Purchase this article with an account.
D. Meikies, O. Stachs, W. Huetz, P. Martius, C. Schlueter, R. Guthoff; Glare perimetry: A new method for quantification of dysphotopsia effects. Invest. Ophthalmol. Vis. Sci. 2009;50(13):1621.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Patients after cataract surgery who score well on traditional measurements of vision often report about light sensations in everyday situations (e.g. headlights of oncoming cars). The aim of this study was to develop a method to quantify such dysphotopsia effects.
Under scotopic conditions the subjects were glared by a light source (Ø 5 mm, 10 kcd/m²) which was placed in the middle of a projection screen (2 m²). A projected white spot (Ø 5 mm, 2 cd/ m²) was programmed to move outwards from the screen center. The glare area where the subject could not distinguish the white spot from the glare effects was evaluated (glare perimetry) and expressed in pixels. The pupil size was measured during the examination by using Plusoptix S04. To validate the method 8 phakic subjects and 25 pseudophakic subjects were enrolled in a preliminary study. The pseudophakic subjects had aspheric diffractive multifocal lens implants with a light distribution of bilateral 50:50 (16 subjects) and 70:30/30:70 (9 subjects) respectively.
Under scotopic conditions a significant difference between the values for the glare area of all investigated pseudophakic eyes (13494±5465 pixel) and the phakic ones (2652±2410 pixel) was found. The glare perimetry showed that glare differed notably between the 50:50 group (12525±3906 pixel) and the 70:30/30:70 group (15217±7468 pixel). The averaged pupil size was 4.3±1.8 mm for the phakic group, 3.6±0.4 mm for the 50:50 group and 3.5±0.4 mm for the 70:30/30:70 group. The coefficient of variation for the glare perimetry in 5 consecutive follow-up examinations was 15% and 16% for 2 examined subjects.
The developed glare perimetry method seems to be useful to quantify subjective glare effects after cataract surgery. Further investigations are necessary to transmit the results into clinical practice. The pseudophakic group with uniform light distribution lenses has shown a better outcome in terms of glare disability in comparison to the group with lenses where the light distribution was asymmetric.
This PDF is available to Subscribers Only