Khairidzan Kamal - Academia.edu (original) (raw)

Papers by Khairidzan Kamal

Research paper thumbnail of Corneal Curvature Measurements Utilizing a New Swept-source Optical Coherence Tomography Tomey OA-2000® and Comparison With IOL Master® 500 in Pterygium Patients

Sains Medika : Jurnal Kedokteran dan Kesehatan

Introduction: Corneal curvature (CC) is an important anterior segment parameter. This study compa... more Introduction: Corneal curvature (CC) is an important anterior segment parameter. This study compared CC measurements conducted with two optical devices in pterygium eyes.Methods: Sixty pterygium eyes of 30 patients were enrolled in this study. CC was measured three times with the optical biometer and topography-keratometer Tomey OA-2000 (Tomey Corporation, Nagoya, Japan), then with partial optical coherence interferometry (PCI) IOL Master 500 (Carl Zeiss Meditec, Dublin, CA) and data were statistically analysed.Results: The measurements revealed in a mean CC of 43.86 ± 1.57 D with Tomey OA-2000 and 43.84 ± 1.55 D with IOL Master. Distribution of data is normal, and no significance difference in CC values was detected (P = 0.952) between the two devices. Correlation between CC measurements was highly significant (r = 0. 99; P < 0.0001). The mean difference of CC values between devices was 0.017 D and 95% limit of agreement was -0.088 to 0.12. Duration taken for measurements with t...

Research paper thumbnail of Mesopic pupillometry in pre-LASIK patients by a placido-disc topographer and hartmann-shack aberrometer

Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Apr 1, 2021

Introduction: Precise pupillometry is crucial to determine ablation optical zone (OZ) size select... more Introduction: Precise pupillometry is crucial to determine ablation optical zone (OZ) size selection in LASIK. Significant difference in the selection induces unwanted postoperative night visual disturbance. Placido-disc topographer and Hartmann-Shack aberrometer are commonly used in LASIK preoperative assessment. However, little is known on the precision and agreement of these devices in pupillometry. Hence, this study aimed to evaluate the precision (repeatability and reproducibility) and inter-device agreement of a Placido-disc topographer and Hartmann-Shack aberrometer in measuring mesopic pupil size in pre-LASIK patients. Methods: Mesopic pupillometry on 38 pre-LASIK patients were performed using both devices by two masked operators, on two separate sessions. Intra-session repeatability, inter-operator reproducibility and inter-device agreement were analysed. A disagreement value of ±0.5 mm and 95% limits of agreement (LoA) were determined. Results: Hartmann-Shack aberrometer demonstrated higher repeatability and reproducibility than Placido-disc topographer in mesopic pupillometry. Ninety-seven percent and all of Hartmann-Shack wavefront aberrometer pupillometry were within ±0.5 mm in repeated sessions and between the operators, respectively. The mesopic pupil size obtained from Placido-disc topographer was significantly larger than Hartmann-Shack aberrometer results (P = 0.02). The agreement between devices was low (LoA > ±1 mm) and only 53% of Placido-disc topographer pupillometry were within ±0.5 mm of Hartmann-Shack aberrometer pupillometry. Conclusion: Hartmann-Shack aberrometer has higher precision within sessions and between operators, and it provides smaller mesopic pupillometry than Placido-disc topographer. Precise mesopic pupillometry could assist refractive surgeons in choosing a correct ablation OZ size during LASIK surgery to improve postoperative outcome.

Research paper thumbnail of In-Vivo Confocal Microscopy: Keratocytes cell density (KCD) Regeneration between Femtosecond LASIK (FS-LASIK) and Photorefractive Keratectomy (PRK)

Research paper thumbnail of Reliability of Pterygium Redness Grading Software (PRGS) in describing different types of primary pterygia based on appearance = Kebolehpercayaan Perisian Penggredan Kemerahan Pterigium (PRGS) dalam mengelaskan pelbagai jenis pterigium berdasarkan perawakan

Universiti Kebangsaan Malaysia, Aug 1, 2020

Research paper thumbnail of Correlation between variation in phacoemulsification surgical techniques and predictability of surgical induced astigmatism

Research paper thumbnail of In-vivo confocal microscopy: comparison of Keratocytes cell density (KCD) between Femtosecond LASIK (FS-LASIK) and Photorefractive keratectomy (PRK) at one month follow-up

To evaluate keratocyte cell density (KCD) regeneration after 1-month laser refractive surgery (FS... more To evaluate keratocyte cell density (KCD) regeneration after 1-month laser refractive surgery (FS-LASIK and PRK) using Heidelberg Retina Tomography III/Rostock Corneal Module confocal microscope (HRT III/RCM) and image analysis. Methods Sixteen eyes of 8 participants who underwent FS-LASIK and PRK involved in this prospective nonrandomised study. Inclusion criteria includes of having moderate to high myopia (spherical equivalent, SE:-3.25D to 9.25D).A flap was created and repositioned back after ablated in FS-LASIK, while in PRK the entire corneal epithelium was removed(flap-less)before ablated. Central corneas were scanned throughout their full thickness using HRTIII/RCM during baseline and post-operative 1 month by single examiner. Morphologic modifications of KCD were evaluated. Using image analysis, KCD was measured in cell/mm2. Two images with non-artefact were selected from each stromal layer for evaluation of KCD and the average mean was taken for analysis. KCD was manually calculated within a region of interest (ROI)set at 0.16mm2 by modification of brightness and contrast. Cells which are more illuminated and refringent were selected and analysed using Wilcoxon signed-rank and Mann-Whitney U test. Results Mean participants' age was 27.25±4.04 years old. Approximately 19% and 33% of KCD reduction were observed in post 1-month FS-LASIK and PRK respectively. Wilcoxon signed-rank test was employed to analyse the mean of KCD. There was significant differences between pre-operative and post 1-month in both groups (P=0.012). Both PRK and FS-LASIK shows lower KCD compared to their baseline (P>0.05). Conclusion KCD regeneration does not occur as early as 1 month in both procedures. Thus, a cohort study is required.

Research paper thumbnail of Tear film and lid margin changes in patients with different types of primary pterygium

Purpose. This study aimed to evaluate tear film and lid margin changes in patients with different... more Purpose. This study aimed to evaluate tear film and lid margin changes in patients with different types of primary pterygium. Methods. A total of 123 participants comprises of normal patients (n=30), patients with type I pterygium (n=30), type II pterygium (n=32) and type III pterygium (n=31) without ocular pathologies were selected from patients who visited an ophthalmology clinic. Ocular surface disease index scores (OSDI), meibomian gland expression (MGE), lid margin abnormality (LM) scores, tear break-up time (TBUT), Schirmer test (SIT) value and multiple tear meniscus values; the lower tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus area (TMA) measured using time-domain ocular coherence tomography were performed. Comparative analyses between groups were performed for all parameters. A statistical significance level of P 0.05). Correlation analysis revealed LM abnormality, MGE and TBUT were significantly correlated with OSDI scores pterygium patients. Conclusions. Advance pterygium cause alteration of tear film and lid margin, which is associated with ocular discomfort. Early detection of lid margin changes seems to be important to understand the relationship between pterygium, tear film functions and changes of the ocular surface

Research paper thumbnail of Deeply Embedded Corneal Foreign Bodies With Fungal Keratitis Secondary to Rambutan Fruit Fall

Cureus, 2022

Rambutan is widely found in remote areas in Southeast Asia. It may lead to serious ocular trauma ... more Rambutan is widely found in remote areas in Southeast Asia. It may lead to serious ocular trauma if it accidentally hits the eyes. This case report describes a patient who presented with deeply embedded cornea foreign body and fungal keratitis following direct ocular trauma by rambutan fruit. This report identified the features of this fruit that had the potential to cause serious ocular trauma. Ocular protection equipment is essential to prevent injury during harvesting the fruit.

Research paper thumbnail of Reliability of Pterygium Redness Grading Software (PRGS) in Describing Different Types of Primary Pterygia Based on Appearance

Sains Malaysiana, 2020

The aim of this study was to evaluate the reliability of Pterygium Redness Grading Software (PRGS... more The aim of this study was to evaluate the reliability of Pterygium Redness Grading Software (PRGS) in describing clinic were recruited in this study. PRGS pterygium redness by analysing digital images of the pterygium and grading it on a continuous scale of 1 (minimum redness) to 3 (maximum redness). An ocular surface expert graded all 93 images in random order. The reliability of PRGS was determined by comparing pterygium redness measured using the software and by the expert. The mean PRGS and by the expert

Research paper thumbnail of Chemo-adjuvant therapy in recurrent conjunctival intraepithelial neoplasia

A 68-year-old Malay male with no known medical illness presented with progressive growth of right... more A 68-year-old Malay male with no known medical illness presented with progressive growth of right conjunctival mass over a few months. Anterior segment examination of the right eye showed an inferior perilimbal elevated gelatinous conjunctival mass measuring 6 mm vertically x 14 mm horizontally with 360° corneal vascularisation. Excision biopsy and histopathological examination revealed areas of dysplastic cells involving the full epithelial thickness, suggestive of conjunctival intraepithelial neoplasia. The patient defaulted follow-up and presented later with recurrence involving the superior two-thirds of the cornea. Pulsed dosing of topical 5-fluorouracil 1% was initiated 4 times daily for a week with 21-day breaks for a total of 4 cycles. Regression of the lesion was noted after two cycles of 5-fluorouracil.

Research paper thumbnail of Prediction of Changes in Optical Quality by Tissue Redness after Pterygium Surgery

World Academy of Science, Engineering and Technology, International Journal of Medical and Health Sciences, 2016

Authors : Mohd Radzi Hilmi, Mohd Zulfaezal Che Azemin, Khairidzan Mohd Kamal, Azrin Esmady Ariffi... more Authors : Mohd Radzi Hilmi, Mohd Zulfaezal Che Azemin, Khairidzan Mohd Kamal, Azrin Esmady Ariffin, Mohd Izzuddin Mohd Tamrin, Norfazrina Abdul Gaffur, Tengku Mohd Tengku Sembok Abstract : Purpose: The purpose of this study is to predict optical quality changes after pterygium surgery using tissue redness grading. Methods: Sixty-eight primary pterygium participants were selected from patients who visited an ophthalmology clinic. We developed a semi-automated computer program to measure the pterygium fibrovascular redness from digital pterygium images. The outcome of this software is a continuous scale grading of 1 (minimum redness) to 3 (maximum redness). The region of interest (ROI) was selected manually using the software. Reliability was determined by repeat grading of all 68 images and its association with contrast sensitivity function (CSF) and visual acuity (VA) was examined. Results: The mean and standard deviation of redness of the pterygium fibrovascular images was 1.88 ± 0...

Research paper thumbnail of Supervised Pterygium Fibrovascular Redness Grading Using Generalized Regression Neural Network

Pterygium is a growth on the eye that can cause blindness, with countries closer to the equator s... more Pterygium is a growth on the eye that can cause blindness, with countries closer to the equator showing higher rate of incidence. However, there is a lack of research to study the severity and properties of the tissue. We propose the use of Generalized Neural Network (GRNN) to objectively quantify redness of the fibrovascular tissue. Comparative analysis using multiple feature selection algorithms indicates that error can be minimized when use with optimal set of features and suitable GRNN spread parameter. Features nominated by Minimum Redundancy Maximum Relevance gives the best performance with SSE = 3.55 and GRNN spread = 0.47.

Research paper thumbnail of Post-pterygium surgery prediction of contrast sensitivity function using fleshiness grade, redness and length of pterygium

Аннотация Предложена математическая модель многопутевой маршрутизации агрегированных потоков с ре... more Аннотация Предложена математическая модель многопутевой маршрутизации агрегированных потоков с резервированием сетевых ресурсов, представленная тензорами пространства с кривизной. Модель маршрутизации ориентирована на использование в сетях с поддержкой услуг связи гарантированного качества. Исследование модели подтвердило эффективность получаемых на ее основе решений.

Research paper thumbnail of Changes in Apical Corneal Curvature in Unilateral Primary Pterygium and Normal Adults Using Simulated-K and Corneal Irregularity Measurement

Introduction: This paper aimed to describe variation in apical corneal curvature between unilater... more Introduction: This paper aimed to describe variation in apical corneal curvature between unilateral primary pterygium and normal adults utilizing simulated-K and corneal irregularity measurement corneal indices. Methods: Total of 100 participants comprises of 50 unilateral primary pterygium eyes from 50 patients and 50 normal adults were recruited in this study. Diagnosis and classification of primary pterygium were done by a consultant ophthalmologist (KMK). Standard optometric examinations were performed in all participants. Simulated-K (SimK) and corneal irregularity measurement (CIM) was objectively measured using a corneal topographer. Three measurements based on best image quality for SimK and CIM were taken by single operator in a same visit. Difference for both SimK and CIM parameters between primary pterygium and normal groups were determined via independent T-test. Results: Overall mean and standard deviation (n = 120) of SimK and CIM were found higher in primary pterygium...

Research paper thumbnail of Correlation of Visual Recovery Time After Laser Refractive Surgery with Preoperative Keratometry and Astigmatism Among Myopic Astigmatism Patients

Introduction: Photorefractive keratometry (PRK) and laser in situ keratomileusis (LASIK) are amon... more Introduction: Photorefractive keratometry (PRK) and laser in situ keratomileusis (LASIK) are among the many types of laser refractive surgery available for the correction of myopic astigmatism. The outcome of the procedure can be affected by several parameters which include patient’s age, optical zone diameter, epithelial hyperplasia, preoperative keratometry as well as astigmatism. Aim: This study aimed to determine the relationship between preoperative keratometry and astigmatism with visual recovery time after laser refractive surgery. Methods: Records of 174 eyes (174 patients) with myopic astigmatism who had been treated with either LASIK (71 eyes) or PRK (103 eyes) at IIUM Eye Specialist Clinic from January 2015 to June 2018, were retrospectively analyzed. Main outcome measure was the time taken for patients to achieve visual acuity (VA) 6/6 (equivalent to 0.00 LogMAR) postoperatively. Value for keratometry parameter was taken from corneal topography while astigmatism magni...

Research paper thumbnail of Measurement of pterygium tissue dry weight using two different tissue preparation techniques in freeze-dry method

Introduction: The proposed freeze-dried approach for estimating pterygium dry weight closes the g... more Introduction: The proposed freeze-dried approach for estimating pterygium dry weight closes the gap which address the possible effect of corneal compression due to pterygium on the corneal surface, translating simple laboratory procedure to a clinical practice which essential in predicting induced-corneal astigmatism. This study aim to compare an objective method in quantifying pterygium dry weight utilizing freeze-dried method via two different tissue preparation methods. Methods: 60 primary pterygium were excised using controlled partial avulsion technique performed by a single surgeon (KMK), and divided into two groups: formalin-fixed (n=30) and non-fixed (n=30). Initially, each sterile container weight was measured and 5ml of 5% buffered formaldehyde were filled and stored for 1 week for formalin-fixed group while, 5ml distilled water were filled for non-fixed pterygium group. Each container was pre-frozen for 12 hours prior to freeze-dried (- 80 oC for 24 hours). The final prod...

Research paper thumbnail of EFFECTIVENESS OF PTechSIA QUESTIONNAIRE IN QUANTIFYING PHACOEMULSIFICATION SURGICAL TECHNIQUE VARIATIONS: A PILOT STUDY

Introduction: Detailed-documentation of phacoemulsification surgical techniques in operative note... more Introduction: Detailed-documentation of phacoemulsification surgical techniques in operative note is not a routine in clinical practice. However, this information is crucial in order to quantify the variations in surgeon’s surgical technique and to further evaluate the surgeon’s surgically induced astigmatism (SIA) predictability. Aim: To assess the effectiveness of Phacoemulsification Technique Related to Surgically Induced Astigmatism (PTechSIA) questionnaire in quantifying the phacoemulsification surgical technique variations. Methods: Four ophthalmic surgeons (Surgeons A, B, C and D) at IIUM Eye Specialist Clinic were involved in this study. A validated self-administered questionnaire with 9 items (PTechSIA, patency number: LY2018002935) was employed to assess the surgeons’ surgical techniques during phacoemulsification. All the responds were scored for each item using Variation Score (VS). Score ‘0’ was given, when a surgeon ticked only one option of the surgical tech...

Research paper thumbnail of Population-based study on axial ocular dimensions and corneal astigmatism

Malaysian Journal of Ophthalmology, 2019

As cataract surgery has evolved over 50 years, there have been changes in the current clinical op... more As cataract surgery has evolved over 50 years, there have been changes in the current clinical ophthalmic practice to improve safety and efficacy in order to achieve perfect postoperative outcomes. Since the 1990s, technological advances such as ocular biometry, phacoemulsification, and intraocular lens (IOL) formulas, as well as many others, have undergone numerous incremental upgrades aiming to produce predictable and reproducible quality results. However, the financial burden of adopting all these proven yet costly technologies in ophthalmological practice, especially in rural areas, has to be justified. In this issue, an epidemiological study on ocular biometrics conducted by the Ministry of Health at the Kuala Pilah Cluster Program has shed some light on a possible strategy to incorporate advanced tools and technology into our public service.

Research paper thumbnail of GLCM Texture Analysis on Different Color Space for Pterygium Grading

GLCM texture features have been widely used to characterize biomedical images. Most of the previo... more GLCM texture features have been widely used to characterize biomedical images. Most of the previous studies using GLCM features to characterize biomedical images only consider single or limited color space due to the use of only one color model. To mimic human color perception, conventional RGB color model may need to be supplemented with other color space models for better human vision representation. This study is aimed to find an optimal set of GLCM features extracted from different color space for pterygium grading. Mimicking human color perception has commonly employed RGB color space, which is shown in this paper is inadequate. GLCM features when extracted in various color space show better representation of human perception (correlation coefficient > 0.6) compared to using RGB color space (correlation coefficient < 0.2).

Research paper thumbnail of Postsurgery Classification of Best-Corrected Visual Acuity Changes Based on Pterygium Characteristics Using the Machine Learning Technique

The Scientific World Journal, 2021

Introduction. Early detection of visual symptoms in pterygium patients is crucial as the progress... more Introduction. Early detection of visual symptoms in pterygium patients is crucial as the progression of the disease can cause visual disruption and contribute to visual impairment. Best-corrected visual acuity (BCVA) and corneal astigmatism influence the degree of visual impairment due to direct invasion of fibrovascular tissue into the cornea. However, there were different characteristics of pterygium used to evaluate the severity of visual impairment, including fleshiness, size, length, and redness. The innovation of machine learning technology in visual science may contribute to developing a highly accurate predictive analytics model of BCVA outcomes in postsurgery pterygium patients. Aim. To produce an accurate model of BCVA changes of postpterygium surgery according to its morphological characteristics by using the machine learning technique. Methodology. A retrospective of the secondary dataset of 93 samples of pterygium patients with different pterygium attributes was used an...

Research paper thumbnail of Corneal Curvature Measurements Utilizing a New Swept-source Optical Coherence Tomography Tomey OA-2000® and Comparison With IOL Master® 500 in Pterygium Patients

Sains Medika : Jurnal Kedokteran dan Kesehatan

Introduction: Corneal curvature (CC) is an important anterior segment parameter. This study compa... more Introduction: Corneal curvature (CC) is an important anterior segment parameter. This study compared CC measurements conducted with two optical devices in pterygium eyes.Methods: Sixty pterygium eyes of 30 patients were enrolled in this study. CC was measured three times with the optical biometer and topography-keratometer Tomey OA-2000 (Tomey Corporation, Nagoya, Japan), then with partial optical coherence interferometry (PCI) IOL Master 500 (Carl Zeiss Meditec, Dublin, CA) and data were statistically analysed.Results: The measurements revealed in a mean CC of 43.86 ± 1.57 D with Tomey OA-2000 and 43.84 ± 1.55 D with IOL Master. Distribution of data is normal, and no significance difference in CC values was detected (P = 0.952) between the two devices. Correlation between CC measurements was highly significant (r = 0. 99; P < 0.0001). The mean difference of CC values between devices was 0.017 D and 95% limit of agreement was -0.088 to 0.12. Duration taken for measurements with t...

Research paper thumbnail of Mesopic pupillometry in pre-LASIK patients by a placido-disc topographer and hartmann-shack aberrometer

Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Apr 1, 2021

Introduction: Precise pupillometry is crucial to determine ablation optical zone (OZ) size select... more Introduction: Precise pupillometry is crucial to determine ablation optical zone (OZ) size selection in LASIK. Significant difference in the selection induces unwanted postoperative night visual disturbance. Placido-disc topographer and Hartmann-Shack aberrometer are commonly used in LASIK preoperative assessment. However, little is known on the precision and agreement of these devices in pupillometry. Hence, this study aimed to evaluate the precision (repeatability and reproducibility) and inter-device agreement of a Placido-disc topographer and Hartmann-Shack aberrometer in measuring mesopic pupil size in pre-LASIK patients. Methods: Mesopic pupillometry on 38 pre-LASIK patients were performed using both devices by two masked operators, on two separate sessions. Intra-session repeatability, inter-operator reproducibility and inter-device agreement were analysed. A disagreement value of ±0.5 mm and 95% limits of agreement (LoA) were determined. Results: Hartmann-Shack aberrometer demonstrated higher repeatability and reproducibility than Placido-disc topographer in mesopic pupillometry. Ninety-seven percent and all of Hartmann-Shack wavefront aberrometer pupillometry were within ±0.5 mm in repeated sessions and between the operators, respectively. The mesopic pupil size obtained from Placido-disc topographer was significantly larger than Hartmann-Shack aberrometer results (P = 0.02). The agreement between devices was low (LoA > ±1 mm) and only 53% of Placido-disc topographer pupillometry were within ±0.5 mm of Hartmann-Shack aberrometer pupillometry. Conclusion: Hartmann-Shack aberrometer has higher precision within sessions and between operators, and it provides smaller mesopic pupillometry than Placido-disc topographer. Precise mesopic pupillometry could assist refractive surgeons in choosing a correct ablation OZ size during LASIK surgery to improve postoperative outcome.

Research paper thumbnail of In-Vivo Confocal Microscopy: Keratocytes cell density (KCD) Regeneration between Femtosecond LASIK (FS-LASIK) and Photorefractive Keratectomy (PRK)

Research paper thumbnail of Reliability of Pterygium Redness Grading Software (PRGS) in describing different types of primary pterygia based on appearance = Kebolehpercayaan Perisian Penggredan Kemerahan Pterigium (PRGS) dalam mengelaskan pelbagai jenis pterigium berdasarkan perawakan

Universiti Kebangsaan Malaysia, Aug 1, 2020

Research paper thumbnail of Correlation between variation in phacoemulsification surgical techniques and predictability of surgical induced astigmatism

Research paper thumbnail of In-vivo confocal microscopy: comparison of Keratocytes cell density (KCD) between Femtosecond LASIK (FS-LASIK) and Photorefractive keratectomy (PRK) at one month follow-up

To evaluate keratocyte cell density (KCD) regeneration after 1-month laser refractive surgery (FS... more To evaluate keratocyte cell density (KCD) regeneration after 1-month laser refractive surgery (FS-LASIK and PRK) using Heidelberg Retina Tomography III/Rostock Corneal Module confocal microscope (HRT III/RCM) and image analysis. Methods Sixteen eyes of 8 participants who underwent FS-LASIK and PRK involved in this prospective nonrandomised study. Inclusion criteria includes of having moderate to high myopia (spherical equivalent, SE:-3.25D to 9.25D).A flap was created and repositioned back after ablated in FS-LASIK, while in PRK the entire corneal epithelium was removed(flap-less)before ablated. Central corneas were scanned throughout their full thickness using HRTIII/RCM during baseline and post-operative 1 month by single examiner. Morphologic modifications of KCD were evaluated. Using image analysis, KCD was measured in cell/mm2. Two images with non-artefact were selected from each stromal layer for evaluation of KCD and the average mean was taken for analysis. KCD was manually calculated within a region of interest (ROI)set at 0.16mm2 by modification of brightness and contrast. Cells which are more illuminated and refringent were selected and analysed using Wilcoxon signed-rank and Mann-Whitney U test. Results Mean participants' age was 27.25±4.04 years old. Approximately 19% and 33% of KCD reduction were observed in post 1-month FS-LASIK and PRK respectively. Wilcoxon signed-rank test was employed to analyse the mean of KCD. There was significant differences between pre-operative and post 1-month in both groups (P=0.012). Both PRK and FS-LASIK shows lower KCD compared to their baseline (P>0.05). Conclusion KCD regeneration does not occur as early as 1 month in both procedures. Thus, a cohort study is required.

Research paper thumbnail of Tear film and lid margin changes in patients with different types of primary pterygium

Purpose. This study aimed to evaluate tear film and lid margin changes in patients with different... more Purpose. This study aimed to evaluate tear film and lid margin changes in patients with different types of primary pterygium. Methods. A total of 123 participants comprises of normal patients (n=30), patients with type I pterygium (n=30), type II pterygium (n=32) and type III pterygium (n=31) without ocular pathologies were selected from patients who visited an ophthalmology clinic. Ocular surface disease index scores (OSDI), meibomian gland expression (MGE), lid margin abnormality (LM) scores, tear break-up time (TBUT), Schirmer test (SIT) value and multiple tear meniscus values; the lower tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus area (TMA) measured using time-domain ocular coherence tomography were performed. Comparative analyses between groups were performed for all parameters. A statistical significance level of P 0.05). Correlation analysis revealed LM abnormality, MGE and TBUT were significantly correlated with OSDI scores pterygium patients. Conclusions. Advance pterygium cause alteration of tear film and lid margin, which is associated with ocular discomfort. Early detection of lid margin changes seems to be important to understand the relationship between pterygium, tear film functions and changes of the ocular surface

Research paper thumbnail of Deeply Embedded Corneal Foreign Bodies With Fungal Keratitis Secondary to Rambutan Fruit Fall

Cureus, 2022

Rambutan is widely found in remote areas in Southeast Asia. It may lead to serious ocular trauma ... more Rambutan is widely found in remote areas in Southeast Asia. It may lead to serious ocular trauma if it accidentally hits the eyes. This case report describes a patient who presented with deeply embedded cornea foreign body and fungal keratitis following direct ocular trauma by rambutan fruit. This report identified the features of this fruit that had the potential to cause serious ocular trauma. Ocular protection equipment is essential to prevent injury during harvesting the fruit.

Research paper thumbnail of Reliability of Pterygium Redness Grading Software (PRGS) in Describing Different Types of Primary Pterygia Based on Appearance

Sains Malaysiana, 2020

The aim of this study was to evaluate the reliability of Pterygium Redness Grading Software (PRGS... more The aim of this study was to evaluate the reliability of Pterygium Redness Grading Software (PRGS) in describing clinic were recruited in this study. PRGS pterygium redness by analysing digital images of the pterygium and grading it on a continuous scale of 1 (minimum redness) to 3 (maximum redness). An ocular surface expert graded all 93 images in random order. The reliability of PRGS was determined by comparing pterygium redness measured using the software and by the expert. The mean PRGS and by the expert

Research paper thumbnail of Chemo-adjuvant therapy in recurrent conjunctival intraepithelial neoplasia

A 68-year-old Malay male with no known medical illness presented with progressive growth of right... more A 68-year-old Malay male with no known medical illness presented with progressive growth of right conjunctival mass over a few months. Anterior segment examination of the right eye showed an inferior perilimbal elevated gelatinous conjunctival mass measuring 6 mm vertically x 14 mm horizontally with 360° corneal vascularisation. Excision biopsy and histopathological examination revealed areas of dysplastic cells involving the full epithelial thickness, suggestive of conjunctival intraepithelial neoplasia. The patient defaulted follow-up and presented later with recurrence involving the superior two-thirds of the cornea. Pulsed dosing of topical 5-fluorouracil 1% was initiated 4 times daily for a week with 21-day breaks for a total of 4 cycles. Regression of the lesion was noted after two cycles of 5-fluorouracil.

Research paper thumbnail of Prediction of Changes in Optical Quality by Tissue Redness after Pterygium Surgery

World Academy of Science, Engineering and Technology, International Journal of Medical and Health Sciences, 2016

Authors : Mohd Radzi Hilmi, Mohd Zulfaezal Che Azemin, Khairidzan Mohd Kamal, Azrin Esmady Ariffi... more Authors : Mohd Radzi Hilmi, Mohd Zulfaezal Che Azemin, Khairidzan Mohd Kamal, Azrin Esmady Ariffin, Mohd Izzuddin Mohd Tamrin, Norfazrina Abdul Gaffur, Tengku Mohd Tengku Sembok Abstract : Purpose: The purpose of this study is to predict optical quality changes after pterygium surgery using tissue redness grading. Methods: Sixty-eight primary pterygium participants were selected from patients who visited an ophthalmology clinic. We developed a semi-automated computer program to measure the pterygium fibrovascular redness from digital pterygium images. The outcome of this software is a continuous scale grading of 1 (minimum redness) to 3 (maximum redness). The region of interest (ROI) was selected manually using the software. Reliability was determined by repeat grading of all 68 images and its association with contrast sensitivity function (CSF) and visual acuity (VA) was examined. Results: The mean and standard deviation of redness of the pterygium fibrovascular images was 1.88 ± 0...

Research paper thumbnail of Supervised Pterygium Fibrovascular Redness Grading Using Generalized Regression Neural Network

Pterygium is a growth on the eye that can cause blindness, with countries closer to the equator s... more Pterygium is a growth on the eye that can cause blindness, with countries closer to the equator showing higher rate of incidence. However, there is a lack of research to study the severity and properties of the tissue. We propose the use of Generalized Neural Network (GRNN) to objectively quantify redness of the fibrovascular tissue. Comparative analysis using multiple feature selection algorithms indicates that error can be minimized when use with optimal set of features and suitable GRNN spread parameter. Features nominated by Minimum Redundancy Maximum Relevance gives the best performance with SSE = 3.55 and GRNN spread = 0.47.

Research paper thumbnail of Post-pterygium surgery prediction of contrast sensitivity function using fleshiness grade, redness and length of pterygium

Аннотация Предложена математическая модель многопутевой маршрутизации агрегированных потоков с ре... more Аннотация Предложена математическая модель многопутевой маршрутизации агрегированных потоков с резервированием сетевых ресурсов, представленная тензорами пространства с кривизной. Модель маршрутизации ориентирована на использование в сетях с поддержкой услуг связи гарантированного качества. Исследование модели подтвердило эффективность получаемых на ее основе решений.

Research paper thumbnail of Changes in Apical Corneal Curvature in Unilateral Primary Pterygium and Normal Adults Using Simulated-K and Corneal Irregularity Measurement

Introduction: This paper aimed to describe variation in apical corneal curvature between unilater... more Introduction: This paper aimed to describe variation in apical corneal curvature between unilateral primary pterygium and normal adults utilizing simulated-K and corneal irregularity measurement corneal indices. Methods: Total of 100 participants comprises of 50 unilateral primary pterygium eyes from 50 patients and 50 normal adults were recruited in this study. Diagnosis and classification of primary pterygium were done by a consultant ophthalmologist (KMK). Standard optometric examinations were performed in all participants. Simulated-K (SimK) and corneal irregularity measurement (CIM) was objectively measured using a corneal topographer. Three measurements based on best image quality for SimK and CIM were taken by single operator in a same visit. Difference for both SimK and CIM parameters between primary pterygium and normal groups were determined via independent T-test. Results: Overall mean and standard deviation (n = 120) of SimK and CIM were found higher in primary pterygium...

Research paper thumbnail of Correlation of Visual Recovery Time After Laser Refractive Surgery with Preoperative Keratometry and Astigmatism Among Myopic Astigmatism Patients

Introduction: Photorefractive keratometry (PRK) and laser in situ keratomileusis (LASIK) are amon... more Introduction: Photorefractive keratometry (PRK) and laser in situ keratomileusis (LASIK) are among the many types of laser refractive surgery available for the correction of myopic astigmatism. The outcome of the procedure can be affected by several parameters which include patient’s age, optical zone diameter, epithelial hyperplasia, preoperative keratometry as well as astigmatism. Aim: This study aimed to determine the relationship between preoperative keratometry and astigmatism with visual recovery time after laser refractive surgery. Methods: Records of 174 eyes (174 patients) with myopic astigmatism who had been treated with either LASIK (71 eyes) or PRK (103 eyes) at IIUM Eye Specialist Clinic from January 2015 to June 2018, were retrospectively analyzed. Main outcome measure was the time taken for patients to achieve visual acuity (VA) 6/6 (equivalent to 0.00 LogMAR) postoperatively. Value for keratometry parameter was taken from corneal topography while astigmatism magni...

Research paper thumbnail of Measurement of pterygium tissue dry weight using two different tissue preparation techniques in freeze-dry method

Introduction: The proposed freeze-dried approach for estimating pterygium dry weight closes the g... more Introduction: The proposed freeze-dried approach for estimating pterygium dry weight closes the gap which address the possible effect of corneal compression due to pterygium on the corneal surface, translating simple laboratory procedure to a clinical practice which essential in predicting induced-corneal astigmatism. This study aim to compare an objective method in quantifying pterygium dry weight utilizing freeze-dried method via two different tissue preparation methods. Methods: 60 primary pterygium were excised using controlled partial avulsion technique performed by a single surgeon (KMK), and divided into two groups: formalin-fixed (n=30) and non-fixed (n=30). Initially, each sterile container weight was measured and 5ml of 5% buffered formaldehyde were filled and stored for 1 week for formalin-fixed group while, 5ml distilled water were filled for non-fixed pterygium group. Each container was pre-frozen for 12 hours prior to freeze-dried (- 80 oC for 24 hours). The final prod...

Research paper thumbnail of EFFECTIVENESS OF PTechSIA QUESTIONNAIRE IN QUANTIFYING PHACOEMULSIFICATION SURGICAL TECHNIQUE VARIATIONS: A PILOT STUDY

Introduction: Detailed-documentation of phacoemulsification surgical techniques in operative note... more Introduction: Detailed-documentation of phacoemulsification surgical techniques in operative note is not a routine in clinical practice. However, this information is crucial in order to quantify the variations in surgeon’s surgical technique and to further evaluate the surgeon’s surgically induced astigmatism (SIA) predictability. Aim: To assess the effectiveness of Phacoemulsification Technique Related to Surgically Induced Astigmatism (PTechSIA) questionnaire in quantifying the phacoemulsification surgical technique variations. Methods: Four ophthalmic surgeons (Surgeons A, B, C and D) at IIUM Eye Specialist Clinic were involved in this study. A validated self-administered questionnaire with 9 items (PTechSIA, patency number: LY2018002935) was employed to assess the surgeons’ surgical techniques during phacoemulsification. All the responds were scored for each item using Variation Score (VS). Score ‘0’ was given, when a surgeon ticked only one option of the surgical tech...

Research paper thumbnail of Population-based study on axial ocular dimensions and corneal astigmatism

Malaysian Journal of Ophthalmology, 2019

As cataract surgery has evolved over 50 years, there have been changes in the current clinical op... more As cataract surgery has evolved over 50 years, there have been changes in the current clinical ophthalmic practice to improve safety and efficacy in order to achieve perfect postoperative outcomes. Since the 1990s, technological advances such as ocular biometry, phacoemulsification, and intraocular lens (IOL) formulas, as well as many others, have undergone numerous incremental upgrades aiming to produce predictable and reproducible quality results. However, the financial burden of adopting all these proven yet costly technologies in ophthalmological practice, especially in rural areas, has to be justified. In this issue, an epidemiological study on ocular biometrics conducted by the Ministry of Health at the Kuala Pilah Cluster Program has shed some light on a possible strategy to incorporate advanced tools and technology into our public service.

Research paper thumbnail of GLCM Texture Analysis on Different Color Space for Pterygium Grading

GLCM texture features have been widely used to characterize biomedical images. Most of the previo... more GLCM texture features have been widely used to characterize biomedical images. Most of the previous studies using GLCM features to characterize biomedical images only consider single or limited color space due to the use of only one color model. To mimic human color perception, conventional RGB color model may need to be supplemented with other color space models for better human vision representation. This study is aimed to find an optimal set of GLCM features extracted from different color space for pterygium grading. Mimicking human color perception has commonly employed RGB color space, which is shown in this paper is inadequate. GLCM features when extracted in various color space show better representation of human perception (correlation coefficient > 0.6) compared to using RGB color space (correlation coefficient < 0.2).

Research paper thumbnail of Postsurgery Classification of Best-Corrected Visual Acuity Changes Based on Pterygium Characteristics Using the Machine Learning Technique

The Scientific World Journal, 2021

Introduction. Early detection of visual symptoms in pterygium patients is crucial as the progress... more Introduction. Early detection of visual symptoms in pterygium patients is crucial as the progression of the disease can cause visual disruption and contribute to visual impairment. Best-corrected visual acuity (BCVA) and corneal astigmatism influence the degree of visual impairment due to direct invasion of fibrovascular tissue into the cornea. However, there were different characteristics of pterygium used to evaluate the severity of visual impairment, including fleshiness, size, length, and redness. The innovation of machine learning technology in visual science may contribute to developing a highly accurate predictive analytics model of BCVA outcomes in postsurgery pterygium patients. Aim. To produce an accurate model of BCVA changes of postpterygium surgery according to its morphological characteristics by using the machine learning technique. Methodology. A retrospective of the secondary dataset of 93 samples of pterygium patients with different pterygium attributes was used an...