32 research outputs found
Quantification of Optic Disc Edema during Exposure to High Altitude Shows No Correlation to Acute Mountain Sickness
BACKGROUND: The study aimed to quantify changes of the optic nerve head (ONH) during exposure to high altitude and to assess a correlation with acute mountain sickness (AMS). This work is related to the Tuebingen High Altitude Ophthalmology (THAO) study. METHODOLOGY/PRINCIPAL FINDINGS: A confocal scanning laser ophthalmoscope (cSLO, Heidelberg Retina Tomograph, HRT3®) was used to quantify changes at the ONH in 18 healthy participants before, during and after rapid ascent to high altitude (4559 m). Slitlamp biomicroscopy was used for clinical optic disc evaluation; AMS was assessed with Lake Louise (LL) and AMS-cerebral (AMS-c) scores; oxygen saturation (SpO₂) and heart rate (HR) were monitored. These parameters were used to correlate with changes at the ONH. After the first night spent at high altitude, incidence of AMS was 55% and presence of clinical optic disc edema (ODE) 79%. Key stereometric parameters of the HRT3® used to describe ODE (mean retinal nerve fiber layer [RNFL] thickness, RNFL cross sectional area, optic disc rim volume and maximum contour elevation) changed significantly at high altitude compared to baseline (p<0.05) and were consistent with clinically described ODE. All changes were reversible in all participants after descent. There was no significant correlation between parameters of ODE and AMS, SpO₂ or HR. CONCLUSIONS/SIGNIFICANCE: Exposure to high altitude leads to reversible ODE in the majority of healthy subjects. However, these changes did not correlate with AMS or basic physiologic parameters such as SpO₂ and HR. For the first time, a quantitative approach has been used to assess these changes during acute, non-acclimatized high altitude exposure. In conclusion, ODE presents a reaction of the body to high altitude exposure unrelated to AMS
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Outcomes of vitreoretinal surgery in patients with X-linked retinoschisis
To assess the outcomes of vitreoretinal surgery in the treatment of vision-threatening posterior segment complications of X-linked retinoschisis.
The authors performed a retrospective analysis of 16 eyes from 11 patients who underwent vitreoretinal surgery. All the patients had a documented positive family history of X-linked retinoschisis, and all patients had bilateral macular disease.
The ages of the patients ranged from 14 months to 37 years (mean age 15.1 years; median age 11.5 years), and postoperative follow-up ranged from 3 months to 10 years (mean 2.8 years; median 1 year). The indications for surgical intervention included rhegmatogenous retinal detachment (12 eyes), vitreous hemorrhage (2 eyes), progression of the schisis cavity through the fovea (2 eyes), cataract associated with a persistent hyperplastic primary vitreous-like condition (2 eyes), and exudative maculopathy (1 eye). The primary surgical intervention included pars plana vitrectomy alone (7 eyes), pars plana vitrectomy and pars plana lensectomy (4 eyes), and a scleral buckle procedure alone (5 eyes). Surgical success (defined as reattachment of the retina, removal of media opacities, or arrest of schisis progression) was achieved in 14 of 16 eyes, after an average of 1.2 procedures per eye. The major reason for reoperations was recurrent retinal detachment due to proliferative vitreoretinopathy. Two eyes were eventually enucleated due to pain associated with neovascular glaucoma resulting from recurrent retinal detachment. Of the remaining 14 eyes, visual acuity improved in 8 eyes and remained unchanged in 6 eyes.
Vitreoretinal surgery is often helpful in stabilizing or improving visual function in patients with posterior segment complications from X-linked retinoschisis