Correlation between Visual Functions and Retinal Morphology in Eyes with Early and Intermediate Age-Related Macular Degeneration.

In early and intermediate age related macular degeneration (ARMD), visual acuity alone has failed to explain the complete variation of vision. The aim of the present study was to determine correlation between different visual functions and retinal morphology in eyes with early and intermediate ARMD. In this single center cross sectional study, patients diagnosed as early or intermediate ARMD in at least one eye were recruited. Visual functions measured were best- corrected distance visual acuity (DVA), near vision acuity (NVA), reading speed (RS), and contrast sensitivity (CS). Parameters such as thickness (RT) and volume (RV) of the retina, outer retinal layer thickness (ORLT) and volume (ORLV), outer nuclear layer thickness (ONLT) and volume (ONLV), retinal pigment epithelium layer-Bruch's membrane complex thickness (RPET) and volume (RPEV) were assessed employing semi-auto segmentation method of Spectralis optical coherence tomography (OCT). Twenty-six eyes were evaluated. DVA, CS, and RS showed significantly good correlation with RPET, ONLT, and ONLV, whereas NVA showed good correlation with ONLV and RPET. The present study concluded that RS, CS, NVA, and DVA represent the morphological alteration in early stages and should be tested in clinical settings. ONLT, ONLV, and RPET morphological parameters can be employed as important biomarkers in diagnosis of early to intermediate ARMD.

HbA1c and retinal sensitivity in diabetics using microperimetry / HbA1c y sensibilidad de la retina medida mediante microperimetría en pacientes diabéticos

Purpose: The purpose of this study was to determine the relationship between HbA1c values and retinal sensitivity at central 10° using the MP-1 microperimeter. Methods: A prospective study was carried out on 32 healthy subjects (control group) and 60 diabetic patients. The diabetic patients were divided into 2 groups. Group 1 comprised of 30 patients without diabetic retinopathy (DR) and group 2 had 30 patients with mild non-proliferative DR. A full-threshold microperimetry of the central 10° of retina (the macula) was performed on all subjects, utilizing 32 points with the MP-1. The relationship between light sensitivity and HbA1c value was calculated using linear regression analysis. Results: Total mean sensitivity at 10° for group 1 without DR, group 2 with mild NPDR and control group were 18.67±0.83, 17.98±1.42 and 19.45±0.34 (dB), respectively. There was a significant difference in total mean retinal sensitivity at 10° between the 3 groups (F(2,89)=18.14, p=0.001). A simple linear regression was calculated to predict HbA1c based on retinal sensitivity. A significant regression equation was found (F(1,90)=107.61, p=0.0001, with an R2 of 0.545). The linear regression analysis revealed that there was a 0.64dB decline in mean retinal sensitivity within the central 10° diameter with an increase of 1mmHg of HbA1c. Conclusion: Retinal sensitivity at the central 10° of the macula is affected by changes in HbA1c values

Objetivo: El objetivo de este estudio fue determinar la relación entre los valores de HbA1c y la sensibilidad de la retina en los 10 grados centrales de la misma utilizando el microperímetro MP-1. Métodos: Se realizó un estudio prospectivo en 32 sujetos sanos (grupo control) y 60 pacientes diabéticos. Los pacientes diabéticos se dividieron en dos grupos: el grupo 1 se compuso de 30 pacientes sin retinopatía diabética (RD), y el grupo 2 incluyó a 30 pacientes con RD no proliferativa leve. Se realizó una microperimetría umbral total de los 10° centrales de la retina (la mácula) a todos los sujetos, utilizando 32 puntos con el MP-1. Se calculó la relación entre la sensibilidad retiniana y el valor de HbA1c utilizando un análisis de regresión lineal. Resultados: La sensibilidad media total a los 10° para el grupo 1 sin RD, el grupo 2 con NPDR leve y el grupo control fue de 18,67 ± 0,83, 17,98 ± 1,42 y 19,45 ± 0,34 (dB), respectivamente. Se observó una diferencia significativa en cuanto a sensibilidad media total de la retina a 10° entre los tres grupos (F(2,89) = 18,14, p = 0,001). Se realizó un análisis de regresión lineal simple para predecir HbA1c en base a la sensibilidad de la retina. Se encontró una ecuación de regresión significativa (F(1,9) = 107,61, p = 0,0001, con R2 de 0,545). El análisis de regresión lineal reveló que existe un descenso de 0,64dB de la sensibilidad media de la retina dentro del diámetro de 10° centrales con un incremento de 1 mmHg de HbA1c. Conclusión: La sensibilidad de la retina en los 10 grados centrales de la mácula se ve afectada por los cambios de los valores de HbA1c

HbA1c and retinal sensitivity in diabetics using microperimetry.

PURPOSE: The purpose of this study was to determine the relationship between HbA1c values and retinal sensitivity at central 10° using the MP-1 microperimeter. METHODS: A prospective study was carried out on 32 healthy subjects (control group) and 60 diabetic patients. The diabetic patients were divided into 2 groups. Group 1 comprised of 30 patients without diabetic retinopathy (DR) and group 2 had 30 patients with mild non-proliferative DR. A full-threshold microperimetry of the central 10° of retina (the macula) was performed on all subjects, utilizing 32 points with the MP-1. The relationship between light sensitivity and HbA1c value was calculated using linear regression analysis. RESULTS: Total mean sensitivity at 10° for group 1 without DR, group 2 with mild NPDR and control group were 18.67±0.83, 17.98±1.42 and 19.45±0.34 (dB), respectively. There was a significant difference in total mean retinal sensitivity at 10° between the 3 groups (F(2,89)=18.14, p=0.001). A simple linear regression was calculated to predict HbA1c based on retinal sensitivity. A significant regression equation was found (F(1,90)=107.61, p=0.0001, with an R2 of 0.545). The linear regression analysis revealed that there was a 0.64dB decline in mean retinal sensitivity within the central 10° diameter with an increase of 1mmHg of HbA1c. CONCLUSION: Retinal sensitivity at the central 10° of the macula is affected by changes in HbA1c values.

Automated pterygium detection method of anterior segment photographed images.

BACKGROUND AND BJECTIVE: Pterygium is an ocular disease caused by fibrovascular tissue encroachment onto the corneal region. The tissue may cause vision blurring if it grows into the pupil region. In this study, we propose an automatic detection method to differentiate pterygium from non-pterygium (normal) cases on the basis of frontal eye photographed images, also known as anterior segment photographed images. METHODS: The pterygium screening system was tested on two normal eye databases (UBIRIS and MILES) and two pterygium databases (Australia Pterygium and Brazil Pterygium). This system comprises four modules: (i) a preprocessing module to enhance the pterygium tissue using HSV-Sigmoid; (ii) a segmentation module to differentiate the corneal region and the pterygium tissue; (iii) a feature extraction module to extract corneal features using circularity ratio, Haralick's circularity, eccentricity, and solidity; and (iv) a classification module to identify the presence or absence of pterygium. System performance was evaluated using support vector machine (SVM) and artificial neural network. RESULTS: The three-step frame differencing technique was introduced in the corneal segmentation module. The output image successfully covered the region of interest with an average accuracy of 0.9127. The performance of the proposed system using SVM provided the most promising results of 88.7%, 88.3%, and 95.6% for sensitivity, specificity, and area under the curve, respectively. CONCLUSION: A basic platform for computer-aided pterygium screening was successfully developed using the proposed modules. The proposed system can classify pterygium and non-pterygium cases reasonably well. In our future work, a standard grading system will be developed to identify the severity of pterygium cases. This system is expected to increase the awareness of communities in rural areas on pterygium.

Corneal Cell Morphology in Keratoconus: A Confocal Microscopic Observation.

PURPOSE: To evaluate corneal cell morphology in patients with keratoconus using an in vivo slit scanning confocal microscope. METHODS: A cross-sectional study was conducted to evaluate the corneal cell morphology of 47 keratoconus patients and 32 healthy eyes without any ocular disease. New keratoconus patients with different disease severities and without any other ocular co-morbidity were recruited from the ophthalmology department of a public hospital in Malaysia from June 2013 to May 2014. Corneal cell morphology was evaluated using an in vivo slit-scanning confocal microscope. Qualitative and quantitative data were analysed using a grading scale and the Nidek Advanced Visual Information System software, respectively. RESULTS: The corneal cell morphology of patients with keratoconus was significantly different from that of healthy eyes except in endothelial cell density (P = 0.072). In the keratoconus group, increased level of stromal haze, alterations such as the elongation of keratocyte nuclei and clustering of cells at the anterior stroma, and dark bands in the posterior stroma were observed with increased severity of the disease. The mean anterior and posterior stromal keratocyte densities and cell areas among the different stages of keratoconus were significantly different (P < 0.001 and P = 0.044, respectively). However, the changes observed in the endothelium were not significantly different (P > 0.05) among the three stages of keratoconus. CONCLUSION: Confocal microscopy observation showed significant changes in corneal cell morphology in keratoconic cornea from normal healthy cornea. Analysis also showed significant changes in different severities of keratoconus. Understanding the corneal cell morphology changes in keratoconus may help in the long-term monitoring and management of keratoconus.

The Relationship Between Tear Ferning Patterns and Non-invasive Tear Break-up Time in Normal Asian Population / Relación entre los patrones del Test de Ferning lagrimal y el TBUT no invasivo en la población normal de Asia

Purpose: To investigate the relationship between tear ferning patterns (TFP) and non-invasive tear break-up time (NIBUT) in normal Asian subjects. Methods: One hundred and forty-five adults with no ocular surface disorders were recruited. TFP and NIBUT were determined. Tears were collected using a capillary tube and allowed to air dry at room temperature for 10min. TFP was later observed using a light microscope and classified according to Rolando's classification. Measurement for NIBUT was obtained using a Tearscope with the slit lamp magnification. Results: It was found that there is no significant difference between gender in TFP (Z=−1.77, P>.05) and NIBUT (Z=−1.475, P>.05). There is also no significant difference between Malay, Chinese, Indian, and other races in TFP, (H(3)=4.85, P>.05) and NIBUT (H(3)=2.18, P>.05). However, there is a significant difference between age groups of 20-29, 30-39, 40-49,and 50-60 years old in both TFP (H(3)=28.25, P<.01) and NIBUT (H(3)=36.50, P<.001). Spearman's correlation showed there was a significant relationship between TFP and NIBUT (r=−0.55, P<.001), age and NIBUT (r=−0.50, P<.001), age and TFP (r=0.41, P<.001), McMonnies score and NIBUT (r=−0.40, P<.001), McMonnies score and TFP (r=0.31, P<.001), as well as age and McMonnies score (r=0.52, P<.001). Conclusion: TFP and NIBUT was age dependent but not gender and race dependent. Older subjects had higher grade of TFP and McMonnies questionnaire score but lower NIBUT value. TFP and NIBUT can be used to assess the tear film quality (AU)

Objetivo: Investigar la relación entre los patrones del test de Ferning (TFP) y el test de rotura lagrimal no invasivo (NIBUT) en sujetos asiáticos normales. Métodos: Se incluyó a ciento cuarenta y cinco adultos, sin trastornos en la superficie ocular. Se calcularon el TFP y el NIBUT. Se recolectaron lágrimas utilizando un tubo capilar, dejándose secar a temperatura ambiente durante diez minutos. Se observó posteriormente el TFP utilizando un microscopio óptico, clasificándose el patrón mediante los criterios de Rolando. La medición del NIBUT se obtuvo utilizando el Tearscope, con imagen ampliada en el biomicroscopio. Resultados: Se comprobó que no existen diferencias por sexo en relación a TFP (Z=-1,77, p>0.05) y NIBUT (Z=-1,475, p>0,05). Tampoco existen diferencias significativas entre las razas Malaya, China, India y demás en relación a TFP, (H(3)=4,85, p>0,05) y NIBUT (H(3)=2,18, p>0,05). Sin embargo, existe una diferencia considerable entre los grupos de edad de 20-29, 30-39, 40-49 y 50-60 años tanto en relación a TFP (H(3)=28,25, p<0,01) como a NIBUT (H(3)=36,50, p <0,001). La correlación de Spearman reflejó una relación significativa entre TFP y NIBUT (r=-0,55, p<0,001), la edad y NIBUT (r=-0,50, p< 0,001), la edad y TFP (r=0,41, p<0,001), la puntuación de McMonnies y NIBUT (r=-0,40, p<0,001), la puntuación de McMonnies y TFP (r=0,31, p<0,001), y la edad y la puntuación de McMonnies (r=0,52, p<0,001). Conclusión: TFP y NIBUT dependen de la edad, pero no del sexo ni la raza. Los sujetos de mayor edad reflejaron un grado superior de TFP y de puntuación del cuestionario de McMonnies, pero un valor inferior de NIBUT. TFP y NIBUT pueden utilizarse para evaluar la calidad de la película lagrimal (AU)

In vivo slit scanning confocal microscopic observation in a patient with moderate and severe keratoconus: a case report.

A 22-year-old Indian female was referred to Sg Buloh hospital with the diagnosis of bilateral keratoconus. On examination, slit lamp biomicroscopy and corneal topography revealed stage 3 keratoconus in the right eye and stage 2 keratoconus in the left eye. Corneal cell morphology in both eyes was evaluated using confocal microscope. In qualitative observation, almost all corneal layers in right eye except endothelium were partially or completely obscured by haze. Additionally, morphological alterations, such as elongation of keratocyte nuclei and cluster of cells, and dark bands in the anterior stroma were observed in right eye. In the left eye, the amount of haze was less, allowing better visibility of the corneal layers compared with the right eye. The dark bands were evident in the posterior stroma. Quantitative analysis showed that anterior and posterior stromal keratocyte density and endothelium cell density were relatively low in the right eye (834.0, 700.5, and 2,133 cells/mm2, respectively) compared with the left eye (934.1, 750.6, and 2,361 cells/mm2, respectively). In this case, the right eye, exhibiting stage 3 keratoconus, showed more morphological alteration, particularly in the anterior stroma compared with the left eye with stage 2 keratoconus. Increased severity of the disease can explain these differences in corneal cell morphology.

Peripheral refraction with different designs of progressive soft contact lenses in myopes.

Aim: The purpose of this study was to compare the changes in relative peripheral refractive error produced by two different designs of progressive soft contact lenses in myopic schoolchildren. Methods: Twenty-seven myopic schoolchildren age between 13 to 15 years were included in this study. The measurements of central and peripheral refraction were made using a Grand-Seiko WR-5100K open-field autorefractometer without correction (baseline), and two different designs of progressive contact lenses (PCLs) (Multistage from SEED & Proclear from Cooper Vision) with an addition power of +1.50 D. Refractive power was measured at center and at eccentricities between 35º temporal to 35º nasal visual field (in 5º steps). Results: Both PCLs showed a reduction in hyperopic defocus at periphery. However, this reduction was only significant for the Multistage PCL (p= 0.015), (Proclear PCL p= 0.830).  Conclusion: Multistage PCLs showed greater reduction in peripheral retinal hyperopic defocus among myopic schoolchildren in comparison to Proclear PCLs.

The Relationship Between Tear Ferning Patterns and Non-invasive Tear Break-up Time in Normal Asian Population.

PURPOSE: To investigate the relationship between tear ferning patterns (TFP) and non-invasive tear break-up time (NIBUT) in normal Asian subjects. METHODS: One hundred and forty-five adults with no ocular surface disorders were recruited. TFP and NIBUT were determined. Tears were collected using a capillary tube and allowed to air dry at room temperature for 10min. TFP was later observed using a light microscope and classified according to Rolando's classification. Measurement for NIBUT was obtained using a Tearscope with the slit lamp magnification. RESULTS: It was found that there is no significant difference between gender in TFP (Z=-1.77, P>.05) and NIBUT (Z=-1.475, P>.05). There is also no significant difference between Malay, Chinese, Indian, and other races in TFP, (H(3)=4.85, P>.05) and NIBUT (H(3)=2.18, P>.05). However, there is a significant difference between age groups of 20-29, 30-39, 40-49,and 50-60 years old in both TFP (H(3)=28.25, P<.01) and NIBUT (H(3)=36.50, P<.001). Spearman's correlation showed there was a significant relationship between TFP and NIBUT (r=-0.55, P<.001), age and NIBUT (r=-0.50, P<.001), age and TFP (r=0.41, P<.001), McMonnies score and NIBUT (r=-0.40, P<.001), McMonnies score and TFP (r=0.31, P<.001), as well as age and McMonnies score (r=0.52, P<.001). CONCLUSION: TFP and NIBUT was age dependent but not gender and race dependent. Older subjects had higher grade of TFP and McMonnies questionnaire score but lower NIBUT value. TFP and NIBUT can be used to assess the tear film quality.

Macular retinal sensitivity using MP-1 in healthy Malaysian subjects of different ages / Sensibilidad macular retiniana utilizando el microperímetro MP-1 en sujetos sanos Malayos de diferentes edades

Purpose: To determine the influence of age and gender on macular sensitivity to light in healthy subjects of 4 age groups using the MP-1 microperimeter. Methods: A prospective study was carried out on 50 healthy subjects (age range: 18-60 years) divided into 4 age groups; 18-30 years, 31-40 years, 41-50 years and 51-60 years. Full-threshold microperimetry of the central 10° of retina was performed utilizing 32 points with the MP-1. Macula area was divided into four quadrants, which were superior nasal (SN), inferior nasal (IN), inferior temporal (IT) and superior temporal (ST). Results: Total mean sensitivity at 10° for age groups 18-30 years, 31-40 years, 41-50 years and 51–60 years were 19.46±0.30, 19.40±0.39, 19.47±0.35 and 18.73±0.75 (dB), respectively. There was a significant difference in total mean retinal sensitivity at 10° and at the four quadrants with age but not for gender. The retinal sensitivity was highest in the IT quadrant and lowest in the SN quadrant for all age groups. The linear regression analysis revealed that there was a 0.019dB, 0.016dB, 0.022dB, 0.029dB and 0.029dB per year age-related decline in mean macular sensitivity within the central 10° diameter in the SN, IN, IT and ST quadrants respectively. Conclusion: Among normal healthy subjects, there was a linear decline in retinal light sensitivity with increasing age with the highest reduction in the superior nasal quadrant and lowest in the inferior temporal quadrant (AU)

Objetivo: Determinar la influencia de la edad y el sexo en la sensibilidad macular a la luz en sujetos sanos de cuatro grupos de edad, utilizando el microperímetro MP-1. Métodos: Se llevó a cabo un estudio prospectivo en 50 sujetos sanos (rango de edad: 18-60 años), divididos en cuatro grupos de edad; 18-30 años, 31-40 años, 41-50 años y 51-60 años. Se realizó una microperimetría de umbral completo de los 10° centrales de la retina, utilizando 32 puntos con el sistema MP-1. El área macular se dividió en cuatro cuadrantes: superior nasal (SN), inferior nasal (IN), inferior temporal (IT) y superior temporal (ST). Resultados: La sensibilidad media total a los 10° para los grupos de edad de 18-30 años, 31-40 años, 41-50 años y 51-60 años fue de 19,46±0,30, 19,40±0,39, 19,47±0,35 y 18,73±0,75 (dB) respectivamente. Se produjo una diferencia significativa de la sensibilidad retiniana media total a los 10°, y en los cuatro cuadrantes, asociada a la edad pero no al sexo. La sensibilidad retiniana fue superior en el cuadrante IT y menor en el SN en todos los grupos de edad. El análisis de la regresión lineal reveló una disminución anual asociada a la edad de la sensibilidad macular media de 0,019dB, 0,016dB, 0,022dB, 0,029dB y 0,029dB dentro del diámetro central de 10° en los cuadrantes SN, IN, IT y ST respectivamente. Conclusión: Entre los sujetos sanos normales, se produjo una disminución lineal de la sensibilidad retiniana a la luz al incrementar la edad, produciéndose la mayor reducción en el cuadrante superior nasal y la menor en el cuadrante inferior temporal (AU)

Macular retinal sensitivity using MP-1 in healthy Malaysian subjects of different ages.

PURPOSE: To determine the influence of age and gender on macular sensitivity to light in healthy subjects of 4 age groups using the MP-1 microperimeter. METHODS: A prospective study was carried out on 50 healthy subjects (age range: 18-60 years) divided into 4 age groups; 18-30 years, 31-40 years, 41-50 years and 51-60 years. Full-threshold microperimetry of the central 10° of retina was performed utilizing 32 points with the MP-1. Macula area was divided into four quadrants, which were superior nasal (SN), inferior nasal (IN), inferior temporal (IT) and superior temporal (ST). RESULTS: Total mean sensitivity at 10° for age groups 18-30 years, 31-40 years, 41-50 years and 51-60 years were 19.46 ± 0.30, 19.40 ± 0.39, 19.47 ± 0.35 and 18.73 ± 0.75 (dB), respectively. There was a significant difference in total mean retinal sensitivity at 10° and at the four quadrants with age but not for gender. The retinal sensitivity was highest in the IT quadrant and lowest in the SN quadrant for all age groups. The linear regression analysis revealed that there was a 0.019 dB, 0.016 dB, 0.022 dB, 0.029 dB and 0.029 dB per year age-related decline in mean macular sensitivity within the central 10° diameter in the SN, IN, IT and ST quadrants respectively. CONCLUSION: Among normal healthy subjects, there was a linear decline in retinal light sensitivity with increasing age with the highest reduction in the superior nasal quadrant and lowest in the inferior temporal quadrant.

A pilot study: the efficacy of virgin coconut oil as ocular rewetting agent on rabbit eyes.

Purpose. An open-label pilot study of virgin coconut oil (VCO) was conducted to determine the safety of the agent as ocular rewetting eye drops on rabbits. Methods. Efficacy of the VCO was assessed by measuring NIBUT, anterior eye assessment, corneal staining, pH, and Schirmer value before instillation and at 30 min, 60 min, and two weeks after instillation. Friedman test was used to analyse any changes in all the measurable variables over the period of time. Results. Only conjunctival redness with instillation of saline agent showed significant difference over the period of time (P < 0.05). However, further statistical analysis had shown no significant difference at 30 min, 60 min, and two weeks compared to initial measurement (P > 0.05). There were no changes in the NIBUT, limbal redness, palpebral conjunctiva redness, corneal staining, pH, and Schirmer value over the period of time for each agent (P > 0.05). Conclusion. VCO acts as safe rewetting eye drops as it has shown no significant difference in the measurable parameter compared to commercial brand eye drops and saline. These study data suggest that VCO is safe to be used as ocular rewetting agent on human being.