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Biomedical subjects

Michel E Farah

Publications and source records attributed to Michel E Farah.

At least 19 recordsLinked to original sources
PubMed2006

Optical coherence tomography evaluation of idiopathic macular hole treatment by gas-assisted posterior vitreous detachment.

PURPOSE: To report a series of patients with Stage II macular hole (MH) treated by gas-assisted posterior vitreous detachment (GAPVD). DESIGN: Interventional case series. METHODS: Six patients (six eyes) with Stage II MH were submitted to a 0.4 ml perfluoropropane (C(3)F(8)) intravitreal injection. Comprehensive ophthalmic examination including best-corrected visual acuity, fundus photography, and optical coherence tomography (OCT) was performed at baseline and one, three, and six months after the procedure. RESULTS: Preoperative OCT revealed Stage II MH in all cases. In five cases, improvement in visual acuity and closure of the macular hole on OCT was observed at one, three, and six months after GAPVD. In one case, although vitreofoveal traction was released, MH closure was not achieved; a full-thickness retinal defect persisted and final visual acuity was 20/100. CONCLUSION: GAPVD may be a viable alternative treatment for Stage II MH.

Fluorocarbons↗
PubMed2005

STRATUSOCT and multifocal ERG in unilateral acute idiopathic maculopathy.

BACKGROUND: Unilateral acute idiopathic maculopathy (UAIM) is a rare entity, in which an inflammatory process involves the macular retinal pigment epithelium (RPE) and outer retina. It represents a wide spectrum of ocular findings not consistently present in all patients, which may lead to difficulties in the recognition of the condition. METHODS: This observational case report presents the third-generation optical coherence tomography (StratusOCT) and multifocal electroretinogram (mfERG) findings in a 31-year-old woman with UAIM in the acute phase as well as two months later, and discusses the role of StratusOCT in the diagnosis. RESULTS: In the acute phase, StratusOCT demonstrated abnormal heterogeneous hyperreflectivity and thickening at the level of the outer retina and RPE in the foveal region. Two months after the initial presentation, StratusOCT examination showed a subfoveal area of homogeneous hyperreflectivity that extended from the RPE to the outer retinal layers with posterior shadowing, and sparse points of hyperreflectivity at several different levels of the neurosensory retina, including its superficial layers. The foveal retinal thickness during the acute phase was thicken compared with that after resolution. Seven days after the initial evaluation, mfERG showed severely reduced N1-P1 amplitudes with normal latencies in the region corresponding to the affected area of the papillomacular bundle and fovea. Two months later, mfERG results were normal. CONCLUSIONS: StratusOCT provided valuable information, allowing for the exclusion of other disorders that might mimic UAIM. mfERG findings were consistent with transient outer retinal dysfunction as the cause of visual loss. We are unaware of previous reports of UAIM studied by these methods and could find no reference to them in a computerized search using MEDLINE.

Acute Disease↗
PubMed2005

Polypoidal choroidal vasculopathy: angiographic characterization of the network vascular elements and a new treatment paradigm.

Macular exudative manifestations secondary to choroidal neovascular lesions remain the leading cause of definitive visual impairment and legal blindness in the elderly. During the past decade, advances in ophthalmic imaging systems have enabled the recognition of presumed new distinct choroidal neovascular lesions that share some unique clinical and angiographic peculiarities as well as better comprehension of the pathophysiologic mechanisms related to such entities. Amongst presumed newer exudative maculopathies, polypoidal choroidal vasculopathy, which has been described as a distinct choroidal abnormality characterized by inner choroidal vascular network of vessels ending in polyp-like structures only identified on indocyanine green angiography and mostly affecting African-American and Asian descendents, has gained special interest from the ophthalmic community particularly because of its growing recognition among patients with clinical appearance of neovascular age-related macular degeneration. Thus far, however, the exact nature of the vascular structure of the polypoidal choroidal vasculopathy lesion remains unclear and data from recent studies have conflicted with the initial concept of a benign exudative maculopathy with long-term preservation of good vision. All together, such factors make difficult the establishment of an appropriate treatment, if any, for the entity. Herein, by using a modified technique of conventional indocyanine green angiography, we demonstrate new information about the morphologic characteristics, and to some extent the blood flow dynamics perfusion, of the polypoidal choroidal vasculopathy lesion. Our results suggest that the PCV lesion should be considered a variety of choroidal neovascularization rather than a distinct clinical entity, characterized by one single large neovascular complex presenting well-defined arterial neovascular vessels arising from one major "ingrowth site" and draining vessels that present aneurysm-like dilations corresponding to the polyp-like structures typically described for the entity. Finally, the visual acuity and angiographic findings observed after selective ingrowth site photothrombosis corroborate the existence of one major "ingrowth site" for the PCV neovascular complex and point toward a new treatment paradigm for this variety of choroidal neovascularization.

Angiography↗
PubMed2005

Comparison of intravitreal versus posterior sub-Tenon's capsule injection of triamcinolone acetonide for diffuse diabetic macular edema.

PURPOSE: To compare the safety and efficacy of intravitreal versus posterior Sub-Tenon's capsule injection of triamcinolone acetonide for diffuse diabetic macular edema. DESIGN: Prospective, double-masked, randomized controlled trial. PARTICIPANTS: Twelve patients (24 eyes) with bilateral diffuse diabetic macular edema. INTERVENTION: One eye of each patient was randomly assigned to receive a single 4-mg triamcinolone acetonide intravitreal injection and the fellow eye to receive a 40-mg triamcinolone acetonide posterior Sub-Tenon's capsule injection. MAIN OUTCOME MEASURES: Changes in visual acuity and central macular thickness obtained using optical coherence tomography were measured during a 6-month follow-up. Potential treatment complications were monitored, including increases in intraocular pressure (IOP) and cataract progression. RESULTS: Both intravitreal and Sub-Tenon's capsule injections of triamcinolone acetonide resulted in significant but transient improvements in central macular thickness. The mean (+/-standard deviation [SD]) central macular thickness in eyes with intravitreal injection was significantly thinner than in the Sub-Tenon's capsule-injected eyes at 1 month (226.8+/-41.7 microm and 431.5+/-165.8 microm, respectively; P = 0.002) and 3 months (242.3 +/- 93.9 microm and 364.7+/-78.2 microm, respectively; P = 0.005) after triamcinolone acetonide injection. The mean visual acuity (logarithm of the minimum angle of resolution) in the intravitreally injected eyes was significantly better than in the Sub-Tenon's capsule-injected eyes at 3 months post injection (0.832+/-0.293 and 1.107+/-0.339, respectively; P = 0.004). Intraocular pressure did not show any significant difference between the 2 forms of triamcinolone acetonide delivery at any follow-up visit, and no eyes had IOPs >25 mmHg. CONCLUSIONS: The findings from our study neither advocate nor support the use of corticosteroids for the treatment of diabetic macular edema, but do imply that both intravitreal and Sub-Tenon's capsule injections of triamcinolone acetonide may be equally tolerated, with short-term performance clearly favoring the intravitreal (4 mg) more than the SBT capsule (40 mg) route for the anatomic and functional aspects of improvement tested in this investigation.

Adult↗
PubMed2004

Intravitreal triamcinolone in the treatment of serous retinal detachment in Vogt-Koyanagi-Harada syndrome.

PURPOSE: To report the use of intravitreal injection of triamcinolone acetonide during the acute phase of Vogt-Koyanagi-Harada disease. DESIGN: Prospective interventional case series. METHODS: Three eyes from two patients at the acute phase of Vogt-Koyanagi-Harada disease with serous retinal detachments were treated with a 4-mg intravitreal injection of triamcinolone acetonide. The following variables were evaluated: visual acuity, intraocular pressure, and height of the serous retinal detachment using optical coherence tomography. RESULTS: The optical coherence tomography images showed a marked decrease in the retinal detachment in the first week after the injection with subsequent return to normal retinal thickness in all eyes. CONCLUSIONS: Intravitreal triamcinolone acetonide provides short-term improvement in visual acuity and serous retinal detachments associated with Vogt-Koyanagi-Harada disease. These findings should be followed by future studies to evaluate long-term effects.

Acute Disease↗
PubMed2004

Retinal peripheral changes after laser in situ keratomileusis in patients with high myopia.

BACKGROUND: Retinal detachment has been reported after laser in situ keratomileusis (LASIK) in myopic eyes. This complication may be related to the risk from myopia before surgery or may be induced by LASIK surgery itself. We performed a study to evaluate retinal peripheral changes after LASIK in patients with high myopia and to correlate symptoms on presentation and vitreoretinal anatomic changes. METHODS: The study was carried out at a university-affiliated hospital in São Paulo between November 1997 and February 1999. Patients scheduled to undergo LASIK were included if their spherical equivalent was greater than 6.00 dioptres. The exclusion criteria were previous retinal treatment and myopic macular degenerations. We performed binocular indirect ophthalmoscopy with scleral indentation and fundus biomicroscopy with Goldmann lens before LASIK and 1, 3 and 6 months after surgery. RESULTS: We examined 198 eyes preoperatively. Of the 198, 50 did not undergo LASIK surgery owing to refractive criteria, and 79 were lost to follow-up. We thus studied 69 eyes. The mean spherical equivalent preoperatively was -8.00 D (standard deviation 1.95 D). Twenty-four eyes had normal retinal periphery preoperatively; all 24 remained without alterations after LASIK. Forty-five eyes had peripheral alterations: 17 (24.6%) had cystic degeneration, 14 (20.3%) had lattice degeneration, 11 (15.9%) had white-without-pressure, 5 (7.2%) had cystic tufts, 3 (4.3%) had pavingstone degeneration, 2 (2.9%) had pigmentary alteration, 1 (1.4%) had holes with free operculum, and 1 (1.4%) had punctiform holes. The only alteration after surgery was almost punctiform holes around the previous cystic tuft 1 month after surgery in one patient. Retinal detachment did not develop in any of the eyes. INTERPRETATION: In this group of patients it appears that LASIK did not lead to progressive peripheral retinal lesions in asymptomatic patients during the period studied.

Adult↗
PubMed2004

Effects of intravitreal indocyanine green injection in rabbits.

PURPOSE: To report the clinical, electrophysiologic, and histologic findings of different concentrations of indocyanine green (ICG) injected into the vitreous cavity of rabbit eyes. METHODS: Forty-two rabbits underwent intravitreal injection of 0.1 mL of ICG in three different concentrations: 0.5 mg/mL (250 mOsm), 5 mg/mL (270 mOsm), and 25 mg/mL (170 mOsm). Fellow eyes were injected with 0.1 mL of balanced salt solution. Biomicroscopy, ophthalmoscopy, electroretinography, fluorescein angiography, and histologic evaluation were performed. RESULTS: Eyes injected with 0.5 mg/mL of ICG showed b-wave latency delay on the first day after injection. Eyes injected with 5 mg/mL of ICG showed b-wave latency delay and decreased b-wave amplitude on the first and seventh days after injection; delayed a-wave latency on the first day after injection was also observed. Eyes injected with 25 mg/mL of ICG showed b- and a-wave amplitude and latency abnormalities during the entire follow-up. Direct correlation of increasing retinal edema proportional to the progressively increasing ICG concentrations was shown on histologic evaluation. CONCLUSION: Intravitreal ICG injection in rabbit eyes may impair retinal function and morphology proportional to the progressively increasing ICG dosages.

Animals↗
PubMed2004

Effects of indocyanine green injection on the retinal surface and into the subretinal space in rabbits.

PURPOSE: To evaluate the effects of indocyanine green (ICG) injection on the retinal surface and into the subretinal space of rabbit eyes. METHODS: Twenty-two Dutch-belted rabbits underwent two-port vitrectomy followed by injection of ICG (5 mg/mL) on the retinal surface and into the subretinal space. Balanced salt solution (BSS) was also injected subretinally. The locations where ICG was delivered (both epiretinal and subretinal) were exposed to light from an endoilluminator for 7 minutes. The animals were examined at 1, 7, and 14 days after surgery. The eyes were studied by fluorescein angiography as well as light and electron microscopy. RESULTS: No damage was observed after epiretinal ICG injection, but subretinal ICG injection resulted in damage to the outer nuclear layer, photoreceptor inner and outer segments, and retinal pigment epithelium. This damage was more severe with longer follow-up. Control experiments without ICG, in which balanced salt solution was injected into the subretinal space or light was delivered on the epiretinal surface, demonstrated only damage to the photoreceptor outer segments. CONCLUSION: Subretinal delivery of ICG (5 mg/mL) in rabbits induces retinal pigment epithelium, photoreceptor inner and outer segment, and outer nuclear layer damage. These mechanisms of damage may explain the retinal pigment epithelium changes that are sometimes seen after ICG-assisted internal limiting membrane peeling in humans.

Animals↗
PubMed2003

Neovascular ingrowth site photothrombosis in choroidal neovascularization associated with retinal pigment epithelial detachment.

PURPOSE: To describe the clinical, angiographic and optical coherence tomography (OCT) findings of patients with choroidal neovascularization (CNV) associated with retinal pigment epithelial detachment (PED) who were treated by neovascular ingrowth site photothrombosis. METHODS: Interventional case reports. After identification of the CNV feeder vessels, two patients had focal photothrombosis of the neovascular ingrowth site using continuous 810-nm laser application after intravenous indocyanine green (ICG) injection and were prospectively followed with fluorescein and ICG angiography as well as OCT. RESULTS: Both patients presented an increase of 3 or more ETDRS lines in visual acuity by 12 months of follow-up. Fluorescein and ICG angiography demonstrated reduced lesion perfusion and regression of the PEDs; accordingly, OCT disclosed decrease in retinal thickness and elevation caused by rapid fluid resolution. There were no significant complications related to the procedure. CONCLUSION: Photothrombosis using 810-nm light to direct laser energy continuously at the neovascular ingrowth site after intravenous ICG infusion is effective in restoring macular architecture and improving vision in patients with CNV complicated by PEDs by means of substantial decrease in the lesion perfusion and resolution of exudative manifestations.

Aged↗
PubMed2003

Retinal capillary hemangioma treatment by indocyanine green-mediated photothrombosis.

PURPOSE: To describe the clinical, angiographic and optical coherence tomography (OCT) findings of a patient with a large retinal capillary hemangioma who was treated by indocyanine green-mediated photothrombosis. Interventional case report. METHODS: An 18-year-old male patient was treated at a tertiary referral center with a novel laser-dye procedure that uses low-irradiance 810-nm laser and intravenous indocyanine green injection and was prospectively evaluated with fluorescein and indocyanine green angiography, as well as OCT. RESULTS: Vision improved from 20/125 to 20/32 + 1 at 1-year follow-up. Fundus photography showed marked reduction of a 3 disk diameters retinal capillary hemangioma. Both fluorescein and indocyanine green angiography demonstrated reduced tumor perfusion and narrowing of the lesion feeder and draining vessels as early as 5 days after indocyanine green-mediated photothrombosis; OCT showed immediate decrease in retinal elevation and complete resolution of subretinal fluid within 2 months of treatment. Minimal laser-induced effects were noted in the vicinity of the tumor. CONCLUSIONS: Photothrombosis using low-intensity, 810-nm light to direct laser energy continuously at the tumor after intravenous indocyanine green infusion was effective in restoring macular architecture and improving vision in a patient with a large peripheral retinal capillary hemangioma by means of substantial occlusion of the tumor vasculature and resolution of subretinal fluid.

Adolescent↗
PubMed2003

Photodynamic therapy with verteporfin for subfoveal choroidal neovascularization in best disease.

PURPOSE: To describe the effects of photodynamic therapy using verteporfin for the treatment of subfoveal choroidal neovascularization (CNV) in Best vitelliform macular dystrophy. DESIGN: Interventional case report. METHODS: A 43-year-old patient with confirmed Best vitelliform macular dystrophy complicated with subfoveal CNV received a single photodynamic therapy session with verteporfin. The patient was prospectively followed with fluorescein angiography and optical coherence tomography. RESULTS: A regression of the neovascular lesion and resolution of the exudative manifestations was observed 3 weeks after treatment; at that time, visual acuity had improved from 20/60 to 20/25. Optical coherence tomography disclosed restoration of normal macular architecture due to fluid resolution and lesion contraction. Up to 2 years from this single treatment, no further change was observed. CONCLUSIONS: Regression of CNV and resolution of subretinal hemorrhage as well as exudative manifestations occurred after photodynamic therapy with verteporfin. Verteporfin therapy may be a viable treatment for subfoveal neovascular lesions in Best vitelliform macular dystrophy.

Adult↗
PubMed2003

Selective occlusion of subfoveal choroidal neovascularization in angioid streaks by using a new technique of ingrowth site treatment.

PURPOSE: To evaluate the visual and angiographic effects, as well as optical coherence tomography (OCT) findings, after a new treatment-neovascular ingrowth-site photothrombosis-in patients with subfoveal choroidal neovascularization (CNV) secondary to angioid streaks. DESIGN: Prospective noncomparative small case series. PARTICIPANTS: Five eyes of 5 patients with angioid streaks in whom fluorescein and conventional indocyanine green (ICG) angiography clearly demonstrated distinct CNV vessels supplying the subfoveal neovascular complex. INTERVENTION: All five eyes were submitted to ICG-mediated photothrombosis of the neovascular ingrowth site. This novel, laser/dye-mediated technique uses large-spot, lower-intensity 810-nm light for continuous application of laser energy to ICG concentrated in vascular lesions. MAIN OUTCOME MEASURES: Visual outcome and the results of fluorescein angiography, ICG angiography, and OCT evaluation. RESULTS: Fluorescein and conventional ICG angiography were sufficient to identify the CNV ingrowth site, which was juxtafoveal in 2 and extrafoveal in 3 of the 5 eyes in this series. Obliteration of the entire neovascular lesion was achieved in all patients within the first hour after ICG-mediated photothrombosis of the CNV ingrowth site. At 1 week, the mean change in best-corrected visual acuity from baseline was +3.2 (+/-1.4) lines. Twelve months after treatment, visual acuity improved by 3 or more lines in all patients, and decreased leakage of fluorescein from the CNV, as well as OCT evidence of reduced or resolved retinal edema, was seen at the last follow-up visit. Major complications, such as immediate severe visual loss and retinal vessel occlusion in the early posttreatment period, were not identified in the 5 patients submitted to the procedure. CONCLUSIONS: Photothrombosis of the CNV ingrowth site by using lower-intensity light to direct laser energy continuously after IV ICG infusion is a safe and effective technique for rapid induction of CNV hypoperfusion in selected patients and is associated with considerable improvement in visual acuity and partial restoration of the retinal architecture up to 12 months after treatment.

Aged↗
PubMed2003

Immediate indocyanine green angiography and optical coherence tomography evaluation after photodynamic therapy for subfoveal choroidal neovascularization.

PURPOSE: To better understand the mechanisms of action of photodynamic therapy (PDT) with verteporfin for subfoveal choroidal neovascularization (CNV), the authors evaluated the retinal and choroidal response immediately after treatment with serial optical coherence tomography (OCT) and indocyanine green angiography (ICGA). METHODS: This study was a prospective, noncomparative case series. PDT was performed on nine eyes of nine consecutive patients who presented with subfoveal CNV due to age-related macular degeneration, and serial evaluation with OCT as well as ICGA was performed at 20-minute intervals for the first 2 hours and then at 1 week, 1 month, and 3 months. RESULTS: In the first 2 hours after PDT, OCT showed an increase in the thickness of the retina in the treatment area due to fluid leakage from the neovascular complex as confirmed by ICGA. At 1 week, marked reduction of intraretinal/subretinal fluid was observed in all patients. Neovascular complex nonperfusion by ICGA was associated with some degree of choroidal hypoperfusion in the treatment area. Return of the foveal contour by OCT was optimal after 1 month of treatment. At 3 months, choroidal reperfusion by ICGA and recurrent intraretinal/subretinal fluid by OCT were observed. CONCLUSIONS: Serial OCT and ICGA evaluation after PDT suggests that the initial successful CNV nonperfusion as shown by fluorescein angiography at 1 week occurs by means of selective PDT damage to the lesion and/or reduced choroidal blood flow in the treatment area, thereby decreasing intraretinal/subretinal fluid and facilitating restoration of the retinal architecture.

Aged↗