Ophthalmic imaging for the diagnosis and monitoring of glaucoma: A review.

The last three decades have been a turning point for early glaucoma diagnosis and monitoring by newly developed imaging techniques. Improvements in imaging of the anterior segment (AS), retinal nerve fibre layer (RNFL), optic nerve head (ONH), and macular ganglion cell complex (GCC) came into existence and broke new ground for early diagnosis and progression survey. This review will summarise the different ophthalmic imaging techniques, their principles, pros and cons, ongoing development processes, and the future of imaging methods. The aim is to provide the clinician with an understanding of the role of imaging methods and provide insight for appropriate use and evaluation of their outputs in glaucoma diagnosis and treatment.

Detecting Common Eye Diseases Using the First Teleophthalmology GlobeChek Kiosk in the United States: A Pilot Study.

PURPOSE: The aim of this study was to assess the benefit and feasibility of the teleophthalmology GlobeChek kiosk in a community-based program. DESIGN: Single-site, nonrandomized, cross-sectional, teleophthalmologic study. METHODS: Participants underwent comprehensive evaluation that consists of a questionnaire form, brief systemic evaluation, screening visual field (VF), and GlobeChek kiosk screening, which included but not limited to intraocular pressure, pachymetry, anterior segment optical coherence tomography, posterior segment optical coherence tomography, and nonmydriatic fundus photography. The results were evaluated by a store-and-forward mechanism and follow-up questionnaires were obtained through phone calls. RESULTS: A total of 326 participatents were screened over 4 months. One hundred thirty-three (40.79%) participants had 1 condition in either eye, and 47 (14.41%) had >1 disease. Seventy (21.47%) had glaucoma, 37 (11.34%) narrow-angles, 6 (1.84%) diabetic retinopathy, 4 (1.22%) macular degeneration, and 43 (13.10%) had other eye disease findings. Age >65, history of high blood pressure, diabetes mellitus, not having a dental examination >5 years, hemoglobn A1c measurement of ≥5.6, predibates risk score of ≥9, stage 2 hypertension, and low blood pressure were found to be significant risk factors. As for the ocular parameters, all but central corneal thickness, including an intraocular pressure >21 mm Hg, vertical cup to disc ratio >0.7, visual field abnormalities, and retinal nerve fiber layer thinning were found to be significant. CONCLUSIONS: GlobeChek kiosk is both workable and effective in increasing access to care and identifying the most common causes of blindness and their risk factors.

Effects of the rigid gas permeable contact lense use on tear and ocular surface among keratoconus patients.

PURPOSE: To investigate changes in tear and ocular surface of patients with keratoconus using rigid gas permeable contact lenses (RGPCL) and compare them against keratoconus patients who were not using lenses as well as a control group of healthy subjects. METHODS: 24 keratoconus patients using RGPCL (Group 1) 22 patients who were not using lenses (Group 3) and 21 healthy subjects (Group 3) were included in the study. Subjective complaints about the subjects' eyes have been investigated using the ocular-surface disease index (OSDI). After the control of best-corrected visual acuity, anterior chamber and fundus examinations were performed. RESULTS: Schirmer (p-value=0.01) and tear break up mean comparison tests (p-value=0.002) revealed significant differences across different groups but tear osmolarity analysis did not (p-value >0.05). Oxford and OSDI scores were compatible with Schirmer and tear break up test comparisons. (for both p-value=0.001) Moreover, no statistical differences were seen in impression cytology measures between groups. (p-value >0.05) CONCLUSIONS: The erosion in the tear film stability is in line with the erosion in the ocular surface epithelium. Taking into account the statistical indifference between the impression cytology measures across groups, the break up time differences may be attributed to the collagen destruction in tear.

Intraocular pressure elevation after intravitreal triamcinolone acetonide injection: a Meta-analysis.

AIM: To report on intraocular pressure (IOP) after intravitreal injections of triamcinolone acetonide. METHODS: Systematic literature review of studies that investigated the effects of an injection of triamcinolone intravitreal triamcinolone acetonide on IOP was conducted according to the Cochrane Collaboration methodology and the reported effects have been analyzed with Meta-analysis. RESULTS: We found that the IOP follows an inverted-U shape pattern over time starting with an average value of 14.81±1.22 mm Hg before the injection, rising to a maximum of 19.48±2.15 mm Hg after one month of injection and falling down to 16.16±1.92 mm Hg after 6mo. Moreover, country of study, age, previous history of glaucoma and gender compositions matter for cross-study were different in reported IOP changes. CONCLUSION: Our findings may be helpful in determining pressure elevation risk of intravitreal triamcinolone acetonide therapy as well as comparing it with those of more recent therapies such as the anti-vascular endothelial growth factor agents.

Effect of Fasting on Corneal Biomechanical and Structural Parameters.

PURPOSE: To evaluate the effects of hunger and thirst on corneal biomechanical and structural parameters during Ramadan fasting. MATERIALS AND METHODS: Corneal biomechanical properties and intraocular pressures of 29 eyes of 29 healthy subjects were evaluated by Reichert ocular response analyzer; and structural and anatomical properties of cornea and anterior eye chamber of same eyes were scanned with Oculus Pentacam anterior segment analyzer. Each eye has been evaluated at 8 am and 4 pm both during and 1 month after Ramadan. Changes of subjects' weight were calculated and their relationship with corneal biomechanical and structural parameters was assessed. RESULTS: Intraday changes in horizontal corneal astigmatism (p = 0.02), anterior chamber volume (p = 0.01), intraocular pressure associated with the Goldmann IOPg (p = 0.02) and corneal resistance factor (CRF) (p = 0.04) were significantly different when measured during the fasting period in Ramadan and 1 month thereafter. Moreover, when we compared 8 am measurements taken during and after Ramadan, we observed significant differences for anterior chamber volume (p = 0.04) and anterior chamber angle values (p = 0.03). Similarly, for 4 pm measurements, there were significant differences for IOPg (p = 0.01) and CRF values (p = 0.00). CONCLUSIONS: Fasting lasting for more than 12 h during Ramadan creates an important window of opportunity to investigate the response of anterior chamber of eye to hunger and thirst. The current study contributes to the existing literature on the effects of dietary habits and water intake on corneal and anterior chamber properties.

Comparative Analysis of Tear Film Levels of Inflammatory Mediators in Contact Lens Users.

PURPOSE: To compare tear films levels of various inflammatory cytokines in asymptomatic contact lens (CL) users. CL users of rigid gas-permeable CLs (RGPCL) (group 1) or silicone hydrogel CLs (SiHCL) (group 2) were compared with non-CL-using healthy subjects (group 3). MATERIALS AND METHODS: Tear samples were collected from subjects in each group after ensuring that there were no complications secondary to CL wear in the CL-wearing participants. Tear-film levels of interleukins (ILs)-1ß, -6, and -8; granulocyte-macrophage colony-stimulating factor (GM-CSF) (using the Luminex method); and leukotriene B4 (LTB4) (using the ELISA method) were determined. Cytokine levels were compared among the three groups using analysis-of-variance (ANOVA) and Kruskall-Wallis tests. RESULTS: There were significant differences in concentrations of IL-1ß, GM-CSF and LTB4 among the three groups (p = 0.002, p = 0.021 and p = 0.009, respectively), as shown by the Kruskall-Wallis test comparing all three groups for the three cytokines. There were no significant differences for IL-6 and IL-8 (p = 0.079 and 0.094, respectively) when all three groups were compared. CONCLUSIONS: There were substantial statistically significant differences between RGPCL users, SiHCL users and control subjects in levels of tear film cytokines. Although CL users were asymptomatic, changes in tear-film levels of several important inflammatory mediators revealed that a chronic inflammatory process occurs during CL wear.

Retinal nerve fiber layer structure abnormalities in patients with Neuro-Behcet's disease.

PURPOSE: Our aim was the evaluation of retinal nerve fiber layer (RNFL) and central macular thickness (CMT) in patients with Neuro-Behcet's disease (NBD) and to compare the results with healthy control subjects. METHODS: We recruited 50 eyes of 25 patients with NBD and 42 eyes of 21 age-matched healthy control subjects. Patients and control subjects underwent a thorough ophthalmic examination, including retinal nerve fiber layer and macular thickness measurements by optical coherence tomography. RESULTS: No significant difference was found between groups for age, sex, intra-ocular pressure and central corneal thickness measurements. The average RNFL in patients with NBD was significantly lower than that of healthy controls (86.92 ± 18.36 µm vs. 99.74 ± 8.73 µm; p = 0.00). There was significant thinning of the RNFL in three of four quadrants of the peripapillary area, superior (107.22 ± 30.91 µm vs. 125.57 ± 20.97 µm; p = 0.00), inferior (110.36 ± 25.57 µm vs. 132.19 ± 12.71 µm; p = 0.00) and nasal (68.84 ± 18.47 µm vs. 74.98 ± 11.42 µm; p = 0.05), in patients with NBD. Average CMT was significantly lower in NBD patients than in control subjects (244.06 ± 26.25 µm vs. 261.69 ± 25.71 µm; p = 0.00). CONCLUSIONS: There are significant differences in average RNFL and CMT between the two groups. RNFL and CMT thicknesses are reduced in patients with NBD compared with the healthy controls.