PERIPHERAL OPTICAL COHERENCE TOMOGRAPHY FINDINGS IN A CHOROIDEREMIA CARRIER.

PURPOSE: To describe the peripheral optical coherence tomography findings in a female choroideremia carrier. METHODS: A 56-year-old woman was referred for visual disturbance complaining of some occasional photopsias and increasing difficulty with her vision at night in both eyes. Best-corrected visual acuity was 20/20 in the right eye and 20/150 in the left eye. Fundus examination revealed mildly tilted disks and peripapillary atrophy with subtle retinal pigment epithelial changes in the periphery. RESULTS: Macular optical coherence tomography in the right eye appeared unremarkable, but the in the left eye, there was diffuse ellipsoid zone band disruption. Green-light fundus autofluorescence revealed mottled areas of decreased autofluorescence in the mid and far periphery creating an irregular mosaic pattern. Peripheral optical coherence tomography scans revealed more diffuse ellipsoid zone alterations than were apparent on the fundus autofluorescence imaging. Genetic testing revealed a heterozygous pathogenic variant in the CHM gene (c.715C>T, p.Arg239). An additional heterozygous mutation was noted in the CNGB1 gene (c.290+2T>C, splice donor). CONCLUSION: Choroideremia carriers may manifest widespread photoreceptor alterations, which may be more extensive than apparent on fundus autofluorescence imaging.

Morphometric analysis of optic nerves and retina from an end-stage retinitis pigmentosa patient with an implanted active epiretinal array.

PURPOSE: To characterize optic nerve and retinal changes in a patient with end-stage retinitis pigmentosa (RP) with an implanted active epiretinal array. METHODS: A 74-year-old man with end-stage X-linked RP underwent implantation of an epiretinal array over the macula in the right eye and subsequent stimulation until his death at 5 years and 3 months after implantation. The optic nerves from this study patient, as well as those from two age-matched normal patients and two age-matched RP patients, were morphometrically analyzed against two different sets of criteria and compared. The retina underlying the array in the study patient was also morphometrically analyzed and compared with corresponding regions of the retina in the age-matched RP patients. RESULTS: Optic nerve total axon counts were significantly lower in the study patient and RP patients than in normal patients. However, there was no significant difference when comparing total axon counts from the optic nerve corresponding to the patient's implanted right eye versus the optic nerves from the RP patients (P = 0.59 and P = 0.61 using the two different criteria). Degenerated axon data quantified damage and did not show increased damage in the optic nerve quadrant that retinotopically corresponded to the site of epiretinal array implantation and stimulation. Except for the tack site, there was no significant difference when comparing the retina underlying the array and the corresponding perimacular regions of two RP patients. CONCLUSIONS: Long-term implantation and electrical stimulation with an epiretinal array did not result in damage that could be appreciated in a morphometric analysis of the optic nerve and retina.

Fluorescent viability stains to probe the metabolic status of aflatoxigenic fungus in dual culture of Aspergillus flavus and Pichia anomala.

The metabolic activity of the aflatoxigenic fungus, Aspergillus flavus co-cultured with the biocontrol yeast, Pichia anomala was examined using several viability stains. Both the FUN-1 stain and the combined use of DiBAC(4)(5) with CDFA-AM stains were applied in this study. The results suggest that the ATP-generating system in A. flavus was inactivated as the ratio of yeasts to fungi increased in the dual culture. A decrease in hyphal membrane potential and esterase activity was substantiated by the combined stains of DiBAC(4)(5) and CDFA-AM. Reduced metabolic function in conjunction with cell wall damage of A. flavus hindered the growth and biomass production of this fungus. Viability stains such as FUN-1 and DiBAC(4)(5) with CDFA-AM may assist in elucidating the biocontrol mechanism by allowing for the visualization of the antagonistic effect of yeast species on target fungi in situ, as well as for screening potent biocontrol yeast agents against fungal pathogens.

Charles bonnet syndrome associated with age-related macular degeneration.

PURPOSE: The visual hallucinations in Charles Bonnet syndrome (CBS) are most commonly attributed to release phenomena that arise due to a paucity of sensory input to visual association areas of the cerebral cortex (Cogan's sensory deprivation theory of visual hallucinations). The authors wished to gain further insight into this mechanism behind CBS by examining a patient who experienced reversible visual hallucinations. METHODS: The authors present a 77-year-old man with a history of severe age-related macular degeneration who experienced formed and moving visual hallucinations associated with CBS shortly after a retinal pigment epithelial detachment (RPED) in his right eye. His visual acuity had been reduced to 20/400 in the right eye. RESULTS: Visual acuity improved to 20/50 in the right eye after a series of Macugen injections led to RPED resolution as evidenced by optical coherence tomography and fluorescein angiography. The visual hallucinations abruptly ceased after this dramatic improvement in visual acuity. CONCLUSION: Reestablishment of high resolution visual input leads to a dramatic and almost immediate increase in the stimulus threshold of visual cortex cells as reflected by resolution of symptoms. The subthreshold signals that reach consciousness to produce visual hallucinations in CBS are thus immediately mitigated.