Indian Journal of Ophthalmology

LETTER TO EDITOR
Year
: 2007  |  Volume : 55  |  Issue : 2  |  Page : 160-

Authors' reply


MC Satia, VD Mody, RI Modi, PK Kabra, M Khamar 
 Department of Pharmacology, Cadila Pharmaceuticals Ltd., 1389, Trasad Road, Dholka - 387 810, Ahmedabad, India

Correspondence Address:
M C Satia
Department of Pharmacology, Cadila Pharmaceuticals Ltd., 1389, Trasad Road, Dholka - 387 810, Ahmedabad
India




How to cite this article:
Satia M C, Mody V D, Modi R I, Kabra P K, Khamar M. Authors' reply.Indian J Ophthalmol 2007;55:160-160


How to cite this URL:
Satia M C, Mody V D, Modi R I, Kabra P K, Khamar M. Authors' reply. Indian J Ophthalmol [serial online] 2007 [cited 2019 Sep 18 ];55:160-160
Available from: http://www.ijo.in/text.asp?2007/55/2/160/30722


Full Text

Dear Editor,

We are happy to notice the interest generated by our article.[1] The purpose of the article was to provide information regarding the corneal penetration and aqueous concentration of topically applied sparfloxacin eye drops. Ocular penetration of sparfloxacin is better than even fourth generation quinolones like moxifloxacin and gatifloxacin[2],[3] which are as good as ofloxacin. We are aware of the report by Gokhale.[4] Corneal precipitates which are seen with topical quinolone[5],[6],[7],[8],[9] uses was not the purpose and so we did not address it in our article. In relation to acquired resistance we would like to add that for a quinolone like sparfloxacin the chance of acquired resistance is inversely proportional to Cmax:MIC ratio. Since this ratio is very high for sparfloxacin compared to other quinolones, the chance of developing resistance is lower. We agree that sparfloxacin is effective against resistant microbial also. This can be explained by its higher ratio. Because of this, it demonstrates its efficacy even when organisms are found to be resistant by routine testing.

References

1Satia MC, Mody VD, Modi RI, Kabra PK, Khamar M. Pharmacokinetics of Topically applied sparfloxacin in Rabbits. Indian J Ophthalmol 2005;53:177-81.
2Chan KP, Chu KO, Lai WW, Choy KW, Wang CC, Lam DS, et al . Determination of ofloxacin and moxifloxacin and their penetration in human aqueous and vitreous humor by using high-performance liquid chromatography fluorescence detection. Anal Biochem 2006;353:30-6.
3Levine JM, Noecker RJ, Lane LC, Snyder RW, Rapedius M, Blanchard J. Aqueous penetration of gatifloxacin and levofloxacin into the rabbit aqueous humor following topical dosing. J Ocul Pharmacol Ther 2004;20:210-6.
4Gokhale NS. Sparfloxacin corneal deposits. Indian J Ophthalmol 2004;52:79.
5Awwad ST, Haddad W, Wang MX, Parmar D, Conger D, Cavanagh HD. Corneal intrastromal gatifloxacin crystal deposits after penetrating keratoplasty. Eye Contact Lens 2004;30:169-72.
6Castillo A, Benitez del Castillo JM, Toledano N, Diaz-Valle D, Sayagues O, Garcia-Sanchez J. Deposits of topical norfloxacin in the treatment of bacterial keratitis. Cornea 1997;16:420-3.
7Wilhelmus KR, Abshire RL. Corneal ciprofloxacin precipitation during bacterial keratitis. Am J Ophthalmol 2003;136:1032-7.
8Awad ST, Wang MX, Cavanagh HD. A case of gatifloxacin crystal deposits in the corneal graft of an 85-year-old man. Eye Contact Lens 2006;32:157.
9Wittpenn JR. Crystallization of gatifloxacin after penetrating keratoplasty. Eye Contact Lens 2005;31:93.