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Arterial occlusions of the retina are potentially sight-threatening diseases which often result in profound visual loss. The aim of this narrative review is to provide an overview of the aetiology, discuss major risk factors, describe the management and systemic assessments and evaluate existing therapies. For this review, an extensive literature search in PubMed was performed. Emboli from the heart or the carotid arteries can cause ophthalmic artery occlusion (OAO), central retinal artery occlusion (CRAO) and branch retinal artery occlusion (BRAO). Most patients with arterial occlusions have vascular risk factors such as arterial hypertension, hyperhomocysteinaemia, carotid stenosis and atrial fibrillation, which also increase the risk of cerebral stroke and myocardial infarction. Therapies such as ocular massage, thrombolysis and anterior chamber paracentesis have been suggested but are still equivocal. However, it is evident that retinal artery occlusion should be immediately treated and accompanied by interdisciplinary collaboration, since early diagnosis and the proper treatment of possible risk factors are important to reduce the risk of further damage, recurrences, other vascular diseases and mortality.

Purpose: To evaluate microscopically whether the print quality and accuracy of sizing of Landolt ring near vision charts are adequate for the calibration of reading charts., Methods: Near vision charts with Landolt rings from Oculus GmbH (C-Test; Wetzlar, Germany), Precision Vision (Woodstock, IL) and the RADNER Charts were examined, as well as custom-made Landolt rings optimized for print quality. Microscopic investigations and measurements were performed by using a Huvitz HSZ 600 stereomicroscope (Nikon NIS Elements software) to evaluate the height of the Landolt rings, the thickness of the lines, and the width of the openings. The deviations from the mathematically correct values, which were calculated as given in the EN/ISO 8596 and by the International Council of Ophthalmology (ICO), were analyzed (calculated for a test distance of 40 cm)., Results: All the near vision charts showed notable deficiencies in print quality and aberrations from the nominal values in the height, thickness of the lines, and width of the openings. The openings were too narrow, whereas the height and thickness of the lines were larger than the nominal values. Even the openings of Landolt rings optimized for print quality were not always within an acceptable 5% tolerance and need further improvement., Conclusion: This study reports inaccuracies in the heights, thicknesses of the lines, and widths of the openings of Landolt rings in all the near vision charts investigated. The extent of these inaccuracies excludes such near vision charts as reference tests for the calibration of reading charts. The x-height in relation to the visual angle still seems to be the most reliable method for standardizing the print sizes for reading charts., (© 2022. The Author(s).)

Purpose: To compare the reading time and reading speed measurements obtained with a stopwatch with those of an automated computer program for measuring reading speed and acuity (rad-rd © ; patent: AT 504635B1/10-2006)., Methods: The rad-rd © was used (in conjunction with a PC and microphone) for the computer-based measurements. In rotation, each of four examiners took a turn reading the 12 sentences from one of the four RADNER Reading Charts to three other examiners, who served as stoppers. The stoppers simultaneously measured the reading time with a stopwatch while a fifth investigator used the rad-rd © to obtain computerized measurements. The stopwatch measurements were then statistically compared with the rad-rd © measurements., Results: The mean reading time obtained with the stopwatch measurements was 4.34 ± 0.57 seconds (196.21 ± 21.79 wpm), versus 4.44 ± 0.59 seconds (192.24 ± 22.20 wpm) by computer measurement (r = 0.84). Of the 144 stopwatch measurements, 97 (67.36%) were shorter, and 47 (32.64%) were equal to (n = 5) or longer than the computer measurements. The mean difference for the shorter measurements was -0.17 ± 0.1 seconds (3.91% of the mean reading time), and the mean difference for the longer measurements was 0.11 ± 0.1 seconds (2.53% of the mean reading time). Most differences ranged from -0.1 to 0.1 seconds (42.36%). The results did not differ significantly among the four stoppers., Conclusion: The rad-rd © is an accurate, automated computer program for measuring reading time. Stopwatch measurements, although subject to inaccuracy from several sources, remain a reliable and simple method for analysis of reading performance., (© 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Presbyopia correction is mainly concerned with the goal of regaining an uncorrected reading performance. Since historic reading charts do not provide a unique standard that is applicable for the analysis of clinical and scientific reading performance, new standardized reading charts have been developed, in order to provide reading performance analyses analogous to modern single-optotype distance acuity measurements: the Bailey-Lovie Word Reading Chart, the Colenbrander English Continuous Text Near Vision Cards, the MNREAD Charts, and the RADNER Reading Charts. The last three are also meant to measure reading speed, thus allowing detailed analysis of the reading capabilities of the patient's functional vision. Furthermore, these reading charts can be declared homologated, based on the standards that were published for reading charts by the Visual Function Committee of the International Council of Ophthalmology (ICO) in 1988. Many research studies have shown that by analyzing the reading performance with homologated reading charts, valuable insight into the reading performance of patients suffering from various diseases can be obtained. These reading charts have also been successfully used in presbyopia research. It therefore seems evident that homologated, standardized reading charts facilitate not only research concerning functional vision in many fields of ophthalmology but also international communication about near visual performance. Homologated reading charts are available in almost all languages and have become a valuable tool in analyzing reading performance. We argue in this review that homologated reading charts are clearly a necessity for presbyopia research.

Purpose: To develop 28 short texts to be used as sentence optotypes in a Danish version of the Radner Reading Chart for the measurement of reading acuity and speed., Method: Forty-six short texts of comparable lexical and grammatical difficulty were constructed. The short texts were tested together with two longer reference texts in 100 persons with visual acuity 6/6, of which 50 were university students (age: 24.7 ± 3.1 years, 36% males) and 50 were blue-collar workers (37.2 ± 13.4 years, 54% males). Study parameters were mean reading speed and error rate per participant, and mean reading time, variance and number of errors per short text., Results: The students read the short texts faster than the blue-collar workers (184 ± 21.4 words per minute (wpm) versus 163 ± 26.3 wpm, p < 0.0001). There was a high correlation between the reference texts and the short texts [Pearson's correlation coefficient = 0.89 (95% CI 0.83-0.92)]. The mean reading time for each of the short texts ranged from 4.4 s to 5.8 s with a mean of 4.96 ± 0.35 s, and the median number of errors was eight. Twenty-eight short texts were selected for sentence optotypes with mean reading times between 4.6 s and 5.2 s, a mean standard deviation of 1.2 s or less and a number of errors of 17 per 100 persons or less., Conclusion: Reading time uniformity in the Danish version of the Radner Reading Chart was comparable to that of the original German version. Education had an influence on reading performance that may warrant stratification for this parameter when reading tests are used in clinical trials., (© 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Purpose: To develop and validate 28 short Italian sentences for the construction of the Italian version of the Radner Reading Chart to simultaneously measure near visual acuity and reading speed., Methods: 41 sentences were constructed in Italian language, following the procedure defined by Radner, to obtain "sentence optotypes" with comparable structure and with the same lexical and grammatical difficulty. Sentences were statistically selected and used in 211 normal, non-presbyopic, native Italian-speaking persons. The most equally matched sentences in terms of reading speed and number of reading errors were selected. To assess the validity of the reading speed results obtained with the 28 selected short sentences, we compared the reading speed and reading errors with the average obtained by reading two long 4th-grade paragraphs (97 and 90 words) under the same conditions., Results: The overall mean reading speed of the tested persons was 189±26wpm. The 28 sentences more similar in terms of reading times were selected, achieving a coefficient of variation (the relative SD) of 2.2%. The reliability analyses yielded an overall Cronbach's alpha coefficient of 0.98. The correlation between the short sentences and the long paragraph was high (r=0.85, P<0.0001)., Conclusions: The 28 short single Italian sentences optotypes were highly comparable in syntactical structure, number, position, and length of words, lexical difficulty, and reading length. The resulting Italian Radner Reading Chart is precise (high consistency) and practical (short sentences) and therefore useful for research and clinical practice to simultaneously measure near reading acuity and reading speed., (Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.)

Purpose: To investigate the effects of arginine-vasopressin (AVP) on intraocular pressure (IOP), orbital venous pressure (OVP), and choroidal blood flow (ChorBF) regulation in anesthetized rabbits., Methods: Mean arterial pressure (MAP), IOP, and OVP were measured by direct cannulation of the central ear artery, the vitreous, and the orbital venous sinus, respectively. Laser Doppler flowmetry was used to record ChorBF. To change the perfusion pressure (PP), MAP was manipulated mechanically with occluders around the aorta and vena cava. In the first group of animals (n = 11) the dose-response relationship was measured. In the second group of animals (n = 8) pressure-flow relationships were determined at baseline and in response to intravenous application of a low (0.08 ng/kg/min) and a high (1.33 ng/kg/min) infusion rate of AVP., Results: AVP caused a dose-dependent increase of MAP and choroidal vascular resistance (ChorR), whereas IOP, OVP, ChorBF, and heart rate (HR) were decreased. In contrast to the high infusion rate, the low infusion rate of AVP had no effect on baseline ChorBF. However, the pressure-flow relationship was shifted downward significantly by both infusion rates at PP below baseline., Conclusions: AVP reduces IOP and OVP significantly and is a potent vasoconstrictor in the choroidal vascular bed. In the choroid, the effect of AVP is not only dose-dependent, but also PP-dependent, which is indicated by the reduced perfusion relative to control with low-dosed AVP at low PP.

Purpose: To study the functional success of neural retinal transplantation by means of retinal surface ganglion cell recordings., Methods: Eight-week-old C3H/HeJ (rd/rd) retinal degeneration mice received transplants (subretinal) in one eye only of neural retinal tissue isolated from newborn normal C57/BL6J mice. Four weeks after transplantation, ganglion cell responses were recorded directly from the retinal surface over the transplant, with a differential bipolar surface electrode. Measurements were performed, both with and without light stimulation. Similar recordings were performed in nontransplant areas of the transplant-recipient eyes, and in age-matched sham-treated and untreated control eyes. After the recordings, the eyes were processed for light and transmission electron microscopy., Results: Histologic examination showed that in some areas, transplanted cells were organized into small sheets and differentiated into photoreceptors with outer segments in intimate contact with the host RPE. No light-driven ganglion cell responses were recordable from the transplant-recipient or control eyes. However, the spontaneous ganglion cell activity was higher in the transplant areas (mean: 10.8 +/-12.0 spikes/1.6 sec) compared with nontransplant areas of these recipient eyes (mean: 2.4 +/- 5.7spikes/1.6 sec; P < 0.001), sham-treated eyes (mean: 2.5 +/- 4.8 spikes/1.6 sec; P < 0.001), and the untreated control eyes (mean: 2.2 +/- 4.4 spikes/1.6 sec; P < 0.001)., Conclusions: Subretinal transplantation of neural retinal tissue results in a local increase of spontaneous ganglion cell activity. The increased activity may be due to the release of neurochemically active substances as a result of the presence of the transplant. Although light responses were not recordable, the technique of retinal surface ganglion cell recording may be useful for assessing the functional success of transplantation.

Purpose: Light-elicited retinal ganglion cell (RGC) responses after fetal neural retinal transplantation have not been demonstrated in animal or human subjects blind from outer retinal degeneration, despite apparent morphologic success. This study was designed to test the hypothesis that the functional success of retinal transplantation may be enhanced by using a young host retina (13 days old)., Methods: At postnatal day (P)13 C3H/HeJ (rd/rd) retinal degenerate mice received a subretinal transplant, in one eye only, of neural retinal tissue isolated from newborn normal C57/BL6J mice. Between 33 and 35 days after transplantation, local electroretinograms (ERGs) and ganglion cell responses were recorded directly from the retinal surface using a differential bipolar surface electrode. Measurements were performed both with and without light stimulation. Similar recordings were also performed in age-matched eyes subjected to sham transplantation, in control eyes that were not subjected to surgery, and in animals eyes that underwent transplantation at 8 weeks of age. After the recordings, the eyes were processed for light and transmission electron microscopy., Results: Three of 10 mice showed bursts of ganglion cell action potentials (ON response only) as well as recordable intraocular ERGs over the transplant in response to 1-second and 200-msec light stimuli. Light-driven ganglion cell responses could not be recorded in areas outside the transplant in all transplant-recipient eyes, age-matched control eyes, and sham-transplantation eyes. Light responses also could not be recorded in animal eyes that received transplants at an older age (8 weeks). Electron microscopic examination confirmed the presence of photoreceptor outer segments in the areas affected by transplantation., Conclusions: This study demonstrates the presence of light-driven ganglion cell responses after subretinal transplantation in a retinal degenerate model. This finding may reflect functional integration of the transplant with the host, but a rescue effect on remaining host photoreceptors cannot be ruled out. The findings suggest, however, that modification of host parameters, such as host age, may be important approaches for improving the functional success of retinal transplantation.

Purpose: A pilot study of human neural retinal transplantation was undertaken to investigate three major issues: whether a safe surgical procedure could be devised for transplantation of neural retinal tissue into the subretinal space, whether the transplant would be accepted in the subretinal space, and whether an improvement in vision could be achieved., Methods: Eight patients with bare light perception (LP) vision due to retinitis pigmentosa (RP) and one patient with bare LP vision due to advanced neovascular age-related macular degeneration (AMD) received subretinal transplants of human fetal retinal microaggregate suspensions without postoperative systemic immunosuppression. The patient with AMD also received a fetal retinal sheet transplant. The ages of the patients ranged from 31 to 94 years (median, 55 years). The pre- and postoperative evaluations included visual function testing, detailed fundus examinations, fundus photography, fluorescein angiography, macular perimetry using a scanning laser ophthalmoscope (SLO), and full field and focal electroretinograms (ERGs)., Results: Three of the eight RP patients demonstrated possible improved light sensitivity during the initial months of follow-up. However, visual improvement disappeared between 3 and 13 months of follow-up. After transplantation, no subject showed any changes in the ERG recordings or SLO macular perimetry relative to their preoperative baseline. No patient experienced a retinal detachment, infection, or extensive bleeding. None of the patients developed retinal vasculitis or intraocular inflammation. In one RP patient, fluorescein angiography and fundus photography documented the formation and maturation of new host retinal vessels in the area of the transplant., Conclusions: Transplantation of fetal retinal photoreceptor suspensions into the subretinal space was achieved safely in nine subjects. Although a definite positive effect on visual function could not be demonstrated, the apparent high tolerance for graft tissue is promising for future efforts in the field of neural retinal transplantation.

Extended aggregates of intracellular axonemal derivatives can be seen within the apical cytoplasm of ciliated cells of apparently healthy domestic pigs. Such alterations were observed in 15 out of 20 animals. Complete (9 + 2) or incomplete (8 + 2 - 5 + 2) intracellular axonemes were found which sometimes arose from mature, irregularly arranged kinetosomes. In addition, bundles of single microtubules and microtubular pairs were found. In previous investigations on the ciliated epithelium of different mammals, intracellular axonemes were investigated only under pathological or experimental conditions. Our findings indicate that these alterations also occur in healthy animals. The extended aggregates of intracellular axonemal derivatives are more likely to be due to a failure of ciliary maturation than to a degradation of incorporated mature cilia.