Effect Of Laser Photocoagulation Research Articles

Effect of laser photocoagulation, antiangiogenic therapy or a combined treatment on refractive outcomes of newborns with ROP.

To determine the refractive outcome after treatment with laser photocoagulation, intravitreal antiangiogenic injection or both, for the treatment of type 1 ROP and/or aggressive posterior ROP using defocus equivalent terms. These results will be compared with the spherical equivalent (SE) notation in an initial refraction (during the first 3 years after treatment) and in a final evaluation (three years after treatment). Clinical charts review of preterm patients who developed type 1 ROP and/or aggressive posterior ROP who were treated with laser photocoagulation, intravitreal antiangiogenic injection, or both, between January 2007 and December 2014 at Fundación Oftalmológica de Santander were reviewed. Refractive error was evaluated at two different time points in three different treatment groups. Seventy-seven eyes (56 patients) with ROP diagnosis treated with laser, antiangiogenics or in a combined scheme were included. Median gestational age was 29 weeks (IQR = 3), median birth weight was 1100 (IQR = 335) and mean corrected age at the time of treatment was 37.3 weeks (SD 2.2). Refractive outcomes in SE terms for the first refraction had a median of -0.50 diopters and in defocus terms, 4.00 diopters (D). For the second refraction, -3.00 diopters and 4.00 diopters (D), respectively. Pearson correlation test result for the first measurement was 93% (p = 0.000) and for the second evaluation was 99% (p = 0.000). Low birth weight had a statistically significant association to the increase of the refractive outcome. The high correlation between SE and DE for refractive errors allows us to confirm that DE is an appropriate metric to report refractive outcomes in this group of patients due to the presence of combined refractive ametropias.

Analysis of the Curative Effect of Laser Photocoagulation in the Treatment of Ocular Fundus Disease

Analysis of the Curative Effect of Laser Photocoagulation in the Treatment of Ocular Fundus Disease

Effect of laser photocoagulation before vitrectomy to hypoxia inducible factor-1alfa and intracellular adhesive molecule-1 in diabetic patients: a randomized clinical trial

Effect of laser photocoagulation before vitrectomy to hypoxia inducible factor-1alfa and intracellular adhesive molecule-1 in diabetic patients: a randomized clinical trial

Clinical Characteristics and Outcome of Laser Photocoagulation for The Treatment of Retinal Hole/Break in Preventing Retinal Detachment at Jakarta Eye Centre (2011-2015)


 
 
 Background: It is almost a consistent recognition that the retinal detachment associated with retinal hole/breaks accounts for some cases of retinal detachments. However, the treatment of retinal hole/breaks without retinal detachment remains controversial. This retrospective study is designed to evaluate the prophylactic effect of laser photocoagulation for the treatment of retinal hole/breaks in order to prevent retinal detachment. 
 Method: Eighty nine eyes of 85 patients with retinal hole/breaks were included in this study. Data is taken from medical record with the requirement of full follow-up for a year. They all were treated with laser photocoagulation around the hole/breaks margin. The average visual acuity of before and after treatment was compared. Furthermore, the laser photocoagulation characteristic (wavelength, power, spot size, exposure time) is measured. 
 Results: The success rate of laser photocoagulation to prevent retinal detachment was 96.6% (86/89). The progression rate to retinal detachment was account for only 3.4% (3/89) of patient getting the laser photocoagulation treatment. The average best corrected visual acuity (BCVA) at 1 year follow up was 0.91 + 0.16, while the average BCVA before photocoagulation was 0.93 + 0.12. The average amount of laser to treat was 638.1 + 443.99 in range of 56 – 1863 spot and the laser photocoagulation is done on the day of diagnosis for 96.6% cases. 
 Conclusion: Photocoagulation reduce the rate of retinal detachment of retinal hole/breaks without the impairment of visual acuity outcome. Therefore, laser photocoagulation is relatively an effective and safe method for the treatment of retinal hole/breaks to prevent retinal detachment. 
 
 

Sickle cell retinopathy: improving care with a multidisciplinary approach.

Sickle cell retinopathy (SCR) is the most representative ophthalmologic complication of sickle cell disease (SCD), a hemoglobinopathy affecting both adults and children. SCR presents a wide spectrum of manifestations and may even lead to irreversible vision loss if not properly diagnosed and treated at the earliest. Over the past decade, multidisciplinary research developments have focused upon systemic, genetic, and ocular risk factors of SCR, enabling the clinician to better diagnose and manage these patients. In addition, newer imaging and testing modalities, such as spectral domain-optical coherence tomography angiography, have resulted in the detection of subclinical retinopathy related to SCD. Innovative therapy includes intravitreal injection of an anti-vascular endothelial growth factor (eg, Lucentis® [ranibizumab] or Eylea® [aflibercept]) which appears comparatively safe and efficient, and may be combined with laser photocoagulation (LPC) for proliferative SCR. The effect of LPC alone does not significantly lead to the regression of advanced SCR, although it helps in avoiding hemorrhage and sight loss. This comprehensive article is based on 10-years retrospective (2007–2017) studies. It aims to present advances and recommendations in SCR theranostics while pointing out the requirement of combinatorial approaches for better management of SCR patients. To reach this goal, we identified and analyzed randomized original and review articles, clinical trials, non-randomized intervention studies, and observational studies using specified keywords in various databases (eg, Medline, Embase, Cochrane, ClinicalTrials.gov).

The Effect of Laser Photocoagulation on Intraocular Pressure in Premature Infants With Retinopathy of Prematurity.

To evaluate the effects of diode laser treatment on intraocular pressure (IOP) of premature infants with retinopathy of prematurity (ROP). The premature infants who underwent retinal laser photocoagulation therapy for ROP, and gestational age-matched, birth weight-matched, and sex-matched premature infants with ROP which recovered spontaneously without any treatment were enrolled into the study. Anterior segment examination and longitudinal IOP and central corneal thickness measurements were performed 5 times as follows: 1 day before the laser treatment (T0), and 24 hours (T1), 1 week (T2), 1 month (T3), and 3 months (T4) after the laser treatment. Premature infants who experienced any complication related to the laser treatment were excluded from the study. Laser treated 67 premature infants and 70 premature infants in control group met inclusion criteria. Significant linear decreases in IOP and central corneal thickness values were measured throughout the study period for both groups (both, P<0.001). These changes were similar in 2 groups. There was a statistically insignificantly (P=0.999) and transient increase in the mean IOP value in the laser-treated group 24 hours after laser treatment. None of the patients in the laser-treated group experienced a shallow anterior chamber or a remarkable IOP elevation. Diode laser treatment for ROP was safe, and did not raise the IOP of premature infants.

Clinical study of laser photocoagulation for the treatment of diabetic retinopathy

Objective To compare the effects of laser photocoagulation alone or combined with medication for diabetic retinopathy (DR). Methods We conducted a prospective study. A total of 344 eyes of 256 patients with DR during January 2013 to June 2015 were chosen and randomly divided into the control group, 164 eyes of 128 cases, and the observation group, 180 eyes of 128 cases. The patients in the control group received laser photocoagulation alone, and patients in the observation group received laser photocoagulation combined with calcium dobesilate and complex thrombolysis treatment. Then the fundus and visual acuity were examined respectively. Results The improving rate of retina in the observation group was 91.11%, which was higher than that 78.05% of the control group, and the difference was statistically significant (χ2=11.41, P=0.001). Moreover, the improving efficiency of visual acuity of patients in the observation group was 87.78%, which was higher than that 71.95% in the control group and the difference was statistically significant (χ2=13.55, P=0.000). Conclusion The treatment of laser photocoagulation combined with medicine therapy for DR can improve DR and vision effectively. Key words: Diabetic retinopathy, nonproliferative; Laser photocoagulation; Calcium dobesilate; Complex Thrombolysis

Ocular hypertension in adult rodents does not affect non‐RGC neurons in the ganglion cell layer but results in severe loss of cone‐photorreceptors

SummaryWe investigate short and long‐term effects of laser photocoagulation (LP) of the limbal tissues‐induced ocular hypertension (OHT) in the innermost and outer layers of the retina (OLR). Adult albino rats or mice were examined 2 weeks to 6 months after LP‐induced OHT. Brn3a‐immunodetection was used to identify retinal ganglion cells (RGCs) and DAPI‐staining to identify all cell nuclei in the ganglion cell layer. Retinas were cut in cross sections for morphometric analysis or prepared as wholemounts to study the entire population of RGCs or L‐ and S‐cones (immunolabeled). OHT resulted in pie‐shaped retinal areas lacking Brn3a+RGCs but with large numbers of DAPI+nuclei. Cross‐sections showed focal regions of degeneration affecting the ORL that became evident by 2 m and progressed up to 6 months after LP. Rat retinal wholemounts showed RGC diminished to 20–25% by 1 m with no further loss, whereas the L‐ or S‐cones showed progressive loss up to 6 months that amounted to 19% or 33% by 1 m, to 62% or 51% by 3 m, and to 66% or 59% by 6 m, respectively. LP‐induced OHT results in selective loss of RGCs within the ganglion cell layer, but there is progressive severe damage of the ORL up to 6 m.

Effect of laser photocoagulation on plasma levels of VEGF-A, VEGFR-2, and Tie2 in infants with retinopathy of prematurity

To report the baseline plasma levels of vascular endothelial growth factor-A (VEGF-A), soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) and soluble Tie2 in infants with treatment-requiring retinopathy of prematurity (ROP) and to investigate the effect of laser treatment on the plasma levels. Blood samples were collected from infants with prethreshold type 1 ROP before, 1 day after, and 1 week after confluent laser photocoagulation. Enzyme-linked immunosorbent assay procedure was used to determine plasma VEGF-A, sVEGFR-2, and sTie2 levels. A total of 48 eyes of 30 infants were included. The mean postconceptional age at which laser photocoagulation was performed was 37.5 ± 2.9 weeks. The mean number of laser spots applied to each eye was 1,480 ± 420. Regression of active retinopathy occurred within 1 week of treatment in all cases. Baseline plasma VEGF-A, sVEGFR-2, and sTie2 levels did not differ between unilateral and bilateral and also zone I and zone II disease. A significantly progressive decrease was observed in plasma VEGF-A, sVEGFR-2, and sTie2 levels at 1 day and 1 week after laser photocoagulation. Plasma levels of VEGF-A, sVEGFR-2, and sTie2 decreased significantly in our patients after laser treatment; however, because of the variability in the measurements, further studies evaluating the clinical value of these angiogenic factors in patients with treatment-requiring ROP are necessary.

Effect of laser photocoagulation and bevacizumab intravitreal in proliferative diabetic retinopathy: review on biomarkers of oxidative stress

Background: This study was aimed to compare the effect of laser photocoagulation (LF), intravitreal bevacizumab (IVB) and combined treatments on biomarkers of oxidative stress such as aldehhyde dehidrogenase (ALDH), malondialdehyde (MDA) level, superoxide dismutase (SOD) activities, and vitreal vascular endothelial growth factor (VEGF) on proliferative diabetic retinopathy (DR) patients.Methods: In this single blind randomized clinical trial, 72 eyes from 69 cases of proliferative DR in Cipto Mangunkusumo Hospital between February 2011 - June 2013 were randomized into 4 groups : 1) control (n = 18); 2) LF pre-vitrectomy (n = 18); 3) IVB pre-vitrectomy (n = 18); and 4) combined IVB and LF pre-vitrectomy (n = 18). One-way ANOVA was used to compare oxidative stress parameters in the four groups.Results: There were no statistically significant differences in the average plasma ALDH activity (0.034 ± 0.02; 0.027 ± 0.02; 0.025 ± 0.02; 0.031 ± 0.11 IU/mg protein; p = 0.66), vitreal MDA level (1.661 ± 1.21; 1.557 ± 1.32; 1.717 ± 1.54; 1.501 ± 1.09 nmol/mL; p = 0.96) and SOD activity) (0.403 ± 0.50; 0.210 ± 0.18; 0.399 ± 0.49; 0.273 ± 0.32 U/mL; p = 0.38) among these four groups, respectively. However, the VEGF vitreal level (pg/mL) showed a statistically significant difference (0.356 ± 0.60; 0.393 ± 0.45; 0.150 ± 0.24; 0.069 ± 0.13; p = 0.05). The VEGF level in combination group was five times lower than the control group (p = 0.05).Conclusion: Combined treatments of DR by IVB and LF were correlated with lower vitreal MDA and plasma VEGF level, but did not have any effect on plasma ALDH and vitreal SOD in proliferative DR. Combined treatments with IVB and LF are recommended for the management of proliferative DR patients.

Effect of Laser Photocoagulation and Intravitreal Bevacizumab Injection on Zone I Retinopathy of Prematurity

Effect of Laser Photocoagulation and Intravitreal Bevacizumab Injection on Zone I Retinopathy of Prematurity

Effect of laser photocoagulation of ciliary processes by single channel of sclera in aphakic glaucoma

Objective To explore the therapeutic effect of laser photocoagulation of ciliary processes by single channel of sclera in aphakic glaucoma.Methods 28 patients (28 eyes)with aphakic glaucoma,sclera incision was done at the 11:00 position,intraocular perfusion at the 3:00 position of the limbus,a probe of semi-conductor diode laser( 810 nm,0.5W)was inserted through the sclera incision,combined with pressing the sclera,ciliary processes were photocoagulated in 90 -200 degree range by the intraocular pressure( IOP) before surgery.Visual acuity,IOP and ocular tissue reaction were observed after surgery.The mean follow-up period was 8 months.Results The intraocular prssure gradually declined,The IOP at the last visit was ( 18.34 ± 1.92) mmHg,which was significantly lower than that before the surgery ( P ＜ 0.05 ).Conclusion Laser coagulation of ciliary processes by single channel of sclera in aphakic glaucoma could reduce the IOP,and decrease the complications. Key words: Glaucoma; Aphakia; Laser coagulation; Ciliary body;

Clinical observation on treating diabetic macular edema with intravitreal triamcinolone acetonide and laser

To evaluate the effect of intravitreal injection of triamcinolone acetonide(IVTA) combining with retinal laser treating for diabetic macular edema(DME). Twenty five patients(32 eyes) with DME who has microangioma in macula lutea were randomly divided into group A, B,C and D(8 eyes each group). Eyes in group A were treated with laser photocoagulation. Eyes in group B were treated with multiplier-532 laser photocoagulation and transpupillary thermotherapy. Eyes in group C were treated with multiplier-532 laser photocoagulation and intravitreal triamcinolone acetonide. Eyes in group D were treated with multiplier-532 laser, transpupillary thermotherapy plus triamcinolone acetonide injection. Intravitreal injection of 4 mg triamcinolone acetonide was done 1 week after laser photocoagulation in group C and D. The visual acuity, intraocular pressure, macular thickness (foveal thickness) of the eyes in 4 groups were observed before and 1, 3 and 6 months after treatment. The visual acuity, intraocular pressure and foveal thickness of the 4 groups before treatment showed no significant difference(p> ). The visual acuity, intraocular pressure, macular thickness of eyes in group A, B were better than those of group C, D at 1, 3 and 6 months after treatment, and they had significant difference(p<0.05), while they didn't show significant difference between group A and B, group C and D(p>0.05). The effect of laser photocoagulation and intravitreal triamcinolone acetonide, laser photocoagulation combining with transpupillary thermotherapy plus triamcinolone acetonide injectionvisual treating for DME was better than laser photocoagulation alone, laser photocoagulation combining with transpupillary thermotherapy.

Effectiveness of Laser Photocoagulation in Clinically Significant Macular Edema With Focal Versus Diffuse Parafoveal Thickening on Optical Coherence Tomography

To evaluate whether increased foveal thickness in clinically significant diabetic macular edema responds differently to modified focal/grid laser photocoagulation in the setting of focal versus diffuse parafoveal thickening as defined by optical coherence tomography (OCT) criteria. The medical records of patients undergoing macular laser procedures for clinically significant diabetic macular edema were retrospectively reviewed. OCT, demographic, and clinical data were recorded for 62 consecutive eyes with clinically significant diabetic macular edema and foveal thickening (> 230 microns). Diffuse parafoveal thickening was defined as having all four parafoveal OCT quadrants greater than 300 microns, whereas focal thickening was defined as having fewer than four quadrants greater than 300 microns. Mean foveal thickness decreased from 331 to 311 microns with relatively stable visual acuity (20/54 vs 20/51) after a single laser treatment session. The diffuse parafoveal edema subgroup (24 eyes) had a mean foveal thickness change from 383 to 366 microns (P = .47) and mildly decreased visual acuity (20/62 vs 20/69). The focal parafoveal edema subgroup (38 eyes) experienced statistically significant foveal thinning from 299 to 276 microns (P = .018) and mildly improved visual acuity (20/48 to 20/43). Increased foveal thickening associated with clinically significant diabetic macular edema responds more favorably to modified focal/grid laser photocoagulation in the setting of focal parafoveal edema by OCT criteria. Statistically significant foveal thinning occurred following treatment in the focal group (P = .018) but not the diffuse group (P = .47). Furthermore, eyes with focal parafoveal edema experienced a more beneficial visual acuity response than those with diffuse edema (P = .049).

Long‐term effect of therapeutic laser photocoagulation on gene expression in the eye

Microarray-based gene expression analysis demonstrated that laser photocoagulation (LPC) of mouse eyes had a long-term effect on the expression of genes functionally related to tissue repair, cell migration, proliferation, ion, protein and nucleic acid metabolism, cell signaling, and angiogenesis. Six structural genes, including five crystallins (Cryaa, Cryba1, Crybb2, Crygc, Crygs) and keratin 1-12 (Krt1-12), the anti-angiogenic factor thrombospondin 1 (Tsp1), the retina- and brain-specific putative transcription factor tubby-like protein 1 (Tulp1), and transketolase (Tkt), a key enzyme in the pentose-phosphate pathway, were all shown to be up-regulated by real-time PCR and/or Western blotting. Immunohistochemistry localized five of these proteins to the laser lesions and surrounding tissue within the retina and pigmented epithelium. This is the first study demonstrating long-term changes in the expression of these genes associated with LPC. Therefore, it suggests that modulated gene expression might contribute to the long-term inhibitory effect of LPC. In addition, these genes present novel targets for gene-based therapies aimed at treating microangiopathies, especially diabetic retinopathy, a disease currently only treatable with LPC.

Effect of laser photocoagulation on the retinal vessel diameter in branch and macular vein occlusion.

To investigate the response of retinal vessel diameters to photocoagulation treatment and their role for the success of laser treatment in patients with retinal vein occlusion. The study included 14 patients with branch vein occlusion or macular vein occlusion. The ophthalmologic examination included best-corrected visual acuity, biomicroscopy, fundus photography, and fluorescein angiography. Retinal vessel diameters were quantified before and after laser photocoagulation using a retinal vessel analyzer. Retinal vessel diameters. In cases manifesting macular vein occlusions, no significant change of the vessel diameter in any vessel was observed during the follow-up period. In the group with branch vein occlusion, all vessels tended to constrict after the laser photocoagulation. The effect of laser treatment on retinal vessel diameters was significant for superotemporal (P =.045, analysis of variance [ANOVA]) and inferotemporal branch veins (P =.03, ANOVA). Vasoconstriction was more pronounced in the occluded branch veins (P =.009, ANOVA) compared with the nonaffected veins (P =.12; ANOVA). The change of visual acuity after 3 months was correlated with the change of vessel diameter 3 months after laser treatment for occluded venular branches (r = 0.78, P =.02, linear regression). There was no correlation between the number of laser burns and the change of vessel diameters in the affected veins in this period (r = 0.12, P =.75, linear regression). Our results show that retinal photocoagulation in patients with branch vein occlusion has a vasoconstrictive effect on occluded veins. The correlation between the change in visual acuity and the change in vessel diameter indicates that branch vein constriction after photocoagulation may be an early indicator of the success of laser treatment.

The capillary blood flow in ischaemic type central retinal vein occlusion: the effect of laser photocoagulation.

To determine the effect of photocoagulation on retinal blood flow (RBF) in eyes with ischaemic type central retinal vein occlusion (CRVO). Retinal blood flow was measured in 12 eyes with CRVO, 12 fellow eyes and 12 eyes of 12 age-matched healthy subjects using the Heidelberg retinal flowmeter (HRF). Microvascular blood flow values (volume, flow, velocity) were recorded from the upper temporal retina and macula. Eyes were re-examined 1 month after photocoagulation. We investigated whether there was a difference in RBF measurements before and after photocoagulation treatment. In eyes with CRVO, mean RBF values (volume, flow and velocity) obtained from the upper temporal retina increased significantly after treatment (paired t-test, p < 0.05). In contrast, mean RBF values from the macula were unaffected by photocoagulation (paired t-test, p > 0.05). Retinal blood flow values from the upper temporal retina obtained from control subjects were significantly higher than the values in eyes with CRVO before and after photocoagulation (unpaired t-test, p < 0.05), but there was no significant difference between control subjects and CRVO patients in RBF values from the macula (unpaired t-test, p > 0.05). Mean RBF values were significantly higher in CRVO patients' fellow-eyes before photocoagulation in the eyes with CRVO (paired t-test, p < 0.05) but were lower than in age-matched healthy control eyes (unpaired t-test, p < 0.05). Macular blood flow did not differ between the eyes with CRVO and fellow eyes (paired t-test, p > 0.05). Laser photocoagulation increased retinal blood flow in eyes with CRVO, but RBF did not reach normal values. Photocoagulation was found to have no effect on RBF in the macular area.

Laser Treatment of Retinal Diseases by Subthreshold Laser Effects

The retinal pigment epithelium (RPE) may play an important role in the therapeutic effect of laser photocoagulation. This suggests a benefit from targeting the RPE instead of the sensory retina. Calculating the actual temperature profile after laser photocoagulation, it can be shown that pulse durations have to be in the order of microseconds (μS) to spare the retina from damage. This is consistent with histological findings after laser exposure with repetitive, 5 μs Nd:YLF laser pulses (527 nm). Therapeutic effects have been shown in patients with diabetic macular edema, drusen, and central serous retinopathy.

Doppler assessment of the effect of laser photocoagulation of communicating vessels in twin-twin transfusion syndrome

Doppler assessment of the effect of laser photocoagulation of communicating vessels in twin-twin transfusion syndrome

Effects of Laser Photocoagulation on Corneal Neovascularization in Rabbits

Corneal neovascularization is a common clinical entity. Although visual acuity is usually impaired and corneal function compromised, there has been only limited success in the clinical management of this condition. We evaluated the efficacy of laser photocoagulation of neovascularization in the rabbit cornea. New vessel formation was provoked by the placement of sutures in the corneas. Rose bengal was injected intravenously and new vessels in the upper part of the corneas were treated with an argon laser. The lower halves were used as controls. Eighteen rabbits were divided into 2 groups. In group A neovascularization was treated 28 days after suture removal, when corneal inflammation had regressed. In group B treatment was performed 3 days after suture removal, when the cornea still exhibited marked inflammation. Postoperatively, the corneas were studied by slit-lamp microscopy, fluorescein angiography, and light, as well as electron microscopy. In group A, treatment led to the immediate occlusion of the vessels and to their gradual disappearance during the course of 3 months. In group B, no occlusion was seen during the 3-month follow-up period. The main histologic findings in the occluded vessels were endothelial cell disruption and degeneration, and the formation of clots. Our results suggest that argon laser photocoagulation using rose bengal is an effective method of occluding corneal new vessels, providing there is no corneal inflammation at the time of treatment.