BackgroundThe waveforms of the pupillary light reflex (PLR) can be analyzed in a diagnostic test that allows for differentiation between disorders affecting photoreceptors and disorders affecting retinal ganglion cells, using various signal processing techniques. This procedure has been used on both healthy subjects and patients with age-related macular degeneration (AMD), as a simple diagnostic procedure is required for diagnosis.ResultsThe Fourier descriptor technique is used to extract the features of PLR waveform shapes of pupillograms and their amplitudes. To detect those patients affected by AMD using the extracted features, multidimensional scaling (MDS) and clustering techniques were used to emphasize stimuli and subject differences. The detection performance of AMD using the features and the MDS technique shows only a qualitative tendency, however. To evaluate the detection performance quantitatively, a set of combined features was created to evaluate characteristics of the PLR waveform shapes in detail. Classification performance was compared across three categories (AMD patients, aged, and healthy subjects) using the Random Forest method, and weighted values were optimized using variations of the classification error rates. The results show that the error rates for healthy pupils and AMD-affected pupils were low when the value of the coefficient for a combination of PLR amplitudes and features of waveforms was optimized as 1.5. However, the error rates for patients with age-affected eyes was not low.ConclusionsA classification procedure for AMD patients has been developed using the features of PLR waveform shapes and their amplitudes. The results show that the error rates for healthy PLRs and AMD PLRs were low when the Random Forest method was used to produce the classification. The classification of pupils of patients with age-affected eyes should be carefully considered in order to produce optimum results.Electronic supplementary materialThe online version of this article (doi:10.1186/s13637-014-0018-x) contains supplementary material, which is available to authorized users.

PurposeTo investigate the etiology of bilateral disc swelling in Japanese.MethodsUsing Kitasato University’s Department of Neuro-Ophthalmology medical records and fundus photographs of the period December 1977 through November 2010, we retrospectively identified 121 outpatients who had been initially confirmed with bilateral disc swelling.ResultsThe most common cause of the bilateral disc swelling was increased intracranial pressure (ICP) (59%); followed by pseudopapillitis (16%); uveitis (8%); hypertensive retinopathy (5%); bilateral optic neuritis, acute disseminated encephalomyelitis (ADEM) and optic disc drusen (all at 2% each); and leukemia (1%). Unknown etiology accounted for 6% of the cases.ConclusionAlthough increased ICP is the most common etiology for bilateral disc swelling, it can also be triggered by a variety of other causes. Pseudopapillitis is the most important progenitor of bilateral disc swelling in Japanese.

This article reviews the literature on point mutation of mitochondrial DNA (mtDNA) among Japanese and the authors' research data on pupil reaction in patients with Leber's hereditary optic neuropathy (LHON). Among Japanese, a higher frequency (80-90%) of point mutation at nucleotide position 11778 of mtDNA was found; other point mutations found were at nucleotide positions 3460, 14484, 13708, 7444, and 3394. Although pupil reaction to light stimulus is usually defective in all types of optic neuropathy, in patients with LHON the reaction was well maintained even when vision was reduced. W cells in the retina may be preserved or less damaged, even when the degenerative process progresses in both X and Y cells. Possible treatment is also described.

The exotropic patient might be able to perceive the binocular stereopsis by moving stereogram that was created by adding clockwise planner rotation without changing the binocular disparity to the static stereopsis target.

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