The recent progress in ophthalmic surgery has been remarkable. Improvement of surgical devices and instruments is essential for this progress, but also essential is progress in the observing system for ophthalmic surgery. In this review, progress in the observing system for vitreous surgery is documented from the surgeon’s point of view. In addition, the patient’s visual perception during vitreous surgery was documented from the patient’s point of view.
We conducted a multicenter questionnaire survey regarding clinical visual acuity charts, to grasp and analyze the current situation and consider proposing a new standard visual acuity chart. The survey response rate was 43.6%. The problems to be solved were variation of evaluation criteria and method by visual acuity chart type, lack of maintenance regarding visual acuity chart luminance and illuminance, discrepancies between examiners in visual acuity measurement, induced errors of visual acuity and subjective refraction, and statistical biases. This study revealed the current problems and points of improvement regarding use of the clinical visual acuity chart.
We investigated the influence of vertical imbalance induced by prismatic effect on horizontal eye position, cyclodeviation and accommodation. Enrolled in the horizontal eye position and cyclodeviation experiments were 6 subjects (average age 22.1 ± 3.5 years); 11 healthy volunteers (average age 21.3 ± 2.6 years) were enrolled in the accommodation experiment. As to the method: using 2, 4 and 6⊿ prisms base up (BU) and base down (BD) at each eye, horizontal eye position and cyclodeviation was measured with synoptophore (Clement Clarke International). Using 1 and 2⊿ prism BU and BD at the dominant eye, accommodation of binocular vision was measured with visual display terminal (VDT) near point optometer NP-200 (TOMEY). Results showed that horizontal eye position tended to increase with the amplitude of horizontal deviation and cyclodeviation tended to change with increase in myopia. Accommodation was reduced in comparison to the control group by 0.82 D wearing 2⊿ BU, and by 1.10 D wearing 2⊿ BD (ANOVA, Scheffé, p < 0.05). These results suggest that vertical deviation induced by prismatic effects influenced horizontal eye position, cyclodeviation and accommodation.