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Biomedical subjects

Luanna R Bartholomew

Publications and source records attributed to Luanna R Bartholomew.

9 recordsLinked to original sources
PubMed2006

Extensibility and scanning electron microscopy evaluation of 5 pediatric anterior capsulotomy techniques in a porcine model.

PURPOSE: To compare the extensibility and scanning electron microscopy (SEM) of 5 currently used pediatric anterior capsulotomy techniques: vitrectorhexis, manual continuous curvilinear capsulorhexis (CCC), can-opener, radio frequency diathermy, and plasma blade in a porcine model. SETTING: Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Extensibility was determined by stretching each capsulotomy until it ruptured and measuring it by calculating the mean stretch-to-rupture circumference of each capsulotomy (20 eyes per technique) as a percentage of its baseline circumference. Edge characteristics were evaluated using SEM. RESULTS: The mean extensibility of each technique tested (vitrectorhexis 161%, CCC 185%, can opener 149%, radio frequency 145%, plasma blade 170%) was significantly different (P<.001, 1-way analysis of variance). The SEM examination found that the vitrectorhexis had a scalloped edge with the whole edge rolled over, presenting a smooth surface toward the inside of the capsulotomy; the manual CCC produced the smoothest edge, with no irregularities noted; the can-opener edge was irregular, showing each puncture of the needle had created a small arc, with occasional regions of the edge rolled over in a "hit-and-miss" fashion; the radio-frequency diathermy capsulotomy edge was ragged, rough, and irregular; and the plasma blade capsulotomy edge was rougher than the manual CCC, but there were fewer irregularities than the radio-frequency diathermy edge had. CONCLUSIONS: The manual CCC technique produced the most extensible porcine capsulotomy, followed by the plasma blade, vitrectorhexis, can-opener, and radio-frequency techniques, in a porcine model. The manual CCC technique also produced the smoothest anterior capsulotomy edge according SEM evaluation.

Animals↗
PubMed2006

Prevention of Staphylococcus aureus endophthalmitis with topical gatifloxacin in a rabbit prophylaxis model.

PURPOSE: The aim of this study was to investigate the prophylactic use of 0.3% gatifloxacin drops to prevent endophthalmitis in a rabbit model. METHODS: Forty (40) New Zealand white rabbits were randomly placed into group A (20 rabbits) where they received 1 drop of 0.3% gatifloxacin in their right eye every 15 min (0, 15, 30, and 45 min), or group B (20 rabbits) where they received 1 drop of balanced salt solution (BSS) in their right eye every 15 min (0, 15, 30, and 45 min). Following this treatment regimen, the anterior chamber of each rabbit was injected with 0.025 mL of saline containing 5 x 10(5) colonyforming units of a clinical isolate of Staphylococcus aureus (vancomycin-sensitive). After the inoculum injection, the treatment regimen continued: group A (1 drop of 0.3% gatifloxacin) or group B (1 drop of BSS) immediately postinjection, 6, 12, 18, and 24 h, at which time the animals were examined in a masked fashion, photographed, anesthetized, euthanized, and the aqueous and vitreous humors collected to determine the number of viable bacteria. RESULTS: The median clinical scores for the gatifloxacin group were significantly lower than the control group (P < 0.05). Bacterial recovery of S. aureus was significantly higher in the control group in both the aqueous and vitreous humor (P < 0.05). CONCLUSIONS: Gatifloxacin-treated eyes demonstrated significantly less inflammation, infection, and culture-positive endophthalmitis (P < 0.05), compared to the control animals. It is important to further investigate the clinical implications from this prophylatic study.

Administration, Topical↗
PubMed2006

Vitreous concentration of topically applied brimonidine-purite 0.15%.

PURPOSE: The aim of this study was to determine the vitreous brimonidine concentration of topically applied brimonidine-Purite 0.15%. METHODS: Patients scheduled for a pars plana vitrectomy were invited to participate in this study after institutional review board (IRB) approval was obtained. Each patient was asked to apply brimonidine-Purite (0.15%) drops in the designated eye either every 12 h (b.i.d.; 9 patients) or every 8 h (t.i.d.; 10 patients) for the 2 weeks proceeding scheduled surgery. The importance of the last topical dose being 12 h (b.i.d. group) or 8 h (t.i.d. group) before the scheduled surgery, was emphasized. Four (4) patients served as controls and did not receive any drops. Vitreous (approximately 0.5-1.0 mL) was aspirated prior to opening the infusion line. Specimens were frozen at -68 degrees C until analyzed. RESULTS: In the b.i.d. group, the mean concentration of brimonidine was 16.74 nM+/-10.33 standard deviation (range, 0.42-34.68 nM; median, 16.38); in the t.i.d. group, the mean concentration of brimonidine was 19.16 nM+/-15.40 standard deviation (range, 0.22-39.48 nM; median, 16.98). A significant difference was observed between the (no drug) control vitreous brimonidine levels and b.i.d. or t.i.d. vitreous levels (P<0.01, <0.01, respectively; n=4, 9, and 10, respectively); and in brimonidine levels between t.i.d. phakic patients and t.i.d. patients with posterior chamber lens (P=0.04; n=4 and 6, respectively). CONCLUSIONS: Brimonidine-Purite 0.15%, topically applied b.i.d. or t.i.d. for 2 weeks prior to collection, acquired vitreous levels of brimonidine at or above the 2-nM concentration known to activate the neuroprotective alpha-2 receptor in animals.

Administration, Topical↗
PubMed2004

Opacification of the visual axis after cataract surgery and single acrylic intraocular lens implantation in the first year of life.

PURPOSE: To report the incidence and risk factors for secondary surgical intervention to treat visual axis opacification (VAO) after cataract surgery and acrylic intraocular lens (IOL) implantation during the first year of life. METHODS: A retrospective review of 29 eyes of 20 patients receiving a hydrophobic acrylic (AcrySof; Alcon, Fort Worth, TX) IOL implantation was conducted. All eyes underwent primary posterior capsulectomy and anterior vitrectomy. Statistical analysis was performed using SPSS for Windows (SPSS, Chicago, IL). RESULTS: Average age at surgery was 4.8 +/- 3.7 months, and average follow-up was 33.4 +/- 16.1 months. Eleven of 29 (37.9%) eyes developed VAO requiring secondary surgical intervention at a median of 4.8 months (95% confidence interval 3.4 to 6.2). Average age at surgery for eyes that subsequently opacified was 3.8 +/- 3.0 months compared with 5.4 +/- 4.0 months for those whose visual axis remained clear (P = 0.26). The relative risk of subsequent VAO surgery was 2.7 for primary surgery performed at or before the first 6 months of life. Opacification was significantly related to eyes with associated ocular anomalies (eg, anterior segment dysgenesis, iris hypoplasia, or persistent fetal vasculature) with a relative risk of 8.6 (P < 0.001). Proliferation of cortex was the most common form of VAO, followed by mixed-type with predominantly fibrous, fibrous alone, or Elschnig pearls. When secondary surgery was required, it occurred primarily during the first 6 months (ie, 9 of 11 patients) after the initial cataract surgery. CONCLUSIONS: When cataract and IOL surgery was undertaken within the first year of life, a secondary surgical procedure was required in 37.9% of eyes to maintain a clear visual axis. Most secondary surgery for VAO occurred within the first 6 months after surgery. Postoperative opacification was most common in eyes with associated ocular anomalies.

Acrylates↗
PubMed2004

Refractive surgery survey 2003.

To determine the refractive surgery preferences of ophthalmologists worldwide, questionnaires were sent to 8920 members of the American Society of Cataract and Refractive Surgery. A total of 1174 questionnaires was returned by the deadline. The practice distribution included 30.0% cataract surgeons, 47.3% comprehensive ophthalmologists, 14.4% refractive surgery (RS) specialists, 4.5% corneal/external disease specialists, 1.9% glaucoma specialists, and < 1% retinal/oculoplastics/pediatrics/neurophthalmologists/researchers/retired. Responses were compared with those in the 2001 and 2002 surveys and demonstrate that RS practice patterns continue to evolve.

Adult↗
PubMed2004

Outflow resistance of the Baerveldt glaucoma drainage implant and modifications for early postoperative intraocular pressure control.

PURPOSE: To determine outflow resistance of the Baerveldt glaucoma implant using different tube configurations. METHODS: Outflow resistance of 6 tube configurations (C1- C6) of Baerveldt implants was measured under conditions of constant pressure perfusion. Pressures ranged from 2 to 55 mm Hg. Venting slits were created using a 7-0 Vicryl, spatulated suture-needle. Seton tubes were occluded by threading a retrograde suture approximately 1.5 cm into the lumen. RESULTS: At pressures between 2 and 55 mm Hg, mean outflow resistance of the normally configured seton (ie, open tube; C1) was 0.41 (+/- 0.6) mm Hg/microL/min. Resistance was unchanged (mean 0.41 (+/- 0.4) mm Hg/microL/min) by the addition of 4 venting slits (C2) to the seton tube. Occlusion of the open seton tube with a 3-0 Supramid suture (C3) significantly increased (P < 0.001) mean outflow resistance to 14.99 (+/- 0.6) mm Hg/microL/min. Occlusion of the tube with a 4-0 Supramid suture (C4) significantly increased (P < 0.001) mean outflow resistance to 1.09 (+/- 0.5) mm Hg/microL/min. In implants where tubes were occluded with a 3-0 Supramid suture, the addition of venting slits (C5) significantly decreased (P = 0.038) mean outflow resistance to 8.98 (+/- 0.4) mm Hg/microL/min. In tubes occluded with a 4-0 Supramid suture, the addition of venting slits (C6) decreased mean outflow resistance to 0.98 (+/- 0.6) mm Hg/microL/min. CONCLUSIONS: Although these results cannot be directly correlated to the clinical setting, they do show that outflow resistance can be modified at the time of surgery by changing tube configuration of the Baerveldt glaucoma implant. Configuration C5 (3-0 Supramid with venting slits) closely approximates the outflow rate in the normal intraocular pressure range.

Drainage↗
PubMed2003

Cataracts and glaucoma in patients with oculocerebrorenal syndrome.

BACKGROUND: Oculocerebrorenal syndrome is an X-linked recessive hereditary oculocerebrorenal disorder characterized by congenital cataract, mental retardation, and Fanconi syndrome of the proximal renal tubules. Other ocular findings include glaucoma, corneal opacity (keloid), enophthalmos, and hypotonia. OBJECTIVE: To describe the treatment of 7 patients (14 eyes) with bilateral cataracts associated with oculocerebrorenal syndrome. Method Retrospective review. RESULTS: Seven patients with oculocerebrorenal syndrome had visually significant bilateral cataracts detected on their first full ophthalmic examination. All underwent bilateral cataract surgery. The mean age (of 14 eyes) at cataract extraction was 1.25 (median, 1.1) months. Glaucoma diagnosis and treatment were more variable. The mean age (of 11 eyes) at glaucoma diagnosis was 24.1 (range, 0.2-70.0) months: the mean age was 0.2 month (of 4 eyes) when glaucoma was diagnosed before cataract extraction, and the mean age was 37.7 months (of 7 eyes) when glaucoma was diagnosed after cataract extraction. All eyes were followed up for a mean of 100.8 (range, 38-190) months. Main Outcome Measure Treatment of 7 patients (14 eyes) with bilateral cataracts associated with oculocerebrorenal syndrome. CONCLUSIONS: Early identification and surgical removal of cataracts is recommended in patients with oculocerebrorenal syndrome. Despite this, visual acuity results will only rarely be better than 20/70, and nystagmus is likely. Patients should be monitored closely and regularly for changes in intraocular pressure, optic nerve cupping, and refractive error to rule out the development of glaucoma.

Cataract↗
PubMed2003

Pediatric cataract surgery and intraocular lens implantation: practice styles and preferences of the 2001 ASCRS and AAPOS memberships.

A survey of pediatric cataract surgery and intraocular lens (IOL) implantation practice patterns of adult and pediatric cataract surgeons was performed in October 2001. Questionnaires were distributed to the American Society of Cataract and Refractive Surgery and the American Association for Pediatric Ophthalmology and Strabismus. The overall return rate was 12.6% and 41.0%, respectively. Results show that pediatric cataract surgery with IOL implantation is being performed at a younger age than 8 years ago. Also, pediatric cataract surgery practice patterns are evolving in step with advances in adult surgery but with notable differences.

Cataract Extraction↗