[Reflection measurement during retinal laser coagulation in patients. Development of an automatically controlled dosimeter].
OBJECTIVE
Retinal laser coagulation has limited reproducibility, because every laser exposition is unpredictably affected by pigmentation and media opacities. This can lead to complications. A feedback-controlled dosimeter would make retinal laser treatment a safer, more reproducible and faster procedure.


METHODS
A reflectometer was developed that allows monitoring of the reflection of laser light during standard photocoagulation. Hundreds of coagulations in rabbit eyes and about 12,000 coagulations in patients undergoing routine laser treatment were recorded.


RESULTS
The results of the first reflectance measurements in humans are presented along with extensive animal studies. A typical reflectance history was found for different lesion intensities. The degree of retinal whitening correlates with reflectance characteristics. These characteristics allow an early prediction of lesion intensity. Motion during laser exposure affects each coagulation in a fashion similar to spot size and exposure time.


CONCLUSIONS
Reflectometry is the currently most effective means of monitoring lesion development. An automatic dosimeter for retinal photocoagulation seems feasible.
Inderfurth
J
J
Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA.
Ferguson
R D
RD
Puliafito
C A
CA
Frish
M B
MB
Birngruber
R
R
D000818:Animals; D004867:Equipment Design; D005240:Feasibility Studies; D006801:Humans; D017075:Laser Coagulation / Q000295:instrumentation*; D011817:Rabbits; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation*; D012164:Retinal Diseases / Q000601:surgery*; D016896:Treatment Outcome
Reflexionsmessung während Netzhautlaserkoagulationen bei Patienten. Entwicklung einer automatisch gesteuerten Dosiseinrichtung.