[Photocoagulation and vitreous growth. Experiments on development of the vitreous (author's transl)].

The examination in optical section of sheep eyes, photocoagulated several months previously, shows a disturbed vitreous growth above the destroyed retinal areas (Figs. 2-4). The shape of the resulting deficiencies of vitreous structure (holes) suggests that the vitreous is produced by retinal elements and develops by appositional growth. Holes above lesions due to photocoagulation in an early developmental stage are longer (Fig. 1a; Fig. 2) than those above photocoagulations in later stages (Fig. 1b; Fig. 4). Holes above lesions with intensive retinal destruction (Fig. 2a; Fig. 4a) produce more important vitreous deficienceis than do weaker coagulations (Fig. 2b). Structural deficiencies, though extensive at first, become less important during further growth (Fig. 1c; Fig. 2c; Fig. 3 shows transverse sections at a deep and superficial level through the holes of Figure 2c), which is a sign that in the retinal scars a regeneration of elements producing vitreous occurs. Apart from the theoretical implications concerning the development of the vitreous, the results of our experiments should be considered when photocoagulating children.