Evaluation of superior rectus muscle attachment following hang-back recession in rabbit eyes.

PURPOSE: The hang-back suture technique has been advocated to decrease the risk of scleral perforation during strabismus surgery. In this study, we evaluated the muscle insertion site in rabbits 4 weeks after a hang-back recession was performed. METHODS: Twenty-five eyes of 13 rabbits underwent hang-back recessions of between 5 and 8 mm of the superior rectus muscle. Four weeks later, the attachment sites were examined. RESULTS: Four weeks following the surgery, 14 muscles (n=25, 56%) were anteriorly displaced. In the 5 mm recession group, one muscle was anteriorly displaced (n=7, 14.3%). In the 6 mm recession group, 50% of the muscles recessed were displaced anteriorly (n=8). The 7 mm hang-back recession group demonstrated forward displacement in five muscles operated (n=6, 83%) and in the 8 mm recession group, all four muscles (100%) were anteriorly displaced. The magnitude of displacement was positively correlated to the amount of the hang-back recession performed (Pearson correlation p<0.001). CONCLUSIONS: Anterior displacement of muscles using the hang-back technique in the rabbit eye is unacceptably high and occurred in 56% of the cases. A positive, statistically significant correlation exists between the amount of recession performed and the number of muscles displaced from their new insertion. Therefore, when performing large recessions using the hang-back technique displacement should be anticipated.

The reculture technique: individualizing the treatment of Acanthamoeba keratitis.

PURPOSE: To assess the efficacy of three drugs in different concentrations against different strains of Acanthamoeba using the reculture technique. METHODS: Cysts and trophozoites were immersed in five separate solutions. The solutions administered included 0.1% and 0.02% polyhexamethylene biguanide (PHMB), 0.1% and 0.02% chlorhexidine, and propamidine isethionate (Brolene). Readings took place after 1, 5, and 24 hours. The cysts and trophozoites were then recultured for an additional period of 48 hours. An effective drug was defined as a medication that inhibited any growth of trophozoites using the reculture technique. RESULTS: Chlorhexidine at concentrations of 0.1% and 0.02% was the only effective drug against all five strains of Acanthamoeba examined, and no trophozoites were detected on plates immersed with this agent. Only 0.1% chlorhexidine was effective in destroying all cysts in the five strains examined. CONCLUSION: We found that 0.02% chlorhexidine was efficient in irradicating all trophozoites and 0.1% chlorhexidine was effective in eradicating all cysts in the samples we examined. Therefore, it may be possible that 0.02% chlorhexidine is a good initial treatment in amoebic keratitis. Sensitivity testing, then, may be performed using the reculture technique and specification of therapy can be made accordingly.

Increased intraocular pressure during treatment for chronic uveitis.

OBJECTIVES: (1) To prospectively evaluate the incidence of increased intraocular pressure (IOP) in patients suffering from chronic uveitis. (2) To identify the main factors responsible for an increase in the IOP among these patients. METHODS: Two hundred and one patients suffering from chronic uveitis were included. Enrolled patients had an initial IOP of 8-18 mmHg. The patients were treated and clinically monitored during a period of 4 years. The IOP was measured at each visit and its changes followed prospectively. All patients were followed up for at least 12 months after enrollment. RESULTS: Twenty-four (12%) of the 201 patients had IOP higher than 24 mmHg at two or more consecutive visits. Of these 24 patients, 19 suffered from bilateral uveitis and 5 had unilateral disease. Four of the 19 patients with bilateral uveitis developed a constant IOP higher than 24 mmHg in both eyes, while in 15 patients an IOP higher than 24 mmHg persisted only in one eye. A close association between the increased IOP and the use of corticosteroids was found in 18 of the 24 cases (75%). This association was ascertained in 16 of these patients by the decrease in IOP levels on discontinuation of the corticosteroid regimen and the renewed increase IOP was due to pupillary block in three cases (12.5%), to iris and angle neovascularization in two (8.3%), and to the inflammatory process per se in one case only (4.2%). CONCLUSIONS: This study demonstrates that a persistent elevation of the IOP in patients suffering from chronic uveitis is, in the majority of cases, associated with the use of corticosteroids.

Anterior capsule adherence to iris leading to pseudophakic pupillary block.

We present a rare case of anterior capsule adherence to the iris following extracapsular cataract extraction with posterior chamber intraocular lens implantation and leading to pseudophakic pupillary block. There were no synechiae at the pupillary margins associated with the capsule/iris adherence, but aqueous was entrapped behind the iris and intraocular pressure rose. Laser iridotomy was temporarily beneficial, but it had to be repeated several times.

Occult ocular damage as a leading sign in the battered child syndrome.

A three-month old, premature female infant is presented with severe bilateral occult ocular damage comprised of cataracts, lenses dislocation, retinal hemorrhages and total funnel-shaped retinal detachment without external signs such as bruises. This severe eye trauma is the result of child abuse. We would like to alert pediatricians as well as ophthalmologists that any ocular injury should raise the possible diagnosis of battered child syndrome even in the absence of other supportive evidence of external trauma.

Idiopathic bilateral branch-artery occlusion in a young woman.

An unusual case of a 17-year-old woman with bilateral branch-artery occlusion is presented. A thorough clinical and laboratory investigation showed no evidence of any abnormality, which was also not found during a follow-up period of three years. The obstruction occurred in both eyes within a period of ten months. The differential diagnosis of branch-artery occlusion in the young is discussed.

The effect of sodium hyaluronate on the corneal epithelium. An ultrastructural study.

The effect of sodium hyaluronate (NaHa) 1% and 0.1% was studied on 14-day chick embryo corneal epithelium by scanning electron microscopy. It was found that NaHa 1% or 0.1% had no toxic effects on the chick corneal epithelium and the normal architecture of the cells and the morphology of the microvilli was well preserved. A combination of NaHa 0.1% and benzalkonium chloride (BAK) 0.01% reduced the toxic effect of BAK on the surface corneal epithelium. NaHa 0.1% provided a better protection of the corneal epithelium against dryness than hydroxyethylcellulose (HEC) 0.1% or phosphate buffer saline (PBS).

Intraocular involvement of Burkitt's lymphoma in a Bedouin child.

A child with a B-cell lymphoma with extensive abdominal disease responded to high doses of chemotherapy. One month later, eye and central nervous system recurrence developed. Intraocular involvement was documented by diagnostic vitrectomy. Differential diagnosis and therapy are discussed.