Recent developments in ophthalmic lasers

Recent developments in the field of ophthalmic lasers include new improvements and upgrades in existing units, new laser delivery systems and new wavelengths, and new applications for treating a wide variety of ophthalmic diseases. In the field of retinal disease, the efficacy of laser treatment in diabetic edema and of panretinal photocoagulation for proliferative diabetic retinopathy have been studied. Complications related to the use of these therapeutic techniques are discussed. The diode laser, which emits at a wavelength of 810 nm, has been found to be clinically useful in the treatment of retinal disease. In the area of glaucoma, a better understanding of argon laser trabeculoplasty and peripheral iridotomy is presented, and comparisons are made with other laser systems, including the neodymium:yttrium-aluminum-garnet and diode lasers. The benefits of contact and noncontact neodymium:yttrium-aluminum-garnet lasers are discussed. In the area of corneal disease, early results from clinical trials of photorefractive and phototherapeutic applications of the excimer laser appear encouraging and suggest that this laser system will play a vital role in the treatment of a number of diseases. Finally, the neodymium:yttrium-aluminum-garnet laser and argon laser are finding a role in the field of oculoplastics.     

Micropulsed Diode Laser Therapy: Evolution and Clinical Applications

Many clinical trials have demonstrated the clinical efficacy of laser photocoagulation in the treatment of retinal vascular diseases, including diabetic retinopathy. There is, however, collateral iatrogenic retinal damage and functional loss after conventional laser treatment. Such side effects may occur even when the treatment is appropriately performed because of morphological damage caused by the visible endpoint, typically a whitening burn. The development of the diode laser with micropulsed emission has allowed subthreshold therapy without a visible burn endpoint. This greatly reduces the risk of structural and functional retinal damage, while retaining the therapeutic efficacy of conventional laser treatment. Studies using subthreshold micropulse laser protocols have reported successful outcomes for diabetic macular edema, central serous chorioretinopathy, macular edema secondary to retinal vein occlusion, and primary open angle glaucoma. The report includes the rationale and basic principles underlying micropulse diode laser therapy, together with a review of its current clinical applications.     

Management of post-vitrectomy persistent vitreous hemorrhage in pseudophakic eyes

PURPOSE: To prospectively assess the effect of neodymium:yttrium-aluminum-garnet peripheral capsulotomy on postvitrectomy hemorrhage in diabetic patients with a posterior chamber intraocular lens (IOL) implant and an intact posterior capsule. DESIGN: Interventional case series. METHODS: This is a prospective case series, clinical practice. PATIENTS: Five vitrectomized, diabetic, pseudophakic patients with persistent vitreous cavity hemorrhage remaining after vitrectomy were selected. They all had a posterior chamber IOL implant with an intact posterior capsule. Additionally, they had all undergone laser panretinal photocoagulation in the involved eye in the past for diabetic retinopathy. Neodymium:yttrium-aluminum-garnet laser capsulotomy outside the optic of the IOL was performed in victrectomized diabetic patients to treat the remaining vitreous cavity hemorrhage. Visual acuity, intraocular pressure (IOP), and fundus examination were measured and done immediately after the laser procedure, in 7 days and in approximately 3 months. RESULTS: The visual acuity was improved at the time of the first follow-up. However, a mild elevation of IOP was noticed in some patients, which was treated with topical dorzolamide. The final visual acuity was dramatically improved, to 20/30 or better, and the IOP was normalized without medication within a few weeks in all five cases. No neovascularization of the iris or elsewhere was noticed in any case. CONCLUSIONS: Neodymium:yttrium-aluminum-garnet laser peripheral capsulotomy appears to be a safe and effective management procedure in treating postvitrectomy hemorrhage in diabetic patients who have previously undergone cataract surgery with posterior chamber lens implant, intact posterior capsule, and extensive panretinal photocoagulation. The vitreous hemorrhage cleared completely in all five cases.     

Neodymium:yttrium-aluminum-garnet laser arteriotomy with embolectomy for central retinal artery occlusion

PURPOSE: To describe a patient with central retinal artery occlusion successfully treated with neodymium:yttrium-aluminum-garnet laser arteriotomy and embolectomy. DESIGN: Interventional case report. METHODS: A 77-year-old woman noted sudden loss of vision after vigorous coughing. A central retinal artery occlusion was diagnosed. Four hours after symptoms appeared, arteriotomy and embolectomy with neodymium:yttrium-aluminum-garnet laser was performed. RESULTS: Displacement of embolus outside the artery with return of retinal perfusion and recovery of vision. Laser treatment also resulted in vitreous hemorrhage and false aneurysm formation of the central retinal artery. CONCLUSIONS: Neodymium:yttrium-aluminum-garnet laser arteriotomy in a patient with central retinal artery occlusion resulted in extrusion of the embolus, reopening of the central retinal artery, and return of vision. This technique warrants further study as a primary treatment for this blinding disorder.     

Decreasing retinal photocoagulation damage: principles and techniques

Conventional suprathreshold retinal photocoagulation is a destructive procedure, but chorioretinal damage can be decreased by changing laser parameters and clinical endpoints. Laser effects can be localized by decreasing laser wavelength, spot size, and exposure duration, as well as by adopting threshold or subthreshold treatment protocols. Problems with short-pulse treatment regimens can be circumvented by the use of repetitively pulsed laser photocoagulators. Preliminary clinical results with reduced-damage photocoagulation methods are promising and await confirmation in larger, controlled clinical trials.     

VEGF-Inhibitoren im Rahmen vitreoretinaler Eingriffe

Vascular endothelial growth factor (VEGF) inhibitors are being used for an increasing number of indications. Beyond the classical use in exudative macular degeneration and macular edema, they are being used, for example off-label as additive treatment together with panretinal laser photocoagulation or in preparation for vitrectomy for ischemic retinopathy. In preparation for vitreoretinal surgery VEGF inhibitors are usually given prior to surgery. When given as an adjunct to laser treatment, VEGF inhibitors can be given either consecutively or parallel to laser photocoagulation. In most cases, however, anti-VEGF treatment does not render laser coagulation dispensable. The greatest danger with anti-VEGF treatment in the context of ischemic retinopathies lies in the fact that proliferative membranes are misjudged or overlooked. In these cases, anti-VEGF treatment can induce contraction of these membranes with induction of consecutive tractional retinal detachment. This review summarizes the current knowledge on VEGF inhibition as an adjunct to vitreoretinal surgery and also points out the gaps in the current knowledge and the need for further research.     

玻璃体视网膜手术治疗严重角巩膜裂伤的临床疗效

目的:探讨、评价并分析玻璃体视网膜手术治疗严重角巩膜裂伤的临床疗效。方法:对我院2009-03/2010-03住院的37例37眼角巩膜裂伤患者行玻璃体切割术治疗,根据术中视网膜情况辅以硅油充填、视网膜激光光凝。结果:手术后随访3～6(平均5)mo,随访中行视力、最佳矫正视力、眼压及眼底检查,部分患眼进行了眼B超、OCT和眼底照相检查。患者中31例31眼玻璃体腔清晰,视网膜复位良好,其中≥0.1者由术前2眼增加到术后的11眼,术后视力不同程度提高28例28眼,术后视力无变化3例3眼;6例6眼术前术后视力无光感,因术后眼球萎缩行眼球摘除联合义眼台植入。结论:玻璃体切割术是治疗严重角巩膜裂伤的有效方法。早期手术治疗,可使大多数患者术后患眼视功能改善,并发症少,手术安全有效。     

Modern retinal laser therapy

Medicinal lasers are a standard source of light to produce retinal tissue photocoagulation to treat retinovascular disease. The Diabetic Retinopathy Study and the Early Treatment Diabetic Retinopathy Study were large randomized clinical trials that have shown beneficial effect of retinal laser photocoagulation in diabetic retinopathy and have dictated the standard of care for decades. However, current treatment protocols undergo modifications. Types of lasers used in treatment of retinal diseases include argon, diode, dye and multicolor lasers, micropulse lasers and lasers for photodynamic therapy. Delivery systems include contact lens slit-lamp laser delivery, indirect ophthalmocope based laser photocoagulation and camera based navigated retinal photocoagulation with retinal eye-tracking. Selective targeted photocoagulation could be a future alternative to panretinal photocoagulation.     

Pharmacological treatment for retinopathy of prematurity

Mandatory screening performed by an experience ophthalmologist remains the most important pillar in the management of retinopathy of prematurity (ROP). The current gold standard for treatment of proliferative ROP is still panretinal laser photocoagulation, depending on severity, in combination with vitreoretinal surgery if necessary. The first case series of off-label intravitreal anti-VEGF treatment are encouraging. In addition to intravitreal anti-VEGF therapy, other treatment concepts such as supplementation with IGF-1 or omega-3 fatty acids also represent interesting pharmacological approaches to the management of ROP. However, larger controlled trials are required to validate the benefits and safety of these systemic treatment approaches.     

Pharmakologische Therapie der Fr��hgeborenenretinopathie

Mandatory screening performed by an experience ophthalmologist remains the most important pillar in the management of retinopathy of prematurity (ROP). The current gold standard for treatment of proliferative ROP is still panretinal laser photocoagulation, depending on severity, in combination with vitreoretinal surgery if necessary. The first case series of off-label intravitreal anti-VEGF treatment are encouraging. In addition to intravitreal anti-VEGF therapy, other treatment concepts such as supplementation with IGF-1 or omega-3 fatty acids also represent interesting pharmacological approaches to the management of ROP. However, larger controlled trials are required to validate the benefits and safety of these systemic treatment approaches.     

Lasers in cataract surgery

Several laser technologies including 1053-nm picosecond, excimer, erbium:yttrium-aluminum-garnet, and neodymium:yttrium-aluminum-garnet (Nd:YAG) have been studied for use in the removal of cataractous lens tissue. Nd:YAG laser phacolysis involves laser pulses striking a titanium target that are incorporated into an irrigation-aspiration probe. With further refinement, Nd:YAG laser phacolysis may provide an alternative means of lens removal through a small incision, however, further study is required.     

正确认识微脉冲激光治疗糖尿病性黄斑水肿的价值

微脉冲激光光凝是通过重复的阈值下极短脉冲光凝来降低组织损伤或实现选择性组织损伤的激光光凝方法.阈值下微脉冲激光与传统激光治疗糖尿病性黄斑水肿(diabetic macular edema,DME)具有相同的维持视力的作用,高密度/低强度微脉冲激光光凝可产生有效治疗效果的同时不对视网膜产生任何可检出的激光损害.微脉冲激光...     

Pilot randomized trial of a nanopulse retinal laser versus conventional photocoagulation for the treatment of diabetic macular oedema

Background: To assess the efficacy of a new nanopulse laser, retinal regeneration therapy for the treatment of diabetic macular oedema. Design: Randomized, non‐inferiority, trial. Participants: 20 eyes of 17 subjects in the retinal regeneration therapy group and 18 eyes of 14 subjects in the conventional group were analysed. Methods: The treatment group received retinal regeneration therapy laser, and the control group received photocoagulation. Main Outcome Measures: The primary outcome was the optical coherence tomography‐measured change in central retinal thickness at 6 months. A secondary outcome was the change in logarithm of minimum angle of resolution visual acuity at 6 months. Non‐inferiority required the one‐sided 95% confidence interval of the mean retinal thickness reduction after retinal regeneration therapy to be within 35 µm of the reduction after control laser. Results: When outliers were included in the dataset, the difference in retinal thickness reduction by analysis of covariance was 10.9 (standard deviation 17.6) mm in favour of the control laser. The difference between groups in retinal thickness reduction was 40.8 mm. If two extreme outliers were excluded, the difference was 5.6 (standard deviation 14.2) mm in favour of the retinal regeneration therapy laser, and the D optical coherence tomography was 18.5 mm. The visual acuity difference between groups was 0.059, meeting non‐inferiority requirements. Conclusions: Although retinal thickness reduction was not unambiguously non‐inferior, in the short‐term, retinal regeneration therapy approximates the clinical efficacy of conventional photocoagulation, stabilizing visual acuity and providing motivation for larger trials assessing retinal regeneration therapy.     

Retinal laser photocoagulation: Benefits and risks

Retinal photocoagulation has been used for approximately 20 yr to treat a number of diseases of the retina and choroid, primarily affecting the vascular systems of these tissues. Within the past 15 yr. lasers have become the preferred photocoagulation instruments. Large-scale controlled clinical trials have conclusively demonstrated their efficacy in the treatment of proliferative diabetic retinopathy. The usefulness of laser treatment in other diseases is suspected, but the evidence is not yet conclusive, and several other large clinical trials are now either in progress or in the final planning stages. Complications of photocoagulation therapy are numerous but in general mild, and the most severe complications are observed only rarely.     

Diabetic macular edema: classification,medical and laser therapy

Purpose. to propose and describe a new classification of diabetic macular edema (DME) based on its etiopathogenetic features and to present efficacy and safety data on medical and laser treatments currently used and under investigation. Methods. available literature on DME has been reviewed and information provided by contact lens biomicroscopy, fluorescein angiography and optical coherence tomomography has been combined; published data from trials and reports investigating effectiveness of medical and laser treatments were also analyzed. Results. DME was classified according to its main etiopathogenetic components: prevalently retinovascular, tractional and with taut attached posterior hyaloid, each of them having peculiar aspects on fundus, angiographic and tomographic examination. Focal laser treatment remains the only effective intervention, as shown by a large randomized controlled trial, but new less-invasive photocoagulation strategies (i.e., light laser photocoagulation and subthreshold micropulse diode laser) as well as pharmacological approaches (i.e., antioxidants, PKC inhibitors, aldose-reductase and AGE inhibitors, VEGF inhibitors, intravitreal triamcinolone) are emerging. Conclusions. based on our review a classification of DME was developed that may prove useful in making the appropriate treatment decision; the new laser and pharmacological treatments currently investigated are promising and need to be confirmed by large, controlled clinical trials.     

New aspects in the laser treatment of glaucoma

Over 50 papers, appearing between October 1989 and September 1990, were reviewed. Among these, 17 were found to be of interest and 2 of outstanding interest. Structural and molecular effects and prevention of postcoagulative pressure rises are discussed under the category of argon laser trabeculoplasty. Papers concerning the size of laser iridotomies and the assessment of their success are also reviewed. A size of at least 150 to 200 mum is recommended. The majority of recommended papers concern parameters for cyclophotocoagulation, clinically and experimentally. Papers on the topic of sclerostomy include one presenting clinical results of treatment with a neodymium:yttrium-aluminum-garnet laser ab interno and another presenting experimental investigation of a partial external trabeculectomy using the excimer laser.     

Ultrasound biomicroscopic evaluation of ciliochoroidal effusion after laser treatment.

We evaluated ciliochoroidal effusion (CE) by ultrasound biomicroscopy (UBM) following diode endophotocoagulation at the end of the vitreoretinal surgery. The aim of our study was to assess any differences in the CE morphology following diode endophotocoagulation or transpupillary krypton photocoagulation, and to demonstrate the influence of diabetes and intravitreal surgery on CE formation. Sixty-six consecutive patients were divided in to four groups. Twenty-nine patients with proliferative retinopathy underwent transpupillary krypton photocoagulation; 11 diabetic patients underwent vitreoretinal surgery and diode endophotocoagulation; 18 nondiabetics underwent vitreoretinal surgery and diode endophotocoagulation; 8 consecutive nondiabetic patients were the control group and underwent vitreoretinal surgery, without laser treatment. UBM was performed in the four groups before and after laser treatment, if performed. We determined, by UBM, not only the presence, but also the thickness of CE. CE was present in all the patients treated by laser, diabetics and nondiabetics, and its thickness was not correlated with the number of laser spots (p = 0.28). CE was seen ultrasonically in all the patients undergoing transpupillary photocoagulation or endophotocoagulation, regardless of diabetes and surgical trauma.     

Study of clinical applications and safety for Pascal® laser photocoagulation in retinal vascular disorders

Purpose: To establish safe laser parameter standards for 10–30 ms Pascal^® laser in clinical practice and to evaluate clinical and visual outcomes using this 532‐nm multi‐spot photocoagulation system. Methods: Retrospective observational case series of 313 patients treated between 2006 and 2008. Evaluation of eight groups: A – panretinal photocoagulation (PRP) for proliferative diabetic retinopathy (PDR); B – focal laser treatment for clinically significant diabetic macular oedema; C – grid laser for diffuse diabetic macular oedema; D – sector PRP for ischaemic branch retinal vein occlusions (I‐BRVO); E – full PRP for ischaemic central retinal vein occlusions (I‐CRVO); F – macular laser treatment for macular oedema secondary to non‐ischaemic BRVO; G – full PRP for rubeosis iridis and/or neovascular glaucoma (NVG) secondary to I‐BRVO, I – CRVO or PDR; H – laser retinopexy for retinal breaks/degenerations. Results: Mean LogMAR visual acuity for all procedures improved postlaser (p = 0.065), and laser prevented visual loss in 85% eyes. Topical anaesthesia was only required. At mean follow‐up of 5 months, 72% procedures had a successful clinical outcome. Significantly higher powers were required for PRP using Pascal^® compared to conventional laser (p = 0.001) in PDR, I‐BRVO, I‐CRVO and NVG. Sixty‐seven per cent of patients (15/20) were successfully treated with single‐session 20‐ms PRP using a mean 1952 burns. There were no laser‐associated adverse effects or ocular complications associated with multi‐spot PRP or macular Pascal^® arrays. Conclusions: The clinical efficacy using 10‐ to 30‐ms pulse duration Pascal^® laser is comparable to conventional standard protocols used for the treatment of vascular retinal disorders. Higher power, 10‐ to 30‐ms pulse duration laser may be safely and effectively used in clinical practice.     

Laser treatment of glaucoma

The authors review the literature published between October 1990 and September 1991 on laser treatment of glaucoma. In particular, they assess their experience and that of other authors regarding both the various types of laser (argon, neodymium:yttrium-aluminum-garnet, diode, pulsed dye, and excimer) and the application techniques (iridotomy, goniotomy, gonioplasty, trabeculoplasty, trabeculopuncture, transpupillary cyclophotocoagulation, transscleral cyclophotocoagulation, sclerostomy, suture lysis, and trabecular ablation) for the parasurgical treatment of glaucoma.     

Ophthalmic laser microendoscope endophotocoagulation.

PURPOSE: The purpose of this article is to describe the function of the ophthalmic laser microendoscope as it pertains to endophotocoagulation in the management of vitreoretinal disease. METHODS: Fifty-four consecutive vitrectomies with endophotocoagulation were performed using the ophthalmic laser microendoscope instead of endoillumination and endophotocoagulation probes. Intraoperative and postoperative efficacy and complications were evaluated. RESULTS: The ophthalmic laser microendoscope was used to illuminate and view the retina and to deliver diode laser energy in the management of posterior retinal breaks, proliferative retinopathies, and proliferative vitreoretinopathy. The technique of endophotocoagulation was similar to that used routinely in vitreoretinal surgery. The photocoagulation lesions that were created were identical to those delivered by standard endophotocoagulation probes. Intraoperative complications were few, consisting of transient mild retinal or choroidal hemorrhages. Severe postoperative complications related to endophotocoagulation or to use of the ophthalmic laser microendoscope were not observed. CONCLUSION: The ophthalmic laser microendoscope appears to be a safe and effective method of delivering diode laser energy to the retina while simultaneously providing illumination, video recording, and a clear endoscopic view despite anterior segment conditions that might otherwise preclude adequate visualization and treatment. Fewer instrument insertions/removals were required for endophotocoagulation. Post-treatment search for peripheral iatrogenic retinal breaks was accomplished by endoscopy.