The role of visual evoked potentials in the diagnosis of optic nerve injury as a result of mild head trauma.

The curve of visual evoked potentials was observed and compared with changes of visual acuity and visual field during a 24-month period in a group of 39 patients with optic nerve injury as a result of mild cerebral trauma. Results of the study showed great improvement of visual acuity and visual field after treatment, and slower and continuous improvement of visual evoked potentials. The main abnormality of visual evoked potentials is the shortening of amplitude, which is recorded to gradually recede after treatment in half of the patients. Authors conclude that the shortening of amplitude can be partially explained by the edema and the compression of fibers in the optic canal. Also, they emphasize that in this type of optic nerve injury visual acuity testing is the best indicator of the promptness and scope of the injury, while visual field research presents the best method for following later delicate changes of visual function.

Neuroophthalmologic diagnosis of the sella turca region.

A chiasm n. optici is shaped by crossed optic nerves. Approximate vertical distance of 10 mm separates chiasm from dorsum sella turca and pituitary fosse. Twenty-five percent of all cerebral tumors appear in the chiasm area and almost half of them cause damages of visual function. Major and sometimes the only symptom is progressive visual loss. This damage appears because tumor masses are huge and are compressing optic nerves. Sellar region lesions must already be spreading suprasellary before patient can notice visual field defects. The sign of advanced process is symmetric or asymmetric loss of visual acuity or visual field defects. The aim of this study was to show the importance of visual field in the diagnosis of sellar disorders as well as in treatments. Eighteen patients with chiasm disorders were analyzed. Visual field was analyzed before and after treatment according to visual field classifications. The study has shown the importance of visual field testing in diagnosis of sellar processes, as well as in following therapy, surgical or conservative.

Anterior ischaemic optic neuropathy in patient with rheumatoid arthritis--case report.

This case report presents a patient with long-lasting rheumatoid arthritis (RA) of fourth clinical grade, having ocular complications. RA was diagnosed according to current modified ARA criteria from 1987. Upon admission to the Department of Ophthalmology clinical examination revealed anterior ischaemic optic neuropathy (AION), which is not characteristic manifestation of RA in the eye. The occurrence of AION in patients with RA has been explained in literature as a secondary manifestation of hypertension in these patients or, by the presence of other connective tissue disease apart from RA (for example, MCTD--mixed connective tissue disease). Both mentioned causes were excluded in our case, as well as any other condition that could lead to AION. Therefore, we had concluded that AION presented a late complication of RA.

Intraocular pressure and visual field defects.

During a five-year study period, therapeutic levels of intraocular pressure (IOP) and visual field defects were assessed in 108 patients with open-angle glaucoma. In a group of 53 glaucoma patients with non-progressive visual field changes (mean age 65.2 +/- 6.3 years), the IOP level was 15.8 +/- 2.6 mm Hg, whereas in a group of 58 patients with progressive visual field changes (mean age 68.7 +/- 8.3 years) the IOP level was 19.9 +/- 2.9 mm Hg. Study results suggested that preservation of the visual field in glaucoma patients requires therapeutic IOP levels of < 16 mm Hg.

Venous tone in glaucoma and hypertension.

The aim of this study was the assessment of physiological venous reflexes in systemically hypertensive and normotensive subjects with primary open-angle glaucoma. The experimental group consisted of 20 normotensive and 20 untreated systemically hypertensive patients with open-angle glaucoma. The control group consisted of 31 volunteers divided into two subgroups: 16 control normotensives and 15 untreated hypertensives. The assessment of venous tone changes was performed by testing venous reflexes. Venoconstriction responses to physiological stimuli were significantly decreased in normotensive glaucoma patients, compared to normotensive controls [for the Valsalva manoeuvre 93.4 +/- 80.2 vs. 413.3 +/- 335.4 venoconstrictive units (VCUs), p = 0.02, and for a deep breath 89.1 +/- 100.1 vs. 316.8 +/- 343.2 VCUs, p = 0.03]. The intensity of venous reflexes in hypertensive glaucoma patients did not differ significantly from that seen in hypertensive controls, due to a significantly weaker flex venoconstriction in hypertensive controls when compared to normotensive controls subjects. This study confirmed the presence of venous dysregulation in subjects with primary open-angle glaucoma and visual field loss as a part of an autonomic dysfunction. Systemic hypertension does not make this condition worse.

Choroidal leiomyoma of vascular origin.

A 38-year-old female patient was admitted for serious retinal detachment. Clinical examination revealed detachment in the lower half of the retina, with a suspect hemispherical tumorous formation. Echography did not positively demonstrate the presence of tumor. Vitrectomy was performed and a tumor fragment was taken for histologic analysis. The finding indicated the presence of leiomyoma choroideae, a very rare and benign smooth muscle tumor.

Early detection of inborn dyschromatopsias in preschoolers and young schoolchildren.

Color vision is one of the most important factors of human vision. Early detection of color vision malfunction in children is of utmost importance, allowing parents and teachers to take appropriate and timely measures for children's future professional orientation. A cohort of 300 children aged 4-6 years (49-86 months) were examined by color vision testing and divided into three age groups of 4-5, 5-6 and > 6 years. Their ability to name the fundamental spectral colors and read Ishihara's pseudoisochromatic plates were recorded. The results obtained are presented in tables and figures. Data analysis showed the youngest group of children to be unsuitable for such testing of color vision. Numerical data revealed considerable percentage deviations as compared to the older groups. In addition, a great difference between the girls and boys indicated psychomotor development to be much faster in girls of that age. Generally, data obtained by the distribution of the results for the two older age groups were consistent with those found in the literature; thus, the authors propose an early examination for the detection of inborn chromatopsia to be performed in preschool children, but not before the age of five. Ishihara's pseudoisochromatic test can be useful in differentiating between dyschromatic and other children, but it is very difficult to implement for singling out dyschromates according to the protan or deutan type.

Classic migraine and visual field defects.

A series of 116 patients with classic migraine were studied to record visual field defects. Thirty-four (29.3%) subjects had defects of the field of vision, 11 of them bilaterally, which made a total of 45 (19.4%) eyes. Downward isopter depression from above and contraction of the field of vision were the most common damages. A homonymous hemianopic defect was found in seven patients. The area of depressed vision helps to some extent in anatomical localization of the damage. Its etiology has not been fully clarified. The authors recommend more extensive clinical examinations of the visual field, i.e. follow-up of each patient with classic migraine by periodical testing of the field of vision.

Hyperbaric oxygen for the treatment of nonarteritic anterior ischemic optic neuropathy.

This clinical study tackled the problem of hyperbaric oxygen in patients with nonarteritic anterior ischemic optic neuropathy. Twenty-one patients were included in the study. The patients were divided into two groups: experimental and control. Experimental group consisted of 10 patients, who had been previously treated with corticosteroids, without significant success. In four patients with a clinical picture of PNO atrophy, medical steroid treatment failed to any significant improvement in visual acuity. In 6 patients, however, this treatment resulted in a significant improvement of both visual acuity and field of vision. These patients showed further improvement on control testing performed six month later. All patients from the control group were treated with corticosteroids per os and by local application, but without any significant improvement as revealed by visual acuity and visual field testing. Authors' results pointed the possibility of conservative treatment of patients with anterior ischemic optic neuropathy, especially those in whom steroid therapy had proved inefficient.

[The role of myopic ametropia in visual field examination]. / Uloga miopske ametropije pri istrazivanju vidnog polja.

The author examined 30 myopic patients to determine the influence of myopic refractive anomaly and adequate correction of close and far vision on the visual field findings established by Goldmann kynetic perimetry in photopia and on the interpretation of the results obtained. The hypothesis was statistically tested by a variance between the two arithmetic mean values. The results have shown that the logarithmic model was the most appropriate one. It has been found that there are virtually no visual field changes in patients with up to---2.50 diopters and without the correction of ametropia, while in patients with---3.0 diopters incipient changes in the form of a narrowed internal isopter were seen.

Risk factors in nonarteritic anterior ischemic optic neuropathy.

The authors have investigated risk factors associated with the occurrence of nonarteritic anterior ischemic optic neuropathy (AION) in 83 patients and 124 eyes. 12% of the patients with nonarteritic AION had diabetes mellitus, 37.3% hypertension, 14.5% atherosclerosis, while the rest (36.2%) were classified as idiopathic. The incidence of bilateral AION was slightly less than 50%. The period in which both eyes get affected is usually 1-2 months or longer. Nonarteritic AION can occur at any age, therefore it is seen in young people as well. The role of arterial hypertension and diabetes in pathogenesis of AION is still to be determined.

[Amblyopia and the visual field]. / Ambliopija i vidno polje.

The author examined 20 hypermetropic eyes with functional amblyopia with application of the objectively sciascopically determined diopters and, separately, without such correction, during the investigation of the visual field using Goldmann kinetic light perimetry in photopia. The starting hypothesis was statistically tested by means of differences of the two arithmetic mean values. Based on the obtained results, the author has found that the values denoting the degree of visual field damage are in correlation with the degree of visual acuity decrease. He also observed that the application of the objectively determined dioptric value leads to the normalization of the visual field in amblyopic persons, although it does not improve visual acuity. This is an important observation, since extensive visual field failings without the introduction of the objectively determined correction may raise suspicion of a retrobulbar inflammation or atrophy of the optic nerve.