visual world. This study investigated the effect of spectacle lenses of varying grades of tint on CS and CV.Method: The study adopted a pre- and postest research design and a sample of 90 participants were selected from the University of KwaZulu-Natal student population using convenience sam-ling. Each participant was screened for patholgy, dyschromatopsia, severe dry eyes (TBUT

Background: Assessment of intraocular pressure (IOP) is an important test in glaucoma. In addition, anterior segment variables may be useful in screening for glaucoma risk. Studies have investigated the associations between IOP and anterior segment variables using traditional statistical methods. The classification and regression tree (CART) method provides another dimension to detect important variables in a relationship automatically. Aim: To identify the critical factors that influence IOP using a regression tree. Methods: A quantitative cross-sectional research design was used. Anterior segment variables were measured in 700 participants using the iVue100 optical coherence tomographer, Oculus Keratograph and Nidek US-500 ultrasonographer. A Goldmann applanation tonometer was used to measure IOP. Data from only the right eyes were analysed because of high levels of interocular symmetry. A regression tree model was generated with the CART method and Pearson’s correlation coefficients were used to assess the relationships between the ocular variables. Results: The mean IOP for the entire sample was 14.63 mmHg ± 2.40 mmHg. The CART method selected three anterior segment variables in the regression tree model. Central corneal thickness was the most important variable with a cut-off value of 527 µm. The other important variables included average paracentral corneal thickness and axial anterior chamber depth. Corneal thickness measurements increased towards the periphery and were significantly correlated with IOP ( r ≥ 0.50, p ≤ 0.001). Conclusion: The CART method identified the anterior segment variables that influenced IOP. Understanding the relationship between IOP and anterior segment variables may help to clinically identify patients with ocular risk factors associated with elevated IOPs.

Recently, there has been increasing interest in understanding central corneal thickness (CCT) measurements in various populations. This may be related to the influence of CCT in the diagnosis, classification and management of glaucoma. In addition, CCT measurements are also important for monitoring corneal diseases and contact lens wear, indicating the overall health of the cornea and assessing eligibility for refractive surgery. This article reviews studies that have reported CCT measurements in non-glaucomatous African sub-populations. The CCT measurements, gender associations and limitations of these studies are highlighted. The findings of these studies and their implications are discussed in relation to global studies reporting on CCT measurements.

Background: Accurate assessment of corneal thickness is essential in corneal refractive surgery, contact lens wear and corneal pathology. Aim: To assess the repeatability (intra-observer, inter-observer and inter-session) of central (0 mm – 2 mm), mid-peripheral (2 mm – 5 mm) and peripheral (5 mm – 6 mm) corneal thickness measurements using the iVue 100 spectral domain optical coherence tomographer (SD-OCT). Setting: Optometry Eye Clinic at the University of KwaZulu-Natal (UKZN). Methods: Corneal thickness measurements were taken on 50 healthy participants by two observers independently. A second set of readings was taken by one observer on another session. Repeatability was assessed using Bland–Altman analysis, the intraclass correlation coefficient, coefficient of variation and one-way analysis of variance (ANOVA) analysis. Results: For all corneal regions, the intraclass correlation coefficients for observer one ranged from 0.942 to 0.999 and that for observer two ranged from 0.946 to 0.999, indicating good intra-observer repeatability. Using linear regression, the corneal thickness measurements were found to be comparable (within 1 µm of each other) in all regions with the exception of the nasal and temporal mid-periphery and periphery. The inter-session repeatability was based on the measurements of observer one only with the mean differences ranging from 0.02 µm to 0.63 µm. Linear regression revealed no significant differences between session 1 and session 2 ( p > 0.05) except for the measurement of minimum corneal thickness. Conclusion: This study found evidence of good intra-observer, inter-observer and intersession repeatability of central, mid-peripheral and peripheral corneal measurements with the iVue 100 SD-OCT.

Background: It has been suggested that retinal thickness varies with demographic variables. Understanding the influence of demographic variables on retinal thickness could improve our knowledge of risk factors for retinal pathologies. Previous studies have focused exclusively on white and African-American populations, with limited attention to black and Indian populations. Aim: To compare retinal thickness in black and Indian myopic students at the University of KwaZulu-Natal (UKZN). Methods: A cross-sectional comparative research design was used. The study was conducted at UKZN, Westville campus. Retinal thickness was measured in 80 healthy myopic students using the Fourier/spectral domain iVue 100 optical coherence tomographer. Retinal thickness measurements of the right and left eyes showed significant correlations, therefore data from only the right eyes were analysed. Racial and gender variations in retinal thickness of the nine Early Treatment Diabetic Retinopathy Study (ETDRS) segments were assessed. Results: The mean central foveal thickness in black participants was 238 μm compared with 243 μm in Indian participants ( p = 0.06). Indian participants had thicker parafoveal thickness measurements whilst black participants had thicker perifoveal thickness measurements. Male participants had thicker retinal thickness measurements in all nine ETDRS segments than female participants. Central foveal thickness showed no significant correlation with spherical equivalent ( r = -0.14, p > 0.05) or axial length ( r = 0.09, p > 0.05). Conclusion: The average central foveal thickness was slightly thinner in black and female participants than in Indian and male participants. Optometrists and ophthalmologists should consider these differences when evaluating black and Indian individuals with foveal retinal diseases.

Aim: To compare retinal nerve fibre layer (RNFL) thickness in black and Indian myopic students at the University of KwaZulu-Natal. Method: Eighty (40 black and 40 Indian) participants of both genders and aged between 19 and 24 years (mean and standard deviation: 21 ± 1.7 years) were included in the study. Refractive errors were assessed with the Nidek AR-310A auto-refractor and via subjective refraction. RNFL thicknesses were then measured using the iVue-100 optical coherence tomography device. Axial lengths were measured with the Nidek US-500 A-scan ultrasound device. Data were analysed by descriptive statistics, t-tests, Pearson’s correlation coefficients and regression analysis. Results: The mean myopic spherical equivalent was significantly more negative amongst the Indian (-2.42 D ± 2.22 D) than amongst the black (-1.48 D ± 1.13 D) ( p = 0.02) participants.The mean axial length was greater amongst the black (23.35 mm ± 0.74 mm) than amongst the Indian (23.18 mm ± 0.87 mm) participants but the difference was not significant. In the total sample ( n = 80), the average global RNFL thickness ranged from 87 μm to 123 μm (105 μm ±9 μm). Mean global RNFL thickness was slightly greater amongst black (108 μm ± 7 μm) than amongst Indian (102 μm ± 9 μm) ( p = 0.00) participants. Mean global RNFL thickness was similar for male (106 μm ± 7 μm) and female (105 μm ± 10 μm) ( p = 0.79) participants.A positive and significant association between myopic spherical equivalent and global RNFL thickness was found for the total sample ( r = 0.36, p = 0.00) and for Indians ( r = 0.33, p = 0.04)but not for the black ( r = 0.25, p = 0.13) participants. There was a negative and significant correlation between axial length and global RNFL thickness amongst the Indian participants ( r = -0.34, p = 0.03) but not amongst the total sample ( r = -0.12, p = 0.30) or the black ( r = 0.06, p = 0.73) participants. Conclusion: The findings suggest that racial differences in RNFL thickness need to be considered in the clinical examination and screening for glaucoma and other optic nerve pathologies amongst black and Indian people. Additionally, the possible influences ofrefractive error and axial length should be considered when evaluating RNFL thickness.

Community service (CS) was introduced inSouth Africa in an attempt to address the shortageand maldistribution of health care professionalswithin the public sector. The Professional Board forOptometry and Dispensing Opticians (PBODO)has approved legislation for the introductionof CS for graduating optometry students. This study examined the perceptions and opinionsof graduating optometry students regarding the proposed CS. A mixed-method design(questionnaires and interviews) was used. Bothapproaches yielded similar results. The quantitativecomponent included 119 participants, aged between 20 and 35 years (mean age and standard deviation;22.8 ± 2.3 years). There were 43.2% Blacks, 28.5%Whites, 19.1% Indians and 9.2% Coloureds. The qualitative part included fourteen participantsfrom the Optometry Department of the University of KwaZulu-Natal. The major themes emergingfrom the questions concerning the participants’ perceived advantages and benefits of CS were (i) it would improve the eye care service delivery to disadvantaged communities; (ii) it would improve the technical and clinical skills of the graduating optometrists and (iii) it would enhance their confidence, personal and social skills. Some of the perceived drawbacks cited by the participants about such service included poor remuneration and concerns about personal safety, transport and accommodation. The findings of this study suggest that graduating optometry students acknowledge the importance of CS in improving access of many South Africans to quality eye care. In order to maximise the full benefits of CS, all stakeholders need to address the highlighted concerns of the participants. (S Afr Optom 2013 72(1) 11-18)

Measurements of central corneal thickness (CCT) and intra-ocular pressure (IOP) are important for both diagnostic and therapeutic purposes. The aim of this study was to investigate the short-term variation and intra-subject repeatability of CCT and IOP measurements made with the Tono-Pachymeter NT530P (Tonopachy™). Fifty one consecutive automatic measurements of CCT and IOP were taken for the right eyes of 15 subjects (11 females and 4 males) aged 20 to 57 years (mean = 32.3 ± 13.5 years). The measured values (CCT and IOP) were compared against each other to establish the intra-subject repeatability and bias of each individual measurement with respect to the means, standard deviations and variances. Three different statistical tests of normality: Kolmogorov-Smirnov (K-S),Lilliefors and Shapiro-Wilks (SW) tests suggested that most of the data was normally distributed,with a few exceptions. The inter-subject or overall mean values and standard deviations for the CCT and IOP samples were 528.2 ± 27.4 μm and 14.4 ±4.3 mmHg respectively. Although possible outliers increased the variability of the measurements of both parameters (CCT and IOP), the data generally showed good repeatability. The results of this study suggest that over short periods of time, the Tonopachy™ gives precise and repeatable measures of CCT and IOP. (S Afr Optom 2012 71(1)12-21)

The purpose of this study was to compare the intraocular pressure (IOP) values measured with the Tono-Pachymeter NT530P (Tonopachy™) and the iCare® rebound tonometer (iCare®) with those obtained by the Goldmann applanation tonometer (GAT). The right eyes of 105 subjects aged 18 to 82 years (mean age = 29.27 ± 14.67 years) were assessed with the three tonometers. Central corneal thickness (CCT) was measured first using the Tonopachy™ and then IOP was measured by Tonopachy™, iCare® and GAT. The data was analyzed with descriptive statistics, paired t-test, correlation and regression analysis. The Bland-Altman method of analysis was used to evaluate agreements between the sets of data from the three devices. The CCT values ranged from 440 µm to 606 µm (mean= 518.49 ± 33.01 µm). There was little or no correlation between CCT and IOP for any of the instruments used in this study (r = 0.29 for Tonopachy™, r = 0.22 for iCare®, r = 0.17 for GAT). The mean IOP measured with the Tonopachy™ was 14.31 ± 3.57 mmHg (range 8.7 mmHg to 31 mmHg) and 16.64 ± 4.38 mmHg (range 8 mmHg to 32 mmHg) using the iCare®. The mean IOP measured with the GAT was 14.79 ± 3.09 mmHg (range 8.7 mmHg to 29.7 mmHg). Using the Bland-Altman method, the upper and lower limits of agreement between the Tonopachy™ and GAT, iCare® and GAT, iCare® and Tonopachy™ were 5.1 mmHg and –4.2 mmHg, 8.6 mmHg and –4.9 mmHg, 7.5 mmHg and –2.8 mmHg respectively. In 79.1% of the eyes studied, the mean IOP difference between Tonopachy™ and GAT was less than 3 mmHg and in 20.9% of the eyes, the difference was greater than 3 mmHg. However, mean IOP differences of greater than 3 mmHg were obtained by iCare® in comparison with GAT (40%) and Tonopachy™ (34.3%) respectively. Findings of this study suggest that the Tonopachy™ yielded IOP readings that were consistent with those of GAT values while iCare® yielded higher IOP values compared to both GAT and Tonopachy™. (S Afr Optom 2011 70(3) 109-116)