OBJECTIVES: To study the virtual reality-pattern visual evoked potential (VR-PVEP) P100 waveform characteristics of monocular visual impairment with different impaired degrees under simultaneous binocular perception and monocular stimulations. METHODS: A total of 55 young volunteers with normal vision (using decimal recording method, far vision ≥0.8 and near vision ≥0.5) were selected to simulate three groups of monocular refractive visual impairment by interpolation method. The sum of near and far vision ≤0.2 was Group A, the severe visual impairment group; the sum of near and far vision <0.8 was Group B, the moderate visual impairment group; and the sum of near and far vision ≥0.8 was Group C, the mild visual impairment group. The volunteers' binocular normal visions were set as the control group. The VR-PVEP P100 peak times measured by simultaneous binocular perception and monocular stimulation were compared at four spatial frequencies 16×16, 24×24, 32×32 and 64×64. RESULTS: In Group A, the differences between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at 24×24, 32×32 and 64×64 spatial frequencies were statistically significant (P<0.05); and the P100 peak time of normal vision eyes at 64×64 spatial frequency was significantly different from the simulant visual impairment eyes (P<0.05). In Group B, the differences between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at 16×16, 24×24 and 64×64 spatial frequencies were statistically significant (P<0.05); and the P100 peak time of normal vision eyes at 64×64 spatial frequency was significantly different from the simulant visual impairment eyes (P<0.05). In Group C, there was no significant difference between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at all spatial frequencies (P>0.05). There was no significant difference in the P100 peak times measured at all spatial frequencies between simulant visual impairment eyes and simultaneous binocular perception in the control group (P>0.05). CONCLUSIONS VR-PVEP can be used for visual acuity evaluation of patients with severe and moderate monocular visual impairment, which can reflect the visual impairment degree caused by ametropia. VR-PVEP has application value in the objective evaluation of visual function and forensic clinical identification.
Humans ; Evoked Potentials, Visual ; Vision, Ocular ; Vision, Binocular/physiology* ; Vision Disorders/diagnosis* ; Virtual Reality

OBJECTIVES: To study the characteristic of contrast visual evoked potentials （CVEP） in patients with ocular trauma. METHODS: Sixty patients defined as ocular trauma by forensic clinical examination in our center were selected, and split into 0.2-0.3 （Group A）, 0.3-0.5 （Group B） and ≥0.5 （Group C） according to the best corrected visual acuity. The variation characteristics of wave amplitude and latency of CVEP under 100%, 25% and 10% contrast were observed and analyzed statistically. RESULTS: （1） Under the same contrast, the wave amplitude of P₁₀₀ decreased with the decrease of stimulus perspective. （2） Under the same stimulus perspective, the wave amplitude of P₁₀₀ decreased with the decrease of contrast （P<0.05）. （3） Under the contrast of 100% and 25% with the same stimulus perspective （except 100% 7' perspective stimulus）, the difference between group A and group B had no statistical significance （P>0.05）. Between group A and group C, group B and group C, the wave amplitude of P₁₀₀ gradually increased with the increase of vision （P<0.05）. Under the contrast of 10% with 15' stimulus perspective, the wave amplitude of P₁₀₀ increased with the increase of vision （P<0.05）. （4） Under the same contrast with the same stimulation perspective, the latency of P₁₀₀ wave shortened with the increase of vision, while the difference had no statistical significance （P>0.05）. Under the same stimulus perspective, the latency of P₁₀₀ wave was prolonged with the decrease of contrast （P>0.05）. CONCLUSIONS CVEP may become one of the possible methods for the evaluation of contrast visual acuity.
Evoked Potentials, Visual/physiology* ; Eye Injuries/physiopathology* ; Humans ; Pattern Recognition, Visual/physiology* ; Photic Stimulation ; Vision, Ocular ; Visual Acuity

PURPOSE: To evaluate the accuracy of postoperative refractive outcomes of combined phacovitrectomy for epiretinal membrane (ERM) in comparison to cataract surgery alone. MATERIALS AND METHODS: Thirty-nine eyes that underwent combined phacovitrectomy with intraocular lens (IOL) implantation for cataract and ERM (combined surgery group) and 39 eyes that received phacoemulsification for cataract (control group) were analyzed, retrospectively. The predicted preoperative refractive aim was compared with the results of postoperative refraction. RESULTS: In the combined surgery group, refractive prediction error by A-scan and IOLMaster were -0.305+/-0.717 diopters (D) and -0.356+/-0.639 D, respectively, compared to 0.215+/-0.541 and 0.077+/-0.529 in the control group, showing significantly more myopic change compared to the control group (p=0.001 and p=0.002, respectively). Within each group, there was no statistically significant difference in refractive prediction error between A-scan and IOLMaster (all p>0.05). IOL power calculation using adjusted A-scan measurement of axial length based on the macular thickness of the normal contralateral eye still resulted in significant postoperative refractive error (all p<0.05). Postoperative refraction calculated with adjusted axial length based on actual postoperative central foveal thickness change showed the closest value to the actual postoperative achieved refraction (p=0.599). CONCLUSION: Combined phacovitrectomy for ERM resulted in significantly more myopic shift of postoperative refraction, compared to the cataract surgery alone, for both A-scan and IOLMaster. To improve the accuracy of IOL power estimation in eyes with cataract and ERM, sequential surgery for ERM and cataract may need to be considered.
Aged ; Biometry/methods ; Case-Control Studies ; Cataract Extraction ; Epiretinal Membrane/*surgery ; Eye ; Female ; Humans ; *Lens Implantation, Intraocular ; *Lenses, Intraocular ; Male ; Optics and Photonics ; Phacoemulsification/*methods ; Postoperative Period ; Refraction, Ocular/physiology ; Retrospective Studies ; Treatment Outcome ; Vision Tests ; Visual Acuity ; Vitrectomy/*methods

PURPOSE: To investigate the effect of watching 3-dimensional (3D) television (TV) on refractive error in children. METHODS: Sixty healthy volunteers, aged 6 to 12 years, without any ocular abnormalities other than refractive error were recruited for this study. They watched 3D TV for 50 minutes at a viewing distance of 2.8 meters. The image disparity of the 3D contents was from -1 to 1 degree. Refractive errors were measured both before and immediately after watching TV and were rechecked after a 10-minute rest period. The refractive errors before and after watching TV were compared. The amount of refractive change was also compared between myopes and controls. The refractive error of the participants who showed a myopic shift immediately after watching TV were compared across each time point to assure that the myopic shift persisted after a 10-minute rest. RESULTS: The mean age of the participants was 9.23 ± 1.75 years. The baseline manifest refractive error was -1.70 ± 1.79 (-5.50 to +1.25) diopters. The refractive errors immediately after watching and after a 10-minute rest were -1.75 ± 1.85 and -1.69 ± 1.80 diopters, respectively, which were not different from the baseline values. Myopic participants (34 participants), whose spherical equivalent was worse than -0.75 diopters, also did not show any significant refractive change after watching 3D TV. A myopic shift was observed in 31 participants with a mean score of 0.29 ± 0.23 diopters, which resolved after a 10-minute rest. CONCLUSIONS: Watching properly made 3D content on a 3D TV for 50 minutes with a 10-minute intermission at more than 2.8 meters of viewing distance did not affect the refractive error of children.
Accommodation, Ocular/*physiology ; Child ; Depth Perception/*physiology ; Disease Progression ; Female ; Humans ; Imaging, Three-Dimensional/*adverse effects ; Male ; Refractive Errors/*physiopathology ; *Television ; Vision, Binocular/*physiology

PURPOSE: The aim of this study is to investigate the clinical characteristics of patients diagnosed with refractive accommodative esotropia (RAE) whose refractive errors were gradually reduced to below +2.00 diopters (D) during follow-up but use of spectacles was still required for maintenance of good ocular alignment. METHODS: We conducted a retrospective review of the medical records of patients diagnosed with RAE from 1995 to 2011. Patients were divided into 2 groups according to their ocular alignment at the last visit. Inclusion criteria were hyperopia > or =+2.00 D detected with cycloplegic refraction at the initial visit, which then became mild hyperopia (<+2.00 D) or myopia during follow-up, with more than 5 years of follow-up. RESULTS: A total of 92 patients met the inclusion criteria. Twenty-six patients showed persistent esotropia (> or =10 prism diopters [PD]) without spectacles (group A) and 66 patients showed good ocular alignment (<10 PD) without spectacles (group B) at the last visit. No statistically significant differences in the spherical equivalent of the refractive errors at the initial and last visit were observed between the two groups. A significantly lower number of positive responses on the Lang I stereotest was observed in group A (n = 1, 3.8%) compared to group B (n = 22, 33.3%) (p = 0.003). There were increasing trends toward group A with worsening stereoacuity measured by the Stereo Fly Stereotest between the two groups (p = 0.016, linear by linear association). The results of the Lang I test, Stereo Fly Stereotest, and duration between the onset of esotropia and prescribing spectacles showed a significant association with the discontinuation of spectacles in the univariate logistic analysis. CONCLUSIONS: Stereoacuity showed more significant associations than refractive errors in RAE with refractive error <+2.00 D but still required spectacles for maintenance of good ocular alignment. The prompt treatment of accommodative esotropia at the onset of esotropia is important for the discontinuation of spectacles.
Accommodation, Ocular/physiology ; Adult ; Aged ; Esotropia/*physiopathology ; *Eyeglasses ; Female ; Follow-Up Studies ; Humans ; Hyperopia/physiopathology/*therapy ; Male ; Middle Aged ; Refraction, Ocular/physiology ; Retrospective Studies ; Vision, Binocular/*physiology ; Visual Acuity/physiology

OBJECTIVETo investigate the relationship between the characteristics of spatial vision deficit and the degree of amblyopia in monocular amblyopes, and to analyze its mechanism with the theory of Magnocellular and Parvocellular pathways.

METHODSOne hundred and eleven patients with monocular amblyopes aged 7-34 were included in this study. Distance best corrected visual acuity (BCVA) in logMAR units and contrast sensitivity function test were performed on both eyes in all patients with ETDRS digital visual chart and functional test system OPTECR 6500. The spatial vision of amblyopic and non-amblyopic eyes was evaluated by the AULCSF, Smax, Frmax and cutSF derived from the curve of contrast sensitivity function.

RESULTSThe degree of amblyopia was significantly correlated with the difference of AULCSF between the amblyopic and non-amblyopia eyes (r=-0.83, P<0.01). BCVA of amblyopic eyes was significantly correlated with AULCSF, CutSF, Smax, Frmax(r=-0.68, -0.80, -0.73, -0.56, respectively; P<0.01). In amblyopic eyes, significant difference in BCVA, AULCSF, Smax, Frmax and CutSF was seen among different amblyopic groups (P<0.01), which was defined by the degree of amblyopia. In non-amblyopic eyes,no significant difference in BCVA, AULCSF, Smax, Frmax and CutSF was noted among different amblyopic groups (P>0.05). In mild amblyopes, no significant difference in AULCSF and Frmax was found between the amblyopic eyes and non-amblyopic eyes (P>0.05), while Smax and CutSF were significantly different. However, in moderate and severe amblyopes, significant differences in BCVA, AULCSF, Smax, Frmax and CutSF was seen between the amblyopic and non-amblyopic eyes (P<0.01). In amblyopic eyes, significant difference in contrast sensitivity was noted in all kinds of spatial frequencies among different amblyopic groups (P<0.01), and in non-amblyopic eyes, significant differences in contrast sensitivity was not seen in all kinds of spatial frequencies among different amblyopic groups.

CONCLUSIONSThe AULCSF, CutSF, Smax and Frmax are accorded with visual acuity for evaluation of the spatial vision of amblyopia. As the severity of amblyopia increases, the overall function of spatial vision in amblyopic eyes gradually decreases, the resolution ability of high spatial frequency is gradually weaken, the peak of contrast detection function gradually descends, and the optimal spatial frequency for contrast detection offsets toward low level of spatial frequency. Mild monocular amblyopia produces spatial contrast sensitivity loss in high spatial vision, suggesting there may be decreased sensitivity of the Parvocellular pathway, and no significant anomalous processing of Magnocellular Pathway. Whereas, in moderate and severe amblyopes, a generalized loss of sensitivity is observed at each spatial frequency. This result shows that both Magnocellular and Parvocellular pathways are damaged in different degrees, especially in Parvocellular pathway.

Adolescent ; Adult ; Amblyopia ; physiopathology ; Child ; Contrast Sensitivity ; Female ; Humans ; Male ; Vision, Ocular ; physiology ; Visual Acuity ; Young Adult

BACKGROUNDIntensive insulin therapy has been found to lessen the progress of diabetic retinopathy (DR) to some extent, while it has also been implicated to be responsible for decrease of DR. We investigated visual function and morphological changes in the macular area in short-term follow-up of patients with type 2 diabetes mellitus after intensive insulin therapy.

METHODSThis was a prospective clinical study of nonproliferative DR patients (102 eyes, 120 patients) undergoing intensive insulin therapy. The Contrast Glare Tester (Takagi CGT-1000) was used to examine contrast sensitivity (CS) and Heidelberg Retina Tomograph (HRT) II and Stratus Model 3000 OCT were used to observe the changes of morphology in the macular area. Follow-up times were pre-intensive therapy, 3 and 6 months post-intensive therapy.

RESULTSCS at low and middle frequencies was higher at 3 and 6 months post-therapy compared with pre-therapy (P < 0.05). Significant differences in CS at low frequency were found between 6 and 3 months post-therapy (P < 0.05). Macular edema index was lower in the first, second, and third rings of the macular area after intensive therapy compared with pre-therapy (P < 0.05). Compared with 3 months post-therapy, the macular edema index was lower in the first, second, and third rings of the macular area at 6 months post-therapy (P > 0.05). No significant differences in the thickness of the first, second, and third rings of the macular area were detected between 3 and 6 months post-therapy and pre-therapy (P > 0.05).

CONCLUSIONCS and macular edema indexes were significantly improved in nonproliferative diabetic retinopathy patients after intensive insulin therapy, but thickness of the macular area was unchanged.

Diabetes Mellitus, Type 2 ; drug therapy ; pathology ; physiopathology ; Follow-Up Studies ; Humans ; Insulin ; therapeutic use ; Macula Lutea ; pathology ; Middle Aged ; Prospective Studies ; Tomography, Optical Coherence ; Vision, Ocular ; physiology

PURPOSE: To determine effectiveness of laser-assisted in situ keratomileusis (LASIK) in the treatment of astigmatism following penetrating keratoplasty (PK). METHODS: We performed a retrospective review of medical records of patients who underwent LASIK following PK and had over 1 year of follow-up data. RESULTS: Twenty-six patients (26 pairs of eyes) underwent LASIK following PK. Mean age of the patients at the time of LASIK was 40.7 years (range, 26 to 72 years). Following LASIK, the mean cylinder was reduced by 2.4 diopters and mean reduction of cylinder after LASIK was 65.4% from the preoperative values at the last follow-up visit. Uncorrected visual acuity became 20 / 50 or better in 69.2% of the eyes after LASIK. Best-corrected visual acuity became 20 / 50 or better in 73.1% of the eyes after LASIK. All of them were intolerable to contact lenses before LASIK. After LASIK, 6 pairs (23.1%) did not need to use contact lenses and 18 pairs (69.2%) were tolerable to using contact lenses or spectacles. There were no significant endothelial cell density changes 12 months after LASIK (p = 0.239). CONCLUSIONS: LASIK is effective in the treatment of astigmatism following PK and increases contact lens and spectacle tolerance.
Adult ; Aged ; Astigmatism/etiology/physiopathology/*surgery ; *Contact Lenses/utilization ; Corneal Topography ; Female ; Humans ; Keratomileusis, Laser In Situ/*methods ; Keratoplasty, Penetrating/*adverse effects ; Lasers, Excimer/*therapeutic use ; Male ; Middle Aged ; Refraction, Ocular/physiology ; Retrospective Studies ; Vision, Binocular/physiology ; Visual Acuity/physiology

Multifocal visual electrophysiology, consisting of multifocal electroretinography (mfERG) and multifocal visual evoked potential (mfVEP), can objectively evaluate retina function and retina-cortical conduction pathway status by stimulating many local retinal regions and obtaining each local response simultaneously. Having many advantages such as short testing time and high sensitivity, it has been widely used in clinical ophthalmology, especially in the diagnosis of retinal disease and glaucoma. It is a new objective technique in clinical forensic medicine involving visual function evaluation of ocular trauma in particular. This article summarizes the way of stimulation, the position of electrodes, the way of analysis, the visual function evaluation of mfERG and mfVEP, and discussed the value of multifocal visual electrophysiology in forensic medicine.
Electrodes ; Electrophysiology ; Electroretinography/methods* ; Evoked Potentials, Visual/physiology* ; Eye Injuries/physiopathology* ; Forensic Medicine/methods* ; Glaucoma/physiopathology* ; Humans ; Image Processing, Computer-Assisted ; Retina/physiopathology* ; Retinal Diseases/physiopathology* ; Vision, Ocular/physiology* ; Visual Acuity/physiology* ; Visual Fields/physiology*

In order to understand the roles of the other subunits, we investigated expression of the NMDA receptor subunits (NR2A and NR2B) in visual cortex of normal and anisometropic amblyopia kittens with different ages in the present study. We examined the expressions of NR2A and NR2B in the visual cortex of the kittens by immunohistochemistry with polyclonal anti-NR2A antibody and anti-NR2B antibody, respectively. Using immunohisto-chemical Streptavidin Perosidase (SP) method, we observed the dynamic changes of NR2A and NR2B with microscope and computer-assisted image analyses. We found that NR2A and NR2B remained low expression after the peak of the critical period of kitten visual development; compared with normal group of the same age, NR2A expresses low. However, the difference is not significant for NR2B before maturation period of visual development. NR2B rises after the maturation period of visual development. According to this, the component of NR2A and NR2B can be affected by anisometropia. This research suggests that the difference of NR2A and NR2B expressions may affect the formation of amblyopia.
Amblyopia ; metabolism ; Animals ; Cats ; Female ; Male ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism ; Vision, Ocular ; physiology ; Visual Cortex ; metabolism