Argon Green Laser Research Articles

Grid laser photocoagulation in diffuse diabetic macular edema

To evaluate the clinical outcome of macular grid laser photocoagulation in the treatment of diffuse diabetic macular oedema. The retrospective study included 30 consecutive patients (41 eyes) who were treated by macular argon green grid laser photocoagulation for diffuse diabetic macular oedema. Follow-up time was 31.4 +/- 19.6 weeks. Visual acuity decreased from 0.25 +/- 0.18 (range, 0.03 - 0.8) to 0.20 +/- 0.18 (range, 0.02 - 0.8) (P = 0.045), representing a change of - 0.9 +/- 2,32 lines. 5 (12.2 %) eyes gained in visual acuity, visual acuity remained unchanged for 23 (56.1 %) eyes, and 13 (31.7 %) eyes showed a visual loss of more than one line. In eyes with a baseline visual acuity > or = 0.2 (N = 24) visual acuity dropped from 0.36 +/- 0.15 (0.2 - 0.8; median 0.3) to 0.29 +/- 0.19 (0.05 - 0.8; median 0.2) (p = 0.038). 3 eyes (12.5 %) gained > or = 2 lines, 11 eyes (45.8 %) lost > or = 2 lines, 10 eyes (41.7 %) remained stable. Mean loss was - 1.63 +/- 2.53 lines. Eyes with a baseline visual acuity < or = 0.2 did not change significantly. In the present study mean visual acuity decreased in the whole population and especially in the subgroup with a baseline visual acuity of > or = 0.2 after macular grid laser photocoagulation for diffuse diabetic macular oedema. Mean visual loss was just below the predefined 2 lines. In view of these results and upcoming new pharmacological and surgical treatment modalities, the significance of grid laser photocoagulation should be re-discussed.

A modified laser test for the identification of retinoschisis

Purpose To describe a modified laser technique for identification of bullous retinoschisis. Design Retrospective interventional case series collected over 10 years. Methods Forty-one eyes with presumed bullous retinoschisis and breaks in the inner layers underwent a low-energy argon green laser application at the same energy as a control spot in adjacent retina. A gray response in the outer layers equal to the control spot was diagnostic of retinoschisis. Results The laser test was positive for retinoschisis in 40 of 41 eyes. In none of the 40 eyes did the elevation progress. Conclusion A low-energy argon green laser application through a break in the inner layers of presumed retinoschisis eliminates the attenuation of the beam and can confirm retinoschisis.

Prophylactic laser treatment in early age‐related maculopathy: an 8‐year follow‐up in a randomized pilot study shows a reduced incidence of exudative complications

To study the effect of mild laser treatment on the incidence of exudative complications in patients with soft drusen maculopathy in a longterm perspective. In a prospective study, 38 patients with early age-related maculopathy and good visual acuity (VA) were randomized either to laser treatment using an argon green laser or to observation. At 8 years, 29 patients remained in the study, 16 in the control group and 13 in the treatment group. During follow-up, mean VA decreased significantly in both groups, to 0.53 in the treatment group (p < 0.05) and to 0.25 in the control group (p < 0.001). At 8 years, 9/16 in the control group showed exudative complications, whereas only 2/13 in the treatment group developed such changes (p < 0.03). In this randomized pilot study, mild laser treatment of soft drusen maculopathy significantly reduced the rate of exudative complications in a longterm perspective. As the study is small, the results should be viewed with caution.

Laser treatment in fellow eyes with large drusen: updated findings from a pilot randomized clinical trial

Purpose To update the findings from the Choroidal Neovascularization Prevention Trial (CNVPT) with respect to resolution of drusen, incidence of choroidal neovascularization, and visual function. Design A multicenter, randomized, controlled, pilot clinical trial. Participants The 120 patients enrolled in the CNVPT. Patients had signs of choroidal neovascularization or retinal pigment epithelial detachment in 1 eye and had ≥10 large (>63-μm) drusen in the contralateral, or fellow, eye. Intervention The fellow eye of 59 patients was assigned randomly to argon green laser treatment consisting of multiple 100-μm spots at least 750 μm from the center of the fovea. The fellow eye of the remaining 61 patients was assigned randomly to observation. Main outcome measures Change in visual acuity was the primary outcome measure. Incidence of choroidal neovascularization, resolution of drusen, change in contrast threshold, change in critical print size for reading, and incidence of geographic atrophy were secondary outcome measures. Results Throughout 4 years of follow-up, there were no statistically significant differences in change in visual acuity, contrast threshold, critical print size, or incidence of geographic atrophy. With additional follow-up, the large increase in the incidence of choroidal neovascularization observed within 18 months of treatment was maintained; however, by 30 months, the incidence in the two treatment groups was the same. Most drusen resolution in treated eyes occurred within 24 months of the initial treatment. Treated eyes that received higher-intensity laser burns had an increased risk of choroidal neovascularization. Among eyes developing choroidal neovascularization in each treatment group, most lesions (two thirds or more) were composed of occult neovascularization only. Conclusions Laser treatment as applied in the CNVPT caused an excess risk of choroidal neovascularization in the first year or so after treatment. The increased early incidence of choroidal neovascularization was not associated with either a harmful or beneficial effect in this pilot study.

Optimal Laser Power to Rupture Bruch's Membrane and the Retinal Vein in the Pig

For laser-induced chorioretinal venous anastomosis to become a viable treatment option for perfused central retinal vein occlusion, laser parameters must be refined to more reliably create venous anastomoses while minimizing complications. The aim of this study was to determine the lowest argon laser power at which Bruch's membrane and the retinal vein are ruptured in 100% of attempts in the porcine eye. Testing was performed on 6 eyes of 3 Yorkshire Cross pigs, using an argon green laser. The spot size was 50 microm and the duration was 0.2 seconds for all applications. Twelve laser powers were tested, from 0.5 to 6 W, increasing by increments of 0.5 W. Light microscopy was used to determine the frequency of rupture of Bruch's membrane and the retinal vein for each power. The rupture rate of Bruch's membrane was 0% at 0.5 W, 5% at 1.0 W, 20% at 1.5 W, 70% at 2.0 W, and 100% for all powers from 2.5 to 6.0 W. The rupture rate of the retinal vein was 0% at 0.5 W, 5% at 1.0 W, 30% at 1.5 W, 60% at 2.0 W, 80% at 2.5 W, and 100% for all powers from 3.0 to 6.0 W. Argon green laser powers of at least 2.5 and 3.0 W were necessary to rupture Bruch's membrane and the retinal vein, respectively, with a 100% success rate in the porcine eye. Because patients with central retinal vein occlusion have secondary retinal edema and may have lenticular opacity, higher laser powers may be required to achieve a 100% rupture rate of these structures.

Adult hematopoietic stem cells provide functional hemangioblast activity during retinal neovascularization. Grant MB, May WS, Caballero S, Brown GAJ, Guthrie SM, Mames RN, Byrne BJ, Vaught T, Spoerri PE, Peck AB, Scott EW. Nat Med 2002;6:607-612.

Bone marrow cells or hematopoetic stem cells were obtained from green fluorescent protein transgenic mice and introduced via intravenous injection into irradiated C57BI/6 mice. This chimeric C57BL/6 mice then underwent argon green laser application to selected venous sites next to the optic nerve to produce venous occlusions. The mice were sacrificed 3 weeks later and retinal flat-mounts were examined by confocal microscopy and immunocytochemistry. Results showed clonal differentiation of the hematopoietic stem cells to all hematopoietic cell lineages as well as endothelial cells that revascularized the adult murine retina. There was also recruitment of endothelial precursors to sites of ischemic injury.—Hans E. Grossniklaus

Long-term visual acuity after argon green laser photocoagulation of juxtafoveal choroidal neovascularization in highly myopic eyes.

To evaluate visual outcomes in patients with high myopia afterjuxtafoveal choroidal neovascularization (CNV) treated with argon green laser photocoagulation. We retrospectively analyzed 23 eyes of 21 patients with high myopia (>6.0 diopters and/or axial length >26 mm) with juxta foveal CNV treated with direct Argon green laser photocoagulation. Mean age at diagnosis was 49.08+/-12.20 years (range, 29 to 71). Mean follow-up was 54.26+/-26.18 months (range 18 to 96). Best corrected visual acuity (BCVA) before treatment was 0.09+/-0.10 (range, 0.01 to 0.40). Two months after treatment it was 0.14+/-0.12 (0.01 to 0.6), significant difference (p=0.02, Student's t-test forpaired data) and aftersix months 0.19+/-0.14 (0.01 to 0.5) (p=0.0002). Mean BCVA decreased with follow-up, to 0.19+/-0.15 (0.01 to 0.4) after two years, 0.16+/-0.15 (0.01 to 0.5) after three years and 0.16+/-0.19 (0.01 to 0.7) after four years, with no significant improvement after the third year (p=0.04). In two cases CNV reappeared. Direct argon green laser photocoagulation in high-myopia juxtafoveal CNV can improve BCVA initially for between two and 24 months. The improvement fades with time, and is no longer significant after the third year.

Laser intervention in macular oedema due to branch retinal vein occlusion

20 out of 25 patients of Branch Retinal Vein Occlusion (BRVO), with macular oedema of more than six months duration and less than one year, with visual acuity (VA) less than 6/18 corrected and without retinal neovascularisation (NVE) or capillary non-perfusion (CNP) were subjected to argon-green laser photocoagulation applied in a macular grid fashion. At the end of two years 14/20 (70%) laser treated eyes in comparison to 2/5 (40%) of the non-laser group had corrected visual acuity of 6/12.

Adult-onset Foveomacular Vitelliform Dystrophy with Retinal Folds

Background: Adult-onset foveomacular vitelliform dystrophy is characterized by a solitary, oval, slightly elevated, yellowish subretinal lesion of the fovea. We examined a patient with adult-onset foveomacular vitelliform dystrophy with stellate retinal folds by optical coherence tomography and scanning laser ophthalomoscopy. Case: A 58-year-old Japanese woman with a complaint of decreased vision in her right eye was diagnosed as having adult-onset foveomacular vitelliform dystrophy. Observations: Ophthalmoscopic examination revealed a yellowish lesion of one-third disc diameter in size at the fovea in the right eye. Fluorescein angiography demonstrated an irregular block of choroidal fluorescence corresponding to the yellowish lesion, which was surrounded by stellate retinal folds. Optical coherence tomography images showed a steep elevation of the retinal pigment epithelium (RPE) as a focally protruded reflective band over an optically clear space. Scanning laser ophthalmoscopy provided morphologic enhancement in the specifically affected layers of the macula. Using an argon green laser, band-shaped bright reflexes were seen in the right fovea. The helium-neon laser revealed a bright patch corresponding to the yellowish lesion over the fovea, which was surrounded by stellate retinal folds. The diode laser revealed a bright patch corresponding to the yellowish lesion. Conclusion: The stellate retinal folds of this patient were considered to be caused by the steep elevation of the RPE with an extracellular accumulation of the vitelliform deposits.

Quantitative Assessment of Macular Appearance with a Scanning Laser Ophthalmoscope in Aging or Diabetic Retinopathy Patients

Changes in the macula caused by aging or diabetic retinopathy were studied with scanning laser ophthalmoscope (SLO). SLO imaging of the macula was done with argon blue, argon green, helium neon, and diode lasers, and the images were recorded on s-VHS video tape. In this study, we examined 29 patients (58 eyes) with no retinal organic change as controls, 8 diabetic patients (16 eyes) without retinopathy, 8 patients (16 eyes) with simple diabetic retinopathy, and 6 patients (12 eyes) with preproliferative diabetic retinopathy. As age increased, the dark area of the macula was enlarged in the argon blue and argon green images. In diabetic patients, the dark area of the macula in patients in their 30 s and 40 s with retinopathy was larger than in diabetic patients without retinopathy (p < 0.05). The dark area of the macula in preproliferative diabetic retinopathy was larger than in patients in their no diabetic retinopathy or simple diabetic retinopathy (p < 0.05). In the 50 s and 60 s, the dark area of the macula in preproliferative diabetic retinopathy was larger than in the controls or in patients with no diabetic retinopathy (p < 0.05). The macular dark area became enlarged with aging. In diabetic patients, the dark area of the macula was enlarged in diabetic patients without retinopathy or with progression in diabetic retinopathy stage. Therefore, quantitative assessment of macular appearance with SLO can be used as a new clinical index.

Laser Therapy in the Management of Choroidal Breast Tumor Metastases

To evaluate the potential of laser photocoagulation as a method of treating small metastatic lesions of breast carcinoma in the choroid. The 10 eyes of 7 patients were treated by Krypton red or argon green laser applications for small choroidal breast carcinoma metastasis with serous detachment of the retina. Before treatment 5 eyes had visual acuity of finger counting and 5 eyes had visual acuity of 6/15 or better. The treatment was repeated once in all eyes, except 1 eye in which it was repeated 3 times. In all eyes, one to two weeks after the treatment the tumor shrunk, the subretinal serous detachment absorbed, the retina flattened, and the visual acuity improved to 6/6-6/21. No reduction in vision was seen after the second treatment until the end of the follow-up period. In 1 eye, new tumors located elsewhere were again twice successfully treated. Patients reported a significant improvement of their quality of vision, as judged subjectively. Laser treatment is a feasible, easy, rapid, and effective therapy for small choroidal breast carcinoma.

Contrast sensitivity following focal laser photocoagulation in clinically significant macular oedema due to diabetic retinopathy.

To evaluate the influence of focal aser photocoagulation on contrast sensitivity in diabetic patients with clinically significant macular oedema (CSMO). A prospective non-comparative interventional study was performed on a group of patients with CSMO at Dr Rajendra Prasad Centre for Ophthalmic Sciences, New Delhi, a tertiary eye care centre. Thirteen diabetc patients (14 eyes) with CSMO and no history of prior photocoagulation were recruited for this study. Direct focal photocoagulation of all leaking microaneurysms was performed using an argon green laser (514 nm). A contact lens was used as a slit lamp delivery system. Evaluation of the best corrected Snellen visual acuity, contrast senstivity, slit lamp biomicroscopy, macular status on direct ophthalmoscopy and fluorescein angiography was carried out 1 month and 3 months after laser photocoagulation. Following direct focal laser photocoagulation, focal CSMO resolved completely in all but one eye, 4-8 weeks later, as seen on slit lamp biomicroscopy and/or fluorescein angiography. Post-treatment, visual acuity remained stationary in eight eyes, improved by one line in three eyes, by two lines in two eyes and by three lines in one eye. The mean +/- SD pretreatment and post-treatment decimal visual acuities were 0.49+/-0.30 and 0.59+/-0.28, respectively. The mean +/- SD pre-laser contrast sensitivity score was 121.3+/-83.6, which increased significantly to a mean +/- SD of 151.6+/-80.5 fo lowing direct focal photocoagulation. Focal argon laser photocoagulation in CSMO in diabetics helps in improving the contrast sensitivity and stabilizes the visual acuity. The changes in contrast sensitivity and visual acuity are independent of each other.

Choroidal neovascularization in myopic eyes after photorefractive keratectomy

Purpose To evaluate the incidence, characteristics, and results of treatment of choroidal neovascularization (CNV) in myopic eyes corrected by photorefractive keratectomy (PRK). Setting University Miguel Hernández, Instituto Oftalmológico de Alicante, Alicante, Spain. Methods This study was of the incidence of CNV in 5936 consecutive eyes that had PRK for the correction of myopia. Mean follow-up was 38.5 months ± 17.4 (SD). Results Extrafoveal CNV developed in the right eye of a 44-year-old woman 26 months after PRK for the correction of −12.00 diopters (D) of myopia. The follow-up after PRK was 38 months. Best corrected visual acuity (BCVA) before PRK was 20/40 (spherical equivalent [SE] −12.00 D). After PRK, BCVA was 20/32 SE −1.75 D). The CNV was treated by direct argon-green laser photocoagulation and did not recur in the subsequent 12 months). After CNV treatment, BCVA was 20/32 (SE −2.25 D). Conclusions The incidence of CNV after PRK for myopia was low. Choroidal neovascularization is a possible complication in myopic eyes, and the risk exists before PRK. After PRK, the risk of CNV in myopic patients did not increase.

Diode laser scatter photocoagulation in diabetic retinopathy

The efficacy of scatter photocoagulation therapy for diabetic retinopathy using the diode laser was compared with that of the argon green laser in a prospective randomized trial involving 50 eyes. Six months after treatment, neovascularization regressed in 16 eyes (64%) in the diode group and 18 eyes (72%) in the argon group. Diode laser appears to be a suitable alternative to argon green laser for scatter photocoagulation in diabetic retinopathy.

Therapeutic options for capillary papillary hemangiomas

PurposeTo describe the results and therapeutic complications of treatment of papillary capillary hemangiomas over the last 13 years. DesignRetrospective, noncomparative, interventional case series. ParticipantsFive cases of unilateral capillary papillary hemangiomas were reviewed. Three patients had von Hippel-Lindau disease, and two had no associated familial or systemic disease. MethodsTwo patients were treated with argon green laser, one patient received argon green and diode photocoagulation, and two patients underwent argon green photocoagulation and diode transpupillary thermotherapy (TTT); two eyes also underwent vitreoretinal surgery. Follow-up ranged from 1 to 13 years. Main outcome measuresThe presence of exudative retinal detachment associated with the activity of the hemangioma and the visual acuity were the two main parameters. ResultsPrompt argon green laser treatment was the most effective therapy; TTT was ineffective. Vitreoretinal surgery, transscleral drainage, and argon endolaser photocoagulation in one case resolved bullous retinal detachment secondary to tumor exudation. Pretreatment visual acuity (VA) levels ranged from 20/25 to counting fingers; posttreatment VA levels ranged from 20/25 to light perception. ConclusionsIf left untreated, papillary hemangiomas may evolve to exudative retinal detachment and marked VA decreases. Although we have not established an ideal therapy, we recommend appropriate treatment on diagnosis. Close follow-up and multiple treatments with argon laser are likely the best therapeutic course.

Relative Efficacy of the Argon Green, Argon Blue-Green, and Krypton Red Lasers for 10-0 Nylon Subconjunctival Laser Suture Lysis

To determine the optimal wavelength for subconjunctival laser suture lysis. 130 black monofilament 10-0 nylon sutures were sewn subconjunctivally into the bare sclera of enucleated rabbit globes. The lowest energy levels facilitating laser suture lysis were determined for the argon green (514.5 NM), argon blue-green (488.0 NM, 514.5 NM), and krypton red (647.1 NM) wavelengths. In addition, absorption spectroscopy was performed on the suture material and conjunctiva using the Perkin Elmer W/VIS Lambda 2 spectrometer. Krypton red produced the fewest buttonhole defects, and it was also the most efficient energy source for suture lysis (P = 0.0001) under nontenectomized conjunctiva. Absorbance spectra studies revealed peak absorbance at 628 NM for the 10-0 nylon suture material. Based on animal and absorption spectroscopy studies, krypton red may be a safer and more efficient wavelength for subconjunctival laser suture lysis.

Retinal Breaks and Rhegmatogenous Retinal Detachment in Association with Branch Retinal Vein Occlusion

To report the incidence and clinical characteristics of retinal breaks and/or rhegmatogenous retinal detachment (RRD) in patients with branch retinal vein occlusion (BRVO). We reviewed the clinical records of 230 eyes of 214 patients with BRVO and identified eyes with retinal breaks and/or RRD. Patients had at least 6 months of follow-up. Seven of 230 eyes (3%) had retinal breaks and 3 eyes (1.3%) had RRD. One of the eyes with RRD had subclinical retinal detachment. All 7 eyes had ischemic disease documented by fluorescein angiography. Two of 7 eyes had concurrent retinal neovascularization. Four eyes with breaks, but without RRD, and the eye with subclinical RRD were managed by argon green laser. Two eyes with RRD were managed successfully with scleral buckling surgery and postoperative supplemental argon green laser. The mean follow-up period was 14.8 +/- 8.3 months. Patients with BRVO should be monitored closely for possible retinal break formation and RRD development.

Localization of IgG in the normal and dystrophic rat retina after laser lesions.

To test the hypothesis that access to extravasated plasma protein IgG may influence photoreceptor survival following laser photocoagulation and to determine whether this correlates with the retinal glial reaction. A total of 45 rats (18 Royal College of Surgeons (RCS) dystrophic and 18 RCS-rdy+ congenic control) were used for this experiment. Nine non-lasered littermates of same age were used as controls. The superior retinas of postnatal day 23 rats were irradiated with a grid pattern of 40 argon green laser lesions of 50 microm in diameter and two powers (150 and 300 mW) for 0.2 s. At various times after laser lesions (up to 14 days), animals were perfused, the retinas snap frozen and sectioned on a cryostat. A one-step immunohistochemical technique was used by incubating with rabbit anti-rat IgG conjugated directly to horseradish peroxidase. Adjacent sections were processed using an antibody to glial fibrillary acidic protein (GFAP) by the standard avidin-biotin complex method. The labelling pattern for extravasated IgG after laser lesion was very similar in both RCS and RCS-rdy+ rat retinas. At 6, 12 and 24 h after lesions, IgG immunoreactivity (IR) was very intense in the lesion core and flanks. The outer plexiform layer (OPL) and photoreceptor inner segments provided a ready pathway for lateral spread of IgG. However, in the outer nuclear layer (ONL), IgG localization was much more restricted. Despite very intense IgG IR in the ONL of the coagulated lesion core, there was always a very sharply delineated boundary where the label abruptly halted. The GFAP labelling in both RCS dystrophic and RCS-rdy+ congenic control rat retinas showed that this boundary was between normal and necrotic cells because there was a core where GFAP was not produced by Müller cells. By 2 days after lesions, the coagulated cells in the lesion core were being removed by phagocytic cells that were IgG IR. Labelled phagocytic cells were also found among the inner and outer segment region on the lesion flanks. There was still IgG IR in the lesion, but the label was faint. No IgG IR was found in the retina at 3, 4, 7 and 14 days after lesions. Absorption control with pure rat IgG showed the label to be specific. The extravasated IgG was derived from the choroidal circulation because at no stage was IgG localized around the retinal vasculature. The IgG labelling was surprisingly widespread and, therefore, did not correlate with photoreceptor sparing, although it preceded the widespread Müller cell expression of GFAP and may, therefore, trigger glial reaction.

Retinal Venous Macroaneurysm Associated With Premacular Hemorrhage

To report an unusual association of a retinal venous macroaneurysm with premacular hemorrhage in a 50-year-old man, using a case report method. The patient exhibited a dense premacular hemorrhage in the left eye. Fluorescein angiography demonstrated that the source of bleeding was an isolated retinal venous macroaneurysm. The anterior surface of the hematoma was opened with an argon green laser, resulting in rapid clearing of the premacular hemorrhage and improvement in vision. Treatment of the retina surrounding the macroaneurysm to prevent recurrence of bleeding was ineffective to achieve occlusion of the lesion. No recurrent hemorrhage occurred during the observation period. Retinal venous macroaneurysm, a quite rare condition, may be complicated by premacular hemorrhage. Argon green laser may be useful in treating such hemorrhage. Hemorrhagic detachment of the internal limiting membrane or subhyaloid hemorrhage in the macula may occur after retinal vessel rupture with physical exertion (Valsalva retinopathy) or in retinal vascular diseases, such as proliferative diabetic retinopathy, and retinal arterial macroaneurysm. Arterial macroaneurysms are a common, well-described retinal vascular disorder. In contrast to retinal arterial macroaneurysms, retinal venous macroaneurysms are quite rare. In this article we describe a patient who presented with premacular hemorrhage that was caused by a retinal venous macroaneurysm. The hematoma and the macroaneurysm were treated with argon green laser.

The effect of the surgeon and the laser wavelength on the response to focal photocoagulation for diabetic macular edema

Objective To determine the effect of the surgeon and the wavelength of laser used on the response to focal photocoagulation for diabetic macular edema. Design Retrospective case-control study. Participants Forty-four matched pairs of cases by two different retina surgeons in the study of surgeon influence were examined. Sixty-nine matched pairs of cases using dye yellow versus argon green laser treatment in the study of wavelength influence also were studied. In both studies, eyes were matched for the only patient-dependent variables affecting outcome: age, initial visual acuity, follow-up time, and diabetic control by diet versus any other method. Intervention Focal laser photocoagulation for clinically significant diabetic macular edema was performed. Main outcome measure Visual acuity at 6 months follow-up was measured. Results For the study in which the only difference was the surgeon, at 6 months follow-up the mean difference in logarithm of the minimum angle of resolution (logMAR) visual acuity was −0.045, 95% confidence interval (−0.160, 0.070). For the study in which wavelength varied, at 6 months the mean difference in logMAR visual acuity was −0.048, 95% confidence interval (−0.147, 0.052). The power of the surgeon study to detect a difference in the logMAR visual acuity of 0.3 is 88% and of the wavelength study to detect this difference is 99%. Conclusion In looking at the 6-month visual outcome after focal laser photocoagulation for clinically significant diabetic macular edema, different fellowship trained surgeons and the choice of green or yellow wavelength had no effect on the treatment outcome.