Imbalance between myopic shift and the minimum amplitude of accommodation: a hypothesis for the pathogenesis of ocular hypertension secondary to drug-induced bilateral acute ciliochoroidal effusion / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To report 5 cases with drug-induced bilateral acute ciliochoroidal effusion(DBACE)and myopic shift, with or without ocular hypertension(OHT), summarize patients' clinical characteristics and recovery process of DBACE, and investigate the possible pathophysiological mechanism.METHODS:A retrospective observational case study conducted from June 2017 to February 2021. The included patients were subjected to a series of ocular examinations listed as follows: 1)best corrected visual acuity; 2)intraocular pressure(IOP); 3)slit-lamp microscopy; 4)fundus photography; 5)ultrasound biomicroscopy(UBM); 6)subjective optometry; 7)axial length and anterior chamber depth. All patients were followed up every 2d until the diopters were completely restored to the state before the disease onset.RESULTS:In total, 5 patients aged 10-45 years old, including 3 female and 2 male patients, were enrolled in this study. All patients were bilaterally involved(5/5), and had myopic shift(5/5), of whom 3 patients had OHT(3/5). With the increase of age, myopic shift decreased, while OHT increased. Based on OHT, the dynamic aggravation process of DBACE was subdivided into 2 stages, stage 1(myopic shift without OHT)and stage 2(myopic shift with OHT). With the deterioration of DBACE, when myopic shift approached or exceeded the minimum amplitude of accommodation(MAA), IOP gradually rose, and DBACE progressed from stage 1 to stage 2. With the recovery of DBACE after discontinuing the suspicious drugs, DBACE in stage 2 first returned to stage 1, and then returned to normal.CONCLUSION:Pathophysiological mechanism of DBACE was subdivided into 2 stages, including stage 1(myopic shift without OHT)and stage 2(myopic shift with OHT). The transition between the two stages depends on the imbalance between myopic shift and MAA.

Varicella-zoster virus as a causative agent of acute retinal necrosis in younger patients / 中华医学杂志(英文版)

BACKGROUND@#Herpes virus is considered to be the pathogen of acute retinal necrosis (ARN) infection. Previous studies have found that patients with ARN caused by the varicella-zoster virus (VZV) are often older, and patients with herpes simplex virus (HSV) induced ARN are considerably younger. However, in our clinical work, we find that VZV is also a pathogen in younger ARN patients. We, therefore, aimed to analyze the common etiology of younger ARN patients.@*METHODS@#A retrospective analysis was made of 20 eyes (18 patients) diagnosed as having ARN in the Department of Ophthalmology of Peking Union Medical College Hospital from 2014 to 2016. All patients were reviewed for demographic data, clinical course, clinical manifestations, time from onset to initial physician visit, duration of follow-up, visual acuity at both presentation and final visit, and treatment strategies. A paired t test was used to compare visual acuity between the presenting vision and those of final follow-up. Vitreous or aqueous specimens from 18 eyes of 18 patients were analyzed with multiplex polymerase chain reaction (mPCR)/quantitative PCR (qPCR) and xTAG-liquid chip technology (xTAG-LCT) to determine the causative virus of ARN.@*RESULTS@#Final best visual acuity (BCVA) improved significantly from 1.36 ± 0.95 (median 20/400) to 0.95 ± 0.82 (median 20/100) (t = 2.714, P = 0.015) after systemic and intravitreal antiviral treatment combined with or without pars plana vitrectomy. PCR and xTAG-LCT results showed four of the five samples in the younger group (32.2 ± 5.2 years) and 12 of the 13 samples in the senior group (53.6 ± 4.9 years) were positive for VZV, and two of the five samples in the younger group were positive for HSV-1.@*CONCLUSIONS@#This study demonstrates that VZV is also a common causative virus for ARN in younger patients. Considering this finding, a systemic antiviral treatment protocol should be immediately changed to intravenous ganciclovir when the patient does not respond to acyclovir before determining the causative virus, especially in younger patients.

Ability of Mn(2+) to Permeate the Eye and Availability of Manganese-enhanced Magnetic Resonance Imaging for Visual Pathway Imaging via Topical Administration / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Manganese-enhanced magnetic resonance imaging (MEMRI) for visual pathway imaging via topical administration requires further research. This study investigated the permeability of the corneal epithelium and corneal toxicity after topical administration of Mn2+ to understand the applicability of MEMRI.</p><p><b>METHODS</b>Forty New Zealand rabbits were divided into 0.05 mol/L, 0.10 mol/L, and 0.20 mol/L groups as well as a control group (n = 10 in each group). Each group was further subdivided into epithelium-removed and epithelium-intact subgroups (n = 5 in each subgroup). Rabbits were given 8 drops of MnCl2in 5 min intervals. The Mn2+ concentrations in the aqueous and vitreous humors were analyzed using inductively coupled plasma-mass spectrometry at different time points. MEMRI scanning was carried out to image the visual pathway after 24 h. The corneal toxicity of Mn2+ was evaluated with corneal imaging and pathology slices.</p><p><b>RESULTS</b>Between the aqueous and vitreous humors, there was a 10 h lag for the peak Mn2+ concentration times. The intraocular Mn2+ concentration increased with the concentration gradients of Mn2+ and was higher in the epithelium-removed subgroup than that in the epithelium-intact subgroup. The enhancement of the visual pathway was achieved in the 0.10 mol/L and 0.20 mol/L epithelium-removed subgroups. The corresponding peak concentrations of Mn2+ were 5087 ± 666 ng/ml, 22920 ± 1188 ng/ml in the aqueous humor and 884 ± 78 ng/ml, 2556 ± 492 ng/ml in the vitreous body, respectively. Corneal injury was evident in the epithelium-removed and 0.20 mol/L epithelium-intact subgroups.</p><p><b>CONCLUSIONS</b>The corneal epithelium is a barrier to Mn2+, and the iris and lens septum might be another intraocular barrier to the permeation of Mn2+. An elevated Mn2+ concentration contributes to the increased permeation of Mn2+, higher MEMRI signal, and corneal toxicity. The enhancement of the visual pathway requires an effective Mn2+ concentration in the vitreous body.</p>

Study of Mn2+-enhanced magnetic resonance imaging for optic visual pathway in vivo / 中华实验眼科杂志

Background Functional magnetic resonance imaging technique based on a manganese (Mn2+) tracer makes labeling the optic nerve in vivo possible.However studies on the optimal concentration and dynamic change after injection of Mn2+ are rare.Objective This study was designed to explore the time- and dose-dependent response for Mn2+-enhanced MRI of visual pathway after intravitreal injection of MnCl2.Methods Different concentrations of MnCl2(0.5,1,2,5,10,15,20,40mmol/L) with a volume of 25μl were intravitreally injected into the left eyes of 48 pigmented rabbits and were randomly divided into eight groups according to the drug concentrations.No reagent reg was injected into the right eyes as controls.MRI was performed at 4,6,8,12,24,48,96 and 168 hours after the administration of MnCl2 to examine the imaging of the optic nerve,chiasma,optic tract,lateral geniculate body and epithalamus.The signal-noise ratio of MRI in visual pathway was calculated and the optimal concentration and best imaging time after injection of MnCl2 were assessed.The use of the animals followed the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results The imaging of the optical nerve in the left eyes was enhanced in comparison with the right eyes 24 hours after injection of 0.5-1 mmol/L MnCl2 with a significant difference in SNR value between these two groups (t=1.17,t=0.95,P>0.05).24 hours after the injection of 2 mmol/L MnCl2 into the left eyes,the SNR value of the optic nerve on the left side was higher than the right side t=8.43,P0.05).The strongest imaging signal in optical nerve was seen in 24 hours after the intravitreal injection of 10-40 mmol/L MnCl2 and decayed gradually from 24 to 168 hours with a transportation speed of (3.32±0.19) mm/h in rabbit visual pathway.SNR value of optic nerve showed a positive correlation with the concentrations of MnCl2 with the regression equation Y=77.786+2.467X(F=20.102,P=0.004,R2=0.770).Conclusion Manganese-enhanced MRI is a viable method for temporospatial visualization of optic never in the pigmented rabbits.The image intensity of MRI is associated with the dose of Mn2+.