Comparison of indocyanine green angiography and optical coherence tomographic angiography in polypoidal choroidal vasculopathy.

PurposeTo compare optical coherence tomographic angiography (OCTA) and indocyanine green angiography (ICGA) images for detecting polypoidal lesions (PLs) and branching vascular networks (BVNs), and to measure the polypoidal areas (PAs) in patients with polypoidal choroidal vasculopathy (PCV).MethodsAll patients underwent ICGA, optical coherence tomography (OCT), and OCTA. We compared the detection sensitivity for PL and BVN, as evaluated by the ICGA and OCTA images. Furthermore, PA measured by ICGA was divided into two groups: one in which the area could be measured by OCTA (ICGA+OCTA+) and the other in which the area could not be measured by OCTA (ICGA+OCTA-).ResultsTwenty-one consecutive eyes of 21 patients (mean age, 73.8±9.8 years) were included. ICGA detected PL in all eyes (100%), whereas OCTA detected PL in 16 eyes (75.2%); ICGA detected BVN in 15 eyes (71.4%), whereas OCTA detected BVN in 20 eyes (95.2%). The mean PA in ICGA+OCTA+ and ICGA+OCTA- was 0.24±0.04 and 0.14±0.01 mm2, respectively; a significant difference was observed between ICGA+OCTA+ PA and ICGA+OCTA- PA (P<0.0001). In addition, the mean PA in the ICGA+OCTA+ group measured by ICGA and OCTA was 0.24±0.04 was 0.19±0.04 mm2, respectively; these values were significantly different (P=0.0046).ConclusionsOCTA might detect more BVNs and fewer PLs compared with ICGA, and PL detected by OCTA might be smaller than those detected by ICGA.

Comparative metabolic study of nimetazepam and its desmethyl derivative (nitrazepam) in dogs.

1. Blood levels of nimetazepam after oral administration to dogs were relatively low at early periods after dosage and reached peak levels (7-7-7-9 mug equiv./ml) after 8 h. The time course of blood levels was similar after oral administration of its desmethyl derivative (nitrazepam) to dogs. Blood levels of the latter, however, were low compared with nimetazepam and reached a peak (5-2-6-3 mug equiv./ml) after 4 h. 2. Recoveries of nimetazepam in urine and faeces were 46 and 52% of the dose for 0-24 h, 27 and 34% for 24-48 h and 4 and 6% for 48-72 h, while those of its desmethyl derivative (nitrazepam) were 63 and 71% for 0-24 h, 12 and 21% for 24-48 h and 2 and 3% for 48-72 h. 3. At least four kinds of reaction were involved in the biotransformation of nimetazepam and its desmethyl derivative (nitrazepam): (i) demethylation at N-1 (ii) hydroxylation at C-3, (iii) subsequent glucuronic acid conjugation of 3-hydroxy derivatives and (iv) reduction of the nitro group at C-7 to an amino group. Reaction (i) proceeded very rapidly in dogs, so that the blood metabolites of nimetazepam were closely similar to those of nitrazepam. For both drugs, the major blood metabolite was nitrazepam. Reaction (ii) was rapidly followed by reaction (iii), and glucuronides were predominantly excreted in urine. Reaction (iv) as well as reaction (iii) are important in the excretion of both drugs. The subsequent acetylation of 7-amino group, however, did not occur in dogs as it did in mice and rats.

Comparative metabolic study of nimetazepam and its desmethyl derivative (nitrazepam) in rats.

1. Nimetazepam distributed more rapidly in the brain than its desmethyl derivative (nitrazepam). The brain concentration of the active metabolites of the former was about twice that of the latter at 1h after oral administration. 2. At least four kinds of reactions were involved in the biotransformation of nimetazepam and its desmethyl derivative (nitrazepam) : (i) demethylation at N-1, (ii) hydroxylation at C-3, (iii) reduction of the nitro group at C-7 to the amino group and (iv) subsequent acetylation of the amino group. 3. The 1-N-demethylation of nimetazepam was slow compared with the other three reactions. 4. Nimetazepam was rapidly hydroxylated at C-3, while the 3-hydroxylation of its desmethyl derivative (nitrazepam) was very slow. 5. The reduction of the nitro group at C-7 and subsequent acetylation were important routes for the excretion of these drugs.