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.     

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.     

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.     

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.     

The short‐sighted perspective of long‐term eye health‐care

Eye health‐care in Australia encompasses patients with chronic disorders being referred to ophthalmologists for detailed assessment and subsequent management. An increasing case load and relative decrease in ophthalmologists predicted over the next few years portend of an upcoming bottleneck in care delivery. To improve the efficiency and effectiveness of patient care within a rapidly changing health system, we propose that minor adjustments to existing services could improve the proficiency of resources. Such changes will require service providers to rethink their positions and roles and actively collaborate with each other for improved patient outcomes.     

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.     

Cup‐to‐disc ratios of Aboriginal and non‐Aboriginal youths

Background: The determination of the cup‐to‐disc ratio (C/D) is a standard procedure in an eye examination and is pivotal in the diagnosis of glaucoma. Determining the size of the C/D ratios of different races of young people may be helpful in determining the genetically predetermined differences between Aboriginal and non‐Aboriginal people. The aim of this study was to determine whether there is a statistically significant difference in the average C/D ratios of young Aboriginal and non‐Aboriginal people. Methods: The overall average C/D ratios of 104 subjects aged between five and 23 years were compared for two age‐matched groups by stereoscopic indirect ophthalmoscopy. Differences between the overall average C/D ratios of the two groups were assessed for significance using an unpaired Student’s t test. Results: While the range of C/D ratios within each group was the same (zero to 0.7), there was a statistical difference (p < 0.001) between the overall average C/D ratios of the Aboriginal (C/D = 0.295) and non‐Aboriginal (C/D = 0.159) groups. Conclusions: Results indicating a difference between the overall average C/D ratios between Aboriginal and non‐Aboriginal young people may have implications for initial assessments of glaucoma in patients of any age.     

Feasibility of multifocal intra‐ocular lens exchange and conversion to the bag‐in‐the‐lens implantation

Purpose: Our purpose was to evaluate the surgical outcome after intra‐ocular lens exchange in patients who presented impairing visual complaints after primary multifocal intra‐ocular lens (MIOL) implantation. In particular, the study was undertaken to look at the number of eyes that could be equipped with the bag‐in‐the‐lens (BIL) IOL after MIOL exchange. Methods: This series consisted of 30 eyes of 21 consecutive patients scheduled for MIOL exchange. In 15 out of the 30 eyes, IOL misalignment was measured on slit lamp anterior segment photo’s after defining the mathematical centres of the IOL optic, pupil and limbus. Results: Diffractive MIOL was more frequently explanted (25; 83%) when compared with refractive MIOL (4; 13%) and progressive optic IOL (1; 4%). In 21 out of the 30 eyes (70%) a bag‐in‐the‐lens could be implanted. In 7 out of the 30 eyes (23%), the capsule was not considered sufficiently stable to accommodate an IOL. An iris‐fixated IOL or a sulcus‐fixated IOL was then implanted. In 2 out of the 30 eyes (6%) the remaining capsular bag could accommodate a traditional lens‐in‐the‐bag only. Eyes that underwent Nd:YAG laser capsulotomy prior to the MIOL exchange needed anterior vitrectomy peroperatively (11 eyes; 37%). Visual acuity improved postoperatively in 13 out of the 30 eyes and remained stable in 17 out of the 30 eyes. Conclusions: Since the BIL technique requires a very well‐preserved capsular bag for the purpose of the IOL implantation, the success rate of BIL implantation after MIOL is a good indicator to evaluate the degree of difficulty to exchange MIOL.     

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.     

Risk factors for incident open‐angle glaucoma: a population‐based 20‐year follow‐up study

Purpose:  To study the effect of potential risk factors on the development of open‐angle glaucoma (OAG) in a population in which pseudoexfoliation (PEX) is a common finding. Methods: In 1984–1986, a population‐based survey of 760 people aged 65–74 years was conducted in the municipality of Tierp, Sweden. From 1988 to 2006, a follow‐up study of the 530 people with normal visual fields has been in progress. To increase the cohort, 273 ophthalmic outpatients were enroled. Reliable visual fields were available for 679 people, representing 6 126 person‐years at risk. A time‐weighted mean intraocular pressure (IOP) for all visits was calculated. Results: Sixty‐four subjects developed definite OAG, 29 of whom were exposed to PEX. Risk factors associated with OAG were higher age, a positive family history, increased IOP and PEX. The age‐standardized rate ratio (SRR) was 14.8 times (95% confidence interval [CI] 7.92–27.8) greater in subjects with mean IOP ≥20 mmHg than in those with mean IOP <20 mmHg. When subjects with IOP <20 mmHg at baseline were affected by PEX, the SRR increased 5.01‐fold (95% CI 1.97–12.8), compared with the unaffected group. However, when mean IOP at follow‐up was taken into account, there was no relationship between OAG and PEX as a distinct risk factor. Among participants in the population survey, 69% of all cases were attributable to a mean IOP ≥20 mmHg. Conclusion: Increased IOP and PEX were serious risk factors for incident OAG. The effect of PEX was mediated by increased IOP.