The effect of rebreathing and hyperventilation on retinal and choroidal vessels measured by spectral domain optical coherence tomography

Objective: The purpose of this study was to examine the vasoreactivity in retina and choroid of the healthy eyes in response to experimentally altered partial arterial pressure of carbon dioxide (PaCO₂) using a non-invasive technique, spectral domain optical coherence tomography (SD-OCT).

Materials and methods: The study included non-smoking participants between 18 and 35 years of age, having visual acuity of 20/20 and with no systemic and ocular diseases. At baseline, the participants breathed room air (normocapnia). Hypocapnia was created with the help of hyperventilation; for this, the participants were instructed to draw deep and quick breaths, resulting one breathing cycle per 2?s. To create hypercapnia subjects rebreathed from a 5?l bag at least 3?min. Choroidal thickness and retinal artery diameter were measured at baseline, and hyperventilation and rebreathing conditions by SD-OCT.

Results: Twenty eyes of 20 healthy subjects were included in this study. Their mean age was 24.90?±?5.32 years. Hyperventilation caused a significant reduction in choroidal thickness, compared with baseline, at all points; whereas rebreathing caused no significant change at all points. The mean diameters of the arteries were 151.80?±?7.88?μm, with a significant decline to 148.90?±?7.25?μm at hyperventilation condition and a significant increase to 153.50?±?7.88?μm at rebreathing condition (p?=?0.018, p?=?0.043, respectively).

Conclusion: This study demonstrated that, SD-OCT was a useful tool in measuring the ocular vascular response under hypercapnia and hypocapnia conditions. These findings may be helpful for further understanding the physiological nature of ocular blood flow and this preliminary study provides a basis for future studies.     

Solitary angiokeratoma of the tongue treated with diode laser

Angiokeratoma is a muco-cutaneous disorder that is usually associated with a number of metabolic disorders. Involvement of the tongue with solitary angiokeratoma, without a systemic or metabolic disease, is very rare. To the best of our knowledge, we report the second case of solitary angiokeratoma of the tongue arising in a 16-year-old woman who was treated with diode laser (810 nm) in our department. This case was partially presented as poster presentation at the 12th Congress of the BaSS, 12–14 April 2007, Istanbul, under the auspices of the Balkan Stomatological Society. An erratum to this article can be found at     

Implant‐Supported Oral Rehabilitation of a Patient with Pemphigus Vulgaris: A Clinical Report

Pemphigus vulgaris (PV) is a rare mucocutaneous vesiculobullous disease characterized by the development of autoantibodies against the desmosomal proteins. Current treatment is largely based on systemic immunosuppression using systemic corticosteroids. Immunosuppressive drugs used in the treatment of the disease may increase the risk of infection and delayed healing, which are of concern in dental treatment procedures in this group of patients. The clinical outcomes of implants in PV have not been investigated. We present a case of PV rehabilitated with an implant‐supported prosthesis with a 32‐month follow‐up and discuss the important points in the surgical and prosthodontic phases.     

Peripapillary choroidal thickness in patients with chronic obstructive pulmonary disease

Objective: To evaluate the peripapillary choroidal thickness of patients with chronic obstructive pulmonary disease (COPD) via enhanced depth imaging optical coherence tomography (EDI-OCT).

Materials and methods: A total of 80 patients with COPD (80 eyes) and 50 control subjects (50 eyes) were enrolled. Choroidal scans and the retinal nerve fiber layer (RNFL) thickness were obtained for all eyes using OCT.

Results: The average peripapillary choroidal thickness measurements of the COPD group (147.58?±?53.53?μm) were lower than the control group (160.84?±?44.73?μm) (p?=?0.068). Inferior segment thicknesses were significantly thinner than the other segments (p?<?0.05). Subfoveal choroidal thickness and RNFL thickness measurements of the COPD group were also lower than those of the control group (p?=?0.111).

Conclusion: Hypoxia in COPD seems to affect the choroidal thickness. Thinning of the choroid may be attributed to increased vascular resistance and reduced blood flow in patients with COPD. The possible effects of the disease to the eye may be clarified through the role of the choroidal vasculature in the blood supply of the anterior optic nerve head.