Effects of Green Diode Laser in the Treatment of Pediatric Coats Disease


To review the effect of green diode laser ablation therapy on retinal structure and functional outcome in patients with advanced Coats disease.


Retrospective, interventional case series.


Fourteen eyes of 13 patients with Coats disease were included in this study. Medical records, Retcam photographs (Clarity Medical Systems, Pleasanton, CA), and fluorescein angiograms were reviewed. All patients initially were treated with green diode laser (532 nm) ablation therapy to areas of the retinal telangiectasis associated with exudation. Main outcome measures included visual acuity, treatment outcome defined as complete resolution of telangiectatic lesions or exudative detachment, and macular status at the end of follow-up.


Before treatment, 1 eye was at stage 2 (telangiectasis and exudation), 12 eyes were at stage 3 (exudative retinal detachment), and 1 eye was at stage 4 (total retinal detachment with glaucoma). Five eyes had highly detached retina of more than 4 mm. Median age at diagnosis was 51 months (range, 0.5 to 153 months). Median follow-up was 39.5 months (range, 15 to 70 months). Median number of green diode laser photocoagulation treatments was 2 (range, 1 to 5). After laser photocoagulation, 13 (93%) of 14 eyes had no active exudation. Functionally, 4 (29%) of 14 eyes had 20/50 or better visual acuity, 3 (21%) of 14 eyes had 20/60 to 20/200 visual acuity, 5 (36%) of 14 eyes had 20/400 to light perception visual acuity, and 2 (14%) of 14 eyes had no light perception visual acuity. No eye was phthisical or enucleated.


Green diode laser therapy can be an effective treatment for advanced Coats disease, even in the presence of a moderate to severely elevated retinal detachment.

Coats disease is an idiopathic condition characterized by vascular abnormalities of the retina that classically presents as telangiectatic and aneurysmal retinal vessels associated with subretinal and intraretinal exudation and often subtotal or total exudative retinal detachment. The most common complication of Coats disease is progressive exudative retinal detachment. Less common but severe complications include iris neovascularization, neovascular glaucoma, and anterior chamber cholesterolosis. It typically is characterized by unilateral (approximately 80% of cases) retinal involvement in young males, with the disease being 3 times more prevalent in males than females. No racial or ethnic association has been established.

The current standard treatment is laser therapy for mild to moderate cases, and cryotherapy, surgical repair, or both for moderate to severe cases. In the past, these treatments have been only somewhat successful in achieving structural improvement or disease resolution. In the largest study to date (n = 124 eyes) using laser, cryotherapy, and surgical repair, 76% of patients achieved structural improvement or stability. Another recently published case series that used infrared laser therapy alone for all stages showed structural improvement in 82% of patients. Herein, we report our experience in treating a consecutive series of patients with Coats disease using green diode laser therapy.


Patients diagnosed with Coats disease and treated with laser from September 2002 through May 2008 at the University of Illinois Eye & Ear Infirmary Retinal Service were identified from a database. Patient age, gender, ethnicity, age at presentation, disease stage at presentation, number and dates of laser therapies, and final treatment and structural outcomes were recorded. All patients were diagnosed, managed, and treated by 1 physician (M.J.S.) at the University of Illinois Eye & Ear Infirmary. While the patients were under anesthesia, the green diode laser ablation therapy was directed to vascular abnormalities, including microaneurysms, macroaneurysms, telangiectatic vessels, and feeding and draining vessels in areas of the retinal exudation. The laser used was a 532-nanometer green diode laser (Iridex Corporation, Mountain View, CA). The specifics of the laser treatment in this study were as follow: each treatment was performed using indirect ophthalmoscopy delivery and 28- and 20-diopter lenses. The console settings began at 200 mW, with a duration of 1000 ms. The interval was controlled by foot pedal and was cycled rapidly to produce a near continuous treatment. The power was titrated higher until vessel whitening was achieved, which generally occurred at 400 to 750 mW; however, in some cases, power as high as 1000 mW was needed. The higher settings were used for treating blood vessels in more highly elevated retina. Patients were followed up regularly with examination under anesthesia, and additional green diode laser ablative therapy was applied at each visit until a treatment end point was reached. The positive end point was complete resolution of the disease as defined by reattachment of the retina or resolution of exudation as evidenced by absence of leaking telangiectasis on fluorescein angiography, and the negative end point was continued exudation with laser treatment deemed to be providing no beneficial effects. Retcam (Clarity Medical Systems, Pleasanton, CA) photography and fluorescein angiography were performed for documentation, comparison, and staging purposes.

Structural assessment on presentation was based on the Coats staging classification previously described ( Table 1 ). The staging was carried out by 1 physician (M.P.B.) retrospectively based on Retcam photographs. Highly elevated retinal detachment was defined as that of more than 4 mm in elevation by ultrasound or indirect ophthalmoscopy. Macular status at final outcome was described as normal, macular atrophy, subretinal fibrosis, or tractional detachment by 2 physicians (M.J.S. and M.P.B.) based on Retcam photographs at final follow-up.


Structural Staging Classification in Coats Disease

Stage Description
0 Regressed; no telangiectasia/exudation
1 Retinal telangiectasia only
2 Telangiectasia and exudation
2A Extra-foveal exudation
2B Foveal exudation
3 Exudative retinal detachment
3A1 Extra-foveal detachment only
3A2 Foveal detachment
3B Total retinal detachment
4 Total retinal detachment and glaucoma
5 Advanced end-stage disease

Classification based on Shields JA, et al.


Fourteen eyes of 13 patients were identified. Table 2 outlined the clinical characteristics of the patients in this study. Sixty-two percent of patients were male and 1 female patient had bilateral disease (eyes 1 and 12). Two female patients had Coats disease associated with extraocular syndromic elements. The median and mean age at diagnosis was 51 months and 57 months, respectively (range, 0.5 to 153 months). The median and mean length of follow-up was 39.5 months and 41 months, respectively (range, 15 to 70 months). The median and mean number of laser treatments applied to each patient was 2 and 2.4, respectively (range, 1 to 5). At diagnosis, 1 eye (7%) had extrafoveal exudation only (stage 2A), 8 eyes (57%) had foveal subtotal retinal detachment (stage 3A2), 4 eyes (29%) had total retinal detachments (stage 3B), and 1 eye (7%) had a total retinal detachment and glaucoma (Stage 4). Five (36%) of 14 eyes had a highly elevated retinal detachment. Figure shows representative cases in this series.


Green Laser for Pediatrics Coats Disease: Patient Characteristics and Outcome

Eye Gender Ethnicity Eye Age at Dx VA at Dx Stage a at Dx No. of Treatments F/U Length (mo) IOP at Final F/U Treatment Endpoint Functional Outcome (Final VA) Structural Outcome Complications
1 F Caucasian OS 1 y 5 mo n/a 2A 2 43 21 No exudation 20/25 Normal None
2 M African Am OD 0.5 mo CF 3B 1 32 20 No exudation 20/200 Moderate atrophy None
3 M Caucasian OD 12 y 6 mo 20/200 3A2 1 27 7 No exudation 20/50 Mild atrophy None
4 M Caucasian OD 8 y 9 mo 20/40 3A2 3 54 14 No exudation 20/30 Normal None
5 F Caucasian OS 3 y 8 mo CF 3B 3 70 14 No exudation 20/400 Mild subfoveal fibrosis None
6 M African Am OS 4 y 7 mo CF 3A2 2 57 17 No exudation CF Moderate subfoveal fibrosis None
7 M Caucasian OS 11 y 10 mo 20/60 3A2 3 15 14 No exudation 20/40 Normal None
8 F Hispanic OD 12 y 9 mo 20/400 3A2 1 57 14 No exudation 20/200 Mild atrophy None
9 M Caucasian OS 2 y 2 mo n/a 3A2 b 5 33 13 No exudation NLP Tractional detachment None
10 M Caucasian OD 6 y 1 mo CF 3A2 b 3 36 8 No exudation 20/160 Moderate subfoveal fibrosis None
11 F African Am OD 4 y 8 mo No F/F 3A2 2 49 20 No exudation LP c Mild atrophy None
12 F Caucasian OD 1 y 5 mo n/a 3B b 2 43 21 No exudation LP Moderate atrophy Cataract (mild)
13 F Hispanic OD 11 mo n/a 3B b 2 31 28 No exudation HM Moderate atrophy Cataract
14 M Caucasian OD 1 y 2 mo n/a 4 b 4 30 35 Persistent exudation NLP Tractional detachment Cataract
Mean 4 y 9 mo 2.4 41

Eye 1 and 12 are from the same patient who has bilateral disease.

CF = count fingers; Dx = diagnosis; F = female; F/U = follow up; HM = Hand motion; LP = Light perception; M = male; mo = month; n/a = not available; NLP = no light perception; RD = retinal detachment; y = year.

a Staging was based on previous published literature. See Table 1 .

b Indicates presence of highly elevated retinal detachment of >4 mm by ultrasound or indirect ophthalmoscopy.

c Patient has developmental delay.


Images from representative cases demonstrating effects of green laser photocoagulation in advanced Coats disease. (Top row far left) Eye 11 at diagnosis showing exudation involving the fovea and retinal detachment temporally. (Top row near Left) Two months after treatment with residual exudation and elevation. (Top row near right) Ten months after initial treatment with residual exudation but no elevation. Second laser treatment was applied at this visit. (Top row far right) Seventeen months after initial treatment showing complete resolution of exudation and elevation. Visual acuity was at least light perception (patient had developmental delay precluding Snellen testing). (Second row far left) Eye 10 at diagnosis showing exudation involving the fovea and highly elevated exudative detachment temporally. Laser was applied at diagnosis and at 2 months. (Second row near left) Four months after initial treatment with improvement of elevation but residual exudation remaining. (Second row near and far right) Fourteen months after treatment with no active exudation. Moderate subretinal fibrosis in the macula was present. Visual acuity was 20/160. (Third row far left) Eye 12 at diagnosis showing total retinal detachment with massive exudation and telangectatic vessels. Laser was applied at diagnosis and at 2 months. (Third row near left) Three months and (Third row near right) 8 months after initial treatment showing marked improvement, although residual exudation and retinal elevation remain. (Third row far right) Thirty-four months after initial treatment showing no residual exudation or retinal elevation. There was moderate atrophy of the macula, and visual acuity was light perception. (Fourth row far left) Eye 13 at diagnosis showing total retinal detachment behind the lens precluding view of optic nerve. Patient initially was referred for enucleation. Laser was applied at diagnosis and (Fourth row near left) at 2 months. (Fourth row near right) Four months after initial treatment showing marked improvement of elevation; the optic disc is visible. (Fourth row far right) Twenty-six months after initial treatment showing no active exudation but moderate macular atrophy with subretinal fibrosis and sclerotic vessels. Visual acuity was hand movements. (Fifth row far left) Eye 14 at diagnosis showing total retinal detachment behind the lens with elevated intraocular pressure. Laser treatment failed to improve exudation 1 month after treatment, and the patient underwent subretinal drainage. (Fifth row near left) Two months after drainage showing flattened posterior pole but total tractional retinal detachment anteriorly 360 degrees. A cataract developed and pars plana vitrectomy and lensectomy was performed at 6 months. (Fifth row near right and far right) Twenty months after diagnosis showing total retinal detachment in a so-called napkin-ring configuration with severe anterior fibrosis causing tractional detachment. Vision was no light perception, and further surgery to flatten the retina was deferred to prevent ciliary body damage and phthisis.

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Jan 16, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on Effects of Green Diode Laser in the Treatment of Pediatric Coats Disease
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