Decreased orbital fat and enophthalmos due to bimatoprost: Quantitative analysis using magnetic resonance imaging.

We quantitatively determined the relation between the decrease in orbital fat and enophthalmos due to bimatoprost using magnetic resonance imaging (MRI). Nine orbits in nine patients were treated unilaterally with bimatoprost for glaucoma or ocular hypertension. The contralateral orbits were used as controls. The volumes of the orbital tissues and the enophthalmos were measured using MRI. The mean volumes on the treated and untreated sides were, respectively, 14.6 ± 2.1 and 17.0 ± 4.3 cm3 for orbital fat (P = 0.04) and 3.4 ± 0.5 and 3.3 ± 0.5 cm3 for total extraocular muscles (P = 0.85). The mean enophthalmos values were 14.7 ± 2.5 and 16.0 ± 2.3 mm on the treated and untreated sides, respectively (P = 0.002). The data acquired by quantitatively measuring the volumes of orbital fat and enophthalmos on MRI showed that each might be reduced by bimatoprost administration. The enophthalmos could be caused by the bimatoprost-induced decrease in orbital fat.
Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: Higashiyama: grants from JSPS KAKENHI; personal fees from Senju Pharmaceutical, personal fees from Pfizer Japan, grants from Alcon Japan, grants from Novartis Pharmaceutical Company, outside the submitted work. Minamikawa: personal fees from Alcon Japan, personal fees from Pfizer Japan, personal fees from Kowa Pharmaceutical Company, outside the submitted work. Kakinoki: grants and personal fees from Alcon Japan, grants from Novartis Pharmaceutical Company, outside the submitted work. Sawada: personal fees from Santen Pharmaceutical Company, personal fees from Bayer, personal fees from Kowa Pharmaceutical Company, grants from Alcon Japan, grants and personal fees from Novartis Pharmaceutical Company, outside the submitted work. Ohji: grants from JSPS KAKENHI; grants and personal fees from Alcon Japan, grants and personal fees from Novartis Pharmaceutical Company, grants and personal fees from Santen Pharmaceutical Company, grants and personal fees from Otsuka Pharmaceutical Company, grants and personal fees from Pfizer Japan, grants and personal fees from HOYA Corporation, grants and personal fees from Senju Pharmaceutical Company, personal fees from Allergan Japan, personal fees from Bayer, personal fees from Kowa Pharmaceutical Company, personal fees from Chuo Sangio Company, personal fees from Topcon Corporation, personal fees from RE Medical Inc., personal fees from Carl Zeiss Japan, outside the submitted work. This does not alter our adherence to PLOS ONE policies on sharing data and materials.