Cirugía monocular de 4 músculos extraoculares para la exotropía monocular de gran ángulo / Unilateral four muscle surgery for extra-large monocular exotropia

Introducción La exotropía recurrente es común después de cirugía para exotropía sensorial monocular constante de gran ángulo. La cirugía generalmente se limita al ojo afectado. El debilitamiento simultáneo de los músculos oblicuos ipsilaterales puede mejorar el efecto de la cirugía de los músculos rectos horizontales al disminuir las fuerzas de abducción. Presentamos los resultados de la cirugía simultánea de debilitamiento de los músculos oblicuos combinados con cirugía del músculo recto horizontal ipsilateral con exotropía monocular constante superior a 35 dioptrías prismáticas (DP). Métodos Serie retrospectiva en casos de retroinserción unilateral del recto lateral combinada con resección del recto medial, y debilitamiento simultáneo de ambos músculos oblicuos ipsilaterales. La medida de resultado fue la alineación ocular en la posición primaria. Resultados Se incluyeron 12 ojos de 12 pacientes. La exotropía preoperatoria mejoró de 57,9±15,1DP (rango 35-80; mediana 60) a 3,3±5,5 (rango 0-16; mediana 0) postoperatoriamente (p<0,005). Dos (66%) pacientes con desviación vertical preexistente tuvieron una resolución de su desalineación vertical postoperatoriamente. En el último seguimiento postoperatorio, el 92% de los pacientes tenían una exodesviación de 10DP o menos y 7 (58%) midieron ortotropía. La abducción postoperatoria midió −0,6±1(0 a −3) y la aducción −0,4±0,7 (0 a −2). Conclusión El debilitamiento de los músculos oblicuos puede mejorar el efecto de la cirugía de los músculos rectos horizontales al disminuir las fuerzas de abducción en casos de exotropía monocular de gran ángulo. Como ventaja adicional, la cirugía del músculo oblicuo se puede utilizar simultáneamente para abordar las desviaciones verticales asociadas (AU)

Introduction Recurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD). Methods Retrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position. Results Twelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9±15.1 (range 35–80; median 60PD) to 3.3±5.5 (range 0–16; median 0PD) postoperatively (p<0.005). Two (66%) patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92% of the patients had an exodeviation of 10PD or less (range 0–16PD median 0PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured −0.6±1 (0 to −3) and adduction −0.4±0.7 (0 to −2). Conclusion Weakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations (AU)

Unilateral four muscle surgery for extra-large monocular exotropia.

INTRODUCTION: Recurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD). METHODS: Retrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position. RESULTS: Twelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9 ±â€¯15.1 (range 35-80; median 60 PD) to 3.3 ±â€¯5.5 (range 0-16; median 0 PD) postoperatively (p < 0.005). Two of 3 patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92% of the patients had an exodeviation of 10 PD or less (range 0-16 PD median 0 PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured -0.6 ±â€¯1 (0 to -3) and adduction -0.4 ±â€¯0.7 (0 to -2). CONCLUSION: Weakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations.

Correlation between optical coherence tomography and glaucomatous optic nerve head damage in children.

AIM: To compare analysis of macular and nerve fibre layer thickness by optical coherence tomography (OCT) with optic nerve head (ONH) morphology based on stereophotography. DESIGN: Prospective observational case-control series. METHODS: Normal and glaucomatous eyes of children (age 4-17 years) were scanned using Stratus OCT (Carl Zeiss Meditec, Dublin, California, USA). Fast macular and retinal nerve fibre layer (RNFL) thickness map were performed on 372 eyes of 222 children. ONH stereophotographs were taken and evaluated by two masked observers using a grading system of 0 to 5 based on both cupping ratio and morphology. OCT3 analyses were compared across ONH grades for different areas around the macula and the peripapillary RNFL. RESULTS: Analysis included OCT values and ONH grading for 139 eyes of 139 children. There was a negative correlation between ONH grade and both macular thickness and RNFL thickness in all areas measured. There was a difference in the correlation identified for black versus white children. CONCLUSION: OCT measurements of RNFL and macular thickness declined with increasing grade of glaucomatous damage seen on stereophotographs in black and white children. Further study will help quantify the value of OCT in the diagnosis and management of paediatric glaucoma.

Safety and efficacy of brimonidine in children with glaucoma.

PURPOSE: Brimonidine is a relatively selective alpha-agonist, which reduces intraocular pressure (IOP) by decreasing aqueous production and increasing uveoscleral outflow. Brimonidine passes through the blood-brain barrier, potentially causing central nervous system (CNS) toxicity. There have been reports of bradycardia, hypotension, hypothermia, hypotonia, and apnea in infants after topical brimonidine. METHODS: We reviewed the IOP data and side effects of children at the Duke University Eye Center placed on brimonidine from June 1997 to October 2000. Brimonidine 0.2% was used for patients whose glaucoma was uncontrolled on maximal tolerated medical therapy. A monocular trial was performed whenever possible, and brimonidine was not prescribed for infants. Included were 32 eyes of 30 patients with uncontrolled IOP and varied glaucoma diagnoses. RESULTS: The mean patient age was 10.5 years, with a mean follow-up on brimonidine of 10.8 months. Most patients were on other glaucoma medications. In 11 of the 32 eyes the IOP data could be interpreted, and in these eyes the IOP decreased from a mean of 22.5 +/- 4.9 mm Hg to a mean of 20.8 +/- 4.0 mm Hg (a mean decrease of 6.7% +/- 10%, P =.04) on brimonidine after a mean follow-up of 11.0 +/- 6.9 months. Two young children (ages 2.4 and 3.7 years) repeatedly were unarousable soon after the administration of brimonidine. Five other children experienced extreme fatigue after brimonidine administration. All symptoms resolved after brimonidine was discontinued. DISCUSSION/CONCLUSIONS: Brimonidine should be used with caution in young children because of the potential for CNS depression. In selected patients, brimonidine has a substantial ocular hypotensive effect.

Combined superior oblique muscle recession and inferior oblique muscle advancement and transposition for cyclotorsion associated with macular translocation surgery.

PURPOSE: The purpose of this study was to evaluate the effects of oblique muscle surgery on the large-angle incyclotorsion resulting from macular translocation surgery for severe age-related macular degeneration. METHODS: Patients undergoing macular translocation (superiorly) at our institution from May 1996 until November 1998 were included. In the Staged Group, strabismus surgery for symptomatic incyclotorsion was performed after the macular translocation, and in the Combined Group, it was performed simultaneous with the macular translocation. Cyclotorsion was quantified using Maddox rod testing. Surgery for incyclotorsion included superior oblique muscle recession combined with inferior oblique muscle advancement and transposition in the affected eyes. The minimum follow-up time was 6 weeks. RESULTS: Fifteen patients (15 eyes) were included (ages 66-89 years). Nine eyes (Baseline Group) had macular translocation surgery before any strabismus surgery; the mean postoperative incylotorsional angle was 33.4 +/- 18.3 degrees (range, 20-80 degrees) after a mean follow-up of 6.6 months. Four of these eyes (Staged Group) underwent oblique muscle surgery for symptomatic incyclotorsion, which reduced the mean incyclotorsion from 26.9 +/- 6.9 degrees (range, 20-35 degrees) to 9. 9 +/- 7.9 degrees (range, 2.5-20 degrees)-a mean reduction of 16.9 +/- 1.3 degrees (P =.00012), after a mean follow-up of 4.6 months. Six additional eyes (Combined Group) had simultaneous macular translocation and oblique muscle surgery, with a mean postoperative cyclotorsional angle of 14.0 +/- 6.7 degrees (range, 4-22.5 degrees), after a mean follow-up of 3.75 months. CONCLUSION: Oblique muscle surgery is effective at reducing the large degree of incyclotorsion resulting from macular translocation surgery and may be used either following or simultaneous with retinal surgery.

The effectiveness of latanoprost for the treatment of pediatric glaucoma.

PURPOSE: Latanoprost is a prostaglandin F2alpha analogue that substantially reduces intraocular pressure (IOP) in adults with open-angle glaucoma or ocular hypertension. The efficacy and safety of latanoprost in children is unknown. We wished to evaluate latanoprost therapy for children with glaucoma. METHODS: This was a prospective study of all patients who were given latanoprost at our institution between September 1996 and January 1998. The baseline IOP was compared with the postlatanoprost IOP for each patient, and side effects and any iris color change were noted at each follow-up examination. Responders were defined as those who had at least a 15% IOP reduction on latanoprost, whereas nonresponders showed less than a 15% IOP reduction on latanoprost. RESULTS: Fifty-seven eyes of 48 pediatric patients with a variety of glaucoma diagnoses and an average age of 7.1 years were included in the study. Of these, 31 eyes of 31 patients had interpretable IOP data; the mean IOP reduction for this group after the addition of latanoprostwas 0.9% (0.2 mm Hg). Six patients (6 eyes) were responders, with an average IOP reduction of 8.5 mm Hg (34%), whereas the majority of patients (25) were nonresponders. In the responders, there was a good correlation (r = 0.9) between baseline IOP and the magnitude of IOP reduction. Responders were significantly more likely to have juvenile open-angle glaucoma and to be older than nonresponders. Systemic and ocular side effects were infrequent and mild, and no patient had noticeable iris color changes. CONCLUSIONS: When used in a group of pediatric patients with a variety of glaucoma diagnoses and on various therapies, latanoprost is effective in only a minority of cases. In selected patients, however, latanoprost shows an impressive ocular hypotensive effect, comparable with that obtained when this drug is used in adults with open-angle glaucoma. This drug appears to be well tolerated in this short-term study of pediatric patients with glaucoma.

Refractive changes after pediatric intraocular lens implantation.

PURPOSE: To report refractive changes after cataract surgery and intraocular lens implantation in infants and children. METHODS: In an ongoing prospective study, the refractive errors of all patients younger than 18 years undergoing intraocular lens implantation were determined at 6 weeks, 3 months, 6 months, and 1 year, and at least yearly thereafter. All patients with greater than 6 months of follow-up were included in the study. RESULTS: Eighty-three eyes of 81 patients were identified. Cataracts were traumatic in 32 eyes (38%) and developmental in 42 eyes (50%). At implantation, the mean (+/-SD) age was 6.3 +/- 4.6 years (range, 9 months to 17 years). The mean follow-up was 26.6 months (range, 6 months to 6.6 years). Patients 0 to 2 years old at the time of implantation demonstrated a mean myopic shift of -3.00 diopters during a mean follow-up period of 2.5 years. Patients 2 to 6 years old at the time of implantation demonstrated a mean myopic shift of -1.50 diopters in a similar follow-up period. Children aged 6 to 8 years experienced a mean myopic shift of -1.80 diopters during a mean follow-up period of 3.0 years, while children older than 8 years at the time of intraocular lens implantation experienced a mean myopic shift of -0.38 diopters during a mean follow-up period of 1.8 years. On average, the operated-on eye showed a greater mean myopic shift than the fellow eye. No statistically significant differences in refractive change were found in comparing amblyopic to nonamblyopic eyes, traumatic to nontraumatic cataracts, or primary to secondary intraocular lenses. CONCLUSIONS: Our data demonstrate a trend toward increasing postoperative myopia in pediatric patients undergoing intraocular lens implantation. This myopic shift is greatest in the younger age groups and persists until at least 8 years of age. There is much variability in the postoperative refractive changes, and predicting exactly when and where the refraction will stabilize for an individual patient is difficult.

A comparison of the Marcus Gunn and alternating light tests for afferent pupillary defects.

OBJECTIVE: The authors compared two methods, the Marcus Gunn test and the alternating light test, for detecting a relative afferent pupillary defect. DESIGN: A randomized, prospective clinical trial. PARTICIPANTS: Fourteen patients with unilateral optic neuropathy. INTERVENTION: The Marcus Gunn and alternating light tests were performed on each patient. MAIN OUTCOME MEASURES: The results of the Marcus Gunn and altemating light tests for detecting a relative afferent pupillary defect on the affected side. RESULTS: The Marcus Gunn test was able to identify the affected eye in only 8 of 14 patients, whereas the alternating light test correctly identified the affected eye in 13 of 14 patients. Results of the Marcus Gunn test were indeterminate in 4 of 14 patients and were incorrect in 2 of 14 patients. Results of the alternating light test were indeterminate in one patient and never incorrectly identified the affected eye. CONCLUSION: The alternating light test is superior to the Marcus Gunn test for detecting relative afferent pupillary defects.

The effect of intraocular pressure on the absorption of air from the vitreous cavity.

BACKGROUND: The duration of an intraocular gas bubble used in vitreoretinal surgery is an important determinant of the safety and effectiveness of intraocular gas use. Considerable variability impedes the clinical determination of this parameter. The aim of the study was to study experimentally the relationship between intraocular pressure (i.o.p.) and the absorption of an intravitreal air bubble. METHODS: We compared the rate of absorption of an intravitreal air bubble in rabbit eyes that had been treated with cyclocryotherapy (n = 17) to the absorption of air bubbles in untreated fellow eyes (n = 17). RESULTS: Intravitreal air bubble persisted longer in the cyclocryotherapy-treated rabbit eye (mean +/- SD 78 +/- 16 h) than in the control fellow eyes (43 +/- 15 h). This difference was statistically significant (P < 0.001). The length of time an air bubble persisted could be predicted from the IOP. CONCLUSIONS: The reason for the increased length of time an air bubble remained in cyclocryotherapy-treated eyes is probably the result of several factors, including primarily reduced aqueous flow and reduced IOP. Our results show that the duration of air injected into the vitreous cavity correlated to IOP. In addition to other known factors, the IOP should be considered in predicting intravitreal gas persistence.

An intravitreal device providing sustained release of cyclosporine and dexamethasone.

PURPOSE: A device that releases cyclosporine and dexamethasone into the eye for extended periods of time might be beneficial in diseases such as proliferative vitreoretinopathy and uveitis. In this study we examine the pharmacokinetics and toxicity of cyclosporine and dexamethasone combined in an intravitreal sustained-release device and the toxicity of a similar device containing only dexamethasone in rabbits. METHODS: Rabbits were divided into three groups for (1) evaluation of the drug tissue levels and device release kinetics following implantation of a device containing 100 micrograms of cyclosporine labeled with 2 microCi of 3H-cyclosporine and 2 mg of dexamethasone; (2) evaluation of the toxicity of this intravitreal device; and (3) evaluation of the toxicity of a similar device containing 2 mg of dexamethasone only. Cyclosporine was measured using a scintillation counter and dexamethasone was measured by high pressure liquid chromatography (HPLC). Toxicity was evaluated by electroretinography, clinical examination, and light microscopy. RESULTS: Vitreous concentrations of cyclosporine (+/- standard deviation) averaged 0.06 (+/- 0.02) microgram/ml over 10 weeks. The average dexamethasone concentration over the 10 week period was 2.9 (+/- 0.9) micrograms/ml. Devices containing cyclosporine and dexamethasone released each drug at rates similar to devices containing cyclosporine or dexamethasone alone. Devices containing both cyclosporine and dexamethasone caused reversible depressions in the b-wave amplitude of photopic and scotopic electroretinograms (ERG's). There was no evidence of toxicity associated with the devices containing dexamethasone only. There was no drug-related toxicity evident on clinical or histopathologic examination of eyes with devices containing the combination of cyclosporine and dexamethasone or dexamethasone alone. CONCLUSIONS: We conclude that the device maintains potentially therapeutic levels of both cyclosporine and dexamethasone in the vitreous. Reversible electroretinographic abnormalities are attributable to cyclosporine. A sustained-release device containing cyclosporine and dexamethasone may be useful for reducing inflammation in diseases such as proliferative vitreoretinopathy and uveitis.

Ultrastructural study of Norrie's disease.

We studied the clinicopathologic and ultrastructural features of a full-term infant with Norrie's disease. The infant had bilateral retrolental fibrous vascular masses and retinal detachment with no other apparent physical abnormalities and no family history of ocular defects. A vitrectomy and a membrane peeling were attempted, and specimens of the retina, the retrolental membrane, and a vascularized epiretinal peripheral mass were examined by light and electron microscopy. The retrolental membrane was composed of layered collagenous tissue and contained structures resembling blood vessels. Inner and outer neuroblastic layers were identified in the retinal tissue, but no vessels were present. In the epiretinal mass, portions of retina and cortical vitreous were seen along with primitive vascular structures. The histologic appearance of these specimens suggests that the major pathologic event of Norrie's disease occurs in the retina in the third to fourth gestational month. We believe the subsequent ocular abnormalities found in this patient were secondary to this early retinal malformation and did not represent a progressive ocular disorder.