The higher visual areas within the temporal cortex are crucial in object recognition. Visual signals received by the retina undergo hierarchical processing and are subsequently transmitted to the temporal cortex via the occipital cortex. Neuronal properties related to various visual at­tributes have been examined to elucidate the neural mechanisms of this pathway. This paper presents these neurophysiological findings and provides an overview of the neural processing underlying object vision.

　The dorsal visual pathway that runs from the primary visual cortex to the inferior parietal cortex is considered the spatial visual pathway. However, it is believed that the dorsal visual pathway generates actions using sensory information, rather than spatial vision. Factually, the inferior parietal cortex contains brain regions that control movements of the hands, eyes, arms, and head, and neurons in these brain regions respond to visual targets for movement and movements themselves. Additionally, studies on the neural basis of decision-making has made remarkable progress, and the conversion from vision to action is a process of information accumulation and decision, such as judging an action option to choose. This study introduces a new way of thinking about the function of the dorsal visual pathway of the cerebral cortex.

　Damage to the primary visual cortex (V1) impairs visual awareness. However, some patients with damaged V1 have the visuomotor ability to locate a visual target in the affected visual field using their rapid eye movements (saccades), despite impaired visual awareness. This phenomenon is known as blindsight. In other words, after a V1 lesion, there are neural pathways that do not drive visual awareness but convert visual information into saccadic movements. We used unilateral V1 lesion monkeys as animal models of blindsight and neurophysiological techniques, positron emission tomography (PET), and technique for pathway-selective blockade using viral vectors to elucidate the visuomotor pathways after V1 lesion. The retino-tectal-pulvinar pathway, via the superior colliculus as a relay point, was important for transmitting visual information to the brain after V1 lesion. In the cortex, the role of LIP in parietal-association cortex increased after the lesion. The LIP receives input from MT/MST areas to which the pulvinar projects strongly, suggesting that this series of pathways is important in saccadic movements to locate a visual target in the affected visual field after V1 lesion. It was found that visual signal through these pathways could not only drive saccades to the visual target, but could also act as a secondary reinforcer in reinforcement learning.

　These studies identified the pathways from the retina to the cortex that are essential for visually guided saccades to a target in the affected visual field by the V1 lesion. It was also shown that this neural pathway not only drives reflexive movements, but also acquires novel behaviors in coordination with the neural mechanisms of reinforcement learning.

Purpose: To study the clinical applications of evaluation indicators to capture visual attention characteristics associated with unilateral spatial neglect (USN) and homonymous hemianopia (HH).

Methods: The participants included a 20-year-old female who had left USN due to right basal ganglia hemorrhage and a 43-year-old female with left HH caused by an acute stroke in the right posterior cerebral artery. Saccadic eye movement (SEM) and smooth pursuit eye movement (SPEM) were measured using an eye tracker (Gazefinder). The evaluation indicators included the “gaze distance of SEM,” “gaze acquisition rate of SEM in the left and right spaces,” and “number of SPEMs with mixed SEM.”

Results: The gaze distances of SEM at an amplitude of 30° were 7.2–23.8° for the patient who had left USN and 28.0–29.6° for the patient who had left HH. The gaze acquisition rates of SEM in the left and right spaces were as follows: 82% in the right space and 12% in the left space for the patient with left USN, and 96% in the right space and 91% in left space for the patient with left HH space.

　The number of SPEMs with mixed SEM were 1–6 in the patient with left USN and 2–3 in the patient with left HH.

Conclusion: Differences were observed in the evaluation indicators between the patient with USN and the patient with HH; thus, these indicators could potentially be clinically applied in the quantitative evaluation of patients with eye movement disorders.

　We report a case of difficult-to-treat intracranial hypertension associated with a history of diabetic nephropathy and peritonitis in a 53-year-old man who was treated for diabetic retinopathy and underwent peritoneal dialysis previously for diabetic nephropathy. Fundus examination revealed optic disc swelling. Corrected visual acuity was 1.2 in both eyes, and magnetic resonance imaging showed no intracranial abnormalities. The patient noticed decreased visual acuity and was re-referred to our hospital for evaluation of exacerbation of bilateral optic disc swelling, 14 months after his initial visit. Corrected visual acuity in his right eye had declined to 0.7, with progression of visual field constriction. Corrected visual acuity in his left eye was 1.2; however, he had multiple scotoma on the nasal side. The cerebrospinal fluid pressure was >350 mmH2O, and the patient’s subjective symptoms improved after lumbar puncture; therefore, papilledema was attributed to intracranial pressure elevation. Although the patient’s symptoms worsened over time, medical and surgical treatment options were limited owing to comorbidities. Therefore, the patient received oral topiramate therapy and underwent periodic lumbar puncture. Symptom progression temporarily halted following treatment; however, severe visual impairment persisted in the right eye.

Introduction: Optic neuritis is an inflammation of the optic nerve that recurs unilaterally or bilaterally. The risks of inflammation are reportedly 28% and 35% at 5 and 10 years, respectively.

Purpose: This study aimed to describe the patient characteristics for recurrent optic neuritis (RNN).

Materials and Methods: We retrospectively analyzed on 473 patients with optic neuritis at the Cicendo Eye Hospital Bandung, from January 1, 2018 to December 31, 2020. The collected data comprised age, sex, laterality, visual acuity, funduscopic examination, color vision, contrast sensitivity, visual field examination, previous treatment, etiology, recurrence interval, and visual function improvement after 1-month follow up.

Results: Forty patients had recurrent optic neuritis, including 25 women and 15 men, 80% being 20-59 years old. Furthermore, bilateral presentation was observed in 52.5% of the patients. The most common etiology was infection, which accounted for 57.5% of the patients. Fundoscopic examination revealed optic disc swelling in 55.8% of patients, whereas the color vision test revealed dyschromatopsia in 60.7%. Decreased contrast sensitivity and diffuse visual field defects were found in 34.3% and 19.8%, respectively. Moreover, 65% had a 1-year recurrence interval. Additionally, 55% had received prior intravenous corticosteroid therapy, and their visual acuity improved by 68.9% after 1-month of follow up.

Conclusion: Recurrent optic neuritis occurred 1 year after the first attack and was more frequent in women with a median age of 28 years. This condition is common in patients with systemic infection and bilateral presentation, and in those previously treated with intravenous corticosteroids, which may improve visual outcomes.