A compound comprising one or more residues of the metalloproteases inhibitors of formula, labelled with one optically active imaging moiety; wherein: n is 2; R is a group selected from biphenyl-4-yl, 4-bromophenyl, 4-(4'-methoxyphenyl)-phenyl, 4-(4'-ethoxyphenyl)-phenyl, 4-phenoxy-phenyl, 4-(4'- methoxyphenoxy)-phenyl and 4-(4'-ethoxyphenoxy)-phenyl; R 1 is-Ra or -ORa, wherein Ra is a group of formula: -(CH 2) p -Z-(CH 2) r -W wherein in said formula III p is an integer from 1 to 4; Z is a divalent linker selected from: - O-, -NR'-, -NR'CO- and -CONR'-; r is an integer from 1 to 4; and W is phenyl or a 5 or 6 membered heterocycle, each of which is optionally substituted by one or more groups selected from: -NH 2, -COR', -CONHR', -COOR', -SO 2 NHR', wherein R' is H or a straight or branched C 1 -C4 alkyl group; one of R 2 and R 3 is H, and the other is a zinc binding group selected from: -COOH, and -CONHOH; G is a group of formula -(CH 2) m -N(R 4)(R 5), wherein m is 2; R 4 is a group selected from: -CORc, -COORc, and -S 2 Rc, wherein Rc is selected from: straight or branched alkyl, aryl, and an arylalkyl having from 1 to 4 carbon atoms in the alkyl chain; R 5 is H; and wherein: i) the optically active imaging moiety is a fluorescent moiety selected from the group consisting of fluorescein, 5-carboxyfluorescein, indocyanine green, Cy5, Cy5.5 and derivatives thereof selected from Cy5.5 mono NH ester or Cy5.5 bis NHS ester; ii) the optically active imaging moiety and the metalloprotease inhibitors are conjugated to each other directly so as to form carboxamido bonds; and iii) the residues of metalloproteases inhibitors of formula are selected from the group consisting of where R, n, R 2, R 3, m, G, p, Z, r and W are as above defined, and the line () represents the point of attachment with the rest of the molecule; and the pharmaceutically acceptable salts thereof. n is 2; R is a group selected from biphenyl-4-yl, 4-bromophenyl, 4-(4'-methoxyphenyl)-phenyl, 4-(4'-ethoxyphenyl)-phenyl, 4-phenoxy-phenyl, 4-(4'- methoxyphenoxy)-phenyl and 4-(4'-ethoxyphenoxy)-phenyl; R 1 is-Ra or -ORa, wherein Ra is a group of formula: -(CH 2) p -Z-(CH 2) r -W wherein in said formula III p is an integer from 1 to 4; Z is a divalent linker selected from: - O-, -NR'-, -NR'CO- and -CONR'-; r is an integer from 1 to 4; and W is phenyl or a 5 or 6 membered heterocycle, each of which is optionally substituted by one or more groups selected from: -NH 2, -COR', -CONHR', -COOR', -SO 2 NHR', wherein R' is H or a straight or branched C 1 -C4 alkyl group; one of R 2 and R 3 is H, and the other is a zinc binding group selected from: -COOH, and -CONHOH; G is a group of formula -(CH 2) m -N(R 4)(R 5), wherein m is 2; R 4 is a group selected from: -CORc, -COORc, and -S 2 Rc, wherein Rc is selected from: straight or branched alkyl, aryl, and an arylalkyl having from 1 to 4 carbon atoms in the alkyl chain; R 5 is H; and wherein: i) the optically active imaging moiety is a fluorescent moiety selected from the group consisting of fluorescein, 5-carboxyfluorescein, indocyanine green, Cy5, Cy5.5 and derivatives thereof selected from Cy5.5 mono NH ester or Cy5.5 bis NHS ester; ii) the optically active imaging moiety and the metalloprotease inhibitors are conjugated to each other directly so as to form carboxamido bonds; and iii) the residues of metalloproteases inhibitors of formula are selected from the group consisting of where R, n, R 2, R 3, m, G, p, Z, r and W are as above defined, and the line () represents the point of attachment with the rest of the molecule; and the pharmaceutically acceptable salts thereof. i) the optically active imaging moiety is a fluorescent moiety selected from the group consisting of fluorescein, 5-carboxyfluorescein, indocyanine green, Cy5, Cy5.5 and derivatives thereof selected from Cy5.5 mono NH ester or Cy5.5 bis NHS ester; ii) the optically active imaging moiety and the metalloprotease inhibitors are conjugated to each other directly so as to form carboxamido bonds; and iii) the residues of metalloproteases inhibitors of formula are selected from the group consisting of where R, n, R 2, R 3, m, G, p, Z, r and W are as above defined, and the line () represents the point of attachment with the rest of the molecule; and the pharmaceutically acceptable salts thereof.