Our results show that in stages of retinitis pigmentosa, before atrophic lesions spread inside the vascular arcades, the pattern of fundus autofluorescence correlates well with functional tests such as perimetry and electroretinography. The ring of increased AF appears to represent the border between functional and dysfunctional retina. This shows that autofluorescence, as a quick and non-invasive imaging tool, may be related to retinal function as well.
Purpose To evaluate retinal sensitivity and fixation patterns in patients with Best's dystrophy by microperimetry (MP) and to correlate the results with static perimetry and retinal morphology seen by autofluorescence (AF). Methods Central 101 visual fields in 11 patients with Best's dystrophy (VA: 0.570.38) were recorded by the Octopus M2 TOP program and by MP (MP1, Nidek Technologies). AF was recorded by HRA (Heidelberg Engineering). Results High correlation (R ¼ 0.75, À0.76, À0.48) was found between static perimetry (MS, MD and CLV indices) and MP. Based on MP and AF results, three groups of patients were formed. Patients in the first two groups fixated inside the central nonuniform hypoand hyperfluorescent AF ring area, next to relative (Group 1) or absolute scotoma (Group 2). Inner parts of the retina close to the fovea were most affected, whereas regions closer to the periphery of the 101 visual field showed near normal function. As the disease progressed, there was an evident shift of fixation to preferential retinal locus (PRL) in eight eyes with visual acuity 0.2 or less (Group 3). Fixation shift was superior in four eyes, temporal in two eyes, and nasal in two eyes. Conclusion MP enabled a highly sensitive topographic monitoring of retinal function, showing central or pericentral fixation in the early stages, until loss of central function, in eyes with VA 0.2 or less, caused evident shift of fixation to PRL. PRL was never situated inside the central uniform hypofluorescent area, but corresponded with the hyperfluorescent ring seen with AF imaging.
The COVID-19 pandemic has severely disrupted the global economy, particularly the tourism sector, thus making the interplay of pandemics and tourism a prominent topic of research. This paper aims to provide an overview of scientific research on the impact of the COVID-19 pandemic on tourism and determine future research directions. The main research questions are: 1) Which research topics related to the impact of the pandemic on tourism have been addressed? 2) What are the bibliometric characteristics of published papers on these topics? 3) What are the directions for future research within this field? A qualitative method was applied to obtain answers by analyzing the scientific papers published between March 2020 and March 2021. By applying the PRISMA protocol, a total of 33 relevant articles were identified, which were subjected to bibliometric analysis using VOSviewer, and finally, content analysis was conducted. Thereby, the following key research areas were distinguished: the impacts and consequences of COVID-19 on tourism, the transformation of tourism and post-pandemic recovery strategies, the changes in behavior from the travelers' perspective, and the issues from the perspective of tourism enterprises. Based on the analysis, new research directions are proposed.
Purpose: Fundus autofluorescence (AF) imaging is a method that shows accumulation of lipofuscin in the retinal pigment epithelium cells in vivo. Fundus AF may be recorded in retinal diseases either by scanning laser ophthalmoscope or by fundus camera using the appropriate filter. The aim of this study was to analyze the AF pattern by both methods. Methods: 20 patients with different retinal diseases including retinitis pigmentosa, cone‐rod dystrophy, Stargardt disease, Best macular dystrophy, central serous retinopathy and age‐related macular degeneration were included in the study. AF images were obtained from each subject using a confocal scanning laser ophthalmosope and digital fundus camera. The distribution and amount of AF were compared by the use of both systems. Results: In all disease entities both instruments showed distinct pattern of AF typical for the disease. Areas of high intensity of AF recorded with HRA matched to areas of increased intensity of AF detected with fundus camera. The distribution of areas of low or absent AF also corresponded well in both systems. Images taken with conventional fundus camera were in general lower contrasted and therefore less sharp. This was particularly true for patients with even mild media opacity. The advantage of fundus camera was however a recording of AF of a greater field of view. Conclusions: AF imaging is a very useful noninvasive method for detecting RPE abnormalities. In clinical practice, when scanning laser ophthalmoscope for recording of AF is not available, conventional digital fundus camera can be used for screening of patients suspected to have retinal disease. Care should be taken in patients with nuclear cataract, as the AF image is influenced by the AF of the crystalline lens by a great amount.
The aim of the study was to asses the neurosensory retinal function in 12 patients (24 eyes) with different stages of Best's disease, by determining how pattern and full field flash ERG responses were related to visual acuity, stage of disease and extent of visual field loss. All patients had typically abnormal EOG responses and normal full field-flash ERG responses. Patients were stratified in two groups according to visual acuity. In the first group 12 eyes with visual acuity better than 0.5, all amplitudes and latencies of PERG P50 and N95 responses were in the normal range. Small central scotoma was detected by static perimetry in four of these eyes. In the second group of 12 eyes with visual acuity 0.5 or less, PERG showed reduced both P50 and N95 amplitudes in five eyes, and N95 solely, in two eyes. All patients had central scotomas detected by static perimetry. Progression of the disease, seen in deterioration of visual acuity and progression of central visual field defects, corresponded well with reduction of both PERG P50 and N95 amplitudes. There was no correlation found between visual acuity and EOG responses. Our results show that in Best's distrophy, pattern ERG is getting abnormal with progression of the disease, indicating relative preservation of neurosensory retina in initial stages of the disease. In contrast to EOG - being abnormal in all the patients regardless of the stage of disease - and full field-flash ERG - being normal in most of the patients - PERG gives opportunity for electrophysiological determination of the progression of the disease.
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