Unilateral mydriasis: a complication of spine surgery in prone position / Midríase unilateral: uma complicação da cirurgia de coluna em decúbito ventral

Abstract Prone position though is commonly used for better access to surgical site, but may be associated with a variety of complications. Perioperative Visual Disturbances or loss is rare but a devastating complication that is primarily associated with spine surgeries in prone position. In this case we report a 42 year old ASA-II patient who developed anisocoria with left pupillary dilatation following lumbar microdiscectomy in prone position. Following further evaluation of the patient, segmental pupillary palsy of the left pupillary muscles was found to be the possible cause of anisocoria. Anisocoria partially improved but persisted till follow up.

Resumo O posicionamento em decúbito ventral, embora comumente usado para melhorar o acesso ao local cirúrgico, pode estar associado a uma variedade de complicações. Distúrbios ou perda visual no Perioperatório é uma complicação rara, mas devastadora, que está principalmente associada à cirurgia de coluna vertebral em decúbito ventral. Relatamos aqui o caso de um paciente de 42 anos de idade, ASA - II, que desenvolveu anisocoria com dilatação pupilar esquerda após microdiscetomia lombar em decúbito ventral. Após uma avaliação adicional do paciente, observamos que a paralisia segmentar dos músculos pupilares esquerdos seria a possível causa de anisocoria. A anisocoria melhorou parcialmente, mas persistiu até o acompanhamento.

Revisiting the impact of phenylephrine hydrochloride on static and dynamic accommodation.

Purpose: Phenylephrine hydrochloride (PHCl), a commonly used mydriatic agent, causes a small but significant deterioration of accommodation. The relative roles of pharmacology and optics in this deterioration, however, remain unascertained. The study determined the combined impact of PHCl concentration (pharmacology) and pupil size (optics) on the static and dynamic characteristics of accommodation. Materials and Methods: A total of 16 emmetropic Indian adults viewed a high-contrast visual target that switched between 67 and 33 cm viewing distance (1.5D stimulus) with their right eye (left eye occluded using infrared transmitting filter) through natural pupils and through 8, 6, 4, and 1 mm diameter artificial pupils. This protocol was repeated once without PHCl and once each with 2.5%, 5%, and 10% PHCl. Consensual accommodation of the left eye was recorded using infrared photorefraction (60 Hz). Results: Relative to no PHCl, the horizontal pupil diameter of left eye was significantly larger (P < 0.001) and the response magnitude and peak velocity of accommodation and disaccommodation were modestly but significantly smaller (P < 0.02 for all) for all concentrations of PHCl tested. There was no significant difference in these parameters across the three drug concentrations (P > 0.4 for all). The response magnitude and peak velocity also decreased significantly with pupil diameter, at similar rates for the no PHCl and the three PHCl conditions (P < 0.001 for all). Conclusion: The reduction in accommodative performance with all drug concentrations and with pupil diameter suggests independent roles of pharmacology and optics in determining accommodative performance with PHCl. The reduction in accommodative performance is, however, modest and may be clinically irrelevant in Indian eyes.

Effect of preoperative use of topical prednisolone acetate, ketorolac tromethamine, nepafenac and placebo, on the maintenance of intraoperative mydriasis during cataract surgery: A randomized trial.

Purpose: To compare the effects of preoperative use of topical anti-inflammatory prednisolone acetate, ketorolac tromethamine, nepafenac and placebo, on the maintenance of intraoperative mydriasis during cataract surgery. Design: Randomized clinical trial. Materials and Methods: This single-center, masked, randomized clinical study comprised 140 patients scheduled for cataract surgery. Patients (35 in each group) were randomized to receive placebo, prednisolone acetate, ketorolac tromethamine 0.4% or nepafenac. These eye drops were administered three times daily for the two days prior to surgery. The pupillary diameters were measured by the surgeon using a compass prior to the corneal section and at the end of surgery. The primary outcome was the number of patients with pupil ≥ 6mm at the end of the surgery; the secondary outcome was the number of patients with pupil ≥ 6mm at the beginning of the surgery. Results: All the patients achieved pupil ≥ 6mm at the beginning of the surgery. The number of patients in the prednisolone (29/35), nepafenac (31/35) and ketorolac (30/35) groups with pupil ≥ 6mm was greater than in the placebo group in the maintenance of intraoperative mydriasis (19/35 – P =0.003). There was no statistical difference among the prednisolone, nepafenac and ketorolac groups in the maintenance of intraoperative mydriasis (P =.791). There were no complications during surgery or related to the preoperative use of the eye drops. Conclusion: Preoperative use of ketorolac, prednisolone and nepafenac was effective in maintaining intraoperative mydriasis when compared with placebo.

Pupila dilatada fixa (síndrome de Urrets-Zavalia) após ceratoplastia lamelar profunda / Fixed dilated pupil (Urrets-Zavalia syndrome) after deep lamellar keratoplasty

A Síndrome de Urrets-Zavalia apresenta achados oculares bem descritos, porém sua fisiopatologia ainda é incerta. A isquemia iriana é o mecanismo proposto mais comum. Descrevemos dois casos submetidos à ceratoplastia lamelar profunda (CLP) realizadas pelo mesmo cirugião que desenvolveram a síndrome. No primeiro caso, a indicação cirúrgica foi para o tratamento de opacidade corneana e, no segundo, para o de ceratocone. No pós-operatório, ambos os pacientes evoluíram com pupila dilatada fixa que não regrediu totalmente apesar do tratamento administrado.

The Urrets-Zavalia Syndrome presents well described ocular findings, even though its physiopathology is still unsure. Iris ischemia is the most common proposing mechanism. We describe two cases that underwent deep lamellar keratoplasty (DLK) performed by the same surgeon and developed the syndrome. In the first case, the surgical indication was for corneal opacity treatment and, in the second case, for keratoconus treatment. During the post-operatory, both patients developed fixed dilated pupil, which didn't regress completely inspite of the onset treatment.

Influência do uso de Tropicamida a 1 por cento na espessura corneana central / Influence of the pupil dilating on the corneal pachymetry

Objetivo: Verificar se existe variação da espessura corneana com a midríase após instilação de Tropicamida a 1 por cento. Local: Clínica de Olhos da Santa Casa de Misericórdia de Belo Horizonte. Métodos: Medidas paquimétricas foram realizadas em 70 olhos de 36 pacientes antes e 30 minutos após a midríase com Tropicamida a 1 por cento. Em cada olho foram realizadas três medidas centrais utilizando o paquímetro ultra-sônico TopconP. G. H. Resultados: A média da espessura corneana encontrada antes da mídriase foi de 527,50mm no olho direito (OD) e 531,15mm no olho esquerdo (OE); após a midríase, 531,57mm e 531,71mm, respectivamente. Não houve diferenças estatisticamente significativas entre a espessura corneana antes a após a mídriase (p+0,083). Conclusão: A mídriase por tropicamida a 1por cento não interfere, estatisticamente, na medida paquimétrica corneana.

Anisocoria observada durante el período de nistagmo post-calórico / Anisocoria observed during post caloric nystagmus period

Este trabajo analiza 26 casos clínicos de pacientes en los cuales se ha observado una anisocoria transitoria durante el periodo de nistagmo posterior a la estimulación calórica; se busca una posible interpretación de este hallazgo. En varios pacientes se complementó el estudio, efectuando una video-oculografía; en dos de ellos se observó anisocoria (miosis unilateral) antes de realizar la prueba calórica. Hubo un 50 por ciento de midriasis unilateral en el periodo de nistagno post-calórico y un 50 por ciento de miosis unilateral. Como conclusión se plantea la posibilidad de una hipofunción del nervio motor ocular común leve, cuando se observa una midriasis unilateral transitoria; al heber una miosis podría corresponder a una lesión del simpático cervical

Síndrome de Urrets-Zavalia na pseudofacia / Urrets-Zavalia syndrome in pseudophakia; report of one case

Os autores descrevem um caso de midríase fixa e irreversível seguida de atrofia iriana e glaucoma observado em um paciente submetido a facectomia extracapsular com implante de lente intraocular. Este quadro constitui a forma completa da Síndrome de Urrets-Zavalia, que é classicamente descrita como uma complicaçäo da ceratoplastia perfurante em portadores de ceratocone. Os autores fazem uma revisäo da literatura e discutem os possíveis fatores etiológicos que possam estar presentes no caso relatado