Diabetic Retinopathy & Medical Retina - aioseducation

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Diabetic Retinopathy and Medical Retina Free Papers Findings at baseline At the initial visit a detachment of the neurosensory retina was confirmed by OCT examination in all patients. Among total 57 leakage sites in 96 eyes, 22 points (38.6%) showed retinal PED , and 35 eyes(61.4%) showed an irregular RPE layer at the site of leakage. Defect in the RPE layer within the PED was observed in 15 leakage sites and those defects exactly corresponded to the leakage points. In 14 cases the defect was located at the margin of the PED except in one case in which it was noticed at the centre of the PED. In 6 cases the PED was irregular. 3 leakage points (5.26%) were underlying a blood vessel. Pigmentary changes were noticed in fluorescein angiography in the affected eye in 25 cases (52.08%), more widespread and extensive pigmentary changes were noticed in 41 eyes (72%) in ICG. In 18 of 57 leakage sites (31.6%), a hyperreflective shadow suggesting fibrin in the subretinal space was observed around theleakage point. In 17 leakage sites (29.82%), sagging of the posterior layer of the neurosensory retina was observed . Pigmentary changes during fluorescein angiography in the fellow eye was noticed in 23 eyes (48%) and in 30 eyes (62.5%) during indocyanine green angiography. PED was noticed in the fellow eye in 12 cases (25%). Findings on follow up Mean follow up period was days 121 days (range: 28–163 days). At the final follow up mean visual acuity was 0.18. At the final examination, complete resolution of the SRF was confirmed in all eyes, although PED remained at the 5 leakage sites. 1 patient had recurrence in the affected eye after resolution of subretinal fluid. Average duration of disappearance of subretinal fluid was. Highly reflective substances began to disappear with resolution of detachment. Fibrinous exudation also disappeared with attachment of retina. The line probably corresponded to the junction of the photoreceptor inner and outer segments (IS/OS), which was invisible in the detached retina and became apparent after the fluid resolved. The VA did not appear to correlate with the presence of irregularities of the IS/OS at the fovea. Findings in cases with no definite leak 6 eyes showed no definite leak on fluorescein angiography. 1 patient had PED and 5 patients had pigmentary irregularities on OCT. 4 eyes showed pigmentary alterations outside the CSC. 5 eyes showed pigmentary changes in ICG extensive than that seen n FA. DISCUSSION Spectral-domain (SD) OCT system is an advanced ophthalmic imaging that reduces the image acquisition time and allows the entire area of interest to be imaged on a detailed retinal structural map. 857
70th AIOC Proceedings, Cochin 2012 The most obvious advantage of truly simultaneous imaging is the negation of the possibility that one of the angiogram is of the higher quality as compared to the other, which may lead to differences in visualization of the pathological states. The other significant advantage of the simultaneous angiography technique is the time sequence correlation. Both the dyes are injected and, therefore, imaged simultaneously. Therefore, the physiological differences in their distribution and circulation through the eye are easily discernible. Furthermore, the differences in response to the pathological states of the retinal and choroidal circulation are made obvious and are readily comparable. Thus, the relative value of each type of dye in normal physiology and different disease processes becomes apparent, which is relevant for both clinical and research purposes. Lastly the time required to perform the entire study is considerably shorter. Patient compliance and investigator‘s ease are noteworthy. HRA has an added advantage of simultaneously carrying out the OCT with FA or ICG. It gives additional information of the pathology. The ability to scan images at 40 kHz help reduce eye movement artifacts and increases patient comfort, providing cleaner images. TruTrack image alignment technology provides eye tracking and guiding of the SD-OCT. This feature aligns images in the same examination and finds the same location in subsequent examinations to track subtle changes over time. Fluorescein angiography has always been a gold standard investigation in cases of CSC. It reveals two main types of leaks inkblot pattern and smokestack type. No definite leak was seen in 19% 21 of cases in a study than 12% in our study. The literature reports 22,23,24,25,26,27,28 the incidence of smokestack leak to be 7 to 25% and that of inkblot leak 60 to 87%. Spitnaz and Huke 26 observed that the leaks are most often found in the superonasal quadrant (33.22%). In our study we also found superonasal quadrant to be the commonest site (33.33%). The usual number of leakages are one or two in various studies 22,25,26 that too in our study. Occassionally, in spite of presence of clinically appreciable CSC no leak is found in FA. Gass 29 had suggested the following possibilities for such a situation – 1) The leaking point has healed; 2) A leak has occurred outside the macular area; 3) In presence of the peripheral retinal hole or a choroidaltumor; 4) Associated with congenital pit of the ONH.; 5) In idiopathic uveal effusion syndrome. CSC without leak may be due to healing of the leaking point or points and delay in the absorption of the subretinal fluid. The development of OCT has provided a better understanding of the mechanism in CSC, especially the abnormalities in the RPE layer. We visualized clearly a minute defect of the RPE within the PED, which seemed 858
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Diabetic Retinopathy & Medical Retina - aioseducation

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