Cyclo‐oxygenase‐2 expression in photon‐radiated and non‐radiated uveal melanomas

Purpose: To determine and compare cyclo‐oxygenase‐2 (COX‐2) expression in photon‐radiated and non‐radiated malignant uveal melanomas and to analyse the correlation between COX‐2 expression and prognosis. Methods: Immunohistochemical staining for COX‐2 was performed on 21 uveal melanomas that were endoresected after prior stereotactic radiotherapy with photons and on 22 tumours that were treated by endoresection without prior radiotherapy. COX‐2 staining was further analysed in respect to cell type, maximal prominence, time interval between radiotherapy and surgery, apoptotic index (AI), proliferative index (PI) and the development of metastatic disease. Results: There was no difference in COX‐2 expression between radiated and non‐radiated melanomas (P > 0.15). COX‐2 staining correlated with neither the tumour prominence (P > 0.40) nor the AI or the PI (both P > 0.35). Tumours with high COX‐2 expression were significantly more likely to develop metastasis (P = 0.022). Conclusion: Radiotherapy with photons does not induce COX‐2 expression in malignant melanomas of the uvea. But high COX‐2 expression may be a marker for poor prognosis.     

Neuroprotective effect of epigallocatechin‐3‐gallate against N‐methyl‐D‐aspartate‐induced excitotoxicity in the adult rat retina

Purpose: Epigallocatechin‐3‐gallate (EGCG), the major polyphenol of green tea, has been suggested to reduce glutamate excitotoxicity. We therefore investigated the potentially protective effects of EGCG against N‐methyl‐d ‐aspartate (NMDA)‐induced excitotoxicity in the retina. Methods: Female Wistar rats (n = 171) were divided into a normal control group (n = 9); saline control group with intravitreal saline injections (n = 54); NMDA control group with an intravitreal NMDA injection and intraperitoneal saline injections (n = 54); and NMDA study group (n = 54) receiving an intravitreal NMDA injection plus intraperitoneal EGCG (25 mg/kg) injections. Starting at 2 days prior to the intravitreal NMDA injection, the intraperitoneal injections were performed daily for the whole study period. At 12 hr, 1, 2, 3 days, 1 and 2 weeks after the intravitreal NMDA injection, the animals were killed. We counted the neurons in the retinal ganglion cell layer (GCL) on histological sections, measured the thickness of Thy‐1 immunoreactivity and assessed the expression of Thy‐1 mRNA by real‐time polymerase chain reaction. Results: At all time‐points, GCL cell density, thickness of Thy‐1 immunoreactivity and expression of Thy‐1 mRNA were significantly (all p < 0.05) lower in the NMDA control group than in the NMDA study group, in which the parameters were significantly (all p < 0.05) lower than in the saline control group and the normal control group. In both groups with an intravitreal NMDA injection, GCL cell density, thickness of Thy‐1 immunoreactivity and expression of Thy‐1 mRNA decreased significantly with increasing follow‐up time. Conclusions: Intraperitoneal application of EGCG resulted in a significantly less marked NMDA‐associated loss of retinal ganglion cells.     

Delayed neovascularization in inflammation‐induced corneal neovascularization in interleukin‐10‐deficient mice

Purpose: To investigate the potential modulatory role of interleukin‐10 (IL‐10) in the suture model for corneal neovascularization. Methods: Neovascularized areas were measured on corneal flat‐mounts in IL‐10^?/? and wild‐type C57BL6 mice. The inflammatory cellular response was characterized with immunohistochemistry. Gene expression was measured by real‐time polymerase chain reaction. Results: IL‐10^?/? mice showed a delayed neovascular response compared to wild‐type animals at day 6 after suture, when approximately half of the cornea was neovascularized. No apparent differences in inflammatory responses or in messenger RNA (mRNA) expression for proangiogenic factors were detected in IL‐10^?/? versus wild‐type mice. Conclusion: IL‐10 appears to have a proangiogenic effect in the suture model for corneal neovascularization that cannot be explained by either IL‐10’s anti‐inflammatory effect or apparent cross‐talk with the angiogenic factors vascular endothelial growth factor (VEGF)‐A, metalloproteinase (MMP)‐2 and MMP‐9, angiopoietin (Ang)‐1 and Ang‐2.     

Ocular characteristics in 10 children with long‐chain 3‐hydroxyacyl‐CoA dehydrogenase deficiency: a cross‐sectional study with long‐term follow‐up

Purpose: To present long‐term ocular complications and electroretinographic (ERG) findings in children with long‐chain 3‐hydroxyacyl‐CoA dehydrogenase (LCHAD) deficiency – a life‐threatening metabolic disease – and the relation to age at diagnosis, treatment and other clinical parameters. Methods: Ten children with LCHAD deficiency underwent repeated ophthalmological evaluations including ERG. Results: All 10 children developed chorioretinal pathology. Regardless of age at diagnosis, initiation of treatment and age at examination, inter‐individual differences were present. Profound chorioretinal atrophy, severe visual impairment and progressive myopia had developed in two teenagers. Milder chorioretinopathy with or without subnormal visual acuity was present in all other children. ERG was pathological in seven children. The chorioretinopathy often started in the peripapillary or perimacular areas. In one patient, unilateral visual impairment was associated with fibrosis. Conclusion: Early diagnosis and adequate therapy might delay but not prevent the progression of retinal complications. Late diagnosis with severe symptoms at diagnosis, neonatal hypoglycaemia and frequent decompensations may increase the progression rate of the chorioretinopathy. LCHAD deficiency, a potentially lethal disease, is sometimes difficult to diagnose. Unusual chorioretinal findings should alert the ophthalmologist to the long‐chain 3‐hydroxyacyl‐CoA dehydrogenase deficiency, especially if there is a history of neonatal hypoglycaemia or failure to thrive.     

Anti‐aquaporin‐4 antibody‐positive optic neuritis

Purpose: It has recently been reported that the anti‐aquaporin‐4 antibody (AQP4‐Ab) can be a specific marker of neuromyelitis optica. We present three cases of optic neuritis (ON) where the patients tested positive for AQP4‐Ab, but showed no neurological signs. Methods: Sera were obtained from 32 Japanese patients with ON and no other neurological abnormalities (mean age 46 ± 20 years). AQP4‐Ab was detected by indirect immunofluorescence staining using human‐AQP4‐transfected HEK 293 cells. Results: AQP4‐Ab was positive in three female patients (aged 9, 64 and 82 years). Their illness was characterized by bilateral severe optic nerve involvement, insufficient visual recovery, and autoimmune abnormalities (such as positive antinuclear antibody). Two of these patients experienced recurrent episodes of ON. In at least two episodes, the intracranial portion of the optic nerve showed significant inflammation on magnetic resonance imaging. Conclusions: These cases indicate that some ON patients have an immunological pathogenesis similar to that seen in neuromyelitis optica. In addition, examination for AQP4‐Ab positivity in the initial phase of ON is important in predicting the prognosis, including the possibility of the development of transverse myelitis.     

N‐chlorotaurine and its analogues N,N‐dichloro‐2,2‐dimethyltaurine and N‐monochloro‐2,2‐dimethyltaurine are safe and effective bactericidal agents in ex vivo corneal infection models

Purpose: N‐chlorotaurine (NCT) and its analogues N‐monochloro‐2,2‐dimethyltaurine (NVC‐612) and N‐dichloro‐2,2‐dimethyltaurine (NVC‐422) are new anti‐infectives for topical treatment for conjunctivitis. The aim of this study was to show that these compounds are safe in an EpiOcular model and effective in corneas infected ex vivo. Methods: Corneal buttons were excised from porcine eyes. In 183 of the 229 corneas, erosion and artificial superficial stromal incision were induced. They were bathed in suspensions of Pseudomonas aeruginosa or Staphylococcus aureus for 24 hr at 37°C and incubated in solutions of the test substances at 37°C and pH 7.1. Subsequently, they were subjected to histology (n = 20) or homogenized followed by quantitative bacterial cultures (n = 209). Ocular irritation was tested using the EpiOcular? tissue system (MatTek Corporation). Results: Bacterial accumulations were detected histologically both on the corneal surface and also in the anterior third of the stroma of incised corneal buttons. All three test compounds at a concentration of 55 mm (equals 1% NCT) reduced the bacterial counts of P. aeruginosa and S. aureus by approximately 5 log10 after 60‐ and 120‐min incubation, respectively. Significant killing was observed as early as after 5‐min incubation. Also intrastromal bacteria were inactivated. In the EpiOcular? tissue model, NCT, NVC‐422 and NVC‐612 had no or very low potential to irritate corneal tissue. Conclusion: N‐chlorotaurine, NVC‐422 and NVC‐612 are non‐irritating in cornea and kill P. aeruginosa and S. aureus, even following penetration into the deeper corneal stromal layers.     

Gender‐related differences in cataract surgery outcome: a 5‐year follow‐up

Purpose: A prospective, longitudinal, population‐based cohort study was performed to analyse gender‐related differences in subjective and objective visual function 5 years after cataract surgery. Methods: All patients (n = 810) who underwent cataract surgery during a 1‐year period (1997–98) at Norrlands University Hospital in Umeå, Sweden, were studied with visual acuity (VA) data and questionnaires (VF‐14) before and after surgery, as well as 5 years later. Five hundred and thirty patients (177 men, 353 women) answered the questionnaire, constituting 90% (530/590) of the survivors. Four hundred and sixty‐seven (156 men, 311 women) also underwent an eye examination. Results: The women were significantly older (P = 0.009) and were more often operated on both eyes (P = 0.005). Before surgery and postoperatively, the women had a significantly lower age‐ and VA‐adjusted VF‐14 score (P = 0.000 and P = 0.036, respectively). This difference was not significant 5 years after surgery (P = 0.16). Five years after surgery, a significantly larger proportion of women had a decline of more than 0.1 logarithm of the minimum angle of resolution of the better‐seeing eye (P = 0.013). There were no significant gender‐related differences in the operated eye. Conclusion: Female cataract surgery patients assess their visual function worse than males after adjustment for age and VA preoperatively and postoperatively. These differences were not significant 5 years after surgery although the men had better best‐corrected visual acuity (BCVA) of their better eye. It is important to be aware of gender‐related differences in perception when performing questionnaire‐based outcome studies.     

SARS‐CoV‐2 and COVID‐19 for the ophthalmologist

The COVID‐19 pandemic has had an unprecedented impact on ophthalmology. This review compiles general aspects of the novel coronavirus and COVID‐19, further dissects the most recent data on the role of the eye regarding disease transmission and manifestations, and summarizes preventive measures in the particular context of eye care.