[Clinical characteristics of acute macular neuroretinopathy in China associated with COVID-19 infection].

Objective: To investigate the clinical features of acute macular neuroretinopathy (AMN) following coronavirus disease 2019 (COVID-19). Methods: This retrospective case series study included 15 patients (28 eyes) diagnosed with AMN at the Department of Ophthalmology, Peking University Third Hospital, from November 2022 to January 2023. The AMN group comprised 4 males and 11 females, with a mean age of (31.36±8.08) years. A control group of 15 individuals [5 males, 10 females; mean age (33.20±5.10) years] who had COVID-19 but did not develop AMN was also included. Data collected for all patients included best-corrected visual acuity (BCVA), slit-lamp examination, dilated fundus examination, color fundus photography, fluorescein fundus angiography (FFA), and optical coherence tomography (OCT) results. Serum cytokine levels, including interleukins (ILs), interferons (IFNs), and tumor necrosis factor-alpha (TNF-α), were measured for both groups. Results: Among the 28 eyes, severe vision loss (BCVA≤0.3) was observed in 3 eyes (10.7%), moderate vision loss (BCVA>0.3 and≤0.5) in 2 eyes (13.3%), and mild vision loss (BCVA>0.5 and≤1.0) in 23 eyes (82.1%). OCT findings in all 28 eyes revealed hyperreflectivity of the outer nuclear layer and disruption of outer retinal structure. Additionally, 3 eyes (10.7%) exhibited cotton wool spots in the posterior pole, 2 eyes (7.1%) showed mild cystoid macular edema with intraretinal hyperreflective dots, and 1 eye (3.6%) presented with paracentral acute middle maculopathy. FFA indicated retinal vasculitis in 2 cases (4 eyes, 14.3%). Serum levels of IL-4, IL-5, IFN-α, and IFN-γ were significantly higher in the AMN group compared to the control group: IL-4 [4.49 (3.66, 6.08) vs. 1.40 (0.62, 1.68) pg/ml], IL-5 [7.34 (5.04, 14.06) vs. 0.17 (0.11, 1.86) pg/ml], IFN-α [8.42 (6.31, 14.89) vs. 0.50 (0.30, 0.83) pg/ml], and IFN-γ [17.93 (12.75, 32.44) vs. 7.43 (0.00, 14.74) pg/ml], with all differences being statistically significant (all P<0.05). Conclusion: AMN following COVID-19 can present with wedge-shaped dark red lesions in the macular area, often accompanied by cotton wool spots and retinal vasculitis. Additionally, there is a significant elevation in various inflammatory cytokines in the serum.

[Vogt-Koyanagi-Harada syndrome in the setting of vemurafenib therapy for metastatic melanoma: a case report].

A 53-year-old female patient complained of 1 week of bilateral visual blurring. She was previously diagnosed with metastatic melanoma of the inguinal lymph nodes and treated with the oral targeted drug vemurafenib. She exhibited aqueous flare in the left eye, and her fundus examination revealed optic disc swelling in the left eye and bilateral serious detachment of the retinal neuroepithelial layer. Fluorescein angiography showed multiple pinpoint hyperfluorescence leakage spots in the prometaphase and appeared as multilobular dye pooling in the late phase. We diagnosed her as Vogt-Koyanagi-Harada syndrome and gave glucocorticoid treatment for eyes. Oral vemurafenib was also taken intermittently under the guidance of an oncologist. After treatment, her bilateral vision improved, the anterior segment inflammation disappeared, and the retinal neuroepithelial layer reattached, with presence of the "sunset glow" fundus.

Assessment of retinal nerve fiber layer internal reflectivity in eyes with and without glaucoma using optical coherence tomography.

OBJECTIVE: To assess the internal reflectivity of the retinal nerve fiber layer in normal, ocular hypertensive, and glaucomatous eyes using optical coherence tomography. METHODS: All patients underwent complete ophthalmic examination and achromatic automated perimetry. Intraocular pressure was 21 mm Hg or less for low-tension glaucoma and normal eyes and at least 25 mm Hg on 2 separate occasions in ocular hypertensive and high-tension glaucoma eyes. All glaucomatous eyes had characteristic glaucomatous optic neuropathy and associated achromatic automated perimetry defect. Relative retinal nerve fiber layer internal reflectivity was measured on optical coherence tomography images using a software program of our own design. RESULTS: We enrolled 98 eyes (19 normal, 34 ocular hypertensive, 17 high-tension glaucoma, and 28 low-tension glaucoma). Relative internal reflectivity was less in eyes with glaucoma than in normal (P<.001, t test) and ocular hypertensive eyes (P<.001, t test). There was no difference in relative internal reflectivity between normal and ocular hypertensive eyes (P =.32) and between eyes with high-tension glaucoma and low-tension glaucoma (P =.43). Internal reflectivity correlated with mean deviation on achromated automatic perimetry (r(2) = 0.49, P<.001, quadratic regression analysis). CONCLUSION: Relative retinal nerve fiber layer internal reflectivity may provide useful information about the extent of retinal nerve fiber layer injury in glaucoma. Arch Ophthalmol. 2000;118:1044-1047

Increasing sampling density improves reproducibility of optical coherence tomography measurements.

PURPOSE: Published series of peripapillary retinal nerve fiber layer (RNFL) measurements using optical coherence tomography (OCT) have sampled 100 evenly distributed points on a 360 degrees peripapillary circular scan. The goal of this study was to determine whether a four-fold increase in sampling density improves the reproducibility of OCT measurements. METHODS: Complete ophthalmic examinations, achromatic automated perimetry, and OCT imaging were performed in all patients. The OCT scanning consisted of three superior and inferior quadrantic scans (100 sampling points/quadrant) and three circular scans (25 points/quadrant). The RNFL thickness measurements and coefficient of variation (CV) were calculated for the superior and inferior quadrants for each sampling density technique. RESULTS: The study included 22 eyes of 22 patients (3 control subjects; 2 patients with ocular hypertension; and 17 patients with glaucoma). Quadrants with associated glaucomatous visual field loss on automated achromatic perimetry had thinner RNFLs than quadrants without functional defects for both the 25- and 100-points/quadrant scans. For quadrants associated with normal visual hemifields (n = 22), there was no difference between the 25- and 100-points/quadrant scans in mean RNFL thickness and CV. Among quadrants with visual field defects (n = 22), RNFL thickness measurements were thinner in the 25-points/quadrant scans than in the 100-points/quadrant scans. The CV for the 25-points/quadrant scans (25.9%) was significantly higher than that for the 100-points/quadrant scans (11.9%). CONCLUSION: Increasing the sampling density of OCT scans provides less variable representation of RNFL thickness. The optimal sampling density to achieve maximal reliability of OCT scans remains to be determined.

Grayscale and proportion-corrected optical coherence tomography images.

BACKGROUND AND OBJECTIVE: The commercially available optical coherence tomography (OCT) scanner displays images in a pre-set window regardless of the projected scan length on the retinal surface. The aim of this study was to demonstrate the true dimensions of proportion-corrected OCT images and the additional information present in grayscale images. MATERIALS AND METHODS: OCT raw data were exported to an IBM-compatible PC and processed to show grayscale and proportion-corrected images using an automated software of our own design. RESULTS: Eyes with cystoid macular edema and retinal pigment detachment were analyzed. Grayscale images showed a finer gradation of signal reflectance. Scan lengths of 2, 4, 6, and 8 mm on the retinal surface showed different qualitative appearances using proportion-corrected software from the printed or on-screen images. CONCLUSIONS: Grayscale OCT images can be used to demonstrate additional information not present in false-color images. The disparity between the standard OCT image format and proportion-corrected images emphasizes the need for quantitative rather than qualitative evaluation of retinal dimensions and internal reflectance.

[An experimental study of ocular contusion in rabbits: the changes in electroretinography].

In rabbits, the amplitude of a-waves and b-waves in the ERG declined following ocular contusion; however, the oscillatory potentials did not change markedly. In the anisodine therapeutic group, the amplitude of a-waves recovered higher than did that in the control group at the 2nd and 4th week post-traumatic, while all a-waves recovered at the 6th week in both groups. The amplitude of b-waves was restored to normal in 72 hours for all eyes. Since the a-wave was sensitive to contusion, it monitored the severity of damage and objectively evaluated the therapeutic effect of treatment.

[An experimental study of ocular contusion and its hemodynamic changes].

The hemodynamic changes in rabbit eyes following contusion were studied with rheoophthalmography (ROG), in which the wave amplitudes were markedly reduced and then recovered in 3 weeks, while in the anisodine-I treated group they recovered in 2 weeks. Contusion of 3 joules disrupted the choroidal circulation and damaged the retina. Anisodine-I improved the vasomotor functions of the choroidal vessels and was effective in treatment of ocular contusion. ROG was a sensitive objective means of estimating the severity of ocular contusion and evaluating the therapeutic effects.

Halofuginone: a potent inhibitor of critical steps in angiogenesis progression.

We have previously demonstrated that halofuginone, a low molecular weight quinazolinone alkaloid, is a potent inhibitor of collagen alpha1(I) and matrix metalloproteinase 2 (MMP-2) gene expression. Halofuginone also effectively suppresses tumor progression and metastasis in mice. These results together with the well-documented role of extracellular matrix (ECM) components and matrix degrading enzymes in formation of new blood vessels led us to investigate the effect of halofuginone on the angiogenic process. In a variety of experimental system, representing sequential events in the angiogenic cascade, halofuginone treatment resulted in profound inhibitory effect. Among these are the abrogation of endothelial cell MMP-2 expression and basement membrane invasion, capillary tube formation, and vascular sprouting, as well as deposition of subendothelial ECM. The most conclusive anti-angiogenic activity of halofuginone was demonstrated in vivo (mouse corneal micropocket assay) by showing a marked inhibition of basic fibroblast growth factor (bFGF) -induced neovascularization in response to systemic administration of halofuginone, either i.p. or in the diet. The ability of halofuginone to interfere with key events in neovascularization, together with its oral bioavailability and safe use as an anti-parasitic agent, make it a promising drug for further evaluation in the treatment of a wide range of diseases associated with pathological angiogenesis.