Huban Atilla

Pattern electroretinography and visual evoked potentials in optic nerve diseases

BACKGROUND To evaluate transient pattern electroretinography (PERG) and pattern visual evoked potential (VEP) for the diagnosis, differential diagnosis and follow-up of optic nerve diseases. METHODS Twenty-nine consecutive patients (14 female, 15 male) with the diagnosis of ischaemic optic neuropathy (n=14) and optic neuritis (n=15) were included in this study. Mean age of the patients with ischaemic optic neuropathy was 63.3+/-3.3 (60-78) years and the mean age of the patients with optic neuritis was 28.3+/-8.4 (19-43) years. In each patient ophthalmological examination and systemic evaluation were done and VEP and PERG were recorded. As a control group, VEP recordings of 35 healthy subjects were included. RESULTS In the ischaemic optic neuropathy group (group 1), mean VEP amplitude (+/-SD) (1.96+/-0.95 microV) was found to be decreased significantly in the affected eyes in comparison to the control group and the unaffected eyes. The delay in latency (116.3+/-20.14 msec in the affected eyes compared with 101.31+/-6.19 msec in unaffected eyes) was statistically significant when compared with the healthy subjects. In the optic neuritis group (group 2), VEP amplitude was decreased (4.13+/-4.04 microV vs 6.97+/-3.35 microV and 6.97+/-4.43 microV) and latency was increased (122.59+/-20.09 msec vs 101.31+/-6.19 msec and 108.76+/-13.57 msec) in affected eyes significantly in comparison to the unaffected eyes and control group, respectively. Even though there were no significant differences for P50 latency and N95/P50 ratios between affected and unaffected eyes in both groups, N95 amplitude decreased significantly in the affected eyes of the ischaemic optic neuropathy patients and N95 latency was found to be decreased in optic neuritis patients. There was no correlation between VEP and PERG findings in both groups. CONCLUSION VEP amplitude decreased significantly in ischaemic optic neuropathies while latency delay was more significant in patients with optic neuritis. PERG findings showed decreased N95 amplitude in ischemic optic neuropathy without associated latency changes.

Color Doppler imaging in uveitis.

Purpose. To evaluate the vascular hemodynamic changes that can be detected with color Doppler imaging (CDI) in diagnosis, differential diagnosis and prognosis of uveitis with different etiologies including Behçets disease. Methods. Four groups consisting of healthy volunteers, uveitis patients with different etiologies and Behçets disease patients with and without ocular involvement were examined by CDI. Central retinal artery (CRA), posterior ciliary artery (PCA), ophthalmic artery (OA) and central retinal vein (CRV) flow velocities and vascular resistances were measured prospectively by a radiologist blinded to the presence and etiology of uveitis. Results. The peak systolic and end-diastolic velocities in CRA and PCA in Behçets disease with ocular involvement were significantly lower than all other groups (p<0.001). Peak systolic and end-diastolic velocities in CRA were lower than the control group in Behçets disease patients without ocular involvement (p<0.001) but there were no differences in PCA and OA flow velocity (p>0.05). In the uveitis group, CRA and CRV flow velocities were significantly lower than in the control group (p<0.001). Conclusions. According to our results, uveitis in Behçets disease is associated with significant reductions of CRA and PCA flow velocities when compared with other types of uveitis and. healthy subjects. In cases without ocular involvement, CRA flow velocities were lower than the control group, but there were no real differences in the PCA and OA values. This suggests that vasculitic involvement of PCA is more specific to Behçets disease and occurs later in the course of the disease. The results also suggest that it may be possible to detect and follow hemodynamic changes in Behçets disease with CDI before clinical findings of ocular involvement become evident.

Effects of intracameral lidocaine on ocular tissues

Purpose: To investigate the ultrastructural changes in iris and corneal tissue induced by intracameral 1% lidocaine infusion applied during lens extraction in a rabbit model.

Comparative efficacy of β-irradiation and mitomycin-C in primary and recurrent pterygium

Purpose To determine the efficacy and safety of mitomycin-C as adjunctive treatment and to compare this drug with beta irradiation with strontium-90 after surgical excision of primary and recurrent pterygia. Materials and Methods The study group consisted of 193 patients with primary and recurrent pterygia who underwent surgical excision with the bare sclera technique. They were divided into two groups according to the type of adjunctive treatment. In group I, 130 patients (141 eyes, 67.8%) were treated with beta irradiation with Sr-90 doses of 1000–7000 cGy. In group II 63 patients (67 eyes, 32.2%) received topical mitomycin-C at a concentration of 0.02% four times daily for one week postoperatively. Recurrence rates, complications and efficacy of these treatments were compared with the chi-square of Fishers exact test. Results The recurrence rates were 6.4% in group I after a mean postoperative follow-up of 89 months and 17.9% in group II after a mean follow-up of 14.9 months. Recurrence rates and complications were higher in group II and the difference was significant (p<0.05, p<0.001). Life-table analysis showed a success rate of 93.6% for Sr-90 and 81.9% for the mitomycin-C, the difference being significant (p<0.005). Conclusions Beta irradiation with Sr-90 after surgical excision was more effective than topical mitomycin-C in patients with primary and recurrent pterygium in terms of recurrence rates, and safer in terms of complications.

Effects of amniotic membrane on wound healing and adhesions in experimental strabismus surgery.

Purpose To evaluate the efficiency of amniotic membrane in prevention of adhesion formation after strabismus surgery. Methods A prospective, controlled study was conducted on 20 eyes of 10 pigmented rabbits. After disinsertion of the superior rectus muscle, under the muscle insertion area to induce adhesion formation, a partial-thickness 4 × 4 mm sclerectomy was performed in both eyes. In the right eyes, a piece of appropriate size human amniotic membrane was sutured on the sclerectomy site. As the control group, left eyes were operated with a similar procedure but without amniotic membrane transplantation. After 2 months, both eyes were enucleated to perform histopathologic examination. Results There was no adhesion between the sclera and muscle in the amniotic membrane group; however, there were various degrees of adhesions in the control group (p=0.004). Fibrosis in rectus muscle was present in 40% of the specimens in the amniotic membrane group and 90% in the control group with a higher grade (p=0.023). The mean number of inflammatory cells was significantly higher in the amniotic membrane group (p=0.005). Conclusions According to our results, amniotic membrane has antifibrotic effect but no anti-inflammatory effect in rabbit eyes due to possible xenograft reaction to human tissues. It is effective in prevention of adhesion formation with possible physical barrier action.

Amiodarone-related optic neuropathy.

BACKGROUND To evaluate a case of atypical optic neuropathy that presented with blurred vision following the use of an antiarrythmic agent. CASE Record of the patient was reviewed to determine the etiology of his optic neuropathy. OBSERVATIONS Ophthalmological examination revealed unilateral optic disc edema with relatively well-preserved visual acuity. In routine tests, results of complete blood count, erythrocyte sedimentation rate, liver and kidney function tests, chest x-ray, Goldmann visual field examination, and brain computed tomography scan were normal. Orbital ultrasonography revealed optic disc edema with prominent optic nerve head and without orbital pathology. CONCLUSIONS Systemic history and drug intake should be investigated in every patient with optic disc edema. Discontinuation of the medication can prevent further optic nerve damage or involvement of the other eye.

Effect of hormone replacement therapy on ocular hemodynamics in postmenopausal women

Purpose To evaluate the effect of hormone replacement therapy on ocular hemodynamics in postmenopausal women. Methods Ocular Doppler ultrasonography was performed in 20 postmenopausal women on hormone replacement therapy (HRT) and in 20 women without treatment, as the control group. Central retinal artery (CRA), posterior ciliary artery (PCA) and ophthalmic artery (OA) flow velocities and vascular resistances were measured prospectively by a radiologist blinded to the therapy. There were no associated systemic or ocular diseases or any medication history. Results The mean age of the patients on HRT was 50.05 ± 4.5 yrs (range 44 - 62). The mean age of the control group was 52.8 ± 4.09 yrs (range 46 - 65). The mean duration of HRT was 1.6 ± 1.4 yrs (range 3 months - 5 years). There were no differences between the groups in terms of flow velocities, vascular resistivities or pulsatility indices of OA, CRA and PCA (p>0.05). Conclusions HRT is essential in postmenopausal women for relief of vasomotor symptoms, cardioprotection and prevention of osteoporosis. Even though vaso-occlusive complications of hormone preparations have been reported, we did not observe any changes in ocular hemodynamics detectable with Doppler ultrasonography.

Inflammatory pigmented paravenous retinochoroidal atrophy.

Purpose To describe an active inflammatory cause of pigmented paravenous retinochoroidal atrophy.Methods A 54-year-old female patient presented with complaints of worsening visual acuity and poor night vision was examined. Fundus examination was performed and color fundus photographs were taken. In addition to fluorescein angiography, visual field examinations and electroretinographic tests were performed. Macular evaluation was performed with optical coherence tomography.Results Both fundi showed circumscribed patches of retinochoroidal atrophy and pigmentation along the retinal veins. She had also marked vitreous cells with snow ball opacities and cystoid macular edema in both eyes. Fluorescein angiography confirmed the presence of a hyperfluorescence due to widespread paravenous retinal pigment epithelial defect while ICG angiography disclosed hypofluorescence in all phases. The electroretinogram showed reduced responses especially in the left eye. Visual field tests showed scotomas corresponding with areas of atrophy along the retinal veins.Conclusions This is a report of the findings in pigmented paravenous retinochoroidal atrophy that is a nonspecific degenerative disease and may occur in association with systemic infections or inflammation. Ocular inflammation with cystoid macular edema is an unusual manifestation of the disease.

Emmetropization in Anisometropic Amblyopia

Purpose: To investigate the process of emmetropization in anisometropic amblyopic subjects during childhood and to determine the effects of spectacle use only and patching. Methods: Retrospectively, the records of patients who were diagnosed as anisometropic amblyopes were reviewed and 132 subjects who were between the ages of 5 to 8 at the time of diagnosis, with minimum follow-up of 3 years, were included in the study. Full ophthalmological examination was performed in every subjects and the information from every visit was retrieved for evaluation. Patients were divided into two groups according to the treatment they applied: patching and spectacle alone. Results: The emmetropization process was similar to normal subjects after 3 years of follow-up, with a change of −0.71 D from the baseline spheric retinoscopy measurement in the spectacle group and −0.53 D in patching group (p > 0.809). Patching and spectacle use did not change the decrease in hypermetropia. Astigmatism and anisometropia scores did not show any difference in two groups in the 3-year follow-up period. Conclusion: The emmetropization process is similar to normal population in anisometropic subjects and spectacle use and patching therapy have no effects on this process. The anisometropia score does not change with patching and stays relatively the same during the follow-up in childhood.

Chiasmal high signal on magnetic resonance imaging in the atrophic phase of leber hereditary optic neuropathy.

A 30-year-old man with Leber hereditary optic neuropathy mutation 11778 displayed no magnetic resonance imaging abnormalities during the acute phase of visual loss in the right eye. Three months later, during the acute phase of visual loss in the left eye, magnetic resonance imaging showed T2 hyperintense signal changes on the right half of the optic chiasm. Six months later, magnetic resonance imaging revealed T2 hyperintense signal changes on both sides of the optic chiasm. This is the first reported case of optic chiasmal involvement on magnetic resonance imaging in the atrophic phase of Leber hereditary optic neuropathy.