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Biomedical subjects

Hugo Quiroz-Mercado

Publications and source records attributed to Hugo Quiroz-Mercado.

16 recordsLinked to original sources
PubMed2006

Intravitreal bevacizumab therapy for neovascular age-related macular degeneration: a pilot study.

PURPOSE: To evaluate the efficacy and safety of intravitreal bevacizumab therapy for neovascular age-related macular degeneration (ARMD). METHODS: Patients with diagnosis of neovascular ARMD without any other ocular pathology were injected with 2.5 mg of intravitreal bevacizumab. A complete ophthalmic examination was undertaken in all patients, including best corrected visual acuity (BCVA), slit lamp biomicroscopy and ocular fundus examination. Ophthalmic follow-up evaluations included visual acuity measurements, optical coherence tomography (OCT) imaging, and fluorescein angiography at first, second and fourth week post injection. RESULTS: 39 eyes of 39 patients were injected. The median age was 76 years-old (range 65-90), median visual acuity was 1.18 logMAR (range 0.18-3.00) and median retinal thickness was 388 microns (range 157-1237). By the fourth week of treatment, the median visual acuity was 0.88 (range 0.18-2.78) and median retinal thickness was 247 microns (range 108-1262). Statistically significant differences were found in visual acuity and retinal thickness before and after intravitreal injection (p=0.002, p<0.001, Wilcoxon rank test). CONCLUSIONS: Our results suggest that intravitreal bevacizumab is well tolerated and is associated with improvement in BCVA and decreased mean retinal thickness by OCT. Further controlled and long term evaluation of intravitreal bevacizumab for the treatment of neovascular ARMD is warranted.

Aged↗
PubMed2005

Intravitreal triamcinolone with transpupillary therapy for subfoveal choroidal neovascularization in age related macular degeneration. A randomized controlled pilot study [ISRCTN74123635].

BACKGROUND: To assess the effect of intravitreal triamcinolone acetonide (iTA) as an adjunctive treatment to transpupillary therapy (TTT) for new subfoveal choroidal neovascular membranes (CNV) in age-related macular degeneration (AMD). METHODS: This prospective randomized controlled pilot study comprised 26 patients scheduled to receive TTT, due to either absent indications for photodynamic therapy or financial issues. Patients were assigned into; Group A (n = 14) received TTT alone and Group B (n = 12) received iTA (4 mg) followed by TTT within one week. Follow ups were at 2 weeks, and 1, 3 and 6 months for; best-corrected visual acuity (BCVA) by ETDRS chart at 4 meters, intraocular pressures (IOP), fluorescein angiography (FAG), and central foveal thickness by optical coherence tomography (OCT). RESULTS: All 26 patients completed 6 months of follow ups. The average age for both groups was 74 years. Occult CNV formed 64% and 41%; classis/predominately classic 21% and 16.6%; and minimally classic 15% and 42.4% of group A and B respectively. At baseline; the mean BCVA was 0.045 for group A and 0.04 for group B; mean CNV size was 6.15 disc diameter (DD) and 2.44 DD; mean OCT foveal thickness was 513 um and 411 um for group A and B respectively with no statistical differences (P = 0.8, 0.07, and 0.19). At six months the proportion of patients gained > or = 1 lines was 14% and 25% (P = 0.136) and stabilization was 86% and 66% (P = 0.336); the mean size of the CNV was 5.63 DD and 2.67 DD (P = 0.162); rate of CNV closure was 64% and 83% (P = 0.275); and the mean OCT central foveal thickness was 516.36 um and 453.67 um (P = 0.341), for group A and B respectively. CONCLUSION: The use of iTA as an adjunctive to TTT for new subfoveal CNV in AMD showed a tendency towards better functional results. However due to the small sample size of the study a statistically significant results could not be reached.

Aged↗
PubMed2005

Vitrectomy with complete posterior hyaloid removal for ischemic central retinal vein occlusion: series of cases.

BACKGROUND: Central retinal vein occlusion (CRVO) is a common retinal vascular disorder with potentially complications: (1) persistent macular edema and (2) neovascular glaucoma. No safe treatment exists that promotes the return of lost vision. Eyes with CRVO may be predisposed to vitreous degeneration. It has been suggested that if the vitreous remains attached to the macula owing to a firm vitreomacular adhesion, the resultant vitreous traction can cause inflammation with retinal capillary dilation, leakage and subsequent edema6. The roll of vitrectomy in ischemic CRVO surgical procedures has not been evaluated. CASE PRESENTATION: This is a non comparative, prospective, longitudinal, experimental and descriptive series of cases. Ten eyes with ischemic CRVO. Vitrectomy with complete posterior hyaloid removal was performed. VA, rubeosis, intraocular pressure (IOP), and macular edema were evaluated clinically. Multifocal ERG (m-ERG), fluorescein angiography (FAG) and optic coherence tomography (OCT) were performed. Follow-up was at least 6 months. Moderate improvement of visual acuity was observed in 60% eyes and stabilized in 40%. IOP changed from 15.7 +/- 3.05 mmHg to 14.9 +/- 2.69 mmHg post-operative and macular edema from 976 +/- 196 microm to 640 +/- 191 microm to six month. The P1 wave amplitude changed from 25.46 +/- 12.4 mV to 20.54 +/- 11.2 mV. CONCLUSION: A solo PPV with posterior hyaloid removal may help to improve anatomic and functional retina conditions in some cases. These results should be considered when analyzing other surgical maneuvers.

Aged↗
PubMed2005

Performing vitreous biopsy by perfluorocarbon-perfused vitrectomy.

PURPOSE: To evaluate the safety and efficacy of perfluorocarbon-perfused vitrectomy (PCPV) as a novel technique in obtaining a large undiluted vitreous biopsy. DESIGN: Cross-sectional interventional study. METHODS: Patients with undiagnosed posterior uveitis scheduled for vitreous biopsy underwent PCPV. A syringe containing 5 ml of perfluorocarbon liquid (PCL) was connected to the infusion line. Aspiration of the central and superior vitreous was initiated with simultaneous infusion of the PCL. RESULTS: Twenty eyes of 20 patients were included in this study. The mean +/- SD amount of PCL used in each eye was 4.50 +/- 0.69 ml. The volume of vitreous sample obtained in each eye was 2.25 +/- 0.413 ml. No complications occurred. CONCLUSIONS: PCPV is a safe and effective method for obtaining large undiluted vitreous biopsy.

Adult↗
PubMed2004

Perfluorocarbon-perfused vitrectomy: a new method for vitrectomy--a safety and feasibility study.

PURPOSE: To evaluate the safety and feasibility of perfluorocarbon-perfused vitrectomy (PCPV) as a technique during vitrectomy for proliferative diabetic retinopathy (PDR) and rhegmatogenous retinal detachment (RRD). METHODS: In an experimental, prospective, noncomparative and interventional study, 28 eyes of 28 patients were submitted to vitrectomy with the PCPV technique, 18 eyes with PDR and 10 with RRD. In this technique we replaced the traditional balanced saline solution (BSS) in the infusion line (conventional vitrectomy) by perfluorocarbon liquids (PCL). Some patients with PDR were treated with oxygenated PCL. Clinical evaluation, electroretinography (ERG), and endothelial cell count (ECC) were used to assess the safety of this procedure. An arbitrary grading system (grades 0-5) was used to classify the surgery and maneuvers to assess feasibility. RESULTS: No eyes had a significant decrease in ECC, and the patients in whom we could obtain ERG postoperatively showed no significant differences from preoperative ERG. In the PDR group (using oxygenated and nonoxygenated PCL), 77.8% were graded 5/5; in the RRD group 90% were 5/5. PCPV allowed better visualization of vitreous and intraocular structures, rapid retinal reattachment, less blood in the vitreous cavity, subretinal fluid resolution, blood confinement, retinal stabilization, and easier dissection of epiretinal membranes. In all cases at least one surgical step was eliminated. CONCLUSIONS: PCPV in humans is a safe and feasible technique. Probably in selected cases the use of PCL offers several advantages over BSS, because of their properties (gravitational forces, immiscibility with bodily fluids, and ability to transport oxygen). Prospective and comparative studies are necessary to establish formal indications and possible contraindications.

Adult↗
PubMed2004

Perfluorocarbon perfused vitrectomy: animal studies.

PURPOSE: To investigate the feasibility and advantages of using perfluorocarbon liquid (PCL) perfusion to remove vitreous during suction-cutting vitrectomy in rabbit and pig eyes. DESIGN: Experimental study. METHODS: Balanced salt solution (BSS) was replaced by PCL perfusion during experimental vitrectomy. Oxygenated or nonoxygenated PCL was used in a recycling or a nonrecycling system. Recycling was achieved by two systems: a manual recycling system or a closed-loop system. The experiments in this study consisted of: an in vitro solubility observation, safety and feasibility of vitrectomy in rabbit eyes, effectiveness of vitrectomy with equal vitrectomy time in rabbit eyes, and retinal stability and pigment and blood dispersion in porcine eyes. Toxicity was assessed by a complete ophthalmic examination, endothelial cell count, electroretinography, and histopathology. RESULTS: Vitreous, blood, and pigments were immiscible in PCL. Manual recycling required less amounts of PCL than nonrecycling (15 vs 25 cc). Oxygenated and nonoxygenated PCL were not toxic. Perfluorocarbon liquid infusion removed more vitreous than balanced salt solution in a 3-minute vitrectomy time using the same settings on the vitrectomy machine. The PCL infusion in porcine eyes stabilized the retina and isolated vitreous cavity from pigment and blood and maintained a clear vitreous cavity. CONCLUSIONS: These data indicate that perfusion of PCL can be used to remove vitreous with a suction-cutting probe in rabbit and pig eyes. Retinal stability and isolation of the vitreous cavity at the time of vitreous removal along with PCL immiscibility and its specific gravity suggest that PCL has a potential clinical use as an irrigating solution to remove vitreous.

Acetates↗
PubMed2003

Acute endophthalmitis following intravitreal triamcinolone acetonide injection.

PURPOSE: To report the clinical features, causative organisms, management, and visual acuity outcomes of eight eyes of eight patients who developed acute postoperative endophthalmitis following intravitreal injection of triamcinolone acetonide (IVTA). DESIGN: Retrospective, multicenter, interventional, case series. METHODS: A retrospective, interventional, case series of all patients with acute postoperative endophthalmitis following IVTA at seven academic clinical centers between March 2001 and July 2002. RESULTS: A total of 922 IVTAs were performed. Eight eyes of eight patients with acute postoperative endophthalmitis were identified in the 6 weeks following IVTA for an incidence of 0.87% (95% confidence interval of 0.38% to 1.70%). The median time to presentation was 7.5 days (range, 1-15 days) after IVTA. The most common clinical findings were iritis (n = 8), vitritis (n = 8), hypopyon (n = 8), pain (n = 7), red eye (n = 6), and decreased vision (n = 5). The median presenting visual acuity was 20/1127 (range, 20/60 to light perception). Initial treatment consisted of vitreous tap and injection of antibiotics (n = 6) or pars plana vitrectomy and injection of intravitreal antibiotics (n = 2). Intraocular cultures yielded identification in seven patients. One demonstrated intracellular gram-positive cocci in chains with numerous polymorphonuclear cells on gram stain. The median postinfection vision was 20/400 (range, 20/40 to no light perception). Three patients ended up with no light perception visual acuity, including enucleation (n = 1) and phthisis (n = 1). CONCLUSIONS: Acute postoperative endophthalmitis following IVTA occurs rapidly and can result in severe loss of vision.

Acute Disease↗
PubMed2002

Spontaneous closure of a large traumatic macular hole in a young patient.

PURPOSE: To report the spontaneous resolution of a traumatic macular hole that was considerably larger than in previously reported cases. DESIGN: Observational case report. METHODS: The clinical and angiographic data of the patient were reviewed. RESULTS: A traumatic 600 x 400 micro macular hole was observed to spontaneously resolve 5 weeks after trauma in a 15-year-old patient. Visual acuity only slightly improved consequently (from counting fingers at 4 meters to 20/200). The clinical appearance of the fovea after macular hole resolution raised the suggestion that a postconcussion retinal necrosis was the mechanism behind the lesion formation in this case. CONCLUSIONS: Spontaneous resolution of a traumatic macular hole is an outcome not limited to small lesions. Larger macular holes may represent retinal tissue loss and consequently a less favorable visual prognosis.

Adolescent↗
PubMedDate not supplied

Human lymphocyte antigen DR7 protects against proliferative retinopathy with type II diabetes mellitus.

BACKGROUND: This study was undertaken in order to analyze the genetic incidence of human lymphocyte antigen diabetic retinopathy (HLA-DR) and its influence in proliferative diabetic retinopathy (PDR). METHODS: We designed a case-control study in which 127 mestizo Mexican patients with DM II and diabetic retinopathy were studied. DNA was extracted and HLA-DR regions were amplified using PCR. Alleles were determined by DNA hybridization. Diagnosis was assessed clinically and by fluorescein angiography. Incidence of HLA-DR alleles in patients was compared with an ethnically matched control group of healthy subjects (n = 98). Statistical significance was established with non-parametric tests. RESULTS: Patients with diabetic retinopathy showed less frequency of HLA-D11 compared with the control group (p = 0.043). NPDR patients with 10 or more years of DM II showed an increase of HLA-DR7 (p = 0.01). CONCLUSIONS: Our results suggest that the presence of HLA-DR7 protects against the development of proliferative disease in the diabetic Mexican population.

Aged↗
PubMedDate not supplied

Pigment epithelium endoscopic laser surgery for treatment of choroidal neovascularization.

PURPOSE: To present a new concept and technique for subretinal surgery. METHODS: Twenty-four eyes of 24 patients with subfoveal choroidal neovascularization (CNV) were included in this study. Nine patients were operated on in Mexico City by one surgeon, 15 patients in Frankfurt by another surgeon. The retina at the posterior pole was detached and subretinal thermal photocoagulation of the CNVs was performed using a 20/19-gauge GRIN rod laser endoscope (Insight Instruments Inc., Sanford, Fla., USA). This procedure was termed PEELS (pigment epithelium endoscopic laser surgery). RESULTS: In 7 patients (Mexico), moderate improvement or stabilization of vision over 6 months or longer was achieved. In 10 out of 12 patients (Frankfurt), stabilization of vision over a follow-up period of 6-18 months was achieved, at least. Serious complications were not observed. Four of the Frankfurt series patients improved their vision. CONCLUSION: PEELS can stabilize or improve vision.

Adult↗
PubMedDate not supplied

Enlarged diode laser spot using indirect ophthalmoscope delivery in conjunction with indocyanine green to treat large choroidal neovascularizations.

BACKGROUND AND OBJECTIVE: To evaluate the effectiveness of a new method of delivering diode laser (810 nm) spots through an indirect ophthalmoscope in conjunction with intravenous indocyanine green to treat choroidal neovascularizations (CNVs) larger than 5,400 microm. PATIENTS AND METHODS: A prospective, non-comparative, interventional case series study was conducted with 8 patients with CNV secondary to age-related macular degeneration. Laser pulses were applied to the CNV within 5 minutes of an intravenous injection of 25 mg of indocyanine green. The laser spot was enlarged up to one disc diameter by shortening the distance between the indirect ophthalmoscope and the 20-diopter viewing lens. The follow-up period was 3 months. RESULTS: Three eyes had an improvement in visual acuity of more than 2 lines, and fluorescein angiography showed stabilization of the membrane and reduction of the hemorrhages and subretinal fluid at the last follow-up. Three other eyes maintained the same visual acuity and two had a decrease in visual acuity of more than 2 lines at the 3-month follow-up examination. CONCLUSION: Laser treatment delivered through an indirect ophthalmoscope system may be used as a palliative treatment for CNVs larger than 5,400 microm.

Aged↗
PubMedDate not supplied

Pars plana vitrectomy and lamina cribrosa puncture in absolute glaucoma.

Two patients with refractory end-stage glaucoma who had no light perception underwent pars plana vitrectomy and lamina cribrosa puncture to relieve pain and decrease intraocular pressure. The patients presented with blind, painful eyes and high intraocular pressure (> 40 mm Hg). After the procedure, the pain was relieved and the intraocular pressure was lowered in both cases. The patients remained asymptomatic. Pars plana vitrectomy and lamina cribrosa puncture might be related to the decrease of intraocular pressure, probably by facilitating drainage of aqueous humor through the optic nerve.

Adult↗
PubMedDate not supplied

Presumed sterile endophthalmitis following intravitreal triamcinolone acetonide injection.

BACKGROUND AND OBJECTIVE: To report acute postoperative, presumed sterile endophthalmitis following intravitreal injection of triamcinolone acetonide (IVTA). PATIENTS AND METHODS: Retrospective, interventional, multicenter study of patients with acute sterile endophthalmitis following IVTA injection. RESULTS: A total of 922 IVTA injections were performed. Eight eyes of 8 patients with presumed sterile endophthalmitis were identified. The incidence of endophthalmitis was 0.87% (95% confidence interval, 0.38% to 1.70%). Median time to presentation was 1.5 days (range, 1 to 7 days). Median presenting visual acuity was 20/563 (range, 20/80 to light perception). Initial treatment included vitreous tap and injection of antibiotics (n = 4), pars plana vitrectomy and injection of intravitreal antibiotics (n = 2), or systemic treatment alone with oral levofloxacin (n = 2). Six of 6 intraocular cultures were sterile. Median follow-up was 5.9 months (range, 4 to 9 months) with a median visual acuity at last follow-up of 20/75 (range, 20/40 to counting fingers). CONCLUSIONS: Acute presumed sterile endophthalmitis following IVTA injection presents early in the postoperative period. Visual outcomes are generally good.

Adult↗
PubMedDate not supplied

Preliminary results of combined simultaneous transpupillary thermotherapy and ICG-based photodynamic therapy for choroidal melanoma.

BACKGROUND AND OBJECTIVE: To evaluate whether the combination of simultaneous hyperthermia by transpupillary thermotherapy and indocyanine green-based photodynamic therapy is an effective treatment for small and medium choroidal melanomas. PATIENTS AND METHODS: Twenty-five patients with small and medium choroidal melanomas were treated with combined simultaneous transpupillary thermotherapy and indocyanine green-based photodynamic therapy. RESULTS: The median age of the 25 patients was 64 years (range, 35 to 88 years). The pretreatment volume of the tumors ranged from 15.9 to 653.5 mm3 (mean, 118.7 +/- 146.6 mm3). After a mean of 2.4 treatments (range, 1 to 5 treatments), all of the tumors but one showed a significant volume reduction without clinical evidence of recurrences. The follow-up ranged from 6 to 59 months (mean, 12 +/- 14 months). Complications included retinal vascular occlusions, edema and superficial scarring of the macula, and rhegmatogenous retinal detachment. CONCLUSIONS: The effects of combined simultaneous transpupillary thermotherapy and indocyanine green-based photodynamic therapy appears to be effective in achieving local tumor control in selected small and medium choroidal melanomas.

Adult↗