Machine learning in optometry

Our previous works have shown the importance of incorporating mathematical models to provide objective quantification in clinical settings. This includes aiding optometrists to make clinical decision based on validated scientific data, not by mere hunches or instincts. We have demonstrated that with the right tool, the application of machine learning – a branch of artificial intelligence – can be leveraged to benefit areas in healthcare including optometry. The aim of this presentation is to provide introductory knowledge to the audience who have little or no knowledge of machine learning with examples of its applications in optometry. To better understand the machine learning concept, hypothetical data of glaucoma cases will be presented. The applications of machine learning in clinical and biomedical domains will be briefly demonstrated based on author’s own research and recent examples available from the literature

Minimal training time in supervised retinal vessel segmentation

In this paper, we perform comparative analysis between different classifiers using the same experimental setup for supervised retinal vessel segmentation. The aim of this paper is to find supervised classifier that can obtain good segmentation accuracy with minimal training time. Minimizing the training time is essential when dealing with biomedical images. The more samples introduced to a learning model, the better it can adapt to the unseen data. The results indicate a trade-off between accuracy and training time can be obtained in a classifier trained by a Neural Network. When tested with a publicly available database, the learning model only requires less than 2 minutes in the learning phase and achieves overall accuracy of 94.54%

The effect of short-term fasting on ocular biometry

Introduction: Islamic religious fasting is an action that inhibits its believers from consuming any food or drink and sometimes fasting can also be observed on Mondays or Thursdays. Ocular biometry parameters which include axial length, anterior chamber angle and depth play significant role in determining the refractive power of the eye as well as in certain ocular conditions. Objective: The purpose of the study was to identify the effect of short-term fasting to the ocular biometry. Method: This prospective study included 37 healthy participants with a mean age of 22.51 ± 0.77 years old. The measurements were done on a day with non-fasting state (at 8.00 a.m. and 4.00 p.m.) and one week later during the fasting period (at 8.00 a.m. and 4.00 a.m.). Anterior chamber and angle were measured using Pentacam HR (Oculus, Germany) while axial length was measured using A-scan (Tomey AL-3000). Result: The results indicated no significant changes between short-term fasting and non-fasting state with all the variables (p > 0.05). Similarly, no significant changes were noted during diurnal fluctuations with all the parameters (p > 0.05). Conclusion: There is no issue of reliability of the ocular biometric data when patients undergo short-term fasting state

Short term effect of virtual reality on eye accommodative ability

Virtual reality (VR) is a fast-growing technology in the world today. Many countries use virtual reality for many purposes such as education, military and entertainment. Despite the benefits of VR, harmful effects of VR on the users are still inconclusive. With only a few reliable studies that investigate the effect of virtual reality on the users especially on the eyes, yet still there are a lot more things we do not know about the effects of VR. The purpose of this study was to compare the amplitude of accommodation before and after watching 3-dimesional (3D) movie utilizing VR and notebook (control group). Thirty-two participants volunteered in this study and all participants underwent amplitude of accommodation (AA) test using Royal Army Force (RAF) rule before and after watching three-dimensional (3D) movie for 30 minutes using VR and two-dimensional (2D) movie by laptop. The amplitude of accommodation between pre- and post-watching 3D movie on VR was insignificantly changed (p= >0.05). The similar trend was also found after 30 minutes watching movie using laptop (p= >0.05). The utilization of VR and laptop for 30 minutes did insignificantly alter the eye accommodation

Corneo-pterygium total area measurements utilising image analysis method

Purpose: To describe an objective method to accurately quantify corneo-pterygium total area (CPTA) by utilising image analysis method and to evaluate its association with corneal astigma- tism (CA). Methods: 120 primary pterygium participants were selected from patients who visited an oph- thalmology clinic. We adopted image analysis software in calculating the size of invading pterygium to the cornea. The marking of the calculated area was done manually, and the total area size was measured in pixel. The computed area is defined as the area from the apex of pterygium to the limbal-corneal border. Then, from the pixel, it was transformed into a per- centage (%), which represents the CPTA relative to the entire corneal surface area. Intra- and inter-observer reliability testing were performed by repeating the tracing process twice with a different sequence of images at least one (1) month apart. Intraclass correlation (ICC) and scatter plot were used to describe the reliability of measurement. Results: The overall mean (N = 120) of CPTA was 45.26 ± 13.51% (CI: 42.38-48.36). Reliability for region of interest (ROI) demarcation of CPTA were excellent with intra and inter-agreement of 0.995 (95% CI, 0.994-0.998; P < 0.001) and 0.994 (95% CI, 0.992-0.997; P < 0.001) respectively. The new method was positively associated with corneal astigmatism (P < 0.01). This method was able to predict 37% of the variance in CA compared to 21% using standard method. Conclusions: Image analysis method is useful, reliable and practical in the clinical setting to objectively quantify actual pterygium size, shapes and its effects on the anterior corneal curvature

Fibrovascular redness grading using Gaussian process regression with radial basis function kernel

Information obtained from redness grading can assist clinician for diagnosis and in making clinical decision. This research work aims to mimic human perception of fibrovascular redness using features extracted from color entropy. Gaussian process regression with the radial basis function kernel has been employed to fuse relevant features and established the model of redness perception. In this paper, we present the results of the radial basis function kernel incorporated as the covariance function in the GPR as the scale, sigma is varied

Measurement of Pterygium Tissue Dry Weight Using Two Different Tissue Preparation Techniques in Freeze-Dry Method

Due to pterygium tissue compression on the corneal surface, it has been hypothesised that the degree of corneal astigmatism caused by pterygium can vary. This study aims to develop a freeze-dried method for estimating net pterygium tissue mass (NPTM) as dry weight. A single surgeon (KMK) excised 60 primary pterygium using the controlled partial avulsion technique and divided them into two groups: formalin-fixed (n=30) and unfixed (n=30). After determining the weight of each sterile container, 5 mL of 5% buffered formaldehyde was added to the formalin-fixed group and stored for one week, while 5 mL of distilled water was added to the non-fixed pterygium group. Each container was pre-frozen for 12 hours before being freeze-dried (-24 hours at -80 degrees Celsius). The result is referred to as the net pterygium tissue mass (NPTM). Using an independent T-test, a comparison of wet and dry weight and percentage of NPTM was conducted between groups. Wet weights for formalin-fixed and non-fixed pterygium were 253.33 82.17 g and 255.17 63.52 g, respectively, while dry weights were 184.92 84.31 g and 179.54 72.85 g. Formalin-fixed pterygium tissue revealed a slightly higher percentage of NPTM than non-fixed pterygium tissue (69.39 13.29% vs. 67.75 13.29%, p = 0.792), but this difference was not statistically significant. The freeze-dried method can be utilised to quantify the NPTM of pterygium fibrovascular tissue and investigate the influence of pterygium translucency on predicting induced-corneal astigmatism

Utilization of Anterior Segment Optical Coherence Tomography Enhanced High Resolution Corneal In Measuring Pterygium Thickness

Introduction: As various pterygium morphologies have been advocated as contributing factor on corneal astigmatism, little support in the literature available in establishing techniques in measuring pterygium thickness as clinical indicator.Objective: The aim of this study was to describe a quantitative method in determining pterygium thickness using anterior segment optical coherence tomography (AS-OCT).Methods: Anterior segment imaging was performed using enhanced high resolution cornea (EHRC) of Visante™ AS-OCT in 120 primary pterygium eyes. Prior to imaging, corneal topography assessment was performed on each pterygium eye in order to identify its topographic location. Based on topography mapping, three meridians (in degrees) were selected as close as possible to the pterygium border, which signify the demarcation of pterygium from the cornea. Reliability testing between intra and inter-observer of AS-OCT imaging modality was examined using intraclass correlation and scatter plot.Results: The overall (n = 120) mean and standard deviation of pterygium thickness EHRC of AS-OCT modality were 0.48 ± 0.10 mm (confidence interval: 0.45 – 0.50). EHRC of AS-OCT also showed excellent intra and intergrader reliability in measuring pterygium thickness with intraclass correlation of 0.997 (confidence interval: 0.994 – 0.998).Conclusions: EHRC of AS-OCT imaging modality is a better choice in assessing pterygium compared to traditional slit-lamp biomicroscopy. This tool is applicable for future work related to better understanding on the role thickness in pterygium morphology, its progression and prediction of induced corneal astigmatism and visual impairment due to pterygium

The contribution of information technology (IT) in conceptualizing the Qur`anic approach on programmed systems of biology

Background: the analytical study on understanding the programmed systems of organisms is increasingly becoming necessary for its practical contribution in enhancing the environmental and human health. The holy Qur`an, in numerous passages, has addressed the design and harmony, in both the physical and biological worlds. The main objective of this Qur`anic approach is to shift human attention to study and understand the natural processes for temporal and religious purposes. Although laws of the physical world are well investigated and established, the natural processes governing the complex systems of biological world, however, are yet to be mastered. The major problem of this field is not only in complexity of the biological phenomena, but also in the relevant method for investigation. To achieve the Qur`anic objectives on study of the natural and human phenomena, however, we need to investigate both of the above problems. Objective: This paper aims to investigate method of conceptualizing the programmed systems of biology as introduced by the Holy Qur`an, and how information technology (IT) can contribute in achieving this important goal. The basic presupposition of the paper is that the new developments of information technology play a vital role in codification and understanding programmed systems of living creatures. Such codification is essential for predicting the future directions of the goal-guided processes of biology. Methodology: The method adopted in the paper is theoretical and analytical in nature. The analytical method of systems biology, based on mathematical modeling and information technology, that aims at codification of the programed systems of biology will be adopted. The relevant Qur`anic verses on natural design and harmony, especially on the biological phenomena at both individual and collective levels, will be collected. Method of understanding such verses from both perspectives of (i) the classical view of Muslim scholars, and (ii) methods of modern evolutionary biology will be investigated. Finally, the paper investigates how modern information technology can contribute in codification of the programed systems of natural biology as embedded in Qur`anic verses. Results & Conclusions: The paper presupposes that proper codification of programed systems of biology has three major implications: (i) explanation and understanding the biological phenomena; (ii) predicting the future directions of the goal-guided processes of biology; and (iii) Mastering the biological processes, by explanation and prediction, has great implication on environmental and human healthcare. Sufficient data on biological phenomena, mathematical analysis, and effective information technologies are essential to achieve these noble goals