Visual field loss in schizophrenia: evaluation of magnocellular pathway dysfunction in schizophrenic patients and their parents

Carolina Pelegrini Barbosa Gracitelli,1 Fabiana Benites Vaz de Lima,2,3 Rodrigo A Bressan,2,3 Augusto Paranhos Junior1 1Department of Ophthalmology, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil; 2LiNC – Interdisciplinary Laboratory of Neuroimaging and Cognition, Department of Psychiatry, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil; 3PROESQ – Schizophrenia Program, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil Purpose: We sought to evaluate the visual pathway deficits in schizophrenic patients, compared with their parents and healthy controls, using Matrix frequency doubling technology (FDT) perimetry. Matrix FDT is an ophthalmic test used to detect visual field loss. Method: A total of 13 patients, 13 parents, and 12 healthy controls were enrolled in the study. Participants were subjected to Matrix FDT perimetry in a single test session. We analyzed the mean deviation for each eye and used a generalized estimated equation to evaluate differences among the groups and correct the dependency between the eyes. Results: The global mean deviation (presented as the mean of both eyes) was significantly lower in the schizophrenic patients than in their parents or controls. Analysis of the general sensitivity of the fibers crossing the optic chiasm showed a difference between the groups (P = 0.006), indicating that the sensitivity of the fibers crossing the optic chiasm was lower than those which did not cross. But when we analyzed the specific groups, the difference between the fibers was not considerable. Comparison of the right and left hemispheres showed that general sensitivity was lower for the left hemisphere, but when we analyzed specific groups, the difference was not significant (P = 0.29). Conclusion: These findings are suggestive of a lower global sensitivity in schizophrenic patients and their parents compared with controls. This difference may be an endophenotype of schizophrenia. The present study adds to a growing body of research on early-stage visual processing deficits in schizophrenia. Keywords: schizophrenic patients, visual processing, endophenotype, frequency doubling technolog

Relationship between motor vehicle collisions and results of perimetry, useful field of view, and driving simulation in drivers with glaucoma

Purpose: To examine the relationship between Motor Vehicle Collisions (MVCs) indrivers with glaucoma and standard automated perimetry (SAP), Useful Field of View(UFOV), and driving simulator assessment of divided attention.Methods: A cross-sectional study of 153 drivers from the Diagnostic Innovations inGlaucoma Study. All subjects had SAP and divided attention was assessed using UFOVand driving simulation using low-, medium-, and high-contrast peripheral stimulipresented during curve negotiation and car following tasks. Self-reported history ofMVCs and average mileage driven were recorded.Results: Eighteen of 153 subjects (11.8%) reported a MVC. There was no difference invisual acuity but the MVC group was older, drove fewer miles, and had worsebinocular SAP sensitivity, contrast sensitivity, and ability to divide attention (UFOV anddriving simulation). Low contrast driving simulator tasks were the best discriminatorsof MVC (AUC 0.80 for curve negotiation versus 0.69 for binocular SAP and 0.59 forUFOV). Adjusting for confounding factors, longer reaction times to driving simulatordivided attention tasks provided additional value compared with SAP and UFOV, witha 1 standard deviation (SD) increase in reaction time (approximately 0.75 s) associatedwith almost two-fold increased odds of MVC.Conclusions: Reaction times to low contrast divided attention tasks during drivingsimulation were significantly associated with history of MVC, performing better thanconventional perimetric tests and UFOV.Translational Relevance: The association between conventional tests of visualfunction and MVCs in drivers with glaucoma is weak, however, tests of dividedattention, particularly using driving simulation, may improve risk assessment.Biomechatronics & Human-Machine Contro

Anterior chamber depth during hemodialysis

Carolina Pelegrini Barbosa Gracitelli,1 Francisco Rosa Stefanini,1 Fernando Penha,1 Miguel Ângelo Góes,2 Sérgio Antonio Draibe,2 Maria Eugênia Canziani,2 Augusto Paranhos Junior1 1Ophthalmology Department, 2Division of Nephrology, Federal University of São Paulo – UNIFESP, São Paulo, Brazil Background: Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD) because of anterior chamber depth changes during this therapy. Purpose: To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods: A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results: There was no difference in the axial length between the three measurements (P = 0.241). We observed a significantly decreased anterior chamber depth (P = 0.002) during HD sessions. Conclusion: Our results support the idea that there is a change in anterior chamber depth in HD sessions. Keywords: anterior chamber, hemodialysis, axial length, acute angle-closure glaucom