Optic coherence tomography (OCT) is one of the most rapid developing technologies in ophthalmology. OCT angiography (OCTA) has been made possible by the development of even faster scanning and sampling techniques, which is the next milestone after stratus OCT and spectral domain OCT. Without the need of injection of the contrast agent, OCTA is capable of providing a three-dimensional reconstruction of the perfused microvasculature within the retina and choroid by detecting the motion of scattering particles such as erythrocytes within sequential OCT cross-sectional scans performed repeatedly at the same location of the eye with different analysis algorithms. Comparing to fundus fluorescein angiography and indocyanine green angiography, with improved OCT technology and understanding, OCTA has showed certain advantages to diagnose retinal and choroidal diseases, especially macular vascular diseases. It is important to establish the contributions that OCTA can make to diagnosing, managing and understanding of ocular fundus diseases.
Objective To investigate the dosage, efficacy and safety of intrav itreal injection of plasmin in producing posterior vitreous detachment (PVD), an d the possible role of plasmin in degrading adhesion glycoproteins of inner limiting membrane (ILM).Methods Twenty eyes of young human cadavers within 24 hours after death were divided into 4 groups that received 0.1 ml balanced salt solution (group 1) as control, 1 (group 2), 2 (group 3), or 3 (group 4) U of human plasmin. Optical and transmission electron microcopies were performed to examine the ultrastructure of the vitreoretinal interface. Electron-immunocytochemical techniques were carried out on ILM to estimate the content of fibronectin (FN) and laminin (LN). Flow cytometry was used for cell viability analysis of variance (ANOVA) and Tukey-test was employed for statistical analysis. Results Microscopy demonstrated that plasmin especially in group 4 cleaved the attachment of the vitreous collagen fibrils to the ILM with no evident damage to the inner retina. The content of LN, FN in ILM decreased with injection of plasmin (group 3 and 4 had statistical significance from control group for FN,P＜0.05; for LN in group 4, P＜0.05). Retinal cell viability was similar for plasmin-treated and control eyes. Conclusion Human plasmin disrupts the attachment of posterior hyaloid to the ILM with no morphologic changes of the inner retina. PVD is induced mostly with injection of 3 U plasmin. (Chin J Ocul Fundus Dis，2003，19：42-45)
ObjectiveTo investigate the clinical characteristics of patients with high-myopia macular hole retinal detachment (MHRD) combined with choroidal detachment and to preliminarily analyze factors associated with postoperative hole closure. MethodsA retrospective clinical case series study. A total of 68 patients with high myopia (68 eyes) with MHRD diagnosed by Department of Ophthalmology, Peking University People’s Hospital from January 2019 to April 2024 were included in this study. Among them, there were 14 males (14 eyes) and 54 females (54 eyes). The mean age was (61.10±9.66) years. All eyes were treated with pars plana vitrectomy (PPV) combined with silicone oil or gas filling. Best corrected visual acuity (BCVA), intraocular pressure, and B-mode ultrasonography were performed. The BCVA test was performed using the Snellen visual acuity chart, which was statistically converted to logarithm of the minimum angle of resolution (logMAR) visual acuity. The range of choroidal detachment was defined according to the number of involved quadrants observed in B-mode ultrasound or surgery, which was divided into 1 to 4 quadrants. Axial length (AL) was measured under retinal reattachment. In 68 eyes, there were 17 eyes with choroidal detachment and 51 eyes without choroidal detachment, respectively. There were 17 eyes with choroidal detachment, and the detachment range involved 1, 2, 2 and 12 eyes in 1, 2, 3 and 4 quadrants, respectively. During operation, 13% C3F8 was filled in 2 eyes, all of which were not complicated with choroidal detachment. 66 eyes were filled with silicone oil. According to whether the patients were complicated with choroidal detachment, the patients were divided into the group without choroidal detachment and the group with choroidal detachment. Independent sample t test, Welch two-sample t test or Mann-Whitney U test were used for comparison between groups. Generalized linear regression and logistic regression were used to analyze the relationship between the aperture size of postoperative unclosed holes and the closed hole after surgery and clinical factors. ResultsAt 3 months after surgery, the logMAR BCVA of the affected eye was 1.29±0.43, with a preoperative to postoperative difference ranging from −1.60 to 0.70 (−0.51±0.51) logMAR units. The AL ranged from 26.6 to 34.3 (29.60±2.12) mm. Among 68 eyes, macular hole of 37 (54.4%, 37/68) eyes were open and 31 (45.6%, 31/68) eyes were closed, respectively. The hole diameter of the open eye was (753±424) µm. There was no significant difference in age, course of disease and AL between the two groups (W=412.0, 477.5, 427.0; P＞0.05). Before operation, BCVA in patients with choroidal detachment was worse (W=257.5) and intraocular pressure was lower (t=4.051) in patients with choroidal detachment compared with those without choroidal detachment, with statistical significance (P＜0.05). At 3 months after surgery, BCVA in patients with choroidal detachment was significantly worse than that in patients without choroidal detachment, with statistical significance (W=284.0, P＜0.05). There were no significant differences in logMAR BCVA difference (t=0.616) and macular hole closure rate (χ2=0.000) before and after surgery (P＞0.05). The reoperation rate of retinal detachment due to persistent or recurrent retinal detachment was significantly higher in the group with choroid detachment than in the group without choroid detachment, and the difference was statistically significant (odds ratio=6.424, P＜0.05). Logistic regression analysis showed that young age was significantly correlated with macular hole closure failure after surgery (β=0.077, P=0.015). There was no correlation between AL, duration of disease, BCVA before surgery, intraocular pressure, wether combined with choroid detachment range and postoperative hole closure (β=−0.072, 0.000, 0.672, −0.085, −0.391; P＞0.05). ConclusionsConcomitant choroidal detachment adversely affected on both pre-operative and post-operative visual acuity in high myopia MHRD. It is closely associated with the risk of recurrent retinal detachment and the needs of multiple operations, but has no significant effect on hole closure rate. Lower age of onset may be a risk factor for macular hole closure.