Developmental Eye Movement (DEM) and King-Devick (K-D) Performance in Multiple Sclerosis.

Eye movement disorders have been reported in patients with multiple sclerosis (MS) as saccadic disturbances. Several methods have been described for the assessment of saccades, including the K-D and DEM tests. The performance of these tests also involves attention, language, and other brain areas which have been reported to be altered in MS patients. The aim of the study was to determine how developmental eye movement (DEM) and King-Devick (K-D) tests are affected in MS-patients. It was also to analyze whether a resolved episode of optic neuritis (ON) has a negative influence. Subjects with MS showed worse outcomes (higher times) in DEM test (72 (26) s and a K-D test (56 (22) s compared to healthy subjects (64 (7) s and 55 (11) s, respectively). However, a previous ON episode did not worsen the MS-times of DEM (80 (33) s or of K-D (62 (33) s. Horizontal saccades with the DEM showed differences between subjects with MS (with and without ON) and healthy ones (p < 0.05), whereas no such differences were found in the vertical saccades. According to the DEM instructions, MS patients would present heterogeneous oculomotor and non-visual disturbances. Regarding the K-D test, only the third card (the most complex one) showed differences (p < 0.05) between groups. These tests can capture impairment of attention, language, and other areas that correlate with suboptimal brain function in addition to the oculomotor dysfunctions present in subjects with MS.

Binocular Vision in Patients with Multiple Sclerosis.

PURPOSE: Oculomotor disorders have been reported in multiple sclerosis (MS) in up to 80% of cases. There have been studies evaluating binocular vision in several neurological diseases, but not in MS. Considering that a high percentage of eye-movement anomalies have been reported, the aim of this study was to analyze binocular vision in these subjects. METHODS: A total of 59 participants with MS - 21 with monocular optic neuritis, eleven with binocular optic neuritis, and 27 without optic neuritis - and 26 age-matched controls were enrolled. Binocular vision was analyzed using near point of convergence (NPC), positive and negative fusional vergence for far and near distance, measurement of heterophoria at both distances with cover and modified Thorington tests, and random-dot stereoscopy. RESULTS: The percentage of subjects with abnormal NPC values was highest in the MS group, followed by the MSONm (MS with optic neuritis in one eye), MSONb (MS with optic neuritis in both eyes), and control groups. MS patients showed an esophoric trend at near distance. Positive fusional vergence showed no significant differences between control and MS groups, but higher variability in recovery was found in MS groups. Negative fusional vergence at near distance showed significant differences between the control group and the two MS groups, with optic neuritis for both break-point and recovery values. A high percentage of patients with MS had alterations on stereopsis. CONCLUSION: Alterations in binocular vision were present in MS, with divergence at near distance and stereopsis the most affected parameters. Likewise, MS patients with optic neuritis showed worse binocular vision.

Ocular fixation and macular integrity by microperimetry in multiple sclerosis.

PURPOSE: To characterize the fixation and macular integrity of subjects with multiple sclerosis (MS) with and without previous optic neuritis (ON) using microperimetry (MP). METHODS: Fifty-five eyes of MS patients, subdivided into three groups (28 eyes without ON, 16 with previous ON, and 11 eyes with previous ON in the contralateral eye), and 43 healthy eyes were enrolled (January-November 2018). All cases were evaluated using the MAIA microperimeter (Centervue), analyzing the following parameters: average macular threshold (AT), fixation indexes (P1 and P2), bivariate contour ellipse area (BCEA) for 95% and 63% of points, and horizontal (H) and vertical (V) axes of the ellipse of fixation. RESULTS: All MS groups showed a significant reduced AT compared with the control group (p < 0.001). This reduction was more representative (p < 0.001) in eyes with previous ON. No statistically significant differences were found between MS patients with and without previous ON (p > 0.05). Mean AT was correlated with the examination time in all three groups (between ρ = - 0.798 p < 0.001 and ρ = - 0.49 p < 0.001). Significant differences in fixation parameters were only found between control and MS with ON groups (p < 0.02). The ratio of the disease showed a significant correlation with fixation parameters in MS groups (p < 0.02), but not with AT. CONCLUSIONS: In MS patients, macular sensitivity is altered, especially in eyes with previous ON. Likewise, a fixational instability is present in MS patients with ON, with more increase of the V axis of the fixation area than of the H. The ratio of the disease also affects the patient fixation pattern.

Corneal biomechanics, retinal nerve fiber layer, and optic disc in children.

PURPOSE: To evaluate the possible associations between corneal biomechanical parameters, optic disc morphology, and retinal nerve fiber layer (RNFL) thickness in healthy white Spanish children. METHODS: This cross-sectional study included 100 myopic children and 99 emmetropic children as a control group, ranging in age from 6 to 17 years. The Ocular Response Analyzer was used to measure corneal hysteresis (CH) and corneal resistance factor. The optic disc morphology and RNFL thickness were assessed using posterior segment optical coherence tomography (Cirrus HD-OCT). The axial length was measured using an IOLMaster, whereas the central corneal thickness was measured by anterior segment optical coherence tomography (Visante OCT). RESULTS: The mean (±SD) age and spherical equivalent were 12.11 (±2.76) years and -3.32 (±2.32) diopters for the myopic group and 11.88 (±2.97) years and +0.34 (±0.41) diopters for the emmetropic group. In a multivariable mixed-model analysis in myopic children, the average RNFL thickness and rim area correlated positively with CH (p = 0.007 and p = 0.001, respectively), whereas the average cup-to-disc area ratio correlated negatively with CH (p = 0.01). We did not observe correlation between RNFL thickness and axial length (p = 0.05). Corneal resistance factor was only positively correlated with the rim area (p = 0.001). The central corneal thickness did not correlate with the optic nerve parameters or with RNFL thickness. These associations were not found in the emmetropic group (p > 0.05 for all). CONCLUSIONS: The corneal biomechanics characterized with the Ocular Response Analyzer system are correlated with the optic disc profile and RNFL thickness in myopic children. Low CH values may indicate a reduction in the viscous dampening properties of the cornea and the sclera, especially in myopic children.

Optic neuritis in pediatric population: a review in current tendencies of diagnosis and management.

Optic neuritis is an inflammation of the optic nerve and may be related to different systemic conditions. The clinical presentation of this pathology usually includes sudden loss of visual acuity (VA) which may be unilateral or bilateral, visual field restriction, pain with eye movements, dyschromatopsia, a relative afferent pupillary defect and optic disk swelling. Optic neuritis in children has specific clinical features and a better prognosis than in adulthood. Although usually appears an underlying viral disease, the main concern for practitioners is the relationship of optic neuritis with multiple sclerosis. In addition to the classical techniques as magnetic resonance imaging (MRI), current tendencies of diagnosis for eye practitioners include new imaging devices as optical coherence tomography (OCT), useful to show a thinning of the retinal fibers layer (RFL) after the inflammatory episode. Regarding the management of these patients, short-term intravenous steroid dosages seem to be the best option to treat acute attacks characterized by a very poor bilateral VA.

Relationship among corneal biomechanics, refractive error, and axial length.

PURPOSE: To evaluate the relationship between different ocular and corneal biomechanical parameters in emmetropic and ametropic healthy white children. METHODS: This study included 293 eyes of 293 healthy Spanish children (135 boys and 158 girls), ranging in age from 6 to 17 years. Subjects were divided according to the refractive error: control (emmetropia, 99 children), myopia (100 children), and hyperopia (94 children) groups. In all cases, corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated with the Ocular Response Analyzer system. Axial length (AL) and mean corneal power were also measured by partial coherence interferometry (IOLMaster), and central corneal thickness (CCT) and anterior chamber depth were measured by anterior segment optical coherence tomography (Visante). RESULTS: Mean (±SD) CH and CRF were 12.12 (±1.71) and 12.30 (±1.89) mm Hg, respectively. Mean (±SD) CCT was 542.68 (±37.20) µm and mean (±SD) spherical equivalent was +0.14 (±3.41) diopters. A positive correlation was found between CH and CRF (p < 0.001), and both correlated as well with CCT (p < 0.0001). Corneal resistance factor was found to decrease with increasing age (p = 0.01). Lower levels of CH were associated with longer AL and more myopia (p < 0.001 and p = 0.001, respectively). Higher values of CH were associated with increasing hyperopia. Significant differences in CH were found between emmetropic and myopic groups (p < 0.001) and between myopic and hyperopic groups (p = 0.011). There were also significant differences in CRF between emmetropic and myopic groups (p = 0.02). Multiple linear regression analysis showed that lower CH and CRF significantly associated with thinner CCT, longer AL, and flatter corneal curvature. CONCLUSIONS: The Ocular Response Analyzer corneal biomechanical properties seem to be compromised in myopia from an early age, especially in high myopia.

Algorithm for correcting the keratometric estimation error in normal eyes..

PURPOSE: To obtain an accurate algorithm for calculating the keratometric index that minimizes the errors in the calculation of corneal power assuming only a single corneal surface in the range of corneal curvatures of the normal population. METHODS: Corneal power was calculated by using the classical keratometric index and also by using the Gaussian equation. Differences between types of calculation of corneal power were determined and modeled by regression analysis. RESULTS: We proposed two options for the selection of the most appropriate keratometric index (n(k)) value for each specific case. First was the use of specific linear equations (depending on the ratio of the anterior to the posterior curvature, k ratio) according to the value of the central radius of curvature of the anterior corneal surface (r(1c)) in 0.1 mm steps and the theoretical eye model considered. The second was the use of a general simplified equation only requiring r(1c) (Gullstrand eye model, n(k) = -0.0064286r(1c) + 1.37688; Le Grand eye model, n(k) = -0.0063804r(1c) + 1.37806). CONCLUSIONS: The generalization of the keratometric index (n(k)) value is not an appropriate approximation for the estimation of the corneal power and it can lead to significant errors. We proposed a new algorithm depending on r(1c), with a maximal associated error in the calculation of the corneal power of 0.5 D and without requiring knowledge of the posterior corneal curvature.

Clinical impact of a spontaneous decentration of a phakic refractive lens.

PURPOSE: To evaluate the clinical impact and possible causes of a spontaneous decentration of a phakic refractive lens (PRL) implanted in a highly myopic eye, and analyzing the visual, refractive, and aberrometric outcome as well as the possible causes for this phenomenon. METHODS: The description of a case of bilateral high myopia corrected by implantation with the phakic intraocular lens (pIOL) PRL (Carl Zeiss Meditec, Germany) is presented and documented. Both eyes had similar anatomical configuration, and therefore, a pIOL (Model 101) with the same size was implanted without any associated intraoperative complication. Clinical outcomes were evaluated during a 3-month follow-up. RESULTS: Implanted pIOLs were properly positioned in both eyes and provided an excellent visual outcome during the immediate postoperative period. However, 1 month after surgery, the patient presented a logarithm of the minimum angle of resolution uncorrected distance visual acuity of 0.15 and 0 in the OD and OS, respectively. Subjective refraction in the OD was +1.00 to 1.00 × 15°, with logarithm of the minimum angle of resolution corrected distance visual acuity of 0. Temporal displacement of the PRL was evident in the biomicroscopic examination and analyzed in detail with advanced imaging techniques finding an asymmetric vault. Regarding aberrometry, larger amounts of primary coma, and spherical aberration were present in the OS. Two months later, the situation remained stable. CONCLUSIONS: Spontaneous PRL decentration is not necessarily associated with a visual quality loss and a bad selection of pIOL size. For implantation of this pIOL, a comprehensive analysis of the zonule would be necessary.