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Biomedical subjects

Nuttawut Rodanant

Publications and source records attributed to Nuttawut Rodanant.

9 recordsLinked to original sources
PubMed2005

Effect of subthreshold infrared laser treatment for drusen regression on macular autofluorescence in patients with age-related macular degeneration.

BACKGROUND: Subthreshold laser therapy has been shown to cause drusen reduction. Using this method, visible laser burns are not created in the retina; presumably, the energy is absorbed by the retinal pigment epithelium (RPE) and stimulates reabsorption of drusen material, sparing photoreceptors from destruction. We hypothesized that autofluorescence (AF) changes would be visible after such treatment and might be sensitive to quantify RPE changes. METHODS: Twenty eyes of 13 patients with non-exudative age-related macular degeneration were studied. Forty-eight subthreshold infrared diode laser spots were applied as treatment to cause drusen regression. Before, immediately after, and 3 months after treatment, color fundus photography, fluorescein angiography (FA), and autofluorescence (AF) imaging were performed. Treated lesions were identified on overlay images of all three imaging methods. RESULTS: : The averaged sensitivity of AF imaging compared with FA was 29.6+/-28.7% versus 10.2+/-12.2% (P=0.008) at the immediate posttreatment time point and 43.5+/-28.7% versus 33.8+/-26.5% (P=0.043) at the 3-month posttreatment time point, respectively. Reduction of drusen at 3 months correlated with the detection sensitivity of AF imaging at the immediate posttreatment time point (P=0.022). CONCLUSION: Immediately after subthreshold laser treatment, AF imaging was more sensitive to detect RPE changes than FA. This suggests that noninvasive AF imaging may allow prediction of the effect of subthreshold laser treatment and might be used to titrate treatment dose.

Aged↗
PubMed2005

Sheathotomy without separation of venule overlying arteriole at occlusion site in uncommon branch retinal vein occlusion.

Two cases of uncommon branch retinal vein occlusion (BRVO) with vein overlying artery at occlusion site that can be found in less than 1% who underwent retinal venule sheathotomy without separation of retinal vessel for decompression of BRVO were reported. Both patients had macular hemorrhage, edema, and area of macular capillary nonperfusion. Visual acuity (VA) worsened to 6/60 in both cases. The retinal venules were dissected around the crossing site without separation of retinal vessels. Intraoperative dilation, pulsation and restoration of downstream blood flow of the involved venules were observed. In the first patient, at 1 day, 2 weeks, and 6 weeks postoperatively, VA improved to 6/36, 6/9, and 6/6, respectively, and remained unchanged at 12 months postoperatively. In the second patient, VA improved to 6/24 on the first day postoperatively and improved to 6/18 at 1 week follow up and continuously improved to nearly normal at 2 months postoperatively then patient lost contact. Postoperative fundus fluorescein angiogram showed dilated and improved perfusion with decreased macular edema in both cases. Optical coherent tomography confirmed remarkable reduction of retinal thickness (from 874 microns preoperatively to 420 microns at 1 week postoperatively) in the second patient. Retinal venule sheathotomy without separation of retinal vessel for decompression of BRVO with venule overlying arteriole at occlusion site could be effective for improving VA and decreased macular edema.

Adult↗
PubMed2004

Valganciclovir therapy for immune recovery uveitis complicated by macular edema.

PURPOSE: To determine whether treatment with valganciclovir will improve visual acuity in eyes with immune recovery uveitis complicated by macular edema. DESIGN: Prospective open label controlled Phase II drug study. METHODS: Five patients with chronic macular edema as a result of immune recovery uveitis were studied. Baseline fluorescein angiograms, best-corrected ETDRS visions, and cytomegalovirus (CMV) lymphoproliferative T-cell function assays were obtained and repeated after three months of valganciclovir therapy (900 mg daily) and again three months after withdrawal of therapy. RESULTS: Vision improved by a mean of 11 letters in the treatment phase (P =.05). Graded angiograms showed three patients had treatment reduction of macular edema. One patient had rebound increase in macular edema after the withdrawal phase. The CMV lymphoproliferative response was not affected by the valganciclovir. CONCLUSION: Results suggest valganciclovir treatment may benefit visual acuity in patients with macular edema from immune recovery uveitis.

AIDS-Related Opportunistic Infections↗
PubMed2004

Preventive versus treatment effect of AG3340, a potent matrix metalloproteinase inhibitor in a rat model of choroidal neovascularization.

PURPOSE: AG3340 (prinomastat) is a nonpeptidic, small-molecular-weight, synthetic matrix metalloproteinase inhibitor (MMPI) with selective inhibitory action of MMP-2, MMP-9, MMP-3, and MT-MMP1. We evaluated AG3340 injected intravitreally to treat choroidal neovascularization in a laser induced rat CNV model. METHODS: In the pretreatment group, the drug was injected the same day after induction of choroidal neovascularization by diode laser. In the treatment group, the drug was injected 2 weeks after induction of choroidal neovascularization (CNV). Fluorescein and indocyanine green angiography were performed to evaluate CNV. ERG recordings and histology were performed to assess toxicity and the CNV lesions. RESULTS: When used at the time of CNV induction, 62.8% of lesions in control versus 22.8% of the laser lesions in treated eyes developed CNV (p < 0.0001). The invading fibrovascular complex was thicker in the control eyes than that in the treated eyes. No signs of toxicity were detected. When used to treat established CNV, the percentage of leakage in treated and control eyes were 54.1% and 58.9% respectively (p > 0.05). Prinomastat was effective when given at the time of induction of CNV in the rat model. Administration of prinomastat 2 weeks after laser induction did not show efficacy. CONCLUSION: Prinomastat was active in the earliest stages of experimental CNV. It might be best used in combination with photodynamic therapy to inhibit recurrence of CNV from temporarily closed new vessels.

Animals↗
PubMed2003

Volumetric analysis of macular edema by scanning laser tomography in immune recovery uveitis.

OBJECTIVES: To evaluate the macular volume in eyes with immune recovery uveitis (IRU) and to describe a new method to quantify macular edema with the use of confocal scanning laser tomography (cSLT). METHODS: A prospective study was performed to assess the macular volume with cSLT in patients with and without IRU. None of the patients enrolled had cytomegalovirus retinitis within 3000 micro m of the fovea. Eight eyes had healed cytomegalovirus retinitis with IRU and cystoid macular edema (group A); 4 eyes had healed cytomegalovirus retinitis with IRU and clinically normal maculas (group B); 18 eyes had no IRU (group C); and 3 eyes underwent pars plana vitrectomy and epiretinal membrane peeling for epiretinal membranes associated with cystoid macular edema and IRU (group D). Patients with IRU underwent standard clinical examinations and cSLT. On cSLT, volume above the reference plane was calculated within a fovea-centered circle of 3 mm in diameter. We devised a novel system for defining the reference plane. Measurements were performed 3 times in masked fashion and the mean was used for analyses. RESULTS: The mean macular volume was highest in group A (1.97 mm3). This was significantly higher (P<.001) than that in groups B (1.15 mm3), C (1.02 mm3), and D (0.86 mm3). CONCLUSIONS: Macular edema in patients with IRU can be consistently and objectively quantitated by cSLT. The method of defining the reference plane used in our study is novel and can be used in other disorders causing macular edema.

AIDS-Related Opportunistic Infections↗
PubMed2003

Ganciclovir release rates in vitreous from different formulations of 1-O-hexadecylpropanediol-3-phospho-ganciclovir.

PURPOSE: To determine the optimal formulation of lipid prodrug, 1-O-hexadecyloxypropyl-phospho-ganciclovir (HDP-P-GCV), for intravitreal delivery. METHODS: Equal concentrations of crystalline or liposomal HDP-P-GCV were exposed to rabbit whole vitreous, core vitreous, peripheral vitreous, human plasma, and heat inactivated rabbit vitreous, and the samples were incubated at 37 degrees C for one week. Aliquots were taken at day 1, 2, 3, and 7 and subjected to HPLC analysis for conversion to GCV. RESULTS: The resultant concentration of GCV from crystalline HDP-P-GCV in vitreous was 198 +/- 49 microM (n = 3) at day 1 and 1253 +/- 248 microM (n = 3) at day 7. The resultant concentration of GCV from the liposomal formulation of HDP-P-GCV in vitreous was much lower, yielding a concentration of 66 +/- 7 microM (n = 3) at day 1 and 243 +/- 39 microM (n = 3) at day 7 (P < 0.001, t Test). When the crystalline HDP-P-GCV was incubated with heat-inactivated vitreous, the detectable GCV concentrations were low (22 microM) and did not increase over time. The concentration of GCV detected from the crystalline HDP-P-GCV in the core vitreous was 19.69 +/- 3.84 microM (n = 3) at day 1 and 1537.36 +/- 177.14 microM (n = 3) at day 7. The concentration of GCV released from crystalline HDP-P-GCV in peripheral vitreous was 32.86 +/- 5.07 microM (n = 3) at day 1 and 1805.78 +/- 327.94 microM (n = 3) at day 7. Detectable GCV concentration from both core and peripheral vitreous samples increased over time, however, the magnitude of GCV release from peripheral vitreous samples was higher (P < 0.05, t Test). CONCLUSION: In vitreous, HDP-P-GCV as a crystalline formulation was converted to GCV more rapidly than liposomal formulation of HDP-P-GCV. Vitreous cells may play an important role in the metabolism of either formulation of HDP-P-GCV delivered into vitreous.

Animals↗
PubMed2002

Predictors of drusen reduction after subthreshold infrared (810 nm) diode laser macular grid photocoagulation for nonexudative age-related macular degeneration.

PURPOSE: To determine the predictors of drusen reduction in eyes with nonexudative age-related macular degeneration (ARMD) treated with subthreshold infrared (810 nm) diode laser macular grid photocoagulation. Additionally, to determine the relationship of laser-induced drusen reduction and best-corrected visual acuity (BCVA) 18 months after laser treatment. DESIGN: Randomized controlled clinical trial. METHODS: Fifty patients (100 eyes) with bilateral nonexudative ARMD were enrolled at two centers. One eye of each patient was randomized to the observation; the other eye was treated with 48 subthreshold (invisible end point) applications of infrared (810 nm) diode laser in a macular grid pattern. The eyes that received subthreshold laser treatment were compared with the eyes that received no treatment. The baseline fundus characteristics (number, size, and distribution of drusen, as well as focal hyperpigmentation) from two macula areas (central 1500 micro diameter, pericentral 1500 micro ring area) on stereo color photographs, the number of laser-induced lesions, and the area of laser induced retinal pigment epithelial (RPE) lesions on fluorescein angiography 3 months after treatment were studied as predictors of major drusen reduction (> or = 50% drusen reduction from baseline) 18 months after laser treatment. BCVA at baseline and 18 months later was compared in observation eyes and in laser-treated eyes. RESULTS: Eighteen months after randomization, 24 (48%) of 50 eyes treated with subthreshold laser had major drusen reduction compared with three (6%) of 50 observation eyes (P =.00001). At 3 months post-treatment in laser-treated eyes with major drusen reduction, the mean number of laser-induced lesions on fluorescein angiography was 30.7 and the mean area of RPE change was 0.81 mm(2) compared with 14.8 laser-induced lesions and 0.35 mm(2) area of RPE change in eyes without major drusen reduction (P =.0001 and P =.0003, respectively). At baseline, fundus characteristics were not significantly different between observation eyes and laser-treated eyes or between the major drusen reduction group and the nonmajor drusen reduction group. At 18 months after treatment, BCVA was not significantly different in laser-treated eyes and in observation eyes. CONCLUSIONS: Subthreshold infrared (810 nm) diode laser macular grid photocoagulation in eyes with nonexudative ARMD significantly reduced drusen 18 months after laser treatment. Both the number of subthreshold laser lesions and the area of RPE changes visible on fluorescein angiography 3 months after treatment appeared to be predictors for major drusen reduction 18 months after treatment. However, it remains to be determined whether laser-induced drusen reduction is beneficial for visual acuity or reduces the incidence of choroidal neovascularization (CNV) in eyes with nonexudative ARMD.

Aged↗