A. Thaler

Reading performance depending on the type of cataract and its predictability on the visual outcome.

Purpose: To investigate the influence of various types of cataract on reading performance in a standardized reading test setting. Setting: Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods: The reading performance of 94 eyes with age‐related cataract and normal macular function was evaluated with the Radner Reading Charts preoperatively and 4 weeks after cataract surgery. Distance visual acuity was tested with the ETDRS charts. Cataracts were graded using the Lens Opacities Classification System (LOCS) III, on which NO is nuclear opalescence and NC is nuclear color. Results: Patients with pure nuclear cataracts (LOCS III: NO/NC 2.1‐5) achieved a normally high MRS (99.84% ± 7.65% of their postoperative MRS): preoperative MRS1: 190.6 ± 30.74 words per minute (wpm); postoperative MRS2: 191.21 ± 29.36 wpm. Patients with mixed nuclear‐cortical cataracts (LOCS III: NO/NC 2.1‐5; C>2) preoperatively achieved 96.96% ± 5.6% of their postoperative MRS (MRS1: 175.77 ± 31.54 wpm; MRS2: 181.34 ± 30.56 wpm). In dense nuclear cataracts (LOCS III: NO/NC>5), the MRS was significantly reduced, achieving only 72.64 ± 19.19% of the postoperative MRS (MRS1: 133.06 ± 39.43 wpm; MRS2: 185.76 ± 40.18 wpm). In posterior subcapsular cataracts, the preoperative MRS (134.1 ± 33.72 wpm) was significantly lower than postoperatively (191.14 ± 27.08 wpm). Conclusions: In contrast to dense nuclear cataracts and posterior subcapsular cataracts, the preoperative reading speed of patients with pure nuclear or nuclear‐cortical cataracts was normal at large print sizes. The preoperative evaluation of reading acuity and speed with standardized reading tests can therefore be used to estimate the postoperative reading performance in the latter 2 types of cataract.

EOG and ERG Components in Ischemic Retinopathy

In 12 adult subjects with ischemic retinopathy and in 2 children with surgically dissected retinal artery EOG light peaks and dark troughs were recorded. Standing potentials, light-induced potentials and dark troughs were reduced significantly in all affected eyes. Standing potential, light-induced oscillation and dark oscillation do not only depend upon the pigment epithelium/receptor unit; the integrity of the inner retinal structures is also of significance. The analysis of slow EOG components alone does not allow to localize and determine the level of retinal defects.

Intraoperative retinal light damage reflected in electrophysiologic data

In a series of 30 unilaterally pseudophakic patients, electroretinograms and electrooculograms were recorded 6 months postoperatively. The unoperated on fellow eyes served as controls High intraoperative retinal light exposure (3.4–7.3 mW/cm2, Zeiss OPMI 6 operating microscope) caused a substantial reduction of electrophysiologic potentials. Light protection prevented deterioration of electroretinogram and electro-oculogram potentials; reducing the bulb voltage, tilting the axis of illumination, filtering short wavelengths and the use of light shields resulted in 4-log-unit lower intensities (0.8–3.7 μW/cm2).

The influence of intravitreously injected silicone oil on electrophysiological potentials of the eye

In a prospective study the effect of silicone oil injected in the vitreous cavity was monitored electrophysiologically in six patients who were treated for retinal detachment. Electroretinograms (ERG) and electrooculograms (EOG) were recorded before, shortly after, and up to four months following the removal of the oil. An evident increase of the standing potential could be observed in all eyes after removal of the silicone oil. In some patients the ERG amplitudes increased also. No fast oscillations and virtually no slow oscillations could be recorded in the EOG. Follow-up studies did not show a significant recovery of the bioelectric activity. Intravitreal silicone oil appears to cause an insulation effect which interferes with the propagation of electrical potentials. The result of the present study do not provide information concerning possible retinotoxic effects of silicone oil.

ERG and EOG in progressive paravenous retinochoroidal atrophy.

A case of paravenous retinochoroidal atrophy was followed over a period of more than 2 years. Rapid progression of the disease was reflected in the deterioration of visual acuity and fields. Electroretinographic recordings revealed reduced photopic and scotopic amplitudes according to the extent of the retinal lesions. In electro-oculography virtually no slow and no fast light-induced oscillations could be recorded. These results suggest an involvement of the entire retinal pigment epithelium.

Fast and Slow EOG Oscillations in Congenital and Acquired Night Blindness

In congenital night blindness of the Schubert-Bornschein type both fast and slow EOG oscillations were found to be normal. In acquired night blindness due to vitamin A deficiency no EOG oscillations a

Fast Oscillation of the Corneoretinal Potential in Ischemic Retinopathy

Clinical electro-oculographic examinations were performed in 21 subjects with unilateral occlusion of the central retinal artery. The values from the unimpaired fellow eyes were used as normal data fo

The Fast Oscillation of the Electro- Oculogram

The dependence of amplitudes and peak latencies of the light-induced fast EOG oscillation was studied using rectangular light stimulation. A linear increase of the amplitude was observed in the intensity range tested (24–3,000 asb). No influence of the time of preadaptation to darkness on the amplitudes could be proven in a range of 20 s to 21 min. The peak latency was not dependent on light intensity. Prolonged peak latencies were observed following short and long periods of dark adaptation.

Oscillations of the Electroretinogram and Electrooculogram in Experimental Ischemic Retinopathy

Temporary occlusion of the central retinal artery in rhesus monkeys changes the oscillatory potentials and the b-wave amplitude in electroretinogram and the slow oscillations in electrooculogram. Redu

The slow electrooculogram oscillation in malignant choroidal melanoma

Electrooculographic recordings were performed in a series of patients with malignant choroidal melanoma. The amplitudes of the light peaks were reduced in all cases compared with the recordings of the normal fellow eyes. The amount of reduction of the light peaks appeared to be dependent on localization of the tumor. The electrooculograms of eyes with tumors of the posterior pole were found to be reduced significantly. Eyes with malignant melanomas located in the peripheral fundus displayed minor reductions.