Challenges in Patients with Trisomy 21: A Review of Current Knowledge and Recommendations.

PURPOSE: To summarize and review the common ophthalmic anomalies in children with trisomy 21 (Down syndrome) in order to propose an update to current clinical recommendations. METHODS: A retrospective chart review, systemic literature review, and international survey of the frequency of ocular abnormalities, screening schedules, and challenging aspects examining children with trisomy 21. The chart review included patients treated at the Department of Ophthalmology at the University Hospital of Zurich over a two-year period. The international survey was submitted to the members of the Swiss Society of Ophthalmology, Slovenian Ophthalmological Society, and European Pediatric Ophthalmology Society. RESULTS: Analysis of 52 patient records during the study period revealed refractive errors (astigmatism: 54% of patients, hyperopia: 26%, and myopia: 15%) as the most common diagnosis, whereas childhood cataract was reported in 5%. This is in concordance with the extended literature review of 249 publications, although congenital cataracts were reported to be higher than at our institution. The survey participants reported great challenges in taking care of these patients, despite their long professional experience (73% with over 10 years of experience). CONCLUSION: Care and treatment of children with trisomy 21 continues to be demanding for paediatric ophthalmologists. We recommend the following examination schedule for these patients: first, ophthalmological examination at 6-12 months of age, then once in 3-6 months for children under 2 years of age, once in 6 months for children 2-5 years of age, annually for children 5-10 years of age, and thereafter, to be decided on an individual basis depending on the presenting ocular abnormalities of the patient.

Visual electrodiagnostics and eye movement recording - World Society of Pediatric Ophthalmology and Strabismus (WSPOS) consensus statement.

Visual electrodiagnostics and eye movement recording are important additional clinical tools in evaluation, diagnosing and management of ophthalmic and neurological disorders. Due to their objectiveness and non-invasiveness they can play an important role in pediatric ophthalmology. The WSPOS (World Society of Pediatric Ophthalmology and Strabismus) consensus statement gives insight into basic principles and highlights the clinical application of both visual electrodiagnostic tests and eye movement recording.

Do Type 1 Diabetes Mellitus and Color-Vision Deficiencies Influence Shade-Matching Ability?

PURPOSE: To evaluate the effect of color-vision deficiencies and type 1 diabetes mellitus (DM) on visual shade-matching ability. MATERIALS AND METHODS: Four groups of participants were investigated: a control group (n = 68); a group with protanomalia (n = 10); a group with deuteranomalia (n = 19); and a group with type 1 DM (n = 13). Color vision was evaluated monocularly using the Ishihara test, Farnsworth-Munsell 100 hue (FM100H) test, Hardy Rand Rittler (HRR) test, and with an HMC Anomaloskop MR (Rayleigh and Moreland tests). The final exam was on a Toothguide Training Box (TTB) and consisted of 15 lightness-chroma-hue tasks. The color difference (ΔE*ab) and the shade-matching score (ΣΔE*ab) were computed, and the correct lightness (L*), chroma (C*), and hue (h*) selections were counted. The means and standard deviations for the ΣΔE*ab, ΔE*ab, L*, C*, h*, Ishihara, HRR, FM100H, and Rayleigh and Moreland tests were calculated. One-way analysis of variance (ANOVA) and post hoc Bonferroni test were used for statistical analyses and a comparison of means (α = .05). The data analyses were performed using SPSS 22.0 for Windows (IBM). RESULTS: The control group selected the shade tab on the TTB significantly better (ΣΔE*ab = 31.57 ± 13.50) than the group with protanomalia (ΣΔE*ab = 55.50 ± 12.36; P < .0001) and the group with deuteranomalia (ΣΔE*ab = 59.18 ± 16.35; P < .0001), but not significantly better than the group with type 1 DM (ΣΔE*ab = 39.43 ± 11.46; P = .368). The group with type 1 DM selected the shade tab on the TTB significantly better than the group with protanomalia (P = .038) and the group with deuteranomalia (P < .0001). CONCLUSION: Participants with color-vision deficiencies are less accurate at shade matching than the control group and the group with type 1 DM.

Does Physical Fatigue Affect Color Vision?

The purpose of this study was to establish whether physical fatigue affects color vision. Thirty healthy participants were included in the study (M:F=15:15), age 25.3±4.4 y, all professional or top amateur athletes. They were exhausted using the Wingate test (WT). Physical fatigue was determined by blood lactate level before the WT and 1, 3, 5, 7 and 10 min after. Color vision was evaluated using the Hardy-Rand-Rittler (HRR) and the Mollon-Reffin Minimalist (MRM) tests before the WT and 5, 10 and 30 min after. Five minutes after the WT 2/30 (6%) showed affected color vision in the protan axis and 25/30 (83%) in the tritan axis. Ten and 30 min after the WT all the participants showed normal color vision in both the deutan and protan axes, whereas 12/30 (40%) and 8/30 (26%), respectively, showed affected color vision in the tritan axis. A gender difference was observed in color vision deficiency and improvement, with female participants being affected more and longer. The study showed that intense physical effort affects color vision with the tritan axis being predominantly affected.

Do blue-light filtering intraocular lenses affect visual function?

PURPOSE: To study different aspects of visual function, macular changes, and subjective differences between the eye with an ultraviolet (UV) and blue-light filtering intraocular lens (IOL) and the fellow eye with a UV-light filtering IOL. METHODS: Thirty patients (60 eyes) with senile cataract had both cataracts extracted, and an IOL was implanted at least 2 years before clinical evaluation. In one eye, AcrySof SA60AT (a UV-light filtering IOL) was implanted, whereas in the contralateral eye, AcrySof IQ SN60WF (a blue-light filtering IOL) was implanted. Each patient underwent visual acuity testing, color vision testing (Ishihara and Farnsworth-Munsell 100-hue tests), and contrast sensitivity (CS) testing. The macula was evaluated with optical coherence tomography and with clinical examination. Patients were asked if they noted any difference between the implanted IOLs concerning visual impression. Subjective visual quality was evaluated using the National Eye Institute Visual Functioning Questionnaire. RESULTS: There was a borderline statistically significant difference in the mean best-corrected visual acuity (p = 0.05). As regards color vision, no significant changes in Ishihara and Farnsworth-Munsell 100-hue error scores were detected between both eyes (p = 0.48 and p = 0.59, respectively). Analysis of CS showed no significant difference between the groups at any spatial frequency. There were also no statistically significant differences in central macular thickness and total macular volume between the two IOL groups (p = 0.72 and p = 0.61, respectively). In both IOL groups, three eyes developed an epiretinal membrane, and six eyes developed early signs of age-related macular degeneration. CONCLUSIONS: This study showed no significant effects of a blue-light filtering IOL on visual acuity and no influence on color perception and CS. After more than 2 years, there were no significant differences in macular changes between the IOL groups. Clinical evidence of the effect of a blue-light filtering IOL on macular protection is still lacking.

Chromatic visual evoked potentials in young patients with demyelinating disease.

The purpose of this study was to evaluate color vision in young patients with demyelinating disease both clinically and electrophysiologically. Thirty young patients (8-28 years, mean age 19 years) with demyelinating disease with or without a history of optic neuritis (ON) were investigated. Color vision was evaluated clinically with the Ishihara test and the Farnsworth-Munsell 100 hue (FM 100 hue) test and electrophysiologically with chromatic visual evoked potentials (cVEPs). Color deficiency axis and error score (ES) obtained with the FM 100 hue test were analyzed. cVEPs to isoluminant red-green (R-G) and blue-yellow (B-Y) stimuli were recorded. The stimulus was a 7 deg circle composed of horizontal sinusoidal gratings with a spatial frequency of 2 cycles/deg and 90% chromatic contrast. Onset-offset mode of stimulation (ON:OFF=300∶700 ms) was used. Since the majority of the patients were adults (>18 years), the negative wave (N wave) of the cVEP respones is the prominent part and therefore was analyzed. Sixty eyes were studied-22 with at least one episode of ON (ON group) and 38 without any clinically evident episode of ON (nON group). The average ES in the ON group was 179.18±171.8, whereas in the nON group it was 87.60±65.34. The average N-wave latency in the ON group was 144±44 ms for the R-G stimulus and 146±56 ms for the B-Y stimulus, whereas in the nON group, it was 117±13 ms for the R-G stimulus and 121±22 ms for the B-Y one. The average N-wave amplitude in the ON group was 9.3±7.1 µV for the R-G stimulus and 5.1±3.9 µV for the B-Y one, whereas in the nON group, it was 10.8±8.3 µV for the R-G stimulus and 6.4±4.3 µV for the B-Y one. A significant difference between the ON and the nON group was found: in the ON group, ES was higher (p=0.01) and N-wave latency was longer (p=0.01) compared with those in the nON group. The study showed that color vision is expectedly more affected in the ON group, but also often in the nON group, which may indicate increased parvocellular visual pathway vulnerability in demyelinating diseases.

Chromatic visual evoked potentials in paediatric population.

BACKGROUND: The purpose of this study was to investigate chromatic visual evoked potential (cVEP) response characteristics during the first year of life and to collect as large database of healthy baby responses as possible. This study also complements our previous studies on cVEP in schoolchildren and preschool children. METHODS: Forty-four healthy babies aged 3-12 months were binocularly tested. cVEP were recorded to isoluminant red-green (R-G) and blue-yellow (B-Y) stimuli. The stimulus represented a circle composed of horizontal sinusoidal gratings with 90 % chromatic contrast and spatial frequency of 2 cycles/deg. Two stimulus sizes (7° and 21°) and onset-offset mode of stimulation (On-300 ms, Off-700 ms) were used. cVEP were recorded from Oz (mid-occipital) position with the reference at Fz. Waveform characteristics and its changes throughout the first year of life were studied. RESULTS: Chromatic visual evoked potential responses were reliably recorded in all but two youngest babies. Characteristic cVEP response consisted of negative-positive-negative complex, positive (P) wave being far more prominent than both negative waves (N1 and N2). cVEP response to larger stimulus size (21°) showed shorter latency and higher amplitude to both (R-G) and (B-Y) stimuli compared to smaller stimulus size (7°). The same was true when comparing R-G versus B-Y stimulus: R-G responses showed higher amplitude and shorter latency than B-Y response, for both stimulus sizes. P wave latency shortened with increasing age throughout the first year of life, both for R-G (R (2) = 0.59) and B-Y (R (2) = 0.41) 21° stimulation. P wave amplitude did not show significant changes throughout the first year of life. CONCLUSIONS: Chromatic visual evoked potential can be reliably recorded after the age of 3 months and show significant maturational changes throughout the first year of life.

Chromatic visual evoked potential responses in preschool children.

The purpose of the study was to analyze chromatic visual evoked potential (VEP) responses to isoluminant red-green (R-G) and blue-yellow (B-Y) stimuli in 30 preschool children (1.5-6 years). The predominant part of the response consisted of a positive (P) wave, which showed age-related latency changes (linear decrease). P wave latency was shorter when using 21° compared to 7° R-G (p=0.004) and B-Y (p=0.044) stimulus and also when using 21° R-G compared to 21° B-Y stimulus (P=0.000). P wave amplitude did not show age-related changes. However, a lower amplitude was recorded when using 7° R-G stimulus (p=0.0013) and also when using B-Y compared to R-G stimulus. We may conclude that chromatic VEP to R-G and B-Y stimuli is reliably recorded in preschool children and that P wave to R-G stimulation shows a higher amplitude and shorter latency than to B-Y stimulus.

Visual evoked potentials to red-green stimulation in schoolchildren.

The aim is to study chromatic visual evoked potentials (VEP) to isoluminant red-green (R-G) stimulus in schoolchildren. Sixty children (7-19 years) with normal color vision were examined, 30 binocularly and 30 monocularly. The isoluminant point was determined for each child subjectively by using heterochromatic flicker photometry, and objectively from recordings. The stimulus was a 7 degrees circle composed of horizontal sinusoidal gratings, with spatial frequency 2 cycles/degrees and 90% contrast, presented in onset-offset mode. VEP were recorded from Oz (mid-occipital) position. Age-dependent waveform changes and changes of the positive and negative wave were studied to both binocular and monocular R-G stimulation. Age-dependent waveform changes were observed to binocular and monocular R-G stimulation. In younger children the positive wave was prominent, whereas in older children also the negative wave became more evident. The latency of the positive wave decreased linearly with age to R-G binocular stimulation. To monocular stimulation no significant changes of the latency were observed. The amplitude of the positive wave dropped exponentially with age to binocular and monocular stimulation. The latency of the negative wave increased linearly with age to binocular and monocular stimulation, whereas the amplitude did not show age-dependent changes. These findings suggest that the chromatic VEP response undergoes evident age-dependent changes during the school-age period.