Recent advances in the diagnosis and treatment of Coats' disease

Unusual anterior and posterior segment features of coats disease

PURPOSE

To report the clinical course and management of unusual anterior and posterior segment features of Coats disease and their relation to the age of the patients to increase the awareness towards these rare clinical features rarely described in the current literature.

METHODS

A retrospective descriptive review of 45 eyes of 45 patients affected by Coats disease was conducted at the Retinoblastoma Referral Center and Ophthalmology Unit of the University of Siena in Italy analyzing data from 2000 to 2022. Medical records and images were revised to find some cases presenting unusual anterior and posterior segment features in patients affected by Coats disease.We identified therefore 4 unusual clinical conditions: retinal macrocysts, anterior chamber cholesterolosis, fovea-sparing Coats disease and secondary vasoproliferative tumor.

RESULTS

Two patients presented with retinal macrocyst (2/45  =  4.4%), one with anterior chamber cholesterolosis (1/45  =  2.2%), two with fovea sparing Coats disease (2/45  =  4.4%) and one with vasoproliferative tumor associated (1/45  =  2.2%) for a total of six (6/45  =  13.3%) patients manifesting unusual anterior or posterior segment features in Coats disease.

CONCLUSION

Unusual anterior and posterior segment features of Coats disease such as retinal macrocyst and anterior chamber cholesterolosis have been more frequently reported in younger children while fovea-sparing and vasoproliferative tumors have been more commonly described in older patients. Age is then a strong prognostic marker which allows to distinguish two different phenotypes of Coats disease: patients younger and older than 3 years old with more aggressive and milder phenotype respectively.

Congenital Malformations of the Eye: A Pictorial Review and Clinico-Radiological Correlations

Congenital malformations of the eye represent a wide and heterogeneous spectrum of abnormalities that may be part of a complex syndrome or be isolated. Ocular malformation severity depends on the timing of the causative event during eye formation, ranging from the complete absence of the eye if injury occurs during the first weeks of gestation, to subtle abnormalities if the cause occurs later on. Knowledge of ocular malformations is crucial to performing a tailored imaging protocol and correctly reporting imaging findings. Together with the ophthalmologic evaluation, imaging may help frame ocular malformations and identify underlying genetic conditions. The purpose of this pictorial review is to describe the imaging features of the main ocular malformations and the related ophthalmologic findings in order to provide a clinico-radiological overview of these abnormalities to the clinical radiologist. Sight is a crucial sense for children to explore the world and relate with their parents from birth. Vision impairment or even blindness secondary to ocular malformations deeply affects children's growth and quality of life.

Adult-onset Coats' disease

Coats disease is an idiopathic retinal vasculopathy characterized by telangiectasia and aneurysm of retinal vessels along with intra and subretinal exudation and fluid. While Coats disease is classically described in young male population, there is an adult variant of Coats disease presenting in adulthood. Adult onset Coats disease have a similar presentation but a slower progression, localised lipid deposition, both peripheral and juxta-macular involvement. In this review article, we have attempted to describe in detail the characteristic clinical features, pathogenesis, investigation modalities and treatment in adult-onset Coats disease.

Clinicopathological Correlations in Enucleated Globes of Late-Stage Coats Disease with a Review of the Literature

BACKGROUND

Coats disease may cause diagnostic dilemma because of its variable clinical presentation that can be suspicious of retinoblastoma. Late sequelae of the disease are blinding with possible enucleation. We demonstrate the main histopathological findings of Coats enucleated eyes with literature review.

METHODS

This was a retrospective study of all enucleated globes diagnosed as Coats disease over 30 years and were reviewed by two pathologists. The corresponding demographic data, clinical presentation, pre-operative clinical impression, and indication for enucleation were collected. Descriptive analysis of our own series data was performed. Our findings were then correlated to published data that were collected from 1983 to 2021 from the PUBMED database in English-written language. Shields classification was used as an inclusion criterion for the published reports to be analyzed.

RESULTS

We had seven enucleated globes with Coats disease. Mean age at presentation was 3.2 years (range 3 months to 9 years). Male predominance was observed in 6 and all cases were unilateral. Strabismus was the most common initial presentation (57%, n = 4), followed by leukocoria (43%, n = 3). Indication for enucleation was mostly suspected retinoblastoma (57%, n = 4). Four eyes were classified as stage 4, and 2 had advanced stage 5 changes. Histopathologically, subretinal fluid with lipid-laden macrophages was seen in all cases, the anterior chamber was shallow in 5/7 with angle neovascularization in 2/7. Telangiectatic vessels were clearly observed in 4/7.

CONCLUSION

Coats disease is a potentially visually disabling disease that is mostly unilateral in 95%, has male predominance of 81%, and wide age range with a mean of 17 years. In Saudi Arabia, the disease seems to present at younger age, tends to be more advanced, and may be indistinguishable from retinoblastoma at the time of diagnosis. Shields staging of Coats is highly recommended to be followed clinically to unify the pathways for treatment and to correlate the concluded outcomes.

Fovea-threatening and fovea-involving peripheral Coats disease: effects of posture and intervention

BACKGROUND

We believe that our experience with patients presenting with Coats disease and macular sparing should be shared with our colleagues. We would like to show the effect of posture and prompt intervention in cases with fovea-threatening and/or fovea-involving peripheral Coats disease (FTPCD). This association has been poorly debated in our specialty and literature. We call the attention for the unexpexted scenario of observing the lost of the fovea during some types of traditional and prompt interventional treatments of these cases with previous 20/20 vision (something that we have been studying and observing for many years). In order to publish our best representative cases, we have chosen 8 Brazilian patients (age range, 7-62 years; 5 male) with FTPCD. All patients underwent multimodal imaging and different treatments (observation, sleep-posture repositioning, laser, intraocular steroids, and/or anti-vascular endothelial growth factor therapy). All patients, initially, informed to adopt a sleeping lateral-down position, favoring exudation shifting to the fovea pre-treatment. Most promptly-treated patients in this way (n = 4), developed subretinal fluid and exudates in the macula and some had irreversible central visual loss (n = 3). Patients with recent fovea-involving exudation who changed postural sleep position (to protect the foveal area) before and during treatment fared better, with some preserved central vision and an intact fovea (n = 5). The fundus status was correlated with the gravitational effects of posture before and after treatment. Despite prepared as an observational/interventional study, with a small number of cases, the most difficult part is documenting the sleep position of these patients and its influence in the outcomes as there is not good way to prove how well or poorly the positioning occurred in our cases. Finally, we also intended to call the attention to the fact that Coats disease must be studied in all its clinical stage variants and not only seen as a potential blinding and incurable ocular disease.

CASE PRESENTATION

This study is a retrospective and/or interventional analysis of eight cases with a less severe clinical variant of classic Coats disease that we refer to as fovea-threatening and fovea-involving peripheral Coats disease (FTPCD). All cases were unilateral with no systemic disease or family history of Coats disease. The bilateral anterior segment and intraocular pressure were normal in all patients. The characteristics of all patients are shown in the Table.

CONCLUSION

The funduscopic features of FTPCD are fundamental to disease understanding and optimal management. Habitual posturing may affect the fundus morphologic features of retinal exudation as observed in all current patients with exudative peripheral Coats disease. When sleep habitual posture is not observed in patients with FTPCD, the effects of prompt invasive treatments can cause rapid visual loss because of foveal subretinal pooling of exudates post-treatment. Initial vigilant adjusting of the habitual sleep posture for several patients with FTPCD, before the indication of traditional invasive treatments (laser and/or pharmacologic medications) can result in improved vision and fundoscopic morphologic features.

Genetic evaluation in phenotypically discordant monozygotic twins with Coats Disease

PURPOSE

To report the unique case of a pair of phenotypically discordant monozygotic twins, with one of them affected by unilateral Coats disease.

CASE REPORT

Both patients underwent a complete ophthalmologic evaluation and were genetically tested with whole-exome sequencing (WES). Any known or unknown potential genetic determinant of Coats disease wasn't found.

CONCLUSION

It may suggest a non-genetic etiology for this disorder. This represents, to the best of our knowledge, the first case of genetic analysis of monozygotic twins, one of whom is affected by Coats disease. Further studies are warranted, including performing genetic analysis directly on retinal biopsy tissue.

Long-term follow-up of a case of Coats disease in a 10-year-old boy with spontaneous peeling of preretinal macular fibrosis: a case report

BACKGROUND

Coats disease is a retinal vascular disorder characterized by aneurysms and telangiectasias. Macular fibrosis is a complication of Coats disease that results in vision loss. Macular fibrosis rarely develops in the natural course and often occurs after treatment with intravitreal bevacizumab, photocoagulation, or cryotherapy. Here, we have described an unusual case of spontaneous peeling of preretinal macular fibrosis in a patient with untreated Coats disease.

CASE PRESENTATION

A 10-year-old Japanese boy presented with vision loss in his left eye. The patient's left visual acuity was 20/28. Fundus examination of his left eye revealed thick preretinal macular fibrosis around the optic disc and macula. In addition, retinal telangiectasis, microaneurysms, hard exudates, and retinal hemorrhages were observed in the left peripheral temporal retina. We diagnosed his condition as Coats disease with preretinal macular fibrosis. Two months later, optical coherence tomography revealed preretinal macular fibrosis detachment at the foveal lesion without any treatment. During follow-up, preretinal macular fibrosis at the macular lesion was completely detached. Further, posterior vitreous detachment was observed and the shape of the macula and the patient's left visual acuity had improved.

CONCLUSIONS

In our case, both formation and spontaneous peeling of preretinal macular fibrosis occurred without any treatment for Coats disease, which is an unusual finding. Vitreous changes might have occurred during the natural clinical course, causing subsequent posterior vitreous detachment and resulting in spontaneous peeling of fibrosis.

Plentiful melanin pigment containing histiocyte-like cells in Coats disease: awareness avoids diagnostic pitfall

Coats disease is an exudative retinal vasculopathy characterized by presence of yellow-golden deposits in the retina and retinal detachment. Sub-retinal fluid drainage performed as a part of therapeutic management makes the fluid amenable to cytological examination. Infection by toxoplasma may closely simulate the ocular symptoms seen in Coats disease. Awareness of the cytological findings in Coats disease helps to clinch accurate diagnosis. We herein present a case of Coats disease with many histiocyte-like cells with plentiful intracytoplasmic melanin pigment in cytology smears from sub-retinal fluid where cytological diagnosis was challenging and a correct diagnosis was made with the aid of ancillary techniques.

Rhegmatogenous retinal detachment in Coats' disease: a case report

BACKGROUND

Coats' disease was originally defined as a unilateral idiopathic exudative retinopathy in young males, characterized by abnormal retinal vascular telangiectasia with intraretinal and subretinal lipid exudation. The retinal detachment is usually exudative. Herein, we describe a case of rhegmatogenous retinal detachment with detectable retinal break in a patient with Coats' disease.

CASE PRESENTATION

A 15-year-old Indo-Aryan male patient presented with sudden painless diminution of vision in his right eye of 4 days duration. Upon examination, the anterior segment in both eyes and left fundus was within normal limits. Dilated fundus evaluation of the right eye revealed telangiectasia of the retinal vessels, with subretinal exudation in superotemporal and superonasal quadrants and presence of subretinal fluid in the superotemporal area extending into fovea. There was also presence of single flap horseshoe tear in the superotemporal quadrant at around the 10 o'clock position in the equatorial region, with no secondary changes. The retina was reattached with encircling band buckle combined with vitrectomy and silicon oil tamponade. Seven months post vitrectomy, lenticular opacification developed, for which he underwent silicon oil removal, along with lens aspiration and implantation of foldable intraocular lens. Over the period of 1 year, his best corrected visual acuity improved from 6/60 to 6/18 in the affected eye at the last follow-up visit. The recovery was uneventful following the subsequent surgery.

CONCLUSION

Coats' disease has a remarkable diversity in clinical presentation and morphology. The disease can also present with an underlying break, which may not be attributed to any iatrogenic modality. The treatment modalities in coats' disease should be tailored individually due to the low incidence of the disease and the great variation in severity upon presentation. Prompt management restores the best possible anatomical outcome and maintains good vision.

Resolution of Foveal Lipid Deposition in Adult-Onset Coats Disease With Combined Focal Laser Photocoagulation and Anti-VEGF Therapy

A major cause of poor visual prognosis in Coats disease is the formation of fibrovascular changes following dense foveal lipid deposition. The authors document the multimodal imaging findings of a 38-year-old woman and a 23-year-old man with adult-onset Coats disease who presented with macular edema and foveal lipid accumulation. Thermal laser targeting individual capillary macroaneurysms combined with intravitreal anti-vascular endothelial growth factor (VEGF) therapy was performed. Although there was a subsequent increase in foveal lipid immediately following the resolution of macular edema, these lipids largely resolved, leaving behind no evidence macular neovascular fibrosis. This report highlights the potential protective effect of combination therapy with thermal laser and intravitreal anti-VEGF therapy for macular exudation associated with Coats disease. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:396-399.].

Clinical features and prognostic factors in 71 eyes over 20 years from patients with Coats' disease in Korea

This retrospective study assesses the clinical features, treatment strategies, and long-term outcomes of patients with Coats’ disease in Korea. Multimodal imaging and medical records of consecutive patients treated between July 2000 and April 2020 at two tertiary centers were evaluated based on onset age (adult vs. childhood [< 18 years]). Factors associated with final visual acuity (VA) and risk of treatment failure were assessed. A total of 71 eyes of 67 patients were included, with subgrouping by onset age showing 45% childhood and 55% adult cases. Overall, Stage 2 disease was most common at presentation (76%), though childhood cases had more Stage 3b (22% vs. 3%, P = 0.02) and greater clock hours of retinal telangiectasia (7 vs. 5, P = 0.005). First-line treatment included laser (25%), combined laser/anti-VEGF (23%), cryotherapy (20%), surgery (16%), and anti-VEGF only (9%). Cryotherapy was associated with a higher risk for secondary interventions (OR 11.8, P < 0.001), required in 56% overall. Despite a 3-line VA decrease in 34% overall, adult cases had superior final VA (P = 0.037). Multivariable regression showed that the number of anti-VEGF injections performed during the initial treatment period was associated with a 9.4 letter improvement in vision (P = 0.041). We observed a higher proportion of adult-onset Coats’ disease than previously reported in other non-Asian populations. An aggressive treatment with the addition of anti-VEGF may yield the most favorable long-term visual outcomes.

External Drainage Alone Versus External Drainage With Vitrectomy in Advanced Coats Disease

PURPOSE

To evaluate the efficacy of transscleral drainage of subretinal fluid (TDSRF) with and without pars plana vitrectomy (PPV), which are performed as an adjunct to ablative therapies in advanced Coats disease.

DESIGN

Retrospective, comparative case series.

PATIENT POPULATION

A total of 31 eyes from 31 consecutive patients with advanced Coats disease at an average age of 47.8 ± 34.2 (2-156) months at the time of the surgery, who underwent TDSRF alone or in combination with PPV.

METHODS

Main outcome measurements were LogMAR visual acuity values, anterior and posterior segment findings, need for further surgery, laser photocoagulation, and anti-vascular endothelial growth factor (anti-VEGF) treatment. Anatomical success was defined as the maintenance of retinal reattachment without any further surgery during follow-up.

RESULTS

Sixteen patients underwent TDSRF alone, and 15 patients underwent combined TDSRF and PPV. Mean follow-up time was 34.8 ± 32.9 months (6-128). Anatomical success rate of combined TDSRF and PPV was higher than that of TDSRF alone (93.8% vs 75%, respectively). The incidence of epiretinal membrane formation, number of laser photocoagulation procedures, and anti-VEGF treatments were statistically significantly higher in the group that underwent TDSRF alone than in those who had combined TDSRF and PPV in the long term. There was an improvement in vision in only 4 eyes (12.9%) (all >3 years old at presentation) during the follow-up.

CONCLUSIONS

Combined TDSRF and PPV appears to be more effective in controlling the disease than TDSRF alone, as an adjunct to ablative procedures for the treatment of advanced Coats disease. The need for additional treatment is much less with the addition of PPV.

Experience with Intravitreal Ranibizumab as an Adjunct to Ablation Therapy in Eyes with Exudative Coats' Disease

Background

Coats’ disease is a rare entity with retinal vascular telangiectasia that can progress to exudative retinal detachment, neovascular glaucoma, and a blind painful eye requiring enucleation. Despite recent therapeutic advances decreasing the need for enucleation, no consensus exists about the optimum management of exudative Coats’ disease. The use of intravitreal anti-vascular endothelial growth factor agents as an adjunct to ablation therapy has been shown to achieve favorable outcomes, but some reports suggest an increased incidence of vitreoretinal (VR) fibrosis and tractional retinal detachment (TRD).

Methods

We retrospectively reviewed records of patients presenting with exudative Coats’ disease (stages 2 and 3) from April 2016 till November 2020. Extracted data included clinical and radiological assessment, stage (Shields’ classification), interventions, and follow-up.

Results

Sixteen eyes were included in the final analysis, of which 4 (25%) were stage 2 and 12 (75%) were stage 3. All eyes underwent intravitreal ranibizumab injection combined with ablation therapy, 14 (87.5%) underwent cryotherapy, 4 (25%) underwent laser ablation, 3 (18.75%) underwent external subretinal fluid drainage, and 3 (18.75%) underwent buckle or vitrectomy surgery. After a median follow-up of 16 months, 11 eyes (68.75%) had complete resolution, 4 (25%) had incomplete resolution, and only one (6.25%) progressed but did not require enucleation. Three eyes (18.75%) developed VR fibrosis, but none progressed to TRD.

Conclusion

Combining intravitreal ranibizumab injection with ablation therapy is effective in managing exudative Coats’ disease. External drainage should be preserved for when ablation therapy is not feasible. Future prospective trials with pre-defined outcomes are required.

Optical Coherence Tomography Angiography Findings After Intravitreal Ranibizumab in Patients With Coats Disease

The aim of this retrospective study was to describe the vascular features in eyes with Coats disease, using optical coherence tomography angiography (OCTA), at baseline and after 3 monthly intravitreal injections of ranibizumab. Fifteen eyes of 15 consecutive patients affected by Coats' disease were recruited in this study. All patients underwent the best-corrected visual acuity (BCVA) evaluation, fundus examination, fluorescein angiography (FA), indocyanine green angiography (ICGA), multicolor imaging, structural Spectral Domain (SD)-OCT and OCTA at baseline and 1 month after the third monthly ranibizumab injection (loading phase). Fifteen patients completed the study, of whom nine were males and six females. Mean age was 20.4 ± 2 years. BCVA was 0.46 ± 0.11 logMar and 0.47 ± 0.12 logMar at baseline and after treatment, respectively (p = 0.164). SD-OCT revealed no significant decrease in central macular thickness (486.33 μm ± 93.37 at baseline vs. 483.4 μm ± 80.97 after treatment; p = 0.915). The subretinal exudates persisted in macular region after intravitreal injections. OCTA showed a general vascular rarefaction in superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillary (CC) that did not change after loading phase. This study showed no functional and vascular improvement following 3 monthly ranibizumab injections. OCTA, non-invasive technique, could be useful during follow up of these patients and provide a better understand of pathogenesis of this disorder.

Coats plus syndrome (cerebroretinal microangiopathy with calcifications and cysts-1): A case report

We present a 6-year-old girl with skin hyperpigmentation, leukoplakia, and onychodystrophy, the classic mucocutaneous triad usually associated with dyskeratosis congenita. The patient also had premature graying of the hair, bone marrow failure, hepatitis, exudative retinopathy, osteopenia with multiple long bone fractures, and intracranial calcifications and brain cysts. Coats plus syndrome is a rare disease with a clinical and genetic overlap with dyskeratosis congenita. This disease is reviewed, with a focus on the pathogenesis of the genetic anomalies and its background as a telomere biology disorder.

Three-year follow-up of Coats disease treated with conbercept and 532-nm laser photocoagulation

BACKGROUND

Coats disease is an idiopathic exudative outer retinopathy caused by abnormal retinal vascular development.

AIM

To evaluate the long-term outcomes of intravitreal conbercept injection with laser photocoagulation as a treatment for Coats disease in adults.

METHODS

This retrospective case series study included patients diagnosed with Coats disease and treated with intravitreal conbercept injection and 532-nm laser photocoagulation at the Ophthalmology Department of Shenzhen People’s Hospital between January 2016 and January 2017. Best-corrected visual acuity (BCVA) measurements, noncontact tonometry, ophthalmoscopy, fundus photography, fundus fluorescein angiography and optical coherence tomography were performed before treatment and at 1 wk, 1 mo, 3 mo, 6 mo, 9 mo, 12 mo, 24 mo and 36 mo after therapy. Best-corrected visual acuity was measured using the early treatment of diabetic retinopathy study chart.

RESULTS

The study included eight eyes of 8 patients (7 men) aged 36.10 ± 6.65 years. The average BCVA of the affected eye before treatment was 51.17 ± 15.15 letters (range, 28–70 letters), and the average central macular thickness was 303.30 ± 107.87 µm (range, 221–673 µm). Four eyes were injected once, three were injected twice, and one was injected three times. Average follow-up duration was 37.33 ± 2.26 mo. Average BCVA of the affected eye was 51.17 ± 15.15 letters before treatment and was increased by 13.50 ± 3.20, 16.25 ± 7.73, 18.25 ± 8.96, 18.03 ± 5.27, 18.63 ± 3.35, 19.75 ± 6.96, 18.05 ± 5.36 and 17.88 ± 3.45 letters at 1 wk, 1 mo, 3 mo, 6 mo, 9 mo, 12 mo, 24 mo and 36 mo after treatment, respectively (P < 0.01). The patients showed varying degrees of subretinal fluid resorption after treatment. None of the patients had serious complications such as increased intraocular pressure, development/progression of cataracts, endophthalmitis or retinal detachment.

CONCLUSION

Intravitreal injection of conbercept combined with 532-nm laser photocoagulation may be a feasible treatment for Coats disease in adult patients.

Fovea-sparing coats disease: A rare clinical entity

PURPOSE

To evaluate the rarity, clinical features and management of Coats disease characterized by fovea-sparing enhancing the importance of pediatric retinal screening and early management to maintain a good visual acuity.

METHODS

Retrospective analysis of approximately 40 patients affected by Coats disease between 2000 and 2020 at the Retinoblastoma Referral Center and Ophthalmology unit of the University of Siena in Italy.

RESULTS

Two patients with fovea sparing Coats disease were included. Both presented an extrafoveal Coats disease (stage 2A by Shields classification) when they were 5 and 6 years old respectively.They had no anterior findings and a presenting visual acuity of 20/20 reflecting the early stage and a milder phenotype of the disease which are indeed more likely to be found in patients older than 3 years at presentation.Both presented telangiectasia and retinal exudation in the affected eye. Standard Argon laser photocoagulation and subsequently Cryotherapy were performed in the telangiectatic retinal periphery of both patients obtaining an excellent control and regression of the disease.

CONCLUSIONS

Careful pediatric retinal screening and early management are crucial to ensure a good visual prognosis in such an early feature of Coats disease as fovea sparing since this condition unfortunately tends to recall the physician's attention in more advanced stages.Due to the extremely poor number of articles regarding such a rare feature of Coats disease like fovea sparing, we report our experience.