Open Access Minireview Article

Detection of Visual Field Loss Progression in Glaucoma: An Overview and Food for Thought

Carlo Aleci

Ophthalmology Research: An International Journal, Page 16-24
DOI: 10.9734/or/2020/v13i130158

The damage to the visual field is the main outcome of glaucoma. Basically, there are two different approaches to establish the rate of the functional loss in this clinical condition: event-based analysis and trend-based analysis. The event-based analysis, that relies on the occurrence of pre-established events to detect the progression of the visual field damage, cannot quantify the decay rate of sensitivity. In turn, the trend-based analysis, that aims to measure the rate of progression according to linear regression models, requires a long follow-up. Despite considerable effort, there is still no consensus on the optimal procedure, and a gold standard is still missing. This paper provides a quick overview of the topic as a tribute to the researchers engaged in this field.

Open Access Original Research Article

Effect of Yellow Filters and Corrective Lenses on Academic Performance of Primary School Children with Abnormal Contrast Sensitivity

C. J. Samuel- Nwokeji, N. C. Ikoro, E. C. Esenwah, A. U. Megwas, Y. C. Azuamah, N. C. Ibe, U. C. Ogbonna

Ophthalmology Research: An International Journal, Page 1-11
DOI: 10.9734/or/2020/v13i130156

Aim: This study compared the effect of yellow filters and corrective lenses on the academic performance of primary school children with abnormal contrast sensitivity.

Study Design: The study employed quantitative study design involving the measurement of variables.

Place and Duration of Study: This study was carried out in Owerri North, Imo State, Nigeria, from February, 2019 to November, 2019.

Methodology: The study included 34 children between 7-12 years old in private and public schools with abnormal contrast sensitivity comprising 7-9 year-olds (64.7%); 10-12 year-olds (35.3%); Males (52.9%) and Females (47.1%). Using basic optometric procedures and Pelli-Robson contrast sensitivity chart, children with abnormal contrast sensitivity were identified for the study. Academic performance was assessed by comparing the previous midterm summative test result (pre-test) with the current midterm summative test result (post-test).

Results: Paired sample t-Test showed no significant difference in academic performance of children using corrective lenses (p = .47), and those using corrective lenses with yellow filters (p = .94) respectively at 95% confidence interval. Also, children using corrective lenses compared with those using corrective lenses with yellow filters showed no significant difference (p =.57) in academic performance. Further, no significant age and gender variation in academic performance was identified (7-9 yrs: p =.38; 10-12 yrs: p =.79; Males: p=.38; Females: p =.79).

Conclusion: Corrective lenses and Corrective lenses with yellow filters had no effect on academic performance of primary school children 7-12 years of age with abnormal contrast sensitivity. 

Open Access Original Research Article

The Effect of Anti-Tubercular Drugs on Retinal Nerve Fiber Layer Thickness Using Optical Coherence Tomography

Punit Kumar Singh, . Prasnnta

Ophthalmology Research: An International Journal, Page 12-15
DOI: 10.9734/or/2020/v13i130157

Purpose: To study the effect of anti-tubercular drugs on retinal nerve fiber layer (RNFL) thickness using optical coherence tomography.

Methods: The study was done in thirty patients newly diagnosed with pulmonary tuberculosis which were given anti-tubercular treatment (isoniazid, rifampicin, ethambutol and pyrazinamide ) at DOTS centre of K. N. TB and Chest hospital (Dr. S.N M C.) Jodhpur. Visual function tests (visual acuity, contrast sensitivity, color vision) and OCT assessment of RNFL done before initiation of treatment and after two month of treatment.

Results: After two months, RNFL thinning was present in 3 eyes out of total 60 eyes in temporal and superior quadrant.

Conclusion: The study revealed that the first line antitubercular drug Ethambutol causes RNFL thinning within two months of initiation of drug in the recomonded dose. In the initial stage of optic nerve toxicity, there are no clinically significant changes seen on posterior segment ophthalmoscopic examination and fundus photography.OCT can find out the retinal nerve fiber layer thinning even if there are minute changes.

Open Access Original Research Article

Genetic Diagnosis of Glaucoma

Hany Mahmoud, Marwa S. Hashim

Ophthalmology Research: An International Journal, Page 25-29
DOI: 10.9734/or/2020/v13i130159

Purpose: Glaucoma, the most prevalent cause of irreversible blindness across the world, is progressive optic nerve degeneration and affection (neuropathy) caused by a mixture of both genetic and environmental factors [1]. The extracellular matrix (ECM) structure of the trabecular Meshwork TM has a major role in intraocular pressure IOP control.  Transforming growth factor beta (TGF-β) is a growth factor that plays major roles in cellular functions, including encouraging extracellular matrix synthesis and vascular angiogenesis. TGFβ2 treatment of TM cells alters ECM components [8] and induces ECM bonds.

Aim of the Study: To study the relationship between family history and glaucoma according to genotype and genetic polymorphism.

Methods: Blood collection and DNA extraction Genotyping: TGFB2 Rs99196 genotyping was done using TaqMan SNP genotyping Assay (ID C___8853564_10). StepOne real time PCR system (Applied Biosystem, Ca, USA) was used for amplifiction.

Statistical Analysis: The sample size of the study group was calculated using a program at (www.openepi.com/SampleSize/ SSCC.htm).

Results: Important genotype differences frequencies were detected between the positive family history and negative family history groups for the codominant, dominant, recessive and overdominant inheritance models.

Conclusion: This study recommends that other polymorphisms of genes associated with glaucoma and the analysis of these gene products and their relationship with disease risk factors should be more studied.

Open Access Original Research Article

Comparison for Kmean and Astigmatism for Orbscan IIz and Pentacam at Different Stages of Keratoconus - A Clinical Study

E. Pateras, Ch. Koufala

Ophthalmology Research: An International Journal, Page 30-40
DOI: 10.9734/or/2020/v13i130160

Aims: To compare results of Orbscan IIz and Pentacam at different stages of keratoconus on Kmean and Astigmatism.

Sample and Study Design: 94 keratoconus patients were included in the study, of which 52 were men and 42 women. Keratoconus patients were screened with Orbscan IIz and Pentacam before undergoing corneal collagen cross-linking. The patients were distributed according to different keratoconus stages.

Place and Duration of Study: University of West Attica Dept Biomedical Sciensce Course Optics & Optometry in collaboration with Athens “Ophthalmiatrio” Clinic during the period between October 2017 to January 2019.

Methodology: Topographic maps correlation of two types of corneal topographers Orbscan IIz and Pentacam. The Kmean values and the Astigmatism presented at different stages of keratoconus were compared.

Results: A Sample of 188 eyes were measured having, 20 eyes (10.6%) with subclinical keratoconus, the correlation coefficient r for Kmean values between Orbscan IIz and Pentacam was 0.9758 (P<0.0001), 44 eyes (23.3%) at stage 1 with the correlation coefficient r=0.8482 (P<0.0001),  33 eyes (17.6%) at stage 2 with the correlation coefficient r=0.8147 (P<0.0001), 67 eyes (35.6%) at stage 3 with the correlation coefficient r=0.797 (P<0.0001), 10 eyes (5.3%) at stage 4 with the correlation coefficient r=0.8455 (P=0.0021), 8 eyes (4.4%) with iatrogenic keratoectasia after refractive surgery having correlation coefficient r=0.928 (P=0.0009).

Conclusion: Statistical differences between Orbscan IIz and Pentacam were found for Kmean in all stages of keratoconus. The performance for Kmean measurement of the corneal topographers Orbscan IIz and Pentacam is satisfactory for both systems in various stages of keratoconus having a very strong correlation (Correlation coefficient r ranged from 0.9758 to 0.7970). Statistical differences between Orbscan IIz and Pentacam were evident also at the Astigmatism measurements at stage 3 and 4.