Development of Postoperative Ocular Hypertension After Phacoemulsification for Removal of Cataracts in Dogs

A cataract is a disease in which the lens of the eye becomes clouded, causing a partial or complete loss of vision. Phacoemulsification (PHACO) is a modern surgical technique used in cataract surgery. Study findings: This study observed changes in intraocular pressure (IOP) after surgery in 31 dogs (48 eyes) with cataracts that visited a veterinary hospital. The procedure involved a lens extraction by PHACO and the implantation of an intraocular lens (IOL). Postoperative ocular hypertension (POH) was defined as a postoperative IOP of 25 mmHg or higher. To assess changes in IOP, IOP measurements were performed at 1, 2, 3, and 20 h, and at 1, 2, 3, 4, and 8 weeks after surgery. The IOP was found to be significantly higher at 1 (<i>p</i> < 0.05), 2 (<i>p</i> < 0.01), and 3 (<i>p</i> < 0.01) hours postoperatively compared with preoperatively. The IOP measurements were compared by dividing them into three groups according to the observation period. The IOP values were measured for three groups: before cataract surgery (Group A: 13.10 ± 8.29 mmHg), 1 to 3 h after cataract surgery (Group B: 17.84 ± 5.33 mmHg), and 20 h to 8 weeks after surgery (Group C: 13.71 ± 4.78 mmHg). The IOP values from 1 to 3 h after surgery (Group B) were significantly higher compared to both Group A (<i>p</i> < 0.01) and Group C (<i>p</i> < 0.001). Conclusions: It is suggested that POH occurring within 0 to 3 h after cataract surgery should be diagnosed as secondary glaucoma, and treatment should be performed accordingly.