coats ajo 2001 shields clasification

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Classification and Management of CoatsDisease: The 2000 Proctor Lecture

JERRY A. SHIELDS, MD, CAROL L. SHIELDS, MD,

SANTOSH G. HONAVAR, MD, HAKAN DEMIRCI, MD, AND JACQUELINE CATER, PHD

PURPOSE: To review the methods and results of man-agement in a large series of patients with Coats disease, to

determine risk factors for poor visual outcome andenucleation, and to propose a practical classification ofCoats disease.

METHODS: In a retrospective consecutive series in 150patients, Coats disease was defined as idiopathic retinaltelangiectasia with intraretinal or subretinal exudation

without appreciable signs of retinal or vitreal traction.We reviewed our experience with management, including

observation, laser photocoagulation, cryotherapy, andvarious techniques of retinal detachment surgery and

enucleation. The anatomic outcome, complications of

treatment, visual results, and reasons for enucleationwere tabulated. Factors predictive of poor visual outcome(20/200 or worse) and enucleation were determined

using Cox proportional hazards regression models. Basedon these observations, a staging classification of Coatsdisease, applicable to treatment selection and ocular

prognosis, is proposed. RESULTS: In 117 patients (124 eyes) with a meanfollow up of 55 months (range, 6 months to 25 years)

primary management was observation in 22 eyes (18%),cryotherapy in 52 (42%), laser photocoagulation in 16

(13%), various methods of retinal detachment surgery in

20 (17%), and enucleation in 14 (11%). Anatomic

improvement or stability was achieved in 76% of eyes,and final visual acuity was 20/50 or better in 17 eyes

(14%), 20/60 to 20/100 in eight (6%), 20/200 to fingercounting in 30 (24%), and hand motion to no lightperception in 49 (40%) Enucleation was ultimately

necessary in 20 eyes (16%).Risk factors predictive of poor visual outcome (20/200

or worse) included postequatorial (P .01), diffuse

(P .01), or superior (P .04) location of thetelangiectasias and exudation, failed resolution of subreti-

nal fluid after treatment (P .02), and presence ofretinal macrocysts (P .02). The main risk factors forenucleation were elevated intraocular pressure (greater

than 22 mm Hg; P less than or equal to .001) and irisneovascularization (P less than or equal to .001).

Coats disease was classified into stage 1, telangiectasia

only; stage 2, telangiectasia and exudation (2A, extrafo-

veal exudation; 2B, foveal exudation) stage 3, exudativeretinal detachment (3A, subtotal; 3B, total); stage 4,

total detachment and secondary glaucoma; and stage 5,advanced end-stage disease. Poor visual outcome (20/200or worse) was found in 0% of eyes with stage 1, 53%

with stage 2, 74% with stage 3, and 100% of stages 4 and5 Coats disease. Enucleation was ultimately necessary in0% of stages 1 and 2, 7% of stage 3, 78% of stage 4, and

0% of stage 5 disease. CONCLUSIONS: Carefully selected treatment can ana-

tomically stabilize or improve the eye with Coats diseasein 76% of eyes. However, poor visual outcome of 20/200

or worse commonly results. Patients who present withstages 1 to 3 Coats disease have the best visual prognosis,and patients with stages 4 and 5 have a poor visualprognosis. (Am J Ophthalmol 2001;131:572583.

2001 by Elsevier Science Inc. All rights reserved.)

COATS DISEASE IS A NONHEREDITARY CONDITION

that is characterized by idiopathic retinal telangi-ectasia, exudation, and exudative retinal detach-

ment.18 It usually occurs unilaterally in young males and,

if untreated, can lead to total retinal detachment andsecondary glaucoma, sometimes requiring enucleation.18

There have been no reports that analyze statistically the

Accepted for publication Jan 18, 2001.From the Oncology Service, Wills Eye Hospital, Thomas Jefferson

University, Philadelphia, Pennsylvania.This study was presented by Dr Jerry Shields as part of the 2000 Proctor

Lecture, University of California San Francisco School of Medicine, SanFrancisco, California, December 7, 2000.

This work was supported by the Eye Tumor Research Foundation,Philadelphia, Pennsylvania, the Award of Merit in Retina Research,Houston, Texas (Dr J. Shields), the Macula Foundation, New York, NewYork (Dr C. Shields), the Hyderabad Eye Research Foundation, Hyder-abad, India (Dr Honavar), and Orbis International, New York, New York(Dr Honavar).

Reprint requests to Jerry A. Shields, MD, Oncology Service, Wills EyeHospital, 900 Walnut St, Philadelphia, PA 19107.

See also pp. 561571.

2001 BY ELSEVIER SCIENCE INC. ALL RIGHTS RESERVED.572 0002-9394/01/$20.00PII S0002-9394(01)00896-0


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clinical factors predictive of poor visual outcome andenucleation. In a recent study of 150 cases, we outlined

criteria for diagnosing Coats disease and for differentiatingit from other causes of exudative retinopathy.8 In thiscommunication, we use the same patient database to

analyze results of treatment, propose a staging classifica-tion, and make recommendations regarding management

of Coats disease.

PATIENTS AND METHODS

RECORDS WERE REVIEWED ON PATIENTS WITH THE DIAG-

nosis of Coats disease from the computerized patientdatabase of the Oncology Service at Wills Eye Hospitalfrom January 1975 through December 1999. We defined

Coats disease as idiopathic retinal telangiectasia and in-traretinal or subretinal exudation without appreciable signsof vitreoretinal traction.8 Other causes of exudative reti-

nopathy that were excluded from this study, as well asgeneral data, referral diagnoses, and clinical features, werereported in a separate study of 150 patients.8 In this study,

we review the methods and results of treatment for patientswith Coats disease in 117 of those patients (124 eyes) who

were managed by us and who had follow-up of 6 months orlonger.

The primary goal of treatment was to eradicate retinal

telangiectasia to achieve resolution of intraretinal andsubretinal exudation with the ultimate goal of preservingthe globe and vision. The selection of management was

based on the clinical findings and the experience of the

senior authors (Drs J. Shields and C. Shields). Dependingon the clinical situation, the selected management was

observation, laser photocoagulation, cryotherapy, and sur-gical repair of retinal detachment, combined with laserphotocoagulation or cryotherapy, or enucleation.

Observation was generally recommended in either oftwo situations. First were patients with telangiectasias andlittle or no exudation and no impending threat to vision.

Second were patients with a comfortable eye but totalretinal detachment, in which there was no hope for useful

vision.Photocoagulation to the telangiectasias was usually se-

lected when there was exudation but no retinal detach-

ment or a very shallow detachment. In the early part ofthis study, xenon arc photocoagulation was used and laterargon laser was employed, originally with slit-lamp delivery

and more recently with indirect ophthalmoscope delivery.Cryotherapy, with a double freeze-thaw method, was

employed when the retinal detachment was shallow

enough to allow approximation of a cryoprobe to thetelangiectasias using scleral indentation. It was usuallyperformed by a transconjunctival technique, but a small

conjunctival incision was sometimes necessary to reachmore posteriorly located telangiectasias.

Surgical reattachment of the retina was often attempted

when the detachment was so extensive that cryotherapy orphotocoagulation would have been ineffective. In most

earlier cases, the surgical approach involved performing asclerotomy and draining subretinal fluid while simulta-neously injecting saline into the anterior chamber or

vitreous.9 More recently, a vitreoretinal surgical approachusing vitrectomy and intravitreal infusion of saline or

expandable gas was employed. Supplemental photocoagu-lation or cryotherapy was applied to the telangiectasias atthe time of retinal reattachment, to eradicate them and

create a chorioretinal adhesion.Enucleation was usually performed when the affected

eye was blind and painful from secondary glaucoma. In

those cases, there was no hope for vision using conserva-tive methods of treatment. Patients were evaluated at3-month to 4-month intervals, depending on the status of

the disease, distance necessary for patient travel, and thedegree of participation by the referring physician.

The methods of initial management and the number

and type of subsequent treatments were reviewed. Theresolution of telangiectasia, retinal exudation, subretinalfluid, and retinal macrocysts and the frequency of late

recurrence and its management were determined. Based onfollow-up examinations, an assessment of the final ocular

outcome (improved, stable, worse,) was made.The final visual acuity and reasons for poor visual acuity

(20/200 or worse) were tabulated. Using univariate and

multivariate analyses, the clinical findings were assessed todetermine the factors predictive of poor visual outcome of20/200 or worse.

The complications of treatment and reasons for enucle-

ation were determined. Using univariate and multivariateanalyses the clinical factors predictive of enucleation were

determined. Based on these data, a staging classification forCoats disease, applicable to treatment selection and ocularprognosis, was proposed (Figure 1).

RESULTS

OF THE 150 PATIENTS (158 EYES) IN THE SERIES, 25 HAD

initial treatment elsewhere, and limited information wasavailable on the techniques and results of management.There were 125 patients (132 eyes) managed exclusively

by the authors of which 117 patients (124 eyes) had atleast 6 months follow-up and were included in thisanalysis. The mean follow up was 55 months (median, 23

months; range, 6 months to 24 years).The methods of management at the time of diagnosis in

the 124 eyes are shown in Table 1. Observation was

recommended for 22 of the 124 eyes (18%), of which sixhad minimal, asymptomatic disease and 16 had advanceddisease with total, bullous retinal detachment. Of the six

cases with minimal disease followed with observation, fiveremained stable and one showed progression and required

cryotherapy. Of the 16 eyes with advanced disease man-

CLASSIFICATION AND MANAGEMENT OF COATS DISEASEVOL. 131, NO. 5 573


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FIGURE 1. Examples of stages of Coats disease (see Table 11). (A) Stage 1. Retinal telangiectasia only. (B) Stage 2A.

Telangiectasia and extrafoveal exudation. The exudation is confined to the equatorial region and the fovea is spared. (C) Stage 2B.

Foveal exudation. (D) Stage 3A1. Subtotal retinal detachment inferiorly, sparing the fovea. (E) Stage 3A2. Subtotal retinal

detachment extending beneath the fovea. (F) Stage 3B. Total exudative retinal detachment. Note the typical telangiectasias and the

yellow-green color to the subretinal fluid. (G) Stage 4. Total retinal detachment behind the lens in eye with secondary glaucoma.

(H) Stage 5. Advanced end stage disease with chronic inflammation, posterior synechia and cataract, secondary to longstanding

retinal detachment.

AMERICAN JOURNAL OF OPHTHALMOLOGY574 MAY 2001


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aged with observation, 13 remained stable with a blind butcomfortable eye and three showed progression to painfulsecondary glaucoma and required enucleation.

Laser photocoagulation was the initial treatment for 16eyes (13%). Cryotherapy was employed in 52 eyes (42%).Surgical management for retinal detachment, combined

with either laser photocoagulation or cryotherapy, wasemployed in 20 eyes (17%). Primary enucleation wasperformed in 14 eyes (11%).

A second treatment was necessary in 60 eyes. Thisincluded cryotherapy in 34, laser photocoagulation in 11,

combined photocoagulation and cryotherapy in four, andenucleation in four. The other seven eyes were treatedwith combinations of drainage of subretinal fluid, cryother-

apy, and scleral bucking procedures. A third treatment wasundertaken in 27 eyes. This included cryotherapy in 13,laser photocoagulation in four, combinations of drainage of

subretinal fluid, cryotherapy, and scleral bucking proce-

dures in eight, and enucleation in two cases. In all, 18 eyes(15%) were observed, 31 (25%) underwent laser photoco-

agulation, 99 (80%) underwent cryotherapy, and 35 (28%)had subretinal fluid drainage with or without scleralbuckling, pars plana vitrectomy, laser photocoagulation, or

cryotherapy. Of the 76 eyes treated with cryotherapy, onetreatment session was necessary in 36 (47%), two sessionsin 19 cases (25%), three sessions in 16 (21%), and four to

five sessions were required in five (7%) to achieve success-ful obliteration of the telangiectasias.

There were 103 eyes in which we were able to followophthalmoscopically the course of the telangiectasia andexudation after treatment (excluding those managed by

primary enucleation, those not treated, and some with hazyocular media). Of those 103 eyes, the telangiectasia re-solved completely in 48 eyes (47%) and partially resolved

in 55 (53%). The mean interval from initial treatment tocomplete resolution of telangiectasia was 15 months (me-dian, 10 months; range, 2 to 123 months). If the retinal

exudation was resolving satisfactorily, attempts to com-pletely eradicate the telangiectasia were not undertaken,because the ultimate goal was to preserve vision and not

necessarily to eradicate all telangiectasiasThe exudation resolved completely after treatment of

the telangiectasias in 46 cases (45%; Figure 2). The mean

time to resolution of the exudation was 17 months (me-dian, 12 months; range, 1 to 42 months). If residual

exudation was not causing visual impairment and thetelangiectasias were controlled, then no further treatmentwas advised.

In 88 eyes with retinal detachment that were treatedand had adequate follow-up information, the detachment

resolved completely in 50 (57%; Figure 3). The mean timefrom the first treatment to resolution of subretinal fluid was9 months (median, 5 months; range, 1 to 43 months). In

38 cases (43%), residual subretinal fluid persisted afterretinal detachment surgery. There were 15 eyes in which aretinal macrocyst was observed in an area of retinal

detachment. The macrocyst resolved after treatment infive eyes, and it persisted in 10.

There was eventual recurrence of telangiectasia and

exudation in six of the 86 eyes (7%) after initial satisfac-tory control of telangiectasia and exudation. The meantime for recurrence was 10 years (median, 9 years; range, 4

to 14 years).The final anatomic outcome, as determined by improve-

ment in the amount of telangiectasias, exudation, and sub-

retinal fluid, was assessed in patients with follow-up of at least6 months (Table 2). There was stabilization or improvement

of the disease process in 76% and worsening in 8%. Overall,20 patients (16%) required enucleation either initially (14eyes) or in the course of management (six eyes).

The final visual outcome was determined in 104 of the124 eyes (Table 3). Of the 104 eyes, the visual acuity was20/50 or better in 17 (16%), between 20/60 and 20/100 in

eight (8%), from 20/200 to finger counting in 30 (29%),

and hand motions to no light perception in 49 (47%), and20 eyes were enucleated. The reasons for final vision of

20/200 or worse included various combinations of persis-tent retinal detachment, exudation, and fibrosis involvingthe fovea (Table 4). The subretinal exudation often

transformed with time into dense fibrous tissue. Thesignificant clinical factors predictive of poor visual acuity(20/200 or worse) are shown in Tables 5 and 6. Using

multivariate analysis, the most significant factors related topoor visual outcome included non-Caucasian race, diffuse,

postequatorial, and superior location of the telangiectasiasand exudation, failure of exudation to resolve after treat-ment, and presence of retinal macrocysts (Table 6).

The treatment complications are shown in Table 7. Ofthe 124 eyes, 86 were managed by interventional treat-ment other than enucleation. There were no serious

complications of treatment in 78 of those eyes (91%).Vitreous hemorrhage occurred in three eyes (3%), and aretinal hole developed in two cases (2%) after cryotherapy.

Although a mild transient retinal detachment (ablatiofugax) was observed frequently after cryotherapy, only twoeyes (2%) had a permanent increase in the extent of

retinal detachment.Enucleation was performed in 20 cases (16%). In 14

cases, it was performed at the time of the initial visit

TABLE 1. Primary Management in 117 Consecutive

Patients (124 Eyes) With Coats Disease

Management Number (%)

Observation 22 (18%)

Photocoagulation 16 (13%)

Cryotherapy 52 (42%)

Retinal detachment repair with subretinal fluid

drainage and cryotherapy or photocoagulation

20 (17%)

Enucleation 14 (11%)



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because of a total retinal detachment, usually associatedwith secondary glaucoma. In the other six cases, enucle-

ation was elected after a period of follow-up with orwithout treatment. The reasons for enucleation in the 20cases, shown in Table 8, included neovascular glaucoma in

nine, severe angle closure glaucoma without iris neovas-cularization in four, blind painful eye without glaucoma insix, and parental concern about slight possibility of reti-

noblastoma in one blind eye (Table 8). The clinical riskfactors predictive of enucleation were identified usingunivariate (Table 9) and multivariate (Table 10) analyses.

With multivariate analysis (Table 10), the most significantfactors were elevated intraocular pressure, and iris neovas-cularization, and heterochromia, usually secondary to iris

neovascularization.Microscopic verification of Coats disease was obtained

in 38 of the 124 eyes. As mentioned, 20 eyes were

enucleated, and all showed retinal telangiectasia, total

retinal detachment, and eosinophilic subretinal fluid con-

taining lipid-laden macrophages and cholesterol clefts.4,5,10

In 12 cases, cytology of subretinal fluid drained through a

posterior sclerotomy at the time of retinal detachmentrepair revealed characteristic cytologic features of Coats

disease, with lipid-laden macrophages and cholesterol

crystals. In six of the earlier cases, diagnostic fine needle

aspiration biopsy of subretinal fluid11 demonstrated typical

cytologic features of Coats disease.

Based on our observations, a staging classification of

Coats disease was devised as follows:

Stage 1: Retinal telangiectasia only

Stage 2: Telangiectasia and exudation

A. Extrafoveal exudation

B. Foveal exudation

FIGURE 2. Resolution of foveal exudation after treatment of peripheral telangiectasia in a 17-year-old male. (Top left) Retinal

telangiectasia located superotemporally. (Top right) Exudation extending into foveal area. The fovea is in lower left part of

photograph. (Bottom left) Area of telangiectasia after 2 years, showing area of pigmentation. (Bottom right) Appearance of fovea

14 years after treatment, showing continued absence of the exudation. Patient was 31 years of age at the time of the photograph.



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Stage 3: Exudative retinal detachmentA. Subtotal detachment

1. Extrafoveal2. Foveal

B. Total retinal detachmentStage 4: Total retinal detachment and glaucomaStage 5: Advanced end-stage disease

Stage 1 is characterized by telangiectasia only (Figure 1,A), stage 2 by telangiectasia and exudation (Figure 1, Band C), stage 3 by exudative retinal detachment (Figures 1,

D, E, and F), stage 4 by total retinal detachment withglaucoma (Figure 1, G), and stage 5 by advanced end-stagechanges (Figure 1, H). Stage 5 disease was defined as a

blind, nonpainful eye with a total retinal detachment,often with cataract and phthisis bulbi, Of the 124 eyesreviewed, there was one eye in stage 1, 10 in stage 2A,

seven in 2B, 25 in 3A1, 24 in 3A2, 37 in 3B, 18 in stage

4, and three in stage 5 (Table 11).

The treatment employed varied with the stage of the

disease. In stages 1 and 5 the most common management

was observation (100%). Cryotherapy was most often usedin stage 2A (50%), 2B (100%), 3A1 (56%), 3A2 (65%),

and 3B (34%). Photocoagulation was the selected initial

treatment in 16 (13%) of our cases, mainly in stages 2 and

3A. Surgical repair of retinal detachment was employed

mainly in eyes with stage 3B disease. The visual outcome

was generally favorable in stages 1 and 2A and was worse

in stage 2B and higher. The chances of enucleation were

greatest in stage 4 because of ocular pain secondary to

glaucoma. (Table 11). In stage 4, enucleation was done

initially in 14 eyes (78%). The other six eyes (22%) that

came to enucleation were initially classified as stage 3

FIGURE 3. Resolution of foveal retinal detachment after treatment of reinal telangiectasia in an 8-year-old male. (Top left) Retinal

telangiectasia and exudation near equator nasally. (Top right) Macular area, showing mild exudation and a serous detachment of

fovea. (Bottom left) Appearance immediately after laser treatment to the telangiectasia. (Bottom right) Macular area 9 months after

treatment, showing resolution of the retinal detachment and only minimal residual exudation.



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disease, but later showed progression, with blindness anddiscomfort.

DISCUSSION

SEVERAL AUTHORS HAVE REPORTED EXPERIENCE WITH

management of Coats disease.1229 Methods have included

diathermy, xenon photocoagulation, argon laser photoco-agulation, cryotherapy, and techniques of surgical reat-tachment of the retina. The main goal of treatment should

be to eradicate the telangiectasias to facilitate resolution ofexudation and salvage as much vision as possible.

Prior publications on management of Coats disease havebeen retrospective studies, often on small groups of pa-tients.1229 In addition, some series6,7 have included con-

ditions that do not meet diagnostic criteria for Coatsdisease, as described originally by Coats1 and more recentlyby others.2,3,8 Many of the conditions that have been

misinterpreted as Coats disease are listed in our prior reporton clinical variations of that disease.8 Because our patientswere managed over a long span of time during which

treatment modalities were changing, it was not possible toconduct a prospective study comparing results of treatmentmethods. Because Coats disease is relatively uncommon

and the degree of involvement varies from case to case, arandomized, prospective study of treatment would probably

not be feasible. Our study is also retrospective, and

therefore, the results must be interpreted with caution.However, the relatively large number of patients in ourseries gave us the unique opportunity to analyze statisti-

cally the risk factors for poor visual outcome and forenucleation. Our observations have allowed us to developinsight into the therapeutic options for Coats disease,

which includes observation, laser photocoagulation, cryo-therapy, surgical approaches to reattach the retina, or

combinations thereof. It is important to realize that pa-tients undergoing treatment need close follow-up and mayrequire additional treatments, depending on clinical devel-

opments.There are two diverse situations in Coats disease where

observation is warranted. First is in eyes with stage 1 and

2A disease with mild telangiectasia and little exudation,

particularly in patients older than 15 years. In olderchildren and young adults, Coats disease is generally less

aggressive and there is less likelihood of progressive exu-dation and retinal detachment. However, treatmentshould be considered if progression is documented. There

were six such cases in our series, and only one showedprogression of the disease during the course of follow-up. Insome older children and young adults, spontaneous regres-

sion of the telangiectasias has been documented.22 Asecond reason to observe Coats disease is in some eyes with

stages 3B and 5 disease, where the blind eye is comfortable,but there is no hope for useful vision. In our study, 13 of 16eyes (81%) with such advanced disease remained stable

during the period of observation.Laser photocoagulation can be used in selected cases of

Coats disease.1421 Several decades ago, xenon photocoag-

ulation was the only available method.1316 Because itcaused more retinal damage and vitreoretinal traction,xenon photocoagulation has been replaced by argon laser

photocoagulation today. More recently, we have employedthe indirect ophthalmoscope delivery system, because it ismore readily used in the operating room in young chil-

dren.24,30 Photocoagulation to the telangiectasia was theinitial treatment in 16 (13%) of our cases (Table 1). In our

experience, laser photocoagulation was most successful

TABLE 2. Final Ocular Outcome in 117 Patients With

Coats Disease (124 Eyes) With Follow-up of at Least

6 Months

Final Outcome Number (%)

Improved 59 (48%)

Stable 35 (28%)Worse 10 (8%)

Enucleation 20 (16%)

TABLE 3. Final Visual Acuity (124 Eyes) With

Coats Disease

Final visual acuity Number (%)

20/50 or better 17 (14%)

20/6020/100 8 (6%)

20/200CF 30 (24%)HMNLP 49 (40%)

Enucleated 20 (16%)

CF counting fingers; HM hand motions; NLP no light

perception.

Data on final visual acuity was available in 104 eyes, with 20

having been enucleated.

TABLE 4. Reasons for Final Visual Acuity of 20/200 or

Worse (79 Eyes) With Coats Disease

Reason Number (%)

Subfoveal fluid 37 (47%)

Foveal exudation 9 (11%)

Subfoveal fibrosis 23 (29%)

Subfoveal hemorrhage 1 (1%)

Macular edema 6 (8%)

Epiretinal membrane 2 (2%)

Optic atrophy 1 (1%)

Percents may not equal 100 because of rounding.



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when there were telangiectasias without retinal detach-

ment (stage 2). Cryotherapy can also be used in such cases.The patient should be reevaluated 3 months after treat-ment and, if vascular changes persist and exudation is not

resolving, a second treatment should be given. With time,remote exudation in the macular area will resolve if theperipheral retinal vascular abnormalities are obliterated. In

some instances, more than three treatments may be nec-essary. It is important to wait at least 3 months beforeconsidering additional laser photocoagulation, because

resolution of the exudation is generally very slow.Cryotherapy is also an important modality in the treat-

ment of Coats disease.1721 It was the initial treatment in

42% of our patients. In our experience, it is the preferredinitial method when there are peripheral telangiectasias

associated with extensive exudation or subtotal retinal

detachment (stage 3A). We have learned that cryotherapy

can be employed even in cases of relatively high detach-ment (stage 3B), provided the peripheral telangiectasiascan be reached with scleral indentation with a cryoprobe.

The preferred method of cryotherapy is a double freeze-thaw technique directly to the vascular abnormalities.Excessive cryotherapy can induce a transient increase in

the extent of retinal detachment (ablatio fugax). There-fore, in cases with diffuse telangiectasias involving allquadrants, it is generally advisable to treat two quadrants

only and to treat the other quadrants in 4 weeks. As in thecase of laser photocoagulation, a second treatment to thesame area should be withheld for approximately 3 months

to allow time for exudation to resolve and to avoidexcessive treatment.

Most authorities agree that the visual prognosis is poor

TABLE 5. Univariate Analysis of Risk Factors for Poor Visual Outcome (20/200 or Worse) in 117 Consecutive Patients (124 Eyes)

With Coats Disease

Variable Good Visual Outcome (n 25) Poor Visual Outcome (n 99) P Value Relative Risk 95% Confidence Interval

Non-Caucasian race 4 16 .018 2.01 1.133.58

Retinal zone mainly affected

Equator to macula 3 6 .007 5.93 1.6321.61

Diffuse* 10 89 .004 5.81 1.7819.02

Retinal telangiectasia

Affecting the superior retinal sector 2 5 .017 0.26 0.090.79

Unresolved retinal telangiectasia 11 46 .001 2.20 1.373.53

Retinal exudation

Diffuse retinal exudation* 10 79 .041 3.42 1.0511.10

Unresolved retinal exudation 7 50 .001 0.45 0.280.72

Subretinal fluid

Unresolved subretinal fluid 3 35 .026 0.57 0.350.94

Presence of retinal macrocyst 1 14 .017 1.60 1.092.35

Late onset recurrence 3 3 .009 0.21 0.060.67

*Diffuse

involvement of retina from ora serrata to foveal region.Superior retinal sector between 10 and 2 oclock.

TABLE 6. Multivariate Analysis of Risk Factors for Poor Visual Outcome (20/200 or Worse) in 117 Consecutive Patients (124

Eyes) With Coats Disease

Variable Good Visual Outcome (n 25) Poor Visual Outcome (n 99) P Value Relative Risk 95% Confidence Interval

Non-Caucasian race 4 16 .04 1.92 1.053.52

Retinal zone predominantly affected

Equator to macula 3 6 .001 12.57 2.7956.55

Diffuse 10 89 .01 6.20 1.5225.31


Affecting the superior retinal sector* 2 5 .04 0.34 0.120.95

Retinal exudation

Unresolved retinal exudation 7 50 .02 0.55 0.330.90

Presence of retinal macrocyst 1 14 .01 1.82 1.162.87

*Superior retinal sector between 10 and 2 oclock.Diffuse involvement of retina from ora serrata to foveal region.



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in patients with total, bullous retinal detachment second-ary to Coats disease.26,29 However, in selected cases, anattempt to repair the retinal detachment surgically may be

justified to prevent the development of neovascular glau-coma. In 1988, Silodor and associates23 reported 13 eyeswith total bullous retinal detachment. Of six such eyes that

were not treated, four developed painful neovascular glau-coma. In contrast, no neovascular glaucoma developed in

any of the seven eyes that had drainage of subretinal fluid,intraocular infusion to flatten the retina, and supplementalphotocoagulation or cryotherapy. More recently, Yoshi-

zumi and associates27 have advocated vitrectomy, internaldrainage of subretinal fluid, intraocular diathermy, andintravitreal gas or silicone oil injection as a means of

salvaging such eyes. Various combinations of these more

aggressive methods were employed as primary treatment in17% of our 124 patients, mainly when there was a total

bullous retinal detachment without secondary elevatedintraocular pressure (stage 3B). This option should beconsidered when there is a reasonable chance of reattach-

ing the retina and preventing neovascular glaucoma, eventhough the visual outcome is expected to be poor.

The concept of late recurrence of Coats disease has not

been adequately emphasized in the literature. We foundthat there was recurrence of the telangiectasia and retinal

exudation in 7% of cases after a mean of 10 years aftersuccessful treatment. This stresses the importance of long-term follow-up of affected patients.

Based on our statistical observations, we believe that theophthalmologist can make a general prediction as to thechances of retaining the eye and preserving vision in

patients with Coats disease. From an anatomic standpoint,improvement or stabilization of the disease was achieved inalmost 76% of our cases (Table 2). Therefore, the majority

of patients respond favorably to treatment, but approxi-mately 25% will become worse or require enucleation. Thevisual outcome in patients with Coats disease varies

considerably (Table 3). Our observations suggest that ifthe patient does not have macular exudation or extensive

retinal detachment, such as in stages 1 and 2A disease,

then a favorable visual outcome can be expected (Table11). Even dense macular exudation may gradually resolve

after successful eradication of the peripheral telangiecta-sias. However, the presence of thick foveal exudation(stage 2B and above) usually portends a worse prognosis,

particularly if a fibroglial nodule is present in the fovea.Patients with a total retinal detachment usually have littleor no useful vision in the affected eye despite treatment.

The fact that 47% of our patients had a final visualacuity in the hand motion to no light perception range

probably reflects the fact that our practice is orientedlargely toward ocular tumors, and we are often referredyoung children with a total retinal detachment in which

exophytic retinoblastoma is a diagnostic consideration.Younger children with Coats disease generally have a moreaggressive clinical course and often have a total retinal

detachment by the time the disease is diagnosed.8,29

Hence, a poor visual outcome is usually anticipated in suchcases. In other practices oriented toward retinal vascular

diseases, it is possible that there would be more referrals forearlier stages of Coats disease and a better visual prognosiscould be anticipated.

The reasons for a poor visual outcome in patients withCoats disease have not been specifically addressed in mostprior publications. We found that persistent subretinal

fluid and late subretinal fibrosis in the foveal area por-tended a worse visual outcome (Table 4). Even with

successful reattachment of the retina, the subretinal exu-dation often leads to irreversible subretinal fibrosis andretinal degeneration. In the multivariate analysis for poor

visual outcome (Table 6), it was not surprising that therewere worse visual results when the telangiectasias andexudation were more extensive and involved the foveal

area.There are few serious complications of the aforemen-

tioned treatments. No major complications were encoun-

tered in 91% of the cases. The occasional complications(Table 7) had little visual impact, because many affectedeyes had advanced disease with little or no visual potential.

In some cases, enucleation for Coats disease is war-ranted. Enucleation was necessary as initial or secondary

treatment in 16% of our patients. As mentioned earlier,

TABLE 7. Complications of Treatment in 86 Eyes With

Coats Disease Managed by Interventional Treatment in

117 Patients (124 Treated Eyes)*

Complications Number (%)

Vitreous hemorrhage 3 (3%)

Retinal hole 2 (2%)Increase in subretinal fluid 2 (2%)

Rhegmatogenous retinal detachment 1 (1%)

No complication 78 (91%)

*Enucleation was performed in 20 eyes and 18 eyes were

observed, without interventional treatment. Those were ex-

cluded from this calculation.

TABLE 8. Management of Coats Disease in 117

Consecutive Patients: Reason for Enucleation in

20 Patients*

Reason for Enucleation Number (%)

Acute neovascular glaucoma 9 (45%)

Angle-closure glaucoma 4 (20%)Suspected retinoblastoma 1 (5%)

Painful blind eye* 6 (30%)

*All enucleated eyes were experiencing some pain.



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younger children with Coats disease often present withacute glaucoma, characterized by pain, nausea, vomiting,

loss of appetite, and lethargy. When this occurs, we believethat palliative enucleation is justified, to spare the child

chronic pain and oral and topical medication. We do notusually recommend diagnostic fine needle aspiration biopsyin such advanced cases. If enucleation is anticipated, then

needle biopsy is an unnecessary additional procedure. Inthe multivariate analysis of risk factors for enucleation, wefound that iris neovascularization with secondary glaucoma

were most important (Table 10). Historically, patientswith Coats disease often underwent enucleation becauseretinoblastoma was a serious diagnostic consideration.31,32

Today, however, features that differentiate Coats diseaseretinoblastoma are better known, and enucleation becauseof erroneous diagnosis of retinoblastoma is less com-

mon.8,33,34

The proposed classification of Coats disease can be helpful

for selecting treatment and predicting the ocular and visual

outcomes (Table 11). Patients with stage 1 disease (telangi-ectasia only) can be managed by either periodic observation

or laser photocoagulation. In stage 1 disease, there is highprobability that the eye can be salvaged and the visual

prognosis is usually favorable. However, stage 1 disease isuncommon in a clinical practice, and Coats disease is usuallymore advanced at the time of diagnosis.

Patients with stage 2 disease (telangiectasia and exuda-tion) are generally best managed by laser photocoagulationor cryotherapy, depending on the extent of the disease and

the preference of the ophthalmologist. If the exudation islimited to one quadrant or located nasally, a reasonablygood visual outcome can be anticipated. In stage 2A, the

visual prognosis is generally good, because the fovea is notinvolved by exudation. Eyes with stage 2B are usuallysalvaged and the visual prognosis is fairly good if the foveal

exudation is not advanced (Figure 2). As mentionedearlier, a dense yellow gray nodule centered within the

foveal exudation usually portends a worse visual outcome.

TABLE 9. Management of Coats Disease in 117 Consecutive Patients (124 Eyes): Univariate Analysis of Risk Factors

for Enucleation

Variable No Enucleation (n 104) E nucleation (n 20) P Value Relative Risk 95% Confidence Interval

Visual acuity 20/60 or worse 92 20 .04 6.47 1.0640.01

Leukocoria 23 8 .02 4.75 1.2318.37

Heterochromia 3 6 .001 25.36 6.28102.48

Mean ocular pressure (mm Hg) 17 35 .001 1.11 1.081.15

Corneal edema 0 5 .001 68.28 16.76278.09

Shallow anterior chamber 3 4 .001 6.12 2.0218.58

Neovascularization of iris 3 9 .001 13.65 5.4834.01


Mean number of sectors affected 2 3 .03 1.57 1.042.39

Mean number of clock hours affected 6 8 .03 1.14 1.011.29

Retinal exudation

Macular exudation 84 20 .007 NA NA

Diffuse retinal exudation* 51 18 .001 7.30 1.6931.60

Mean number of sectors affected 3 4 .01 2.53 1.245.16


Subretinal fluidDiffuse subretinal fluid* 58 20 .001 NA NA


Mean percent affected 65 93 .02 1.03 1.011.05

NA relative risk and 95% confidence interval could not be calculated.

*Diffuse involvement of retina from ora serrata to foveal region.

TABLE 10. Management of Coats Disease in 117 Consecutive Patients (124 Eyes): Multivariate Analysis of Risk Factors

for Enucleation

Variable No Enucleation (n 10 4) En ucl ea ti on ( n 20) P V alue Relat ive Risk 95% Confidence Inter val

Heterochromia 3 6 .001 12.86 3.1852.02

Mean intraocular pressure (mm Hg) 17 35 .001 1.10 1.061.15

Neovascularization of iris 3 9 .001 13.65 5.4834.01



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Patients with stage 3A disease (subtotal retinal detach-ment) can generally be managed by photocoagulation orcryotherapy. Even if the retinal detachment involves the

fovea, it will resolve when the telangiectasias are eradi-cated (Figure 3). Laser photocoagulation is less effective inareas of retinal detachment, and cryotherapy is often

preferable in such instances. Patients with stage 3B (totalretinal detachment) can be managed with cryotherapy ifthe detachment is shallow but may require an attempt at

surgical reattachment if the detachment is bullous andimmediately posterior to the lens.

Patients who present with stage 4 disease (total retinal

detachment with glaucoma) are often best managed by

enucleation to relieve the severe ocular pain. Patients with

stage 5 disease generally have a blind, but comfortable, eyeand require no aggressive treatment.

In summary, we have reviewed our experience with

management of Coats disease, determined statistical fac-

tors predictive of poor visual outcome and enucleation,

and proposed a useful classification of this condition.

Treatment should be directed toward obliterating thetelangiectasias, thus facilitating resolution of the exuda-

tion and retinal detachment. In the early stages, this can

be best achieved with laser photocoagulation or cryother-

apy. More advanced cases may require surgical techniquesof retinal reattachment, combined with photocoagulation

or cryotherapy. Advanced cases with secondary glaucoma

often require enucleation. The proposed staging classifica-tion should assist the ophthalmologist in selecting treat-

ment and in predicting the prognosis for salvaging the eye

and preserving vision. Carefully selected treatment can

anatomically stabilize or improve the eye with Coats

disease in 76% of cases. However, poor visual outcome of20/200 or worse commonly results. Patients who present

with stages 1 to 3 Coats disease have the best ocularprognosis. We believe that earlier diagnosis and prompt

treatment will result in better visual outcome and fewer

enucleations for Coats disease in the future.

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2. Mandava N, Yannuzzi LA. Coats disease. In: Guyer DR,

TABLE 11. Management of 117 Patients (124 Eyes) With Coats Disease: Staging Classification, Visual Outcome, and Frequency

of Enucleation

Stage Staging Criteria Number (%)

Management Modality* Outcome

Observation,

Number (%)

PC,

Number (%)

Cryotherapy,

Number (%)

RD Repair,

Number (%)

Poor VA,

Number (%)

Enucleation,

Number (%)

Stage 1 RT 1 (%) 1 (100%) 0 0 0 0 0

Stage 2 TEx

2A Extrafoveal Ex 10 (8%) 4 (40%) 1 (10%) 5 (50%) 0 3 (30%) 0

2B Foveal Ex 7 (6%) 0 3 (43%) 7 (100%) 0 6 (86%) 0

Stage 3 TExRD

3A Subtotal RD

3A (i) Extrafoveal RD 24 (19%) 4 (17%) 10 (42%) 14 (58%) 2 (8%) 16 (67%) 1 (4%)

3A (ii) Foveal RD 24 (19%) 2 (8%) 12 (50%) 15 (63%) 2 (8%) 16 (67%) 1 (4%)

3B Total RD 37 (30%) 4 (10%) 4 (10%) 31 (84%) 18 (49%) 31 (84%) 4 (11%)

Stage 4 TExTotal RDGl 18 (15%) 0 0 4 (22%) 4 (22%) 4 (22%) 14 (78%)

Stage 5 End-stage disease 3 (2%) 3 (100%) 0 0 0 3 (100%) 0

Ex exudation; Gl glaucoma; PC photocoagulation; RD retinal detachment; RD repair subretinal fluid drainage with or without

scleral buckling, pars plana vitrectomy, laser, photocoagulation, or cryotherapy; RT

retinal telangiectasia; VA

visual acuity 20/200 orworse.

*Includes all primary and subsequent management.

TABLE 12. Staging Classification of Coats Disease, Visual

Outcome, and Frequency of Enucleation

Stage

Poor Visual

Outcome*

Enucleation

Outcome

Stage 1: Retinal telangiectasia only (n 1) 0% 0%

Stage 2: Telangiectasia and exudation

A. Extrafoveal exudation (n 10) 30% 0%

B. Foveal exudation (n 7) 86% 0%

Stage 3: Exudative retinal detachment

A. Subtotal detachment

1. Extrafoveal (n 25) 70% 8%

2. Foveal (n 23) 70% 0%

B. Total detachment (n 37) 94% 11%

Stage 4: Total detachment; glaucoma (n 18) 100% 78%

Stage 5: Advanced end-stage disease (n 3) 100% 0%

*Visual acuity 20/200 or worse (excluding enucleated eyes).



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