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Purpose: To investigate the contribution to the photopic negative response (PhNR) of the electroretinogram (ERG) by retinal ganglion cells (RGCs). The PhNR was assessed longitudinally following optic nerve transection (ONTx). Methods: Photopic ERGs were recorded from each eye of an anesthetized (ketamine/xylazine, 60 mg/kg and 5 mg/kg) Brown Norway rat using custom made electrodes (PT-IR Tef., A-M System Inc). ERGs were elicited using green Ganzfeld flashes (11.38 scd/m2, 22.76 cds/m2) and a rod suppressing green-background (40 cd/m2). PhNRs were compared before and after optic nerves were transected. Cresyl violet stained retinal flatmounts were used to estimate cell loss in the ganglion cell layer 3 and 15 weeks after optic nerve transection. The pharmacological effect of 1.3 μM intravitreal TTX on the PhNR was also evaluated. Results: There was a significant loss (p <0.05) in the PhNR of 20, 36, 34, 35, 48, 48 and 56% for ONTx eye versus the contralateral eye, at post ONTx times of 24 h, 1, 2, 3, 4, 8 and 15 weeks. B-wave amplitudes of ONTx eyes were not significantly different from the control eyes. In ONTx eyes, mean cell loss in the retinal ganglion cell layer was 27 and 55% at the 3 week and 15 week time periods. In the eyes with ONTx, the decline of PhNR amplitudes was correlated positively with RGC loss (r = 0.98; p < 0.01). Thirty minutes after intravitreal TTX injection, the PhNR was significantly reduced (57%, p<0.01). Conclusions: There was a time-dependent decline in the PhNR after ONTx, as exemplified by a 35% reduction from 1–3 weeks, a 48% decline for 4–8 weeks and a 56% decline after 15 weeks. The correlation between the decline in the PhNR and retinal ganglion cell loss suggests that the PhNR depends on inner retina integrity and the PhNR may be important biological signal or detecting glaucomatous damage and the monitoring of RGC function changes in early glaucoma.

One patient with the clinical diagnosis of Wegener's disease suffered from bilateral progressive uveitis and corneal melting which did not react to steroid and immunosuppressive therapy. Cyclosporin A produced dramatic improvement within 5 days, of both the uveitis and the corneal melting. The second patient had severe progressive corneal melting and scieral melting in one eye, which did not react to corticosteroid therapy or grafting of the defects. The corneal melting stopped completely on Cyclosporin A therapy for two months. Gum hypertrophy was only seen as a side effect of cyclosporin A therapy in one patient, no severe side effects such as kidney or liver dysfunctions were noted.

Treatment of retinitis by cytomegalovirus (CMV) in AIDS patients requires frequent repetitive injections of intravitreal ganciclovir (GCV). This study was undertaken to establish experimentally whether the intravitreal application of liposomally-entrapped GCV could prolong intraocular therapeutic levels when compared with the intravitreal injection of free GCV, and the clinical effectiveness of this approach in AIDS patients. Intraocular concentration of GCV was determined by means of an ELISA test in rabbit vitreous 2, 3, 7, and 14 days after a single intravitreal injection of either different doses of the free drug (0.2–20 mg) or 1 mg of liposomally-entrapped GCV. After 72 h, only the vitreous of rabbits injected with doses of free GCV greater than or equal to 5 mg showed therapeutic levels of the drug; no GCV was detected after 72 h with any of the doses applied. Moreover, the microscopic study revealed GCV-induced damage in retinal structures in the animals injected with a free GCV dose greater than or equal to 15 mg. Intravitreal injection to rabbits of 1 mg of liposomally-encapsulated GCV showed no retinal toxicity at any of the time points studied, and therapeutic levels were detected up to 14 days after injection (4.67 ± 0.39 μg/ml). Five AIDS patients suffering CMV retinitis were injected with 0.5 mg of liposomally-entrapped GCV (2 mg of lecithin). Complete remission of the CMV retinitis was observed already at the third injection of 0.5 mg GCV (one per week) and relapse did not occur during the 2–4 month follow-up of the patients. In view of the results presented, it can be concluded that intravitreal injection of liposomally-encapsulated GCV increases the time period required for reinjections in the treatemnt of CMV retinitis.

The experiments confirm that the inner surface of the cornea acts as a semipermeable membrane. The osmotic pressure of the aqueous humour has a certain influence on the thickness of the cornea, but the effect is limited. Thus, it is proved that the hypertonicity of the aqueous or the tears cannot alone explain the normal deturgescent state of the cornea. Some vital activity of the corneal tissue is also required.

In a preliminary report (Houtman et al., 1977) some of the characteristics of vertical vergence movements were mentioned. One of the most striking features appeared to be their slowness, compared to the horizontal disjunctive eye movements. This is a report of further studies on the dynamic characteristics of the vertical disjunctive eye movements. Their velocity appears to be independent of the magnitude of the disparity. Also in contrast to horizontal disjunctive eye movements, the gain of the system is not linear to the amplitude of the stimulus.

In 1965 we could show, that the cornea verticillata - in 1905 described by Fleischer — is not an idiopathic dystrophy of the cornea, but a manifestation of Fabry's glycolipidosis, as well in the homozygotic, as in the heterozygotic stage. To this thesaurismoses of the corneal epithelium we have in addition now two other thesaurismoses, which have exactly the same morphological aspect, and which cannot be differentiated by clinical methods. They are the ones which can be either attributed to chloroquine or to amiodarone.

The decision to use therapy in toxoplasma retinochorioiditis depends on the location of the active lesion and the presence of vitreous activity. In eyes with dense vitreous clouding it can be difficult to see whether the macular region is involved or not. In theory the localisation of a lesion can be estimated on the basis of the flash ERG. The standard flash electroretinogram was recorded in 23 patients with inactive toxoplasma retinochorioiditis lesions in the retina. In 17 cases a lesion was present within the central 12° of the visual field, 8 of these had a reduced photopic ERG. In 15 patients lesions were found outside the central 12°, in 8 of whom the scotopic ERG was reduced. We conclude that the ERG can be of use in indicating the scar location in patients with dense vitreous clouding.

To report a case of deferoxamine-induced retinopathy characterized by electroretinography (ERG), optical coherence tomography angiography (OCT-A), and other multimodal imaging. This is an observational case report of one patient. Full-field ERG was performed. OCT-A, spectral-domain optical coherence tomography (SD-OCT), color fundus photography, and fundus autofluorescence were used to characterize the retinopathy induced by deferoxamine use. A 64-year-old man with a history of β-thalassemia intermedia presented with worsening visual acuity, nyctalopia, and electronegative ERG. OCT-A revealed atrophy of the choriocapillaris in areas of hypoautofluorescence, corresponding to regions of retinal atrophy. SD-OCT showed disruption of the ellipsoid zone, granular hyperreflective deposits within the retinal pigment epithelium, thinning of the retinal layers, and extensive choroidal sclerosis and atrophy of the retinal pigment epithelium. Deferoxamine-induced retinopathy can manifest with electronegative maximal ERG responses, and OCT-A can be used to detect deferoxamine toxicity.