[Phototoxic maculopathy after arc welding: value of multifocal ERG]

Therapeutic benefit of melatonin in experimental feline uveitis

Uveitis is a frequent ophthalmic disorder which constitutes one of the main causes of blindness in domestic cats. The aim of this report was to analyze the effect of melatonin on experimentally induced uveitis in cats. Bacterial lipopolysaccharide (LPS) was injected intravitreally into one eye from intact cats, while the contralateral eye was injected with vehicle. Melatonin was orally administered every 24 hr to a group of ten cats, from 24 hr before until 45 days after intravitreal injections. Eyes were evaluated by means of clinical evaluation, intraocular pressure (IOP), blood-ocular barrier integrity (via measurement of protein concentration and cell content in samples of aqueous humor [AH]), electroretinogram (ERG), and histological examination of the retinas. In LPS-treated eyes, several clinical signs were observed until day 45 postinjection. The treatment with melatonin significantly decreased clinical signs and prevented the reduction in IOP induced by LPS. In LPS-injected eyes, melatonin significantly preserved the blood-ocular barrier integrity, as shown by a decrease in the number of infiltrating cells and protein concentration in the AH. Mean amplitudes of scotopic ERG a- and b-waves were significantly reduced in eyes injected with LPS, whereas melatonin significantly prevented the effect of LPS. At 45 days after injection, LPS induced alterations in photoreceptors and at the middle portion of the retina, whereas melatonin preserved the retinal structure. These results indicate that melatonin prevented clinical, biochemical, functional, and histological alterations induced by LPS injection. Thus, melatonin might constitute a useful tool for the treatment of feline uveitis.

Multifocal electroretinogram and Optical Coherence tomography spectral-domain in arc welding macular injury: a case report

Background

the purpose of this study was to report a binocular photic retinal injury induced by plasma arc welding and the follow-up after treatment with vitamin supplements for a month. In our study, we used different diagnostic tools such as fluorescein angiography (FA), optical coherence tomography (OCT) and multifocal electroretinogram (mfERG).

Case presentation

in the first visit after five days from arc welding injury in the left eye (LE) the visual acuity was 0.9 and 1.0 in the right eye (RE). FA was normal in both eyes. OCT in the left eye showed normal profile and normal reflectivity and one month later, a hyperreflectivity appeared in the external limiting membrane (ELM). The mfERG signal in the LE was 102.30 nV/deg2 five days after the injury and 112.62 nV/deg2 after one month and in the RE respectively 142.70 nV/deg2 and 159.46 nV/deg2.

Conclusions

in cases of retinal photo injury it is important for the ophthalmologist to evaluate tests such as OCT and the mfERG in the diagnosis and follow-up of the patient because the recovery of visual acuity cannot exclude the persistence of phototoxic damage charged to the complex inner-outer segment of photoreceptors.

[Unilateral photic maculopathy caused by welder's flash]

We report the case of a patient who had a unilateral photic maculopathy due to welder's flash. This patient complained of a loss of visual sensitivity on the left determined using multifocal electroretinography and macular field of vision, with macular sensitivity.

The clinical applications of multifocal electroretinography: a systematic review

Multifocal electroretinography (mfERG) is an investigation that can simultaneously measure multiple electroretinographic responses at different retinal locations by cross-correlation techniques. mfERG therefore allows topographic mapping of retinal function in the central 40-50 degrees of the retina. The strength of mfERG lies in its ability to provide objective assessment of the central retinal function at different retinal areas within a short duration of time. Since the introduction of mfERG in 1992, mfERG has been applied in a large variety of clinical settings. This article reviews the clinical applications of mfERG based on the currently available evidence. mfERG has been found to be useful in the assessment of localized retinal dysfunction caused by various acquired or hereditary retinal disorders. The use of mfERG also enabled clinicians to objectively monitor the treatment outcomes as the changes in visual functions might not be reflected by subjective methods of assessment. By changing the stimulus, recording, and analysis parameters, investigation of specific retinal electrophysiological components can be performed topographically. Further developments and consolidations of these parameters will likely broaden the use of mfERG in the clinical setting.

Welder’s maculopathy?

OBJECTIVE

The aim of this study was to verify or to disprove whether the term 'Welder's maculopathy' or 'Welding arc maculopathy' has to be considered being a justifiable occupational hazard and is to be annexed to the list of occupational diseases.

METHODS

Multifocal electroretinography (MERG) and thorough ophthalmologic examinations were performed in a group of 89 welders. The matched control group comprised 81 subjects who had never been exposed to welding. All participants of this study were examined by a specialist of occupational medicine prior to the MERG.

RESULTS

Multifocal electroretinography as well as ophthalmological tests did not reveal a significant morphological or functional differences between the welders and the control group. On an average, the welders' visual acuity appeared to be better than that of the control group. This phenomenon could be attributed to the so-called healthy worker effect.

CONCLUSION

Welding arc maculopathy seems to be rather a sequel of occupational accidents and negligence of safety regulations. The results of this study indicate that the usual protective measures in professional welding appears to be sufficient in order to prevent an occupational risk of welding arc maculopathy.