Facoemulsificação em cães, com e sem implante de lente intra-ocular em piggyback: estudo clínico da inflamação pós-operatória / Phacoemulsification in dogs with and without intraocular lens implantation in piggyback: Clinical study of postoperative inflammation

A uveíte peri e pós-operatória é o maior problema da cirurgia para extração de catarata no cão, sendo considerada o fator mais importante para o sucesso cirúrgico, imediato e tardio. Diversos protocolos pré e pós-operatórios utilizando agentes anti-inflamatórios esteroidais e não-esteroidais têm sido empregados na tentativa de controle da uveíte cirurgicamente induzida. O objetivo do presente estudo foi avaliar a reação inflamatória pós-operatória, clinicamente e por meio da pressão intraocular (PIO), após a cirurgia de facoemulsificação para extração de catarata em cães, com e sem implante de lente intraocular (LIO) em piggyback. Empregaram-se, 25 cães portadores de catarata, subdivididos em dois grupos: G1 (com implante de LIO), G2 (sem implante de LIO). A técnica cirúrgica adotada foi a facoemulsificação bimanual unilateral. Avaliações clínicas e mensurações da PIO foram aferidas antes do procedimento cirúrgico (0) e nos tempos 3, 7, 14, 21, 28 e 60 dias após o ato cirúrgico. Cães do grupo G1 apresentaram sinais clínicos de uveíte visivelmente mais intensos, relativamente aos do G2. Entretanto, a PIO não demonstrou diferença significativa entre os dois grupos analisados, nem entre os olhos operados e os contralaterais. A utilização de duas LIOs humanas em piggyback no cão é exequível, porém suscita mais inflamação e complicações no pós-operatório.

Perioperative and postoperative uveitis is the main problem in cataract surgery in dogs, affecting short-term and long-term postoperative success. Numerous therapeutic methods involving both steroidal and non-steroidal anti-inflammatory agents have been used to reduce surgically-induced uveitis. The purpose of this study was to investigate the postoperative inflammatory reaction and intraocular pressure after phacoemulsification surgery for cataract extraction with and without intraocular piggyback lens (IOL) implantation in dogs. A total of 25 dogs were divided into two groups: Group 1 (with IOL implantation) and Group 2 (without IOL implantation). The performed surgical technique consisted of unilateral bimanual phaco-emulsification. Clinical assessment and intraocular pressure were measured before surgery (0) and at 3, 7, 14, 21, 28, 60 days after the surgery. Clinical assessment revealed inflammatory reaction more severe in dogs of G1 when compared to G2. Intraocular pressure did not differ significantly either between G1 and G2 or operated and non-operated eyes. Intraocular lens (IOL) implantation using piggyback technique with human IOL is a possible method to be performed in canine ophthalmology. However, nursing care is necessary as the the procedure induces inflammation and complications in the postoperative period.

Glaucoma in aphakia and pseudophakia after congenital cataract surgery.

Glaucoma is one of the most common causes of visual loss despite successful congenital cataract surgery. The overall incidence does not appear to have decreased with modern microsurgical techniques. The onset of glaucoma may be acute or insidious and notoriously refractory to treatment. Angle closure glaucoma may occur in the early postoperative period; but the most common type of glaucoma to develop after congenital cataract surgery is open angle glaucoma. Several risk factors have been identified and both chemical and mechanical theories have been proposed for its pathogenesis. Unlike children with congenital glaucoma, those with paediatric glaucoma following congenital cataract surgery are usually asymptomatic despite high intraocular pressure. They may require regular evaluation under anaesthesia, whenever there are any suspicious findings. Unlike congenital glaucoma, the first line of treatment for glaucoma in aphakia/pseudophakia may be medical. Traditional trabeculectomy in paediatric glaucoma following congenital cataract surgery has met with limited success. The addition of antimetabolites to trabeculectomy is known to inhibit fibrosis and enhance the success, but carries the lifelong risk of bleb-related endophthalmitis. Drainage implant surgery is a viable option to achieve longterm intraocular pressure control in this refractory group of patients. Cycloablative procedures may provide temporising treatment and should be reserved for patients with low visual potential. Diagnosis of glaucoma following congenital cataract surgery requires lifelong surveillance and continuous assessment of the problem. Further research is needed to understand the pathophysiology, prevention and treatment of this sight-threatening complication following successful cataract surgery in children.

Angle closure glaucoma following pupillary block in an aphakic perfluoropropane gas-filled eye.

We report the case of a 35-year-old aphakic patient who developed an intractable secondary glaucoma due to angle closure after pupillary block following the use of perfluoropropane (C3F8) gas at a nonexpansile concentration of 14%.

Post-penetrating keratoplasty glaucoma.

To study the risk factors in the development of glaucoma following penetrating keratoplasty, we retrospectively analysed 190 eyes of 185 consecutive patients who had undergone surgery during 1990. The donor button was larger by 0.2 mm and 0.5 mm in phakia and aphakia/pseudophakia patients, respectively. Over a mean follow-up period of 14.5 months, 52 of the 190 eyes (27.4%) either developed glaucoma de novo or had worsening of preexisting glaucoma. Of these 52 eyes, 38 were managed medically and 14 required surgery. From our study, aphakia (37%), pseudophakia (24%), preexisting glaucoma (81.8%), and regrafting (43.18%) were found to be the significant risk factors in the development of glaucoma following penetrating keratoplasty.