Biomedical subjects

Helga P Sandoval

Publications and source records attributed to Helga P Sandoval.

At least 19 recordsLinked to original sources

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

Evaluation of 0.4% ketorolac tromethamine ophthalmic solution versus 0.5% ketorolac tromethamine ophthalmic solution after phacoemulsification and intraocular lens implantation.

PURPOSE: The aim of this study was to compare the effectiveness and patient tolerance of 0.4% ketorolac tromethamine ophthalmic solution and 0.5% ketorolac tromethamine ophthalmic solution after routine phacoemulsification and lens implantation. SETTING: The setting for this study was the Storm Eye Institute and Magill Research Center for Vision Correction, Medical University of South Carolina (Charleston, SC). METHODS: This work was a prospective, double-masked study that included 40 eyes of 40 patients randomly assigned to receive topical treatment with 0.4% ketorolac or 0.5% ketorolac, starting 15 min prior to routine phacoemulsification and foldable posterior chamber intraocular lens implantation. Following the procedure, patients were instructed to use the assigned treatment agent 4 times a day after surgery for 1 week and twice a day for 3 weeks, when drops were discontinued. Slit-lamp examination, intraocular pressure (IOP), laser cell and flare measurements, and subjective patient tolerance were evaluated postoperatively at 1, 7, and 30 d. Comparisons between the 2 groups were made at each visit, as well as comparisons to baseline. A P=value less than .05 was considered statistically significant. RESULTS: At day 1, a higher percentage of patients (70% vs. 40%) reported symptoms (mainly foreign body sensation and stinging/burning) in the 0.5% ketorolac group, compared to the 0.4% ketorolac group. No significant differences were found between the 2 groups over time regarding best-corrected visual acuity (BCVA), IOP, slit-lamp assessment of cells, and cell and flare measured using the laser cell/flare meter. CONCLUSIONS: Treatment with 0.4% ketorolac tromethamine ophthalmic solution is as effective as 0.5% ketorolac tromethamine ophthalmic solution in reducing inflammation after routine cataract surgery. Patients reported less discomfort using 0.4% ketorolac.

Aged↗

PubMed2006

Bronchogenic squamous cell carcinoma presenting as cicatrizing conjunctivitis.

PURPOSE: To report a case of cicatrizing conjunctivitis as the initial manifestation of a bronchogenic squamous cell carcinoma. METHODS: Case report of a 57-year-old patient with bilateral history of ocular pain, redness, and discharge, with no apparent predisposing factors. Examination revealed chemosis, pseudomembrane, and symblepharon formation, and multiple ulcerated pustular and vesicular periocular and perioral lesions literature review. RESULTS: Skin biopsy was compatible with bullous pemphigoid. Two months later he developed respiratory symptoms, and a squamous cell carcinoma was diagnosed. CONCLUSIONS: This case demonstrates cicatrizing conjunctivitis as a possible paraneoplastic syndrome associated with squamous cell lung carcinoma.

Carcinoma, Bronchogenic↗

PubMed2006

Randomized, double-masked clinical trial evaluating corneal endothelial cell loss after cataract extraction and intraocular lens implantation: Fluid-based system versus ultrasound phacoemulsification.

PURPOSE: To assess the endothelial cell loss after cataract extraction using a fluid-based system and compare it with conventional ultrasound. METHODS: A total of 46 eyes of 23 patients with up to 3+ bilateral cataract were included. The first eye was randomized to either fluid-based system or conventional ultrasound, and the fellow eye received the alternate system. Visual acuity and ultrasound pachymetry were measured preoperatively and at 1 day, 1 week, and 1 and 3 months postoperatively. Specular microscopy was performed preoperatively and 3 months after the surgery. Data was analyzed using the paired t test and Wilcoxon signed rank test. A P value less than 0.05 was considered statistically significant. RESULTS: Postoperatively, no significant differences were found among the groups. However, there was a significant difference (P < 0.01, analysis of variance with Tukey as posttest) in corneal pachymetry at day 1 after the surgery compared with baseline in both groups. There was a 6.3% and 7.9% loss of endothelial cells in the fluid-based system and ultrasound group, respectively. CONCLUSION: Visual acuity, pachymetry, and endothelial cell loss after cataract extraction and intraocular lens implantation using a fluid-based system is similar to conventional ultrasound.

Cell Count↗

PubMed2005

Refractive Surgery Survey 2004.

To determine the refractive surgery (RS) preferences of ophthalmologists worldwide, questionnaires were sent to 8897 members of the American Society of Cataract and Refractive Surgery. A total of 1053 questionnaires were returned by the deadline. The practice distribution included 29.5% cataract surgeons, 48.8% comprehensive ophthalmologists, 11.6% RS specialists, 5.1% cornea and external disease specialists, 1.9% glaucoma specialists, 1.1% retina specialists, and <1.0% oculoplastics/pediatrics/researchers/retired. Results were compared with those in the 2003 survey and demonstrate that refractive surgery continues to develop and change.

Adult↗

PubMed2005

Effect of hinge location on corneal sensation and dry eye after laser in situ keratomileusis for myopia.

PURPOSE: To evaluate the effects of a superior or nasal hinge location on corneal sensation and dry eye after laser in situ keratomileusis (LASIK). SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: This prospective randomized masked study included 47 patients having bilateral myopic LASIK surgery. The first eye was randomly assigned to have a nasal or superior hinge flap; the fellow eye had the alternate location. Visual acuity, contrast sensitivity, corneal sensation, basic secretion test, tear film breakup time, conjunctival and corneal staining, and a subjective questionnaire were evaluated preoperatively and postoperatively at 1 week and 1, 3, and 6 months. The Wilcoxon signed rank test and paired t test were used for comparison. RESULTS: Dry eye occurred with the same frequency in both groups. However, eyes with the nasal hinge had significantly better nasal sensation than those with the superior hinge (P<.05) at 1 month. CONCLUSION: Better nasal corneal sensation was found at 1 month in the nasal hinge group but there was no difference in any other parameters measured.

Adult↗

PubMed2005

Cryptococcus albidus keratitis after corneal transplantation.

PURPOSE: To report suspected donor-to-host transmission of Cryptococcus albidus after penetrating keratoplasty. METHODS: Review of the literature and a case report of a 69-year-old woman who underwent penetrating keratoplasty for Fuchs corneal dystrophy and developed persistent corneal infiltrates 7 months postoperatively are presented. RESULTS: Cryptococcus albidus was cultured from the original donor tissue at the time of the repeat keratoplasty. CONCLUSION: This case demonstrates an unusual case of cryptococcal keratitis after keratoplasty suspected to be a donor-to-host transmission.

Aged↗

PubMed2004

Flap thickness accuracy: comparison of 6 microkeratome models.

PURPOSE: To determine the flap thickness accuracy of 6 microkeratome models and determine factors that might affect flap thickness. SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: This multicenter prospective study involved 18 surgeons. Six microkeratomes were evaluated: AMO Amadeus, Bausch & Lomb Hansatome, Moria Carriazo-Barraquer, Moria M2, Nidek MK2000, and Alcon Summit Krumeich-Barraquer. Eyes of 1061 consecutive patients who had laser in situ keratomileusis were included. Age, sex, surgical order (first or second cut), keratometry (flattest, steepest, and mean), white-to-white measurement, laser used, plate thickness, head serial number, blade lot number, and occurrence of epithelial defects were recorded. Intraoperative pachymetry was obtained just before the microkeratome was placed on the eye. Residual bed pachymetry was measured after the microkeratome cut had been created and the flap lifted. The estimated flap thickness was determined by subtraction (ie, mean preoperative pachymetry measurement minus mean residual bed pachymetry). RESULTS: A total of 1634 eyes were reviewed. Sex distribution was 54.3% women and 45.7% men, and the mean age was 39.4 years +/- 10.6 (SD). In addition, 54.5% of the procedures were in first eyes and 45.5%, in second eyes. The mean preoperative pachymetry measurement was 547 +/- 34 microm. The mean keratometry was 43.6 +/- 1.6 diopters (D) in the flattest axis and 44.6 +/-1.5 D in the steepest axis. The mean white-to-white measurement was 11.7 +/- 0.4 mm. The mean flap thickness created by the devices varied between head designs, and microkeratome heads had significant differences (P<.05). Factors that explained 78.4% of the variability included microkeratome model, plate thickness, mean preoperative pachymetry, Kmin, surgery order, head serial number, blade lot number, and surgeon. Factors such as age, sex, Kmax, Kaverage, white to white, and laser had no significant correlation to flap thickness. CONCLUSIONS: The results demonstrated variability between the 6 microkeratome models. Device labeling did not necessarily represent the mean flap thickness obtained, nor was it uniform or consistent. Thinner corneas were associated with thinner flaps and thicker corneas with thicker flaps. In addition, first cuts were generally associated with thicker flaps when compared to second cuts in bilateral procedures.

Adult↗

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

Safety and efficacy of ketorolac tromethamine 0.4% ophthalmic solution in post-photorefractive keratectomy patients.

PURPOSE: To evaluate the safety and analgesic efficacy of ketorolac tromethamine 0.4% ophthalmic solution in postoperative photorefractive keratectomy (PRK) patients. SETTING: Fifteen clinical sites in the eastern and southern United States. METHODS: This pooled analysis of 2 multicenter, randomized, double-masked, vehicle-controlled, parallel-group studies comprised 313 patients having unilateral PRK. After surgery, patients were treated with 1 drop of ketorolac tromethamine 0.4% ophthalmic solution (Acular(R) LS) (n = 156) or vehicle (n = 157) 4 times daily for up to 4 days. Pain intensity, pain relief, use of escape medication, and severity of ocular symptoms were assessed. Adverse events, epithelial healing, and visual acuity were recorded. RESULTS: There was significantly less pain intensity experienced by patients in the ketorolac group (P<.001). During the first 12 hours post PRK, 50% fewer patients in the ketorolac group than in the vehicle group had severe to intolerable pain (41.6% [64/154] and 84.5% [131/155], respectively). The median time to no pain was 30 hours in the ketorolac group and 54 hours in the vehicle group (P<.001, survival analysis). Ketorolac patients reported significantly greater pain relief than vehicle patients throughout the study (P<.001). Ketorolac patients used significantly less escape medication than vehicle patients for 48 hours post PRK (P< or =.008). Treatment-related adverse events occurred in 2.6% (4/156) of ketorolac patients and 6.4% (10/157) of vehicle patients. CONCLUSION: Ketorolac 0.4% ophthalmic solution is safe and effective in reducing ocular pain when used 4 times daily for up to 4 days post PRK.

Adolescent↗

PubMed2004

Comparison of wavefront sensing devices.

Wavefront measurement is an emerging technology that can evaluate low-order and high-order aberrations. This review compiles the different wavefront sensing devices and compares the most popular Hartmann-Shack aberrometers.

Diagnostic Techniques, Ophthalmological↗

PubMed2004

Evaluation of preoperative and postoperative prophylactic regimens for prevention and treatment of diffuse lamellar keratitis.

PURPOSE: To investigate preoperative and postoperative prophylactic treatment with different pharmacological agents before flap cutting and exposure to a diffuse lamellar keratitis (DLK) causative agent. SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: The study comprised 48 eyes of 24 Dutch-belted rabbits. Three days before a corneal flap was cut and the corneal interface was exposed to Pseudomonas aeruginosa lipopolysaccharide endotoxin, a DLK causative agent, the eyes were randomly assigned to treatment with a mast-cell stabilizer, a nonsteroidal antiinflammatory drug (NSAID), or a corticosteroid or left without treatment as controls. The treatment was maintained throughout the 1-week follow-up. Slitlamp examinations and photographs were performed at 1, 3, 5, and 7 days; DLK was graded by a masked observer from 0 (no DLK) to IV. Corneal interface scrapings were performed in selected eyes on day 7. RESULTS: At the end of the follow-up, 36 eyes were available for evaluation. At 1 week, 100% of the control eyes and the eyes treated with the mast-cell stabilizer developed DLK; in the NSAID-treated and corticosteroid-treated eyes, the DLK rate was 86% and 70%, respectively. At 1 day, the severity of DLK was significantly lower in eyes treated with the mast-cell stabilizer (0.44) and at 7 days, it was significantly lower in corticosteroid-treated eyes (0.3) than in the control group (1.5 and 1.4, respectively) (P<.05, Wilcoxon test). Corneal interface scraping from an eye with grade III DLK showed numerous inflammatory cells. CONCLUSIONS: Preoperative and postoperative treatment with corticosteroids significantly reduced the severity of DLK compared to the untreated control eyes in this animal model. Treatment with a mast-cell stabilizer and an NSAID had less effect on the postoperative course of DLK.

Animals↗

PubMed2004

Endothelial cell integrity after phacoemulsification with 2 different handpieces.

PURPOSE: To investigate corneal endothelial cell loss in fresh phakic human autopsy cadaver eyes after phacoemulsification (PE) with a conventional handpiece or a new oscillatory handpiece. SETTING: Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Twenty fresh phakic human autopsy globes were randomized to PE with a conventional handpiece (n = 10) or an oscillatory handpiece (n = 10). The main parameters evaluated were age, nucleus density, amount of ophthalmic viscosurgical device (OVD) used, and mean PE time and ultrasound (US) power. After surgery, the corneas were excised and the endothelia were vitally stained with trypan blue and alizarin red. Light microscopy was used to assess the endothelial cell loss. RESULTS: The mean age, density of the nucleus, OVD used, and US power were similar between the groups. The mean PE time was less with the NeoSoniX handpiece (0.71 minutes +/- 0.39 [SD]) than with the conventional handpiece (1.05 +/- 0.53 minutes). The mean number of dead endothelial cells was significantly lower in the oscillatory handpiece group (31.3 +/- 24.2 cells/mm(2)) than in the conventional handpiece group (60.4 +/- 46.8 cells/mm(2)) (P<.001, Mann-Whitney rank sum test). CONCLUSIONS: Less corneal endothelial cell loss occurred after PE with an oscillatory handpiece than with a conventional handpiece. Further randomized clinical trials are recommended to validate this study.

Adult↗

PubMed2004

Corneal endothelial cell damage after lens extraction using the fluid-based system compared to ultrasound phacoemulsification in human cadaver eyes.

PURPOSE: To compare the endothelial cell damage after lens removal using a fluid-based system to conventional ultrasound. METHODS: Twenty human cadaver eyes were randomized to undergo phacoemulsification using either a fluid-based system or conventional ultrasound. After surgery, each corneoscleral button was removed, stained and damaged endothelial cells per square millimeter were assessed using light microscopy. RESULTS: Fluid-based system mean damaged endothelial cells/mm was 60.2 +/- 24.1 compared with 60.4 +/- 42.6 when using conventional ultrasound (P = 0.248). CONCLUSION: The fluid-based system is as safe for the corneal endothelium as conventional ultrasound during cataract removal in human cadaver eyes.

Adult↗

PubMed2003

Rapid diagnosis and treatment of mycobacterial keratitis after laser in situ keratomileusis.

We report the results of laser in situ keratomileusis (LASIK) in a 51-year-old woman with subsequent mycobacterial keratitis diagnosed by staining with acid-fast and fluorochrome methods, a technique known to have good sensitivity and specificity for mycobacteria. A rapid diagnosis was made without waiting for cultures, and treatment was instituted, including tapering of topical steroids and appropriate antibiotic therapy. The result was preservation of the LASIK flap and a favorable visual outcome at 6 months.

Amikacin↗

PubMed2003

Diffuse lamellar keratitis: evaluation of etiology, histopathologic findings, and clinical implications in an experimental animal model.

PURPOSE: To induce diffuse lamellar keratitis (DLK) and investigate the potential causative agents in an animal model. SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: In 70 eyes of 35 Dutch Belted rabbits, a corneal flap was cut and the interface randomly exposed to 1 of 7 substances: Pseudomonas aeruginosa endotoxin, 1 of 2 Staphylococcus aureus exotoxins, meibomian gland secretion, povidone-iodine 10%, Palmolive Ultra soap, and Klenzyme soap. Slitlamp examinations were performed 1, 3, 5, and 7 days postoperatively. The DLK was staged from 1 to 4. On day 7, the rabbits were killed and the eyes enucleated and processed for histopathologic examination. RESULTS: At the end of the study, 54 eyes (46 exposed, 8 control) were available for evaluation. The 8 eyes studied concurrently in the control group remained clear and did not show interface inflammation. Thirty-one of 46 eyes (67%) treated with the various test substances developed DLK. The highest DLK rates were found with the cleaning soap Palmolive Ultra (100%; P =.022) and P. aeruginosa lipopolysaccharide endotoxin (90%; P =.026). CONCLUSIONS: Interface inflammation was consistently induced in the animal model. All 7 agents caused DLK in at least some eyes. The histopathologic evaluation showed the morphologic profile of the marked inflammatory cellular reaction that occurred in almost all the specimens.

Animals↗

PubMed2003

Corneal flap complications in refractive surgery: Part 2: postoperative treatments of diffuse lamellar keratitis in an experimental animal model.

PURPOSE: To induce diffuse lamellar keratitis (DLK) and investigate a prophylactic treatment with pharmacological agents. SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Charleston, South Carolina, USA. METHODS: In 100 eyes of 50 Dutch Belted rabbits, a nasal corneal flap was cut and the interface inoculated with Pseudomonas aeruginosa lipopolysaccharide endotoxin (n = 50) or Palmolive Ultra soap (n = 50). The eyes were randomly assigned to treatment with a mast-cell stabilizer, a nonsteroidal antiinflammatory drug (NSAID), a fluoroquinolone antibiotic agent, a corticosteroid, or left without treatment as a control. Slitlamp examinations and photographs were performed 1, 3, 5, and 7 days postoperatively, and DLK was graded by a masked observer from 0 (no DLK) to stage 4. RESULTS: At the end of the study, 80 eyes were available for evaluation. Ninety-four percent of the untreated eyes developed DLK compared to 56% of eyes treated with NSAIDs and 63% of eyes treated with steroids (P<.05, Fisher exact test). The DLK rates with the mast-cell stabilizer and fluoroquinolone antibiotic agent were 86% and 76%, respectively. The DLK incidence in the latter 2 groups was not significantly different from that in the control eyes (P>.05, Fisher exact test). CONCLUSIONS: Postoperative prophylactic treatment with NSAIDs and corticosteroids led to a statistically significantly lower incidence of postoperative DLK. The study demonstrated that corticosteroids and NSAIDs can be used to treat DLK after LASIK. While steroids are a generally accepted treatment for DLK, NSAIDS may offer an additional potent modality.

Animals↗

PubMed2003

Corneal flap complications in refractive surgery: Part 1: development of an experimental animal model.

PURPOSE: To report the outcome, learning curve, and complication rates of an experimental animal model for corneal flaps in refractive surgery. SETTING: Magill Research Center for Vision Correction, Storm Eye Institute, Charleston, South Carolina, USA. METHODS: Corneal flaps with a nasal or a temporal hinge were created in 190 eyes of 95 Dutch Belted rabbits using the Automated Corneal Shaper microkeratome (Bausch & Lomb Surgical). Diffuse lamellar keratitis (DLK) was induced by inoculating the corneal interfaces with 1 of 7 substances. Postoperatively, the eyes were examined with a slitlamp. Special emphasis was placed on corneal flap complications and the relationship between slipped flaps and hinge position and/or inoculation agent. RESULTS: A good corneal flap was achieved in 174 eyes (92%). The eyes with a nasal hinge had a lower incidence of slipped flaps (14%) than eyes with a temporal hinge (37%) (P =.02). CONCLUSION: With the animal model described, corneal flaps were created in a precise and reproducible way in more than 90% of eyes. Nasal hinged flaps showed less postoperative displacements than temporal hinged flaps and are adequate for further study.

Animals↗