PubMed Health⌕ Search

Biomedical subjects

Gaurav K Shah

Publications and source records attributed to Gaurav K Shah.

At least 19 recordsLinked to original sources
PubMed2006

Vitreous and aqueous penetration of orally administered moxifloxacin in humans.

OBJECTIVE: To investigate intraocular penetration of moxifloxacin hydrochloride after oral administration. METHODS: Prospective study of 15 patients scheduled for vitrectomy between September and November 2004 at the Barnes Retina Institute, St Louis, MO. Aqueous, vitreous, and serum samples were analyzed from 15 patients after oral administration of 2 tablets containing 400 mg of moxifloxacin. Assays were performed using high-performance liquid chromatography. RESULTS: The mean +/- SD moxifloxacin concentrations in plasma (n = 15), vitreous (n = 13), and aqueous (n = 13) samples were 3.56 +/- 1.31 microg/mL, 1.34 +/- 0.66 microg/mL, and 1.58 +/- 0.80 microg/mL, respectively. Mean +/- SD sampling times after oral administration of the second moxifloxacin tablet for plasma, vitreous, and aqueous were 2.94 +/- 0.81 hours, 3.77 +/- 0.92 hours, and 3.71 +/- 0.89 hours, respectively. The percentages of plasma moxifloxacin concentration in the vitreous and aqueous were 37.6% and 44.3%, respectively. Minimal inhibitory concentrations against 90% levels were exceeded against a wide spectrum of gram-positive and gram-negative pathogens in the vitreous and aqueous. CONCLUSIONS: Moxifloxacin has a spectrum of coverage that encompasses the most common organisms in endophthalmitis. The pharmacokinetic findings of this investigation reveal that orally administered moxifloxacin achieves therapeutic levels in the noninflamed eye. Because of their broad spectrum of coverage, low minimal inhibitory concentration against 90% levels, good tolerability, and excellent oral bioavailability, fourth-generation fluoroquinolones may represent a major advance for managing posterior segment infections.

Administration, Oral↗
PubMed2006

Short-term intraocular pressure trends following intravitreal pegaptanib (Macugen) injection.

PURPOSE: To report the changes and trends in intraocular pressures (IOP) following intravitreal injection of Pegaptanib (Macugen) for the treatment of exudative age-related macular degeneration. DESIGN: Retrospective chart review. METHODS: Review of 79 patients who underwent 122 consecutive Pegaptanib injections. Analysis of the short-term effect of Pegaptanib injections on IOP was performed. RESULTS: Baseline mean IOP was 15.73 +/- 3.41 mm Hg (mean +/- standard deviation) with a range of 9 to 27 mm Hg. Postinjection mean IOP was 24.47 +/- 6.29 mm Hg with a range of 8 to 36 mm Hg. Mean IOP change from baseline to roughly 30 minutes after Pegaptanib injection was 8.74 +/- 7.23 mm Hg. At the 5- to 7-day follow-up visit, IOP had normalized. CONCLUSIONS: Pegaptanib injection in this limited series seems to be safe from an IOP standpoint in the short-term. IOP monitoring postinjection may not be necessary.

Aptamers, Nucleotide↗
PubMed2006

Outcomes of macular hole surgery and shortened face down positioning.

PURPOSE: Internal limiting membrane (ILM) peeling in macular hole surgery may allow a shortened period of face down positioning. This study reports the results of macular hole surgery combined with shortened (3-day) face down positioning. METHODS: The study was a retrospective review of data for 21 patients (21 eyes) treated for a macular hole by a single surgeon (G.K.S.). All patients underwent standard 3-port pars plana vitrectomy with triamcinolone-assisted ILM peeling and gas tamponade with 16% C3F8 or 25% SF6. Patients were instructed to remain in a face down position for 3 days at least 8 hours a day and to avoid flat on back positioning. RESULTS: The main outcome of anatomical closure was achieved in 20 (95%) of 21 eyes. Snellen visual acuity improved >2 lines in 76% (16/21) of patients. No patient lost >1 line of Snellen visual acuity. Two patients had postoperative increased (>24 mmHg) intraocular pressure that was successfully treated with pressure-lowering drops. Initial surgery failed to achieve hole closure in one patient, but with a second surgery and similar face down positioning, the hole was closed. CONCLUSIONS: This study found that macular hole surgery with ILM peeling and a shortened period of face down positioning achieves excellent anatomical closure and is not associated with significant adverse outcomes.

Aged↗
PubMed2005

Penetration pharmacokinetics of topically administered 0.5% moxifloxacin ophthalmic solution in human aqueous and vitreous.

OBJECTIVE: To investigate the penetration of 0.5% moxifloxacin hydrochloride into the aqueous and vitreous after topical administration in humans. METHODS: A prospective, nonrandomized study of 20 patients scheduled for vitrectomy surgery between September 1 and December 31, 2003. Aqueous and vitreous samples were obtained and analyzed after topical administration of 0.5% moxifloxacin hydrochloride, every 2 hours (q2h) or every 6 hours (q6h), for 3 days before surgery. Assays were performed using high-performance liquid chromatography. RESULTS: Mean +/- SD moxifloxacin concentrations in the q2h group for the aqueous (n = 9) and vitreous (n = 10) were 2.28 +/- 1.23 and 0.11 +/- 0.05 microg/mL, respectively. Mean +/- SD moxifloxacin concentrations in the q6h group for the aqueous (n = 10) and vitreous (n = 9) were 0.88 +/- 0.88 and 0.06 +/- 0.06 microg/mL, respectively. The minimum inhibitory concentration for 90% of isolates (MIC(90)) was far exceeded in the aqueous for a wide spectrum of key pathogens, whereas it was not exceeded in the vitreous for several organisms. However, the minimum inhibitory concentration for 50% of the isolates was exceeded in the q2h vitreous group for Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Bacillus cereus, and other gram-negative pathogens. CONCLUSIONS: The Endophthalmitis Vitrectomy Study revealed that 94.2% of isolates from postoperative endophthalmitis are gram-positive pathogens. Moxifloxacin has a spectrum of coverage that appropriately encompasses the most common organisms in endophthalmitis. The pharmacokinetic findings of this investigation show that relatively high aqueous levels can be achieved after topical administration. Further studies will help define the precise role of 0.5% moxifloxacin ophthalmic solution in the treatment of or prophylaxis against intraocular infections.

Administration, Topical↗
PubMed2005

Management of endogenous fungal endophthalmitis with voriconazole and caspofungin.

PURPOSE: Voriconazole, a new generation triazole, has been shown to achieve therapeutic intraocular levels after oral administration. Caspofungin is the first approved agent from a new class of antifungals, the echinocandins. This series describes experience at two centers using these novel antifungals to treat endogenous fungal endophthalmitis. DESIGN: Retrospective review. METHODS: Treatment of five patients with Candida endophthalmitis are reviewed. Postmortem intraocular voriconazole concentrations on a sixth patient are presented as well. RESULTS: All patients had systemic cultures positive for Candida species. Three patients had prompt resolution of intraocular mycosis with intravenous and oral voriconazole, caspofungin, or both. The fourth patient with bilateral disease responded well to i.v. voriconazole and caspofungin but had a recurrence when discharged on oral voriconazole and i.v. caspofungin. This patient had a bowel resection with an ileostomy; therefore, absorption of oral voriconazole may have been inadequate. Bilateral amphotericin B intravitreal injection ultimately treated this patient. The fifth patient received 100 microg/0.1 ml of intravitreal voriconazole (final vitreous concentration approximately 25 microg/ml) followed by oral voriconazole and responded favorably. Our sixth patient had multisystem failure and passed away 1 week after initiating intravenous voriconazole for non-ocular candidemia. Postmortem HPLC analysis of the aqueous and vitreous revealed voriconazole concentrations of 1.52 microg/ml and 1.12 microg/ml, respectively (MIC90 of Candida albicans is 0.06 microg/ml). CONCLUSIONS: Voriconazole and caspofungin appear to be powerful weapons to add to the existing armamentarium against fungal endophthalmitis. Further studies are warranted to define precisely the role of these new agents alone or in combination with other antifungals.

Administration, Oral↗
PubMed2005

Determination of aqueous and vitreous concentration of moxifloxacin 0.5% after delivery via a dissolvable corneal collagen shield device.

PURPOSE: To determine the penetration of moxifloxacin 0.5% in the human aqueous and vitreous when delivered by a presoaked collagen shield. SETTING: University-based clinical practice. METHODS: Moxifloxacin 0.5% was administered before vitrectomy surgery in 10 patients using a 24-hour dissolvable cross-linked corneal collagen shield delivery device. Aqueous and vitreous samples were obtained after the shield was placed for 4 hours in the first 5 patients and for 24 hours in the second 5 patients. Assays were performed using high-performance liquid chromatography. RESULTS: Delivery of moxifloxacin via a collagen shield revealed a mean aqueous concentration of 0.30 microg/mL +/- 0.17 (SD) 4 hours after placement (n = 5). Vitreous levels at 4 hours and aqueous and vitreous levels at 24 hours were negligible using this route of administration. Peak aqueous moxifloxacin levels occurred soon after shield placement. This is when high concentrations of moxifloxacin are most needed to clear the aqueous of bacteria. The minimum inhibitory concentration at which 90% of the isolates were inhibited for organisms commonly responsible for endophthalmitis was exceeded in the 4-hour aqueous group. Negligible concentrations were detected at 24 hours. CONCLUSIONS: Although aqueous moxifloxacin levels achieved through the use of a collagen shield delivery device are lower than via topical drops, there are several advantages to this route of delivery that make it appealing in the immediate postoperative period. Future studies will be needed to define precisely the role of fourth-generation fluoroquinolones and presoaked collagen shields in the prophylaxis or management of intraocular infections.

Aged↗
PubMed2005

Visual outcomes and complications of epiretinal membrane removal secondary to rhegmatogenous retinal detachment.

PURPOSE: To examine visual outcomes after surgery for removal of epiretinal membrane after retinal detachment (RD) repair, and to identify possible complications. DESIGN: Retrospective case series. PARTICIPANTS: Seventy-five patients who underwent surgery for removal of an epiretinal membrane after RD repair. METHODS: Retrospective chart review of 75 patients who underwent surgery for removal of an epiretinal membrane after RD repair over a 10-year period. Follow-up ranged from 6 to 124 months (mean, 49). MAIN OUTCOME MEASURES: Measurement of final visual acuity (VA). RESULTS: After epiretinal membrane removal, VA increased 0.43 logarithms of the minimum angle of resolution (95% confidence interval, 0.27-0.58; t = 5.47, P = 0.000). Sixty-six patients (88%) had a VA at final follow-up greater than their preoperative VA. Forty-nine patients (70%) had a final VA equal to or greater than their best VA after RD repair. Final VA of 20/60 or better was achieved in 65.3% of eyes. Of the 43 eyes that were phakic at the beginning of the study, 34 (79.1%) underwent cataract extraction before final follow-up. Five eyes (6.7%) had a recurrent RD after membrane removal. Sixteen eyes (21.3%) developed a recurrent epiretinal membrane, 1 of which (1.3% of all eyes) was visually significant, requiring repeat surgery. CONCLUSIONS: Epiretinal membrane development is a known complication of RD repair. Visual acuity can be improved in these patients by removal of the epiretinal membrane, with excellent results. In this series, recurrent membrane formation is not visually significant. Careful follow-up is needed to detect recurrent RD.

Adolescent↗
PubMed2005

Progression of visual loss and time between initial assessment and treatment of wet age-related macular degeneration.

PURPOSE: To determine whether the time elapsed from initial (referral) diagnosis of neovascular (wet) age-related macular degeneration (AMD) to assessment and treatment by a retinal specialist is associated with visual deterioration in the intervening period. METHODS: A prospective pilot study of 38 consecutive AMD patients who presented with newly diagnosed subfoveal choroidal neovascularization was conducted in a tertiary care retinal practice. All eligible subjects underwent clinical examination and digital fluorescein angiography at the time of assessment by a retinal specialist. Correlations were performed to assess the association between continuous independent variables and any visual deterioration since initial diagnosis. Multivariate linear regression models with stepwise techniques were used to evaluate any association between visual progression and time elapsed, while controlling for potential clinical covariates. RESULTS: Of the 38 patients, 32 (84%) met the inclusion and exclusion criteria; no differences in important variables were noted between those included and those excluded. The median time between initial diagnosis and referral assessment and treatment was 28 days (interquartile range=36.5 days); some degree of visual loss developed in 14 (44%) of the subjects. The elapsed time was correlated with progression of visual loss (r=0.50, p=0.003). Multivariate linear regression demonstrated that only time elapsed and lesion type based on fluorescein angiography were associated with progression of visual loss (R2=0.491, F(4,28)=6.744, p=0.001); lesion size, age and sex were not significantly associated with progression of visual loss. INTERPRETATION: Delay in assessment and treatment of new-onset wet AMD by a retinal specialist is associated with a higher risk of visual loss.

Aged↗
PubMed2005

Drug pricing for a novel treatment for wet macular degeneration: using incremental cost-effectiveness ratios to ensure societal value.

OBJECTIVE: Health economic models can assist policy-makers in determining the value of novel treatments from the viewpoint of society. In this context, value is defined as the benefit of treatment, given its cost. A new treatment for wet age-related macular degeneration (AMD), juxtascleral administration of anecortave acetate, 15 mg for depot suspension (Retaane), is now in a late-phase clinical trial. In a theoretical analysis, we sought to determine the cost at which this treatment might offer economic value to society, using incremental cost-effectiveness ratios (ICERs). METHODS: A series of 1-year cost-utility models was created for the investigational treatment and standard treatment (photodynamic therapy [PDT] with verteporfin [Visudyne]). Value to society was defined in terms of theoretical associated ICERs (in US dollars): $100,000 per quality-adjusted life-year (QALY), $50,000/QALY, $20,000/QALY and $0/QALY, the point of economic indifference. Models were created from the societal perspective and included a patient-derived utility assessment involving regression equations to estimate time trade-off preferences, event probabilities derived from a randomized clinical trial comparing the safety and efficacy of anecortave administration and PDT with verteporfin, decision analysis and relevant costing information. RESULTS: An ICER of $100,000/QALY would be associated with an anecortave cost of $3022/vial, an ICER of $50,000/QALY with an anecortave cost of $2986/vial and an ICER of $20,000/QALY with an anecortave cost of $2964/vial. The point of economic indifference between anecortave administration and standard therapy would occur with an anecortave cost of $2950/vial. INTERPRETATION: In theory, an anecortave cost of $2986/vial is associated with an ICER of $50,000/QALY, the threshold used by many health technology assessment and reimbursement agencies.

Clinical Trials, Phase III as Topic↗
PubMed2005

Photodynamic therapy for juxtafoveal choroidal neovascularization due to ocular histoplasmosis syndrome.

PURPOSE: To report the use of photodynamic therapy with verteporfin in patients with juxtafoveal choroidal neovascularization (CNV) for ocular histoplasmosis syndrome (OHS). METHODS: Retrospective review. Data regarding the following variables were extracted from patient charts: demographic characteristics, previous surgeries, angiographic features, number and time of treatments, follow-up time, and change in visual acuity. RESULTS: This study sample consisted of 23 eyes of 23 consecutive patients who were treated with photodynamic therapy for the management of juxtafoveal CNV. When post-treatment visual acuity (mean logMAR acuity=0.321) was compared to baseline acuity (mean logMAR visual acuity=3.89) vision improved by more than three Snellen lines in 30% of eyes, remained the same (+/-2 Snellen lines) in 52% of eyes, and worsened (greater than a two-line loss in visual acuity) in 18% of eyes. Although this series was uncontrolled, the patients had a trend toward a therapeutic benefit when compared to published natural history of similar cases (OR=0.292, P value=0.071 when compared to data from the Macular Photocoagulation Study for treatment of juxtafoveal lesions). CONCLUSION: Photodynamic therapy with verteporfin may be beneficial in patients with juxtafoveal CNV secondary to OHS in terms of both visual stabilization and improvement.

Adult↗
PubMed2005

Photodynamic therapy with verteporfin for peripapillary choroidal neovascularization.

PURPOSE: To evaluate the efficacy of photodynamic therapy with verteporfin in the management of symptomatic extrafoveal peripapillary choroidal neovascularization (CNV). METHODS: Seven eyes of seven patients with symptomatic peripapillary CNV underwent visual acuity testing, ophthalmic examination, color photography, and fluorescein angiography to evaluate the results of photodynamic therapy with verteporfin. Patients were offered treatment following the development of hemorrhage, subretinal fluid, or lipid if it was associated with visual symptoms. A standard nomogram was used to dose Visudyne, application was performed in three separate 30-second zones confluent over the extent of the lesion. The light dose per unit area applied to the retina was approximately 18 J/cm. RESULTS: Five of the seven had CNV limited to the peripapillary area associated with age-related macular degeneration; the remaining two eyes had presumed ocular histoplasmosis syndrome. In five of the seven eyes, two treatments were needed and in two eyes only one treatment was necessary to elicit resolution of active leakage. Retreatment was performed at an average of 76 days after initial treatment. Baseline best-corrected visual acuity (BCVA) ranged from 20/20 to 20/150. Final BCVA ranged from 20/20 to 20/80. In all eyes except for one, which had a pretreatment vision of 20/20, at least two lines of Snellen visual acuity improvement were achieved. Resolution of submacular fluid, hemorrhage, or exudates was noted in six eyes; in the remaining eye there was persistence of subretinal lipid. There were no complications including optic neuropathy in any of the treated eyes. Follow-up ranged from 6 to 13.5 months following last treatment (mean, 10 months). CONCLUSION: Photodynamic therapy with verteporfin for extrafoveal symptomatic peripapillary CNV appears to be effective in improving vision and promoting the resolution of subfoveal exudates, hemorrhage, or fluid. A randomized controlled study with longer follow-up is justified.

Adult↗
PubMed2005

Triamcinolone-assisted internal limiting membrane peeling.

PURPOSE: To review our experience with triamcinolone-assisted pars plana vitrectomy for internal limiting membrane (ILM) peeling for various retinal diseases. METHODS: Twenty-one patients underwent surgery in which intraoperative triamcinolone acetonide (TA) was used. Indications for surgery included epiretinal membrane (3 patients), branch retinal vein occlusion associated with macular edema (2), traction retinal detachment (3), diabetic macular edema (4), vitreous hemorrhage with diabetic macular edema (4), macular hole (4), and cystoid macular edema (1). RESULTS: TA was useful in the removal of the ILM in all cases. There were no intraoperative complications or toxicity. The mean follow-up was 22 weeks (range, 9-30 weeks). Eleven patients improved by >or=2 Snellen lines, 1 lost >or=2 Snellen lines, and 9 were within 2 Snellen lines of preoperative vision at the last follow-up. CONCLUSIONS: The intraoperative use of TA improves visualization of ILMs associated with a variety of conditions. No intraoperative or postoperative complications were observed. TA-assisted removal of the ILM appears to be safe and cost effective. TA-assisted ILM peeling should be considered as an alternative to the use of intraoperative dyes.

Aged↗
PubMed2004

Pars plana vitrectomy with internal limiting membranectomy for refractory diabetic macular edema without a taut posterior hyaloid.

BACKGROUND: This is a retrospective study designed to investigate the effect of pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling on diabetic macular edema in eyes that do not have a taut hyaloid and have been refractory to standard laser treatment. METHODS: Review of 26 eyes of 20 patients consecutively were treated with PPV with ILM peel for refractory diabetic macular edema. Eyes were included if they had been unresponsive to conventional treatment defined as at least two focal laser applications by a retina specialist. Paired t-testing was performed to determine if a change in both optical coherence tomography (OCT)-measured retinal thickness and logarithm of the minimum angle of resolution (logMAR) visual acuity occurred prior to and following PPV with epiretinal membrane vitrectomy. In addition, we performed multivariate regression analysis to determine if any clinical variables predicted a change in visual acuity. RESULTS: The mean age in the sample was 65 years (range 29-81 years). The mean follow-up time was 242 days (range 35-939). Sixteen of the 26 eyes were phakic and the remaining ten were pseudophakic. There was a statistically significant improvement of mean visual acuity from a preoperative logMAR vision of 1.0 to a best postoperative vision of 0.75 (p=0.016, paired t-test). Thirteen (50%) of the 26 eyes gained at least two lines of best-corrected Snellen acuity, three (11.5%) had a decline of at least two lines, and ten (38.5%) showed stable visual acuity. Regression analysis demonstrated that baseline worse visual acuity was the only clinical variable that was associated with improvement in visual acuity (beta=0.602, p=0.016; R (2)=28.7). Fourteen eyes had preoperative and postoperative OCT. Thirteen eyes (93%) had a significant decrease in foveal thickness; with an average preoperative thickness of 575 mum compared to a postoperative average of 311 mum (t=3.65, p=0.002). No surgical complications were observed during the follow-up period. CONCLUSIONS: Surgery for refractory diabetic edema without a taut hyaloid is associated with a significant improvement in visual acuity and diminution of retinal thickness as measured by OCT. Further investigations are warranted to define the role of surgery in the management of persistent diabetic macular edema.

Adult↗
PubMed2004

Internal limiting membrane peeling using triamcinolone acetonide: histopathologic confirmation.

PURPOSE: To report histopathologic confirmation of the internal limiting membrane (ILM) using triamcinolone acetonide (TA). DESIGN: Interventional case report. METHODS: One eye of one patient who underwent macular hole repair using TA suspension to help visualize the internal limiting membrane (ILM). The specimen was sent to pathology. RESULTS: Triamcinolone acetonide greatly improved the visualization of the ILM; the peeled area was seen as an area lacking white specks. The macular hole closed with an improvement in vision. No adverse effects were observed during the follow-up period. The specimen was identified as ILM by histopathologic examination. CONCLUSION: Peeling of the ILM is facilitated by the use of TA. Microscopic confirmation of ILM was made.

Basement Membrane↗