Purpose of this study was to characterize retinal disease in Usher syndrome using fundus autofluorescence and optical coherence tomography. Study included54 patients (26 male, 28 female) aged 7-70 years. There were 18 (33%) USH1 and 36 (67%) USH2 patients. 49/52 (94%) patients were found to carry at least one mutation in Usher genes. Ophthalmological examination included assessment of Snellen visual acuity, color vision with Ishihara tables, Goldmann visual fields (targets II/1-4 and V/4), microperimetry, fundus autofluorescence imaging and optical coherence tomography. Average age at disease onset (nyctalopia) was significantly lower in USH1 than USH2 patients (average 9 vs. 17 years, respectively; p ( 0.01); however no significant differences were found regarding type of autofluorescence patterns, frequency of foveal lesions and CME, rate of disease progression and age at legal blindness. All representative eyes had abnormal fundus autofluorescence of either hyperautofluorescent ring (55%), hyperautofluorescent foveal patch (35%) or foveal atrophy (10%). Disease duration of more than 30 years was associated with a high incidence of abnormal central fundus autofluorescence (patch or atrophy) and visual acuity loss.
COBISS.SI-ID: 547244
Achiasmia is a rare disorder of visual pathway maldevelopment that can show diverse clinical and magnetic resonance imaging spectra. The aim of this studywas to define the characteristics of visual evoked potentials (VEPs) thatdifferentiate abnormal optic-nerve-fibre decussation in children with achiasmia versus children with albinism and healthy children. In four childrenwith achiasmia, the following VEP characteristics were studied and compared to children with ocular albinism and with healthy control children: (a) flash and pattern onset VEP interhemispheric asymmetry; (b) flash N2, P2 and onset C1 amplitudes and latencies; (c) interocular polarity differences ininterhemisphere potentials; and (d) chiasm coefficients (CCs). In the children with achiasmia, VEPs were related to an absence of or reduced optic-nerve-fibre decussation at the chiasm and showed: ipsilateral asymmetry,significantly higher VEP amplitudes over the ipsilateral hemisphere (p ( 0.05), interocular inverse polarity and negative CC. Other VEP features (uncrossed asymmetry and positive CC) were also seen if additional visual pathway maldevelopment (such as severe optic nerve hypoplasia and/or absence of the optic tractus on one side) were associated with achiasmia. In the children with albinism, the VEPs were related to excess optic-nerve-fibre decussation at the chiasm and showed: contralateral asymmetry, significantly higher VEP amplitudes over the contralateral hemisphere (p ( 0.001), interocular inverse polarity and negative CC. In achiasmia and albinism, the VEPs to flash stimulation were more robust and more clearly distinguished between the conditions compared with the VEPs to pattern onset stimulation. VEPs in achiasmia are associated with absent or reduced optic-nerve-fibre decussation, where ipsilateral interhemispheric asymmetry is associated with interocular inverse polarity and a negative CC.
COBISS.SI-ID: 29828313
Purpose: To determine whether the vitreous levels of interleukin 8 (IL-8) and vascular endothelial growth factor (VEGF) of patients with proliferative diabetic retinopathy (PDR) were associated with poor visual acuity after vitrectomy. Methods: Observational cross-sectional study. Patient clinical characteristics and preoperative eye characteristics (63 eyes): visual acuity,iris neovascularization, vitreous haemorrhage, macular detachment, macular oedema, active retinal neovascularization, neovascularization of the disc, burned out PDR (defined as natural end stage of PDR with inactive membranes without previously performed laser photocoagulation) and panretinal photocoagulation were registered prior to vitrectomy for each patient. Vitreous VEGF and IL-8 levels were measured using the cytometric bead array method. Poor postoperative visual acuity was defined as visual acuity of (20/200 and was checked 2 years after vitrectomy. Results: Twenty-one of the 63 eyes (33.3%) had poor visual acuity after vitrectomy. Univariate analysis showed that vitreous levels of IL-8, the absence of panretinal photocoagulation, preoperative macular detachment and poor preoperative visualacuity were significantly associated with poor final visual acuity aftervitrectomy. A stepwise multiple logistic regression analysis showed thatelevated vitreous levels of IL-8 (p ( 0.0001), macular detachment (p = 0.011) and the absence of panretinal photocoagulation (p = 0.03) were independent predictors for poor visual outcome. Conclusions: Elevated vitreousIL-8 level could either be a marker of ischaemic inflammatory reaction, or it could play a role in deteriorating visual acuity by DR progression or both. Further studies are needed to provide better understanding of IL-8 and inflammation involvement in visual prognosis in PDR.
COBISS.SI-ID: 27754201
This is the first study in Slovenia to characterise LHON and the first study to describe electrophysiological biomarkers of this disease in early stages. Also, Slovenian patients have been found to have different genetic picture compared to other studies.
COBISS.SI-ID: 2120364
This is a fundamental clinical study that assesses the role of objective electrophysiological diagnostics to discriminate between the nystagmus caused by early-onset retinal dystrophies and infantile nystagmus in young children.
COBISS.SI-ID: 2016428
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.
COBISS.SI-ID: 1425836
Purpose: To correlate clinical bleb characteristics and the expression of human leukocyte antigen (HLA)-DR by conjunctiva with the outcome of trabeculectomy. Patients and methods: In this cross-sectional study, bleb morphology was assessed at slit lamp using the Moorfields Bleb Grading System in 85 eyes of 85 patients. Conjunctival specimens were collected from superiorconjunctiva by impression cytology and analyzed for the expression of HLA-DR on epithelial and antigen-presenting cells. The success of trabeculectomy was defined as intraocular pressure (21 mm Hg without antiglaucoma drops. Differences in bleb characteristics and expression of HLA-DR between eyes with surgical success and failure were examined. Results: Fifty-eight of 85 eyes with successful trabeculectomy had significantly greater central and maximal area of the bleb (P(0.001) with decreased vascularity of the central (P=0.02) and peripheral part of the bleb (P=0.03).The expression of HLA-DR on conjunctival epithelial cells and antigen-presenting cells was not different between the eyes with successful and failed trabeculectomy and also not between the eyes with and without topical glaucoma medication or topical corticosteroid eye drops. Conclusions:Successful trabeculectomy was associated with greater area and decreased vascularity of the bleb but not with diminished expression of inflammatory marker by ocular surface. Presence of subclinical inflammation ineyes without eye drops may result from the transcellular aqueous pathway towards the ocular surface, especially in functioning blebs with adjunctive mitomycin C.
COBISS.SI-ID: 28675289
A Nd:YAG laser photodisruption is a well-established tool for intraocular surgery, such as treatment of posterior capsule opacification that affects the visual function. During the intraocular procedure, called laser capsulotomy, the excitation pulse is focused several times just behind the posterior capsule and intraocular lens to create the central opening in the opacified capsule. We built an in vitro experiment to (1) clarify the influence of the distance between the intraocular lens and the posterior capsule on the total pulse energy required for the capsulotomy, and (2) investigate the main mechanisms responsible for the posterior capsule opening. In our in vitro model, different distances between the solid boundary (imitating an intraocular lens) and the membrane (imitating the posterior capsule) simulate different types of posterior capsule opacification. Our results show that procedure efficiency decreases by decreasing distance between the lens and the capsule. We also explain that for smaller distances between the pulse focus and the membrane, plasma and shock wave are responsible for the capsule disruption. Here, a risk of collateral damage significantly increases. On contrary, the membrane and the bubble jet disrupt the membrane, when pulse focus is moved away and the risk of intraocular lens damage decreases. However, the membrane disruption is not very effective, if it is placed near the solid boundary that inhibits the membrane jet.
COBISS.SI-ID: 14475803