Threshold laser coagulation and {HEAD ~ PDT} may be administered within {TAIL ~ the same treatment session} or either may be administered first and the other may be administered within ninety days 
Threshold laser coagulation and { HEAD ~ PDT } may be administered within { TAIL ~ the same treatment session } or either may be administered first and the other may be administered within ninety days
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH