Choroidal Imaging Using Spectral-Domain Optical Coherence Tomography
Background: A structurally and functionally normal choroidal vasculature is essential for retinal function. Therefore, a precise clinical understanding of choroidal morphology should be important for understanding many retinal and choroidal diseases. Methods: PUBMED (http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed ) was used for most of the literature search for this article. The criterion for inclusion of an article in the references for this review was that it included materials about both the clinical and the basic properties of choroidal imaging using spectral-domain optical coherence tomography. Results: Recent reports show successful examination and accurate measurement of choroidal thickness in normal and pathologic states using spectral-domain optical coherence tomography systems. This review focuses on the principles of the new technology that make choroidal imaging using optical coherence tomography possible and on the changes that subsequently have been documented to occur in the choroid in various diseases. Additionally, it outlines future directions in choroidal imaging. Conclusion: Optical coherence tomography is now proven to be an effective noninvasive tool to evaluate the choroid and to detect choroidal changes in pathologic states. Additionally, choroidal evaluation using optical coherence tomography can be used as a parameter for diagnosis and follow-up.
Techniques, Rationale, and Outcomes of Internal Limiting Membrane Peeling
Background: The internal limiting membrane represents the structural interface between the retina and the vitreous and has been postulated to serve several essential functions. Recently, internal limiting membrane peeling has been used in the treatment of a variety of retinal disorders. We review the history, techniques, rationale, and outcomes of internal limiting membrane peeling. Methods: A review of the literature. Results: Internal limiting membrane peeling has been used to successfully treat a variety of retinal disorders including macular hole, epiretinal membrane, diabetic macular edema, retinal vein occlusion, and others. Conclusion: Internal limiting membrane peeling may serve as an important component in the armamentarium of retinal surgery.
No abstract available
Diagnostic and Therapeutic Challenges
No abstract available
Increased Retinal Blood Flow Velocity in Patients With Early Diabetes Mellitus
Purpose: To compare retinal blood flow velocity in small vessels of patients with early diabetes mellitus (DM), without any morphologic changes related to diabetic retinopathy, with that in a control group. Methods: The authors used the retinal function imager to measure blood flow velocities, from many small vessels, simultaneously. Twenty-three eyes of 14 patients with early DM and 51 eyes of 31 healthy subjects were enrolled. Differences between the patients and the control group were assessed by mixed linear models. Results: Venous average velocity significantly increased in the DM group (3.8 ± 1.2 vs. 2.9 ± 0.5 mm/second, P < 0.0001) than in the healthy subjects. Arterial velocity of DM patients was also significantly higher (4.7 ± 1.7 vs. 4.1 ± 0.9 mm/second, P = 0.03). There was no statistically significant difference between groups in age, gender, heart rate, and systolic blood pressure. The diastolic blood pressure in the DM patients was lower than that in the healthy group (P = 0.03). Conclusion: There was an increase in arterial and venous retinal blood flow velocities of patients with early DM with no diabetic retinopathy. These findings support the notion that abnormalities in vessel function exist in diabetic eyes before the development of structural changes. This noninvasive approach facilitated the assessment of early hemodynamic abnormalities and may assist in screening and monitoring.