Transpupillary Diode Laser Research Articles

Transscleral vs transpupillary diode laser photocoagulation for the treatment of zone II type 1 retinopathy of prematurity: Anatomical and refractive outcomes.

Purpose:To compare the anatomical and refractive outcomes of transscleral diode versus transpupillary laser photocoagulation for the treatment of zone II type 1 retinopathy of prematurity (ROP).Methods:In this prospective comparative interventional case series, infants with type 1 ROP in zone II were assigned to either transpupillary or transscleral laser based on the surgeons’ expertise area. The rate of regression, need for retreatment, and structural and biometric outcomes at month 6 were evaluated and compared between the two treatment groups.Results:In total, 209 eyes were enrolled; 145 eyes of 77 infants and 64 eyes of 33 infants and were in transscleral and transpupillary groups, respectively. There was no significant difference in baseline characteristics between the groups. There was no significant difference in retreatment rates (1.6% vs. 3.4%; P = 0.669) and progression to stage 4 (1.6% vs. 2.8%; P = 0.999) between the transpupillary and transscleral groups, respectively. At month 6, the mean spherical equivalent was 0.31 ± 3.57 and 0.44 ± 2.85 diopters, and the axial length was 18.28 ± 6.22 and 18.36 ± 6.87 mm in the transpupillary and transscleral groups, respectively, without a significant difference between groups. There was no significant difference in the rate of myopia (43.8% vs. 33.8%; P = 0.169) and high myopia (4.7% vs. 4.8%; P = 0.965) in transpupillary and transscleral groups at month 6.Conclusion:The transpupillary and transscleral laser photocoagulation routes are both effective in the treatment of zone II type 1 ROP and show no significant differences in anatomical or refractive outcomes in relation to the route chosen.

Retinal choroidal and retinal nerve fiber layer thickness in former preterm and full-term infants aged 4 to 8years.

To compare the retinal thickness at the fovea center, peripapillary retinal nerve fiber layer (RNFL) thickness and choroidal thickness (CT) in former preterm and full-term infants. A total of 121 healthy children aged 4-8years were divided 4 groups: group 1; children born on time, group 2; preterm children without a history of retinopathy of prematurity (ROP), group 3; preterm children with a history of spontaneously regressed ROP and group 4; preterm children who underwent diode laser photocoagulation for ROP. The retinal thickness at the fovea, peripapillary RNFL thickness at global, superior, inferior, nasal and temporal quadrants and submacular CT at 7 different points were measured by using spectral-domain optical coherence tomography. The mean retinal thickness at the fovea center was statistically higher, whereas the mean RNFL thickness values in global, nasal, superior and inferior quadrants were statistically lower in group 4. No difference was found in the mean submacular CT value of any point between the groups. Transpupillary diode laser photocoagulation treatment for ROP seems to cause an increase in macular thickness and a decrease in RNFL thickness.

Bedside Diode Laser Photocoagulation Under Remifentanil Analgesia for Retinopathy of Prematurity: Early Structural Outcomes.

Objectives:To evaluate one-year structural outcomes of bedside diode laser photocoagulation with remifentanil analgesia for retinopathy of prematurity (ROP) and discuss clinical and demographic characteristics of infants and other possible risk factors that may affect the outcome.Materials and Methods:The medical records of premature infants who were treated with bedside transpupillary diode laser photocoagulation under remifentanil analgesia for ROP were evaluated for clinical and demographic characteristics, accompanying systemic risk factors, laser parameters, complications of treatment, retreatment rate and one-year structural outcomes.Results:One-hundred and ninety-five eyes of 99 infants (59 males, 40 females) were recruited for the study. The mean gestational age and birth weight were 27.4±2.3 weeks (23-34) and 1003.3±297.8 g (570-2250), respectively. Laser therapy was performed for high-risk prethreshold ROP in 66.2% of eyes, aggressive posterior ROP (APROP) in 15.4% and threshold ROP in 18.4%. The mean number of laser spots was 1510.4±842.1 per laser session. No adverse effects of laser photocoagulation were observed except small lens opacities in two eyes and corneal opacity in one eye. Retreatment was needed in only three eyes, and vitreoretinal surgery was needed in six eyes of six patients despite laser treatment. Anatomic outcome was favorable in 189 eyes (96.9%) at the end of a 1-year follow-up. Presence of dilated and tortuous iris vessels (p=0.002) and tunica vasculosa lentis (p=0.009) along with type of ROP (APROP and stage 4a ROP at initial presentation) (p=0.001) were associated with poor anatomical outcome.Conclusion:Accurate and timely bedside transpupillary diode-laser photocoagulation under remifentanil analgesia is an effective and safe treatment modality for ROP, and may prevent vision-threatening retinal detachment and reduce the need for vitreoretinal surgery.

Anterior segment ischemia following diode laser photocoagulation for aggressive posterior retinopathy of prematurity.

To describe the clinical and demographical characteristics and treatment outcomes of the premature infants who were presented with the signs of anterior segment ischemia (ASI) following transpupillary diode laser photocoagulation for aggressive posterior retinopathy of prematurity (APROP). The records of the premature infants who developed ASI following bilateral laser photocoagulation between November 2010 and December 2013 in a single institution for the treatment of APROP were retrospectively reviewed. The clinical and demographical characteristics, laser parameters, anterior segment complications, and structural outcomes were evaluated. Nine eyes of five infants (three males, two females) were recruited for the study. Mean gestational age (GA), birth weight (BW), and postmenstrual age (PMA) at the time of laser ablation were 28.2 ± 2.5 weeks, 1,287.0 ± 483.4 g and 34.8 ± 2.2 weeks, respectively. All eyes were treated with a near-confluent pattern of laser ablation. Several anterior segment complications were observed including corneal edema (nine eyes), posterior synechia (nine eyes), pupillary membranes (five eyes), shallow anterior chamber (three eyes), hyphema (three eyes), and focal lens opacities (two eyes), of all resolved completely. Permanent dense cataracts observed in two eyes of two infants who were scheduled for lensectomy and anterior vitrectomy. None of the eyes progressed to phthisis bulbi. Anterior segment ischemia after laser treatment of APROP is a rarely encountered clinical entity. Mild and transient cases may resolve without any long-term sequelae but severe ones may progress to permanent cataract requiring further surgery.

Diode Laser Photocoagulation for Retinopathy of Prematurity: Outcomes After 7 Years of Treatment

This study aimed to evaluate the outcome of transpupillary diode laser photocoagulation for retinopathy of prematurity (ROP) at one institution in Romania. This retrospective case series included all infants who received indirect diode laser photocoagulation for ROP between January 1, 2006, and December 31, 2012. The 160 eyes of 83 infants were classified into two categories: 136 eyes (85%) with classic disease (stage III ROP in zones 1 or 2) and 24 eyes (15%) with aggressive posterior ROP (AP-ROP). ROP regressed in 141 eyes (88.12%). The success rate was significantly better in the classic ROP group (94.11%) compared to the AP-ROP group (54.16%) (P < .001). The ROP regression rate after the laser treatment was 88% in this series.

Outcome of transpupillary diode laser photocoagulation for retinal diseases

Background: Diode lasers have been used in ophthalmic practice for several years. They are useful in the management of vasoproliferative retinopathies and have been shown to be comparable in efficacy to the argon laser. Aim: To report on the outcome of transpupillary diode laser treatment for retinal diseases. Patients and Methods: A retrospective study carried out using the case files of patients that had retinal diode laser photocoagulation between June 2011 and May 2012 at the Jos University Teaching Hospital, Jos, Nigeria. Information retrieved included patients' age, sex, diagnosis, indication for retinal laser photocoagulation, prelaser and postlaser visual acuity (VA), best corrected VA, and operative complications. Results: A total of 31 eyes of 21 patients had transpupillary retinal laser photocoagulation during the study period. The commonest indication for retinal laser photocoagulation was proliferative diabetic retinopathy (PDR), and this was seen in 16 eyes (52%). Six eyes (19%) had both PDR and clinically significant macular edema (CSMO), while 3 eyes had CSMO only. Other indications were retinal vein occlusion (RVO) with secondary neovascularization (four eyes), proliferative sickle cell retinopathy (one eye), and traumatic retinal tear (one eye). Following laser therapy in those with diabetic retinopathy, VA improved by at least a line in 6 eyes, remained the same in 13 eyes, and deteriorated in 2 eyes. Neovascular regression was observed in 13 eyes and resolution of macular edema in 3 eyes. In the eyes with RVO, neovascular regression was observed in two eyes. Conclusion: Transpupillary diode laser photocoagulation was beneficial in the treatment of retinal diseases. Fibrovascular proliferation with significant fibrous tissue component was, however, associated with poor response to laser treatment in proliferative retinopathies.

Transscleral diode laser retinal photocoagulation for the treatment of threshold retinopathy of prematurity

To evaluate the outcomes of transscleral diode laser photocoagulation for treatment of threshold retinopathy of prematurity (ROP). Retrospective interventional case series of infants with ROP treated at our center with transscleral diode laser retinal photocoagulation. All patients were followed for 2 months, and regression of ROP, unfavorable outcomes, and incidence of adverse effects were assessed. A total of 103 eyes of 52 infants with ROP at the threshold stage were treated with transscleral diode laser photocoagulation under topical anesthesia, without conjunctival incision. Supplemental transpupillary diode laser photocoagulation was used for posterior zone 2 and zone 1 in 5 eyes. In 99 eyes (96.1%) neovascularization regressed completely; in 96 eyes (93.2%) the outcome was favorable. In the other 3 eyes, macular dragging formed after regression of neovascularization. Four eyes progressed to more advanced stages of ROP. Repeated laser therapy was performed with the same technique in 10 eyes (9.6%). There was no statistically significant association of unfavorable outcomes with age, birth weight, gestational age, clocks of retinal involvement, and rush disease. No adverse effects of diode laser treatment were observed except for mild injection and edema of conjunctiva in all patients, small conjunctival lacerations in 10 eyes, and small self-limited vitreous hemorrhage in 2 eyes. Transscleral laser treatment may be technically easier for the treatment of retinal periphery, especially in poorly dilating pupils, and obviates the occasional anterior segment complications of the transpupillary approach. This technique can be performed under topical anesthesia.

Involution of threshold retinopathy of prematurity after diode laser photocoagulation

Objective To characterize the process of involution of threshold retinopathy of prematurity after transpupillary diode laser photocoagulation. Design Retrospective case series. Participants Neonates with threshold retinopathy who underwent diode laser photocoagulation of the peripheral avascular retina. Methods A retrospective chart review was done of the weekly examination records of infants treated for threshold disease. Features that were studied included the presence of residual stage 3 neovascularization, plus disease, and development of retinal detachment (RD). Main outcome measures Timing of full involution and/or development of an RD. Results Of 262 eyes of 138 infants treated, full involution without RD was seen in 8%, 43%, 64%, 73%, and 86% of eyes at postoperative weeks 1, 2, 3, 4, and 9±3, respectively. Retinal detachments were diagnosed cumulatively in 0%, 1.5%, 4.2%, 6.5%, and 14% of eyes at weeks 1, 2, 3, 4, and 9±3, respectively. Conclusions Full involution of laser-treated threshold retinopathy of prematurity required more than 2 weeks in more than half of treated eyes. Most RDs were not detected until ≥3 weeks after treatment.

Transpupillary diode laser retinopexy in dogs: ophthalmoscopic, fluorescein angiographic and histopathologic study.

To evaluate the ophthalmoscopic, fluorescein angiographic and light microscopic effects of diode laser retinopexy application in the tapetal and nontapetal fundus in the dog, and to ascertain appropriate laser power settings for production of photocoagulative lesions in these two regions. Three adult female Beagle dogs. Laser burns were applied to selected areas in the fundus with an indirect headset delivery system using settings varying from 100 to 200 milliWatts (mW) and from 100 to 600 milliSeconds (mS) with total delivered energy ranging between 15 and 100 milliJoules (mJ). The dogs were then monitored by ophthalmoscopic examination and fluorescein angiography at regular intervals for 7-28 days. Histopathologic studies were performed at 7, 14 and 28 days after laser application. The diode laser produced ophthalmoscopically visible lesions in the nontapetal fundus with all laser settings used, and the appearance of these lesions corresponded to the energy levels used, and degree of pigment in the lased region. Gray-white colored lesions with minimal subsensory retinal edema were seen with settings as low as 100 mWatts/150 mSeconds. In the tapetal fundus, laser burns were more difficult to produce, less repeatable, and required higher energy levels. Laser burns appeared as bronze, dark green or black discolorations of the tapetum with varying degrees of subsensory retinal edema. Lesions were more reproducible and were achieved with lower settings in the tapetal area of the tapetal/nontapetal junction. Ophthalmoscopically, depigmentation and repigmentation of the RPE (nontapetal fundus) and degenerative changes in the overlying retina (tapetal fundus) developed in the laser burns over the 28-day study period. Fluorescein angiographic studies showed disruption of the blood-retinal barrier at the level of the RPE and fluorescein leakage into the subsensory retinal space was seen in most lesions at 24 h, was minimal at 3 days, and had resolved by 7 days. Histologically, grayish-white lesions in the nontapetal fundus, and bronze to small black lesions in the tapetal fundus were typically characterized by outer retinal necrosis and RPE migration. Gliosis was considered minimal, was confined to the retina, and no inflammatory cells were seen. Peripheral intense white lesions (nontapetum) and lesions with a black center (tapetal fundus) were characterized by more extensive panretinal and choroidal necrosis. Most of the nontapetal lesions and a few in the tapetal fundus showed the formation of a central retinal detachment. The diode laser effectively produces lesions suitable for retinopexy in both the nontapetal, pigmented fundus and the tapetal fundus, although variably so in the latter region. Initial laser settings of 100-150 mW/200 mS for the pigmented fundus, and 150 mW/200-300 mS for the peripheral tapetal fundus are recommended, and the clinician should gradually increase time interval settings to achieve a grayish-white lesion in the nontapetum, and a bronze to slightly black lesion in the tapetal fundus. If possible, retinopexy should be applied to the peripheral tapetal area or tapetal/nontapetal junction.

Choroidal neovascular membrane associated with optic nerve coloboma in a patient with CHARGE association

Purpose To report a patient with CHARGE association ( coloboma, heart disease, choanal atresia, growth retardation, genital hypoplasia, and ear abnormalities) who developed a choroidal neovascular membrane in association with an optic nerve coloboma. Design Interventional/observational case report. Methods A 21-month-old boy with CHARGE association developed a grayish choroidal neovascular membrane associated with lipid exudation, subretinal fluid, and retinal hemorrhage at the temporal edge of his right optic nerve coloboma. Results The patient underwent transpupillary diode laser of the choroidal neovascular membrane. Five months later, it and the serous retinal detachment had resolved. Conclusions Patients with CHARGE association may develop choroidal neovascular membrane with serous retinal detachments in association with optic nerve colobomas. These neovascular membranes may be treated successfully with transpupillary diode laser.

Acquired cataracts after diode laser photocoagulation for threshold retinopathy of prematurity

Purpose To report the incidence of acquired cataract after diode laser photocoagulation for threshold retinopathy of prematurity at our institution. Design Retrospective, noncomparative, interventional case series. Participants One hundred fifty-three infants (293 eyes) with threshold retinopathy of prematurity. Intervention Transpupillary diode laser photocoagulation. Main outcome measure Acquired cataract formation. Results One cataract (0.003%) in 293 eyes occurred after transpupillary diode laser photocoagulation. This cataract consisted of peripheral cortical punctate lenticular opacities that were not progressive or visually significant. Conclusions The risk of acquired cataract after transpupillary diode laser photocoagulation for threshold retinopathy of prematurity is low. Transpupillary diode laser photocoagulation may be safer than argon laser photocoagulation for treatment of threshold retinopathy of prematurity.

Therapeutic outcomes of cryotherapy versus transpupillary diode laser photocoagulation for threshold retinopathy of prematurity

Introduction: We undertook this study to compare the clinical outcomes in patients treated for threshold retinopathy of prematurity (ROP) with transpupillary diode laser photocoagulation versus transscleral cryotherapy. Methods: A retrospective chart review was performed of patients treated for threshold ROP at our institution between 1988 and 1997. Cryotherapy was used to treat patients before 1992, and diode laser was used thereafter. One hundred fifteen eyes of 63 patients underwent cryotherapy, and 130 eyes of 70 patients underwent laser treatment. Because strong concordance exists between fellow eyes treated for ROP, statistical analysis was done for right eye outcomes only. Demographics, short-term complications, and treatment parameters were compared on the entire cohort of patients. Structural outcomes were compared between a group of 79 cryotreated eyes (39 OD, 40 OS) and a group of 113 laser-treated eyes (56 OD, 57 OS). Mean cycloplegic refraction was compared between a group of 38 cryotreated eyes (18 OD, 20 OS) and a group of 90 laser-treated eyes (46 OD, 44 OS). Visual acuity for preverbal and nonverbal children was estimated and converted to a Snellen visual acuity equivalent. Geometric mean visual acuity was then compared between a group of 44 cryotreated eyes (22 OD, 22 OS) and a group of 92 laser-treated eyes (47 OD, 45 OS). Patients were included in each outcome analysis if adequate documentation was present in the patient record. Results: Demographics and short-term complications were not significantly different between the 2 groups. In the statistical group, 22 of 39 right eyes (56.4%) in the cryotherapy group versus 49 of 56 right eyes (87.5%) in the laser group had resolution of ROP after treatment ( P = .0008). Mean spherical equivalent cycloplegic refraction at 12 months of age and over the follow-up period was not significantly different between the cryotherapy and laser groups. Estimated geometric mean visual acuity in the cryotherapy group was 20/103 and in the laser group was 20/49 at 12 months of age ( P = .0099). Conclusions: Diode laser photocoagulation was associated with a better long-term structural outcome and visual acuity compared with cryotherapy for the treatment of threshold ROP. Refractive error was not significantly different between the 2 groups over an equivalent follow-up period. (J AAPOS 1999;4:234-40)

Postvitrectomy hypotonia : the role of the vitreous and retinochoroidal lesions

The pathomechanisms of hypotonia after vitrectomy remain obscure. To examine the possible escape of intraocular fluid through the ocular wall, hydraulic fluid conductivity was measured across preparations of retina, pigmented epithelium, and choroid isolated from rabbit eyes 1, 3, 5, or 7 weeks after the production of laser or cryopexy lesions. The hydraulic conductivity measured in a modified Fischbarg-Bourguet chamber, was 0 in controls. At 1 and 3 weeks after transpupillary diode laser coagulation of the equatorial retina, hydraulic conductivity was measurable. However, the conductivity of these preparations returned to 0 by 5 weeks. After transscleral cryopexy, conductivity remained elevated for 7 weeks. Break-up of residual cortical vitreous with hyaluronidase increased the conductivity of "mature" cryopexy lesions to the values obtained 1 week after injury. These results suggest that there is escape of fluid across retinochoroidal lesions; fluid conductance typically decreases over time; an intact cortical gel can hinder conductance and seal the retinochoroidal leak. Thus, the risk factors for hypotonia appear to include extensive retinochoroidal lesions and the absence of a normal cortical vitreous in aphakia and/or after aggressive vitrectomy.

Histopathologic and ultrastructural findings of photocoagulation lesions produced by transpupillary diode laser in the rabbit retina.

Transpupillary retinal photocoagulations were performed on ten eyes of five pigmented rabbits using a diode laser (Nidek Co., LTD, Aichi, Japan) emitting infrared radiation at 800 nm wavelength. A histological and an ultrastructural study on the treated eyes were done at 1, 3, 5, and 7 days after retinal photocoagulations. The purpose of this study was to observe the sequential changes in the retina and the choroid following transpupillary diode laser retinal photocoagulations at the parameters of laser power which produced a grayish white retinal discoloration with distinct white center. It seemed that the lesion was grade 3 retinal photocoagulation by Tso et al's classification. It appeared that the parameters necessary to produce grade 3 photocoagulation lesions were 160 mW power, and 0.2 second duration at 200 microns size. In general, with an agreement to other reports, histologic study of the diode laser lesions showed that the outer retina was damaged more severely than the inner retina. However, on day 1 after laser treatment, the alterations were more profound in the inner retina than in the outer retina and an occasional swelling of the axons in the nerve fiber layer was observed on the ultrastructural study. The results observed have not been found in other previous studies and suggest that the inner retina might be injured directly by 800 nm wavelength diode laser radiations. Thus we could conclude that 800 nm wavelength diode radiation might be absorbed by melanin pigment and also by other chromophores contained in inner retinal tissues. Further studies must follow to verify the laser-tissue interactions in diode laser retinal photocoagulations.

Histopathologic characteristics of diode laser-induced chorioretinal adhesions for experimental retinal detachment in rabbit eyes.

A retinal break and localized retinal detachment were induced in 10 rabbit eyes. The retinal break was treated within regions of detached retina using diode laser transscleral retinopexy (four eyes), diode laser indirect ophthalmoscopy (two eyes), or retinocryopexy (two eyes). Two eyes were left as untreated controls. The clinical and histopathologic effects were studied 1 day and 3 weeks after initial treatment. Suitable chorioretinal adhesions were induced with all treatment modalities. The extent of tissue effects was greater in cryopexy and smaller in laser treatment. The histopathologic characteristics of the lesions induced by diode laser indirect ophthalmoscopy were similar to those seen with transscleral diode treatment and were more focal than those seen with cryopexy. Transscleral and transpupillary diode laser photocoagulation were effective in inducing chorioretinal adhesions in detached retina in this experimental model in rabbits.

Clinicopathologic Correlation of Diode Laser Burns in Monkeys

One hundred twenty-five retinochoroidal photocoagulation burns, produced by a transpupillary diode laser (810 nm) in six eyes of three cynomolgus monkeys, were evaluated by clinicopathologic correlation for up to 9 weeks after laser treatment. Diode burns of clinical grade 2 strength were comparable to those described for argon laser. However, diode burns of clinical grade 3 strength produced choroidal changes more intense than those described for argon laser. Where present underneath photocoagulation sites, ciliary nerves in choroid or sclera consistently showed scarring. Prospective randomized controlled clinical trials to document possible clinical equivalence or superiority of diode treatment have not yet been performed. Potential clinical advantages of the diode laser include its weight, size, durability, price, absence of visible flash, and its ability to produce burns that profoundly affect the choroid.

Semiconductor Diode Laser Photocoagulation in Retinal Vascular Disease

The authors successfully performed clinical transpupillary retinal photocoagulation in 30 eyes of 26 patients with retinal vascular disease using a gall ium-aluminum-arsenide (GaAIAs) diode laser emitting at 805 nm. Retinal photocoagulation was performed at treatment powers of 300 to 1300 mW and exposure durations of 0.2 to 0.5 seconds with a 200-µm diameter treatment spot. Patients treated with both diode and argon green lasers required 4.5 ± 1.8 times greater mean laser energy with diode compared with argon to create ophthalmoscopically similar lesions. Parallel experimental retinal photocoagulation in Chinchilla rabbits required 3.1 ± 0.9 times more power to create ophthalmoscopically similar lesions with the diode laser than with the argon laser. Intraoperative subretinal hemorrhage occurred rarely in patients with an incidence of 4 (0.044%) of 9021 treatment spots. Patients complained of moderate-tomarked pain in 10 (43%) of 23 treatments initiated under topical anesthesia. A transpupillary diode laser may be used clinically to perform therapeutic retinal photocoagulation.