Correlation of ocular motor reading strategies to the status of adaptation in patients with hemianopic visual field defects
Schoepf D, Zangemeister WH:. Ann N Y Acad Sci.1993; 682:404-408
To compensate for hemianopia it is necessary to have appropriate ocular motor strategies for eflicient use of the remaining half of the visual field. We demonstrated that patients with pure hemianopia and foveal sparing optimally learn to compensate their visual handicap in reading by active and motivated visual training. The purpose of the present study is to analyze in detail the different ocular motor reading strategies that hemianopic patients develop to compensate their visual handicap corresponding to their "relative" status of ocular motor adaptation in reading. Therefore, the eye and head reading path of ten well-selected patients with hemianopic visual iield defects due to different aetiology was completely analyzed under this aspect. The "relative” status of ocular motor adaptation was marked according to the mean reading rate, the frequency of acoustical reading errors, and the most frequentl-y applied ocular motor reading strategies. The apparatus and methods used were the same as previously described.2 All patients had to read two groups of four different texts with distinct content. In a low-letter density mode the texts had 28 letters per line, and in high-letter density mode each text had 46 letters per line. The task was performed under two varying conditions: a head-lixed condition and a head-free-to-move condition. The patients were asked to read the texts as accurately and as quickly as possible.