Second cluster of strabismus cases after periocular anesthesia without hyaluronidase.

We describe a second cluster of cases of iatrogenic strabismus that occurred in clinical practices following cataract surgeries that occurred in 2000 when hyaluronidase was once again unavailable for use in periocular anesthetic regimens. Twelve cases of transient or permanent strabismus were referred by 4 anterior segment surgeons who had no previous cases of postcataract strabismus when performing periocular injections with hyaluronidase. The charts of the patients were reviewed retrospectively. Recurrence of an increase in postoperative strabismus when hyaluronidase became unavailable for a second time supports the concept that this enzyme may be more important than previously suspected in preventing damage to the extraocular muscles after periocular anesthetic injections.

Orbital wall approach with preoperative orbital imaging for identification and retrieval of lost or transected extraocular muscles.

PURPOSE: To report the results of an anterior approach along the orbital wall to recover a lost or transected extraocular muscle. METHODS: This is a retrospective review of lost or transected muscles retrieved by an anterior orbitotomy approach to the adjacent orbital wall because they were unable to be recovered by a standard conjunctival approach. Magnetic resonance imaging or computed tomography was performed on all subjects before surgery. RESULTS: Six patients underwent anterior orbitotomy via an orbital wall approach; all had undergone an attempted retrieval from a standard transconjunctival approach that failed. Five muscles had been lost from surgical or traumatic transection, and 1 muscle had been lost during strabismus surgery. The muscle location at retrieval ranged from 20 to 25 mm (mean, 23 mm) posterior to the limbus. The duration that these muscles were disinserted ranged from 7 days to 7.5 years (mean, 24 months). Preoperative deviation in primary gaze ranged from 15 to 50 PD, whereas first day postretrieval deviations all measured less than 8 PD. After a mean follow-up of 162 weeks, the mean deviation in primary gaze was 2 PD (range, orthotropia to 7 PD of esotropia). CONCLUSIONS: Anterior orbitotomy along the orbital wall with preoperative orbital imaging of extraocular muscle anatomy and function combine to create a valuable approach for retrieval of a lost or transected muscle. This technique may successfully retrieve lost or transected muscles that previously were irretrievable when using a standard transconjunctival approach.

Stereoacuity and depth perception decrease with increased instrument magnification: comparing a non-magnified system with lens loupes and a surgical microscope.

PURPOSE: To evaluate the effect of instrument magnification used in eye surgery on stereoacuity and depth perception. METHODS: Twenty-one subjects (10 clinical ophthalmologists familiar with loupes and operating microscopes and 11 non-ophthalmologists) with normal near vision and stereoacuity were tested with the Randot Stereotest viewed unmagnified, with a 4x loupes (450 mm focal length), and with a 16x operating microscope. RESULTS: Total scores: 8 errors in 210 test steps with the unmagnified observations, 25/210 with loupes, and 30/210 with the microscope. The statistical differences in these scores were "statistically highly significant" for all three tests (p = 0.002); and "significant" for the unmagnified versus loupe (p = 0.007) and unmagnified versus microscope (p = 0.002). Test viewing through the microscope, the greatest errors occurred (total errors = 1840 seconds of arc), less with the loupes (total 1150") and least without magnification (total 220"). Errors and scores for 10 experienced ophthalmologists were no different (p > or = 0.55, p = 1.00) from the 11 non-ophthalmologist subjects. CONCLUSIONS: Stereoacuity and depth perception decrease when viewing a test target with loupes or with a microscope, with the effect worsening as magnification increases. Familiarity with the magnifying equipment did not improve stereoacuity.

Propionibacterium acnes as a cause of visually significant corneal ulcers.

PURPOSE: To report Propionibacterium acnes as a cause of vision-threatening infectious keratitis and to discuss culture isolation and antibiotic treatment. METHODS: Retrospective case series presentation collected from three academic medical centers. RESULTS: Six cases of P. acnes infectious keratitis are presented, all of which were associated with a compromised corneal barrier or environment. All cases were culture-positive on thioglycolate broth; none became positive before 7 days of growth. No other organisms were isolated from any culture, and the growth of P. acnes occurred in some cases despite negative gram stains. CONCLUSION: P. acnes can produce vision-debilitating keratitis when the cornea is compromised. Growth in culture should be monitored for at least 10 days to ensure isolation of this fastidious organism. P. acnes may respond to several different antibiotics that have gram-positive coverage, but it should be treated with vancomycin to enhance clearance of the organism.

An ultrasound biomicroscopic study of eyes after deep sclerectomy with collagen implant.

OBJECTIVE: This study aimed to assess the natural history of eyes after deep sclerectomy with collagen implant (DSCI), a nonperforating glaucoma-filtering surgery. DESIGN: The design was a prospective, longitudinal, observational, and nonrandomized study. PARTICIPANTS: Forty-five eyes of 41 patients with medically uncontrolled open-angle glaucoma were studied. INTERVENTION: Deep sclerectomy with collagen implant was performed. MAIN OUTCOME MEASURES: Ultrasound biomicroscopy (UBM) of the sclerectomy site was performed 1, 2, 3, 6, 9, 12, and 18 months after surgery. The following parameters were assessed: length and height of the collagen implant, thickness of the residual trabeculodescemetic membrane, and bleb appearance. RESULTS: Mean intraocular pressure decreased from a preoperative value of 26.3 +/- 3.5 mmHg (mean +/- standard deviation) to a postoperative value of 16.6 +/- 3.1 mmHg (mean +/- standard deviation) at 18 months (P < 0.001). The UBM findings showed a subconjunctival filtration with a nonperforated thin trabeculodescemetic membrane. In 23 eyes (51%), a hypoechoic area in the suprachoroidal space was observed. The thickness of the trabeculodescemetic membrane was stable throughout the study with a mean value of 0.13 mm +/- 0.02 (mean +/- standard deviation) at 18 months. The collagen implant dissolved slowly within 6 to 9 months, leaving a tunnel in the sclera. CONCLUSIONS: The UBM findings are consistent with intraocular pressure lowering by aqueous filtration through the thin remaining trabeculodescemetic membrane to an area under the scleral flap, which was maintained open by the collagen implant. The authors speculate that aqueous humor then reached the subconjunctival space and, eventually, was filtered through the thin scleral wall into the suprachoroidal space. Complete resorption of the collagen implant occurred between 6 and 9 months after surgery.

Preseptal cellulitis and orbital wall destruction secondary to nasal cocaine abuse.

PURPOSE: To report preseptal cellulitis and orbital bone destruction as ocular manifestations of nasal cocaine abuse. METHOD: Case report. We examined a 40-year-old male nasal cocaine abuser with diabetes mellitus and with signs of preseptal cellulitis. Computed tomographic imaging of the cranium was performed, and a nasal cavity biopsy specimen was obtained. RESULTS: Computed tomographic findings showed extensive cartilaginous and bony destruction involving the nasal septum and medial wall of the left orbit, and the nasal biopsy specimen disclosed inflammatory exudate with neutrophils. CONCLUSIONS: Nasal cocaine abuse induces mucoperichondrial ischemia and may be associated with cartilaginous and bony destruction as well as preseptal cellulitis.

Loss of serum antibodies to a conformational epitope of HIV-1/gp120 identified by a human monoclonal antibody is associated with disease progression.

Serum antibody reactive with epitopes within the CD4 binding site (CD4BS) of HIV-1/gp120 on infected cells was measured by inhibition of binding of a human monoclonal antibody, F105, which recognizes a conformational epitope within this region. Serum samples from 27% of ARC/AIDS patients blocked binding of F105 to this epitope, while samples from 100% of asymptomatic seropositive patients blocked binding. F105 blocking activity increased in 87% of asymptomatic donors who maintained stable disease over a 3-6 year period and decreased in 50% of asymptomatic patients with progressive disease. Moreover, serum samples from patients with stable disease exhibited higher titers of F105 blocking activity. The presence of F105 blocking activity also correlated with serum neutralization of virus. When diluted 1:640, serum with low F105 blocking activity neutralized only 20-30% of viral cytopathic effect (CPE), while serum with high F105 blocking activity neutralized > 80%. Serum neutralization was enhanced by the addition of F105. Seroreactivity to infected cells was detectable within 6 months of seroconversion, but F105 blocking activity was delayed by an additional 6-12 months, as was the development of high titers of neutralizing antibody. These data support the notion that the humoral response to the CD4BS on gp120 may be important in the maintenance of health.

Molecular cloning of the human gene for von Willebrand factor and identification of the transcription initiation site.

A series of overlapping cosmid genomic clones have been isolated that contain the entire coding unit of the human gene for von Willebrand factor (vWf), a major component of the hemostatic system. The cloned segments span approximately 175 kilobases of human DNA sequence, and hybridization analysis suggests that the vWf coding unit is approximately 150 kilobases in length. Within one of these clones, the vWf transcription initiation site has been mapped and a portion of the vWf promoter region has been sequenced, revealing a typical "TATA box," a downstream "CCAAT box," and a perfect downstream repeat of the 8 base pairs containing the transcription start site. Sequencing of a segment of another genomic clone has revealed the vWf translation termination codon. Where tested, comparative restriction analysis of cloned and chromosomal DNA segments strongly suggests that no major alterations occurred during cloning and that there is only one complete copy of the vWf gene in the human haploid genome. Similar analyses of DNA from vWf-producing endothelial cells and nonexpressing leukocytes suggest that vWf gene expression is not accompanied by gross genomic rearrangements. In addition, there is significant homology of C-terminal coding sequences among the vWf genes of several vertebrate species.