Pigmented and depigmented lesions of the ocular fundus

Advances in multimodal imaging for diagnosis of pigmented ocular fundus lesions

Pigmented ocular fundus lesions can range from benign to malignant. While observation is reasonable for asymptomatic benign lesions, early recognition of tumours that are vision or life threatening is critical for long-term prognosis. With recent advances and increased accessibility of multimodal imaging, it is important that providers understand how to best use these tools to detect tumours that require early referral to subspecialty centres. This review aims to provide an overview of pigmented ocular fundus lesions and their defining characteristics using multimodal imaging. We cover the spectrum of pigmented ocular fundus lesions, including freckle and focal aggregates of normal or near-normal uveal melanocytes, retinal pigment epithelium (RPE) hyperplasia, congenital hypertrophy of the RPE, RPE hamartoma associated with familial adenomatous polyposis, congenital simple hamartoma of the RPE, combined hamartoma of the retina and RPE (congenital hypertrophy of the RPE), choroidal nevus, melanocytosis, melanocytoma, melanoma, adenoma, and RPE adenocarcinoma. We describe key diagnostic features using multimodal imaging modalities of ultra-widefield fundus photography, fundus autofluorescence, optical coherence tomography (OCT), enhanced-depth imaging OCT, ultrasonography, fluorescein angiography, indocyanine green angiography, and OCT angiography (OCTA), with particular attention to diagnostic features that could be missed on fundus examination alone. Finally, we review what is on the horizon, including applications of artificial intelligence. Through skilled application of current and emerging imaging technologies, earlier detection of sight- and life-threatening melanocytic ocular fundus tumours can lead to improved patient prognosis.

Choroidal Melanocytic Hamartoma

We report on a case series that revealed flat, choroidal lesions on optical coherence tomography (OCT) and on enface MultiColor® (MCI) imaging of the fundus but were not noticeable on clinical examination or conventional color fundus images. This observational study included 12 eyes from 11 patients who had distinct, orange-colored lesions on MCI. Retinal imaging was conducted using conventional color fundus photography and OCT. On the color fundus images and the blue and green reflectance channels of MCI, each of the lesions was difficult to distinguish. On the infrared channel, the lesion was identified as bright white in color and bright orange on the multicolor image. The lesion was identified on OCT as a flat, homogeneous hyperreflective lesion involving the choroid, with an intact overlying retinal pigment epithelium and retinal layers. A comparison of the clinical and imaging features with other known entities led to the conclusion that the lesion was a distinct clinical entity. The presence of melanin in the lesion was confirmed based on the retinal imaging findings and the light absorption properties of melanin. As a result, the lesion was named as 'choroidal melanocytic hamartoma'. A longer follow-up is required to confirm the benign nature of this clinical entity.

Systemic considerations with pigmented fundus lesions and retinal pigment epithelium hamartomas in Turcot syndrome

PURPOSE OF REVIEW

To illustrate retinal pigment epithelium hamartomas (RPEHs) in a patient with known Turcot syndrome and to demonstrate the significance of these lesions in other colonic polyposis syndromes.

RECENT FINDINGS

The presence of multiple, bilateral RPEHs is a specific marker for familial adenomatous polyposis (FAP). Recent studies have noted RPEHs in associated syndromes including Gardner and Turcot syndromes. Herein, we illustrate an 18-year-old male patient with known brain medulloblastoma who was documented 7 years later to have asymptomatic RPEHs in both eyes, demonstrating hypo-autofluorescence.

SUMMARY

This patient with previous medulloblastoma and known Turcot syndrome was later found to have typical RPEHs, a feature that is important in family screening. Confirmation of RPEHs related to Turcot syndrome was made, and genetic evaluation confirmed germline mutation in the adenomatous polyposis coli (APC) gene. Observation was advised. Due to the fairly rapid progression to colorectal cancer if untreated, ophthalmologists should be aware that RPEHs can be the first extracolonic manifestation of FAP, Gardner syndrome, and Turcot syndrome.

Torpedo-like lesions in the ocular fundi of Gardner syndrome: hiding in plain view

Background: The coexistence of fundus torpedoes and Gardner syndrome was initially reported in 1989 and 1992 by Gass and Roseman. Gardner syndrome is a dominantly inherited disease characterized by a multitude of potentially lethal gastrointestinal polyps. Over the ensuing quarter century, several publications demonstrated uncommon, but easily recognized, fundus lesions called Torpedo Maculopathy in apparently normal individuals. These fundus abnormalities were thought to be single and isolated without systemic associations. During the same period of time, a variety of nonspecific fundus abnormalities were described in Gardner syndrome, which, in retrospect, included highly specific lesions that closely resembled macular torpedoes and sometimes were indistinguishable from them.Patient and methods: We now report a confirmed case of Gardner syndrome with numerous fundus torpedoes, and carefully analyze the voluminous literature of both Gardner syndrome and Torpedo Maculopathy.Results: We demonstrate shared features of the fundus lesions in both diseases, and hypothesize that they may have genetic as well as ophthalmoscopic similarities in common.Conclusions: We therefore recommend that individuals with classic isolated torpedoes undergo evaluations for mutations in the Gardner gene (Adenomatous polyposis coli) and for the presence of gastrointestinal polyps and other systemic features of Gardner syndrome. We also suggest that apparently normal individuals, who are genetically related to patients with known classic torpedoes, undergo inspection of their fundi for the possible presence of characteristic lesions.

Bilateral idiopathic choroidal hyperpigmentation

PURPOSE

To report a series of cases showing bilateral circumpapillary hyperpigmentation on routine fundus examination.

METHODS

In this observational case series, three patients showing bilateral circumpapillary hyperpigmentation on routine fundus examination were included. Multimodal retinal imaging was done for these cases.

RESULTS

Multimodal imaging of the lesion showed the hyper pigmentation to be confined to the choroid. The optical coherence tomography scans described the features through the hyperpigmented area, adjacent hypopigmented area and the normally pigmented area of the fundus as suggestive of choroidal hyper melanosis. Follow-up of these lesions over a period of 2-6 years showed no change in the vision or characteristics of the lesion.

CONCLUSION

Bilateral circumpapillary hyperpigmentation needs to be considered as a differential for bilateral peripapillary pigmented lesions.

Diffuse bear-track retina: profound, bilateral, grouped congenital pigmentation of the retinal pigment epithelium in an infant

Grouped congenital hypertrophy of the retinal pigment epithelium is a conspicuous ocular anomaly wherein highly pigmented, demarcated but flat retinal lesions arise from the retinal pigment epithelium. These lesions ("bear tracks") typically increase in size as they approach the retinal periphery. The discovery of pigmentary lesions in a young infant with a poor red reflex warrants urgent ophthalmological and electrodiagnostic review to exclude serious diagnoses, including an early-onset severe retinal dystrophy. We present the case of a 2-month-old boy with marked bear-tracks over the entirety of each retina, but with normal electrodiagnostic findings, genetics, and visual behavior.

Torpedo Retinopathy

Purpose

Torpedo lesions in the retina are rare. This study aimed to investigate torpedo-shaped lesions in the retina in an adult population and to determine the spectrum and features of the disease.

Methods

The review of a database for clinical diagnosis identified nine patients who were diagnosed with torpedo-shaped lesions in the retina between June 2017 and February 2019. Fundus photography and optical coherence tomography (OCT) imaging were used to analyze the cases. Multicolor imaging was also performed.

Results

Nine patients with torpedo-shaped lesions in the fundus were identified. Fundus images revealed that the lesion involved the macula in six eyes; in the remaining three eyes, the lesion was present outside the macula. OCT identified six patients with type 1 torpedo lesions, one with type 2, and two with type 3. On multicolor imaging, the lesion was visualized as a region of increased reflectance in blue, green, and infrared light in all eyes, with notably increased infrared reflectance in eyes with focal choroidal excavation. Choroidal neovascular membrane was evident in one patient on OCT angiography.

Conclusion

Torpedo lesions in the retina can occur away from the macula and exhibit features similar to those of torpedo maculopathy. As such, the authors propose a change in the nomenclature for torpedo lesions in the retina from "torpedo maculopathy" to "torpedo retinopathy."

Multimodal imaging characteristics of congenital grouped hyper- and hypo-pigmented fundus lesions

BACKGROUND

The imaging characteristics of congenital grouped pigmentation of the retinal pigment epithelium (CGP-RPE) and its non-pigmented variant - grouped congenital albinotic retinal pigment epithelial spots (GCARPES) are poorly defined in the literature. Our case series reports their multimodal imaging characteristics across a spectrum of presentations.

METHODS

A retrospective review of patient records was conducted on patients seen at the Centre for Eye Health between January and December 2016. The multimodal imaging findings across four cases is described using optical coherence tomography (OCT), infrared imaging, ultra-widefield imaging, fundus photography and fundus autofluorescence (FAF).

RESULTS

Case 1 is a 55-year-old female with a bilateral presentation of CGP-RPE showing typical features. Case 2 is a 28-year-old male with a classical presentation of GCARPES in the left eye. Case 3 is a 33-year-old female with unilateral CGP-RPE and an atypical solitary congenital hypertrophy of the retinal pigment epithelium (CHRPE) in the same eye. Case 4 is a unilateral presentation in an 11-year-old female with unusual characteristics. Ocular imaging characteristics of CGP-RPE lesions varied between patients: OCT showed visible RPE changes in cases 3 and 4 but not case 1. The pattern of FAF and infrared imaging also varied with most lesions displaying a pattern of hypo-autofluorescence, but some central lesions in case 3 exhibited hyper-autofluorescence. All lesions were visible with fundus photography.

CONCLUSION

FAF can be helpful in alerting clinicians to the presence of lesions that may be difficult to visualise funduscopically and OCT can be helpful in differentiating between CGP-RPE and its variants from more sinister ocular conditions. All in all, these findings highlight the variable manifestation of CGP-RPE and its variants on multimodal imaging; the diagnosis of CGP-RPE and its variants should remain based on its characteristic funduscopic appearance.

The advantages of intermediate-tier, inter-optometric referral of low risk pigmented lesions

Purpose

Pigmented ocular lesions are commonly encountered by eye‐care professionals, and range from benign to sight or life‐threatening. After identifying a lesion, the primary care professional must establish the likely diagnosis and decide either to reassure, to monitor or to refer. The increasing use of ocular imaging technologies has contributed to an increase in the detection rate of pigmented lesions and a higher number of referrals, which may challenge existing pathways of health‐care delivery. Specialist services may be over‐burdened by referring all patients with pigmented lesions for an opinion, while inter‐optometric referrals are underutilised. The aim of this study was to describe the referral patterns of pigmented lesions to an optometry led intermediate‐tier collaborative care clinic.

Methods

We performed a retrospective review of patient records using the list of patients examined at Centre for Eye Health (CFEH) for an initial or follow up pigmented lesion assessment between the 1/7/2013 and the 30/6/2016. Analysis was performed on: patient demographic characteristics, the referrer's tentative diagnosis, CFEH diagnosis and recommended management plan.

Results

Across 182 patient records, the primary lesion prompting referral was usually located in the posterior segment: choroidal naevus (105/182, 58%), congenital hypertrophy of the retinal pigment epithelium (CHRPE; 11/182, 6%), chorioretinal scarring (10/182, 5%) or not specified (52/182, 29%). Referrals described a specific request for ocular imaging in 25 instances (14%). The number of cases with a non‐specific diagnosis was reduced after intermediate‐tier care assessment (from 29% to 10%), while the number of diagnoses with less common conditions rose (from 2% to 21%). There was a 2% false positive referral rate to intermediate‐tier care and a first visit discharge rate of 35%. A minority required on‐referral to an ophthalmologist (22/182, 12%), either for unrelated incidental ocular findings, or suspicious choroidal naevi. Conditions most amenable to optometric follow up included: 1) chorioretinal scarring, 2) choroidal naevus, and 3) CHRPE.

Conclusions

Intermediate‐tier optometric eye‐care in pigmented lesions (following opportunistic primary care screening) has the potential to reduce the number of cases with non‐specific diagnoses and to increase those with less common diagnoses. The majority of cases seen under this intermediate‐tier model required only ongoing optometric surveillance.

Pigmented Lesions of the Retinal Pigment Epithelium

: The primary eye care practitioner assumes an important role in clinical decisions involving the differentiation between malignant and nonmalignant pigmented lesions. A misdiagnosis may have profound consequences on patient management and visual or life prognosis. However, information on these lesions, particularly their appearance using advanced imaging, is fragmented throughout the literature. The purpose of this review is to describe these features in detail, so that the implications of this information on clinical practice are more readily apparent. Clinically relevant descriptions of pigmented lesions of the retinal pigment epithelium using traditional and advanced imaging modalities in the literature were collated and integrated with findings from patients seen at the Centre for Eye Health. The information was then organized and tabulated. Finally, a flow diagram was created to be used as a clinical reference in the differential diagnosis of pigmented lesions of the retinal pigment epithelium.