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ABSTRACT
Unilateral retinal pigment epithelium dysgenesis (URPED) is one of the exceedingly rare conditions of the retina. Herein, the first case of URPED in Pakistan is reported in a 33-year male who presented with a uniocular decrease in vision in his right eye. His general, ophthalmic, and family history were unremarkable. His right eye fundus examination revealed a pale centrally atrophic area bounded by scalloped fringe-like margins in the peripapillary region. The lesion showed hypo-autofluorescence on fundus autofluorescence. Optical coherence tomography (OCT) scan showed central atrophy, thinned-out ellipsoid, and interdigitation zone with hyperplastic changes in the retinal pigment epithelium (RPE). The left eye revealed no abnormal findings either on clinical examination or on imaging modalities. He was diagnosed with URPED with preserved vision. No treatment was required. The patient was counselled about the nature of his disease, associated complications, and the need for its long-term follow-up.
Key Words: Retina, Vision, Unilateral retinal pigment epithelium dysgenesis.
INTRODUCTION
Unilateral retinal pigment epithelium dysgenesis (URPED) was initially reported by Cohen et al. as unilateral, leopard-spot lesions in the retinal pigment epithelium (RPE).1 The characteristic clinical features of the disease are well-defined, scalloped margins of RPE, hyperplasia, and fibrosis, and the remarkable inversion of fundus autofluorescence (FAF) with hyperfluorescence observed on fundus fluorescence angiography (FFA).2 These characteristic findings were recently reported in two Asian patients by Zhu et al.3 With only 24 reported cases worldwide, and only a few from Asia, this is the first case of URPED in Pakistan to the best of authors’ knowledge.
CASE REPORT
A 33-year Afghan male presented with blurred vision in his right eye for the last few months. His ophthalmic history was unremarkable as was his past medical or drug history. His family history was negative for any familial disorders. Any ocular trauma or an inflammatory episode was denied. On examination, his best corrected visual acuity was 20/30 in the right eye and 20/25 in the left eye.
Examination revealed normal anterior segments of both eyes with intraocular pressures in the normal range. The posterior pole of his right eye showed a large flat solitary lesion, yellowish pale in colour, extending from the optic disc to the inferior half of the macula bordered by fringe-like margins. The central area of the lesion showed RPE atrophy, with fibrotic hyperplastic RPE changes in the scalloped borders (Figure 1A). A greyish zone of hypopigmentation was seen in the mid-periphery. The vascular arcades appeared normal. The posterior segment in the left eye was unremarkable.
The FAF of the right eye revealed a markedly hypo-autoflourescent lesion on the macula with scalloped fringe-like margins. The inferior mid-periphery of the fundus showed a triangular hypo-autoflourescent area surrounded by a zone of hyper-autoflourescence indicating a gravitational tract (Figure 1B).
Figure 1: (A) Right-eye fundus photograph showing a yellow pale lesion with scalloped fringe-like margins. (B) Fundus autofluorescence (FAF) with marked hypo-autoflourescent area correlating with fundus photo. Gravitational tract inferiorly (arrow).
Table I: Characteristics of published cases of unilateral retinal pigment epithelium dysgenesis worldwide.
|
S.No |
Year |
Origin |
Author |
Journal |
Laterality |
Age |
Gender |
Presenting vision |
SD=OCT |
Complications/ Findings |
Treatment |
Final vision |
|
1 |
2002 |
White |
Cohen et al. |
Arch Ophthalmol |
OS |
34 |
M |
20/20 |
- |
CNV on FFA |
Krypton laser |
20/20 |
|
2 |
|
White |
|
|
OD |
27 |
M |
20/25 |
Central atrophy, thickened sensory retina, cystic changes, ERM |
ERM/ vascular tortuosity/ Progression over 7 years |
|
20/40 |
|
3 |
|
White |
|
|
OD |
16 |
F |
20/20 |
- |
- |
- |
20/20 |
|
4 |
|
White |
|
|
OD |
27 |
M |
20/128 |
- |
CNV- FFA |
Krypton laser |
20/126 |
|
5 |
2008 |
- |
Berthout et al. |
J Fr Ophthalmol |
|
36 |
F |
- |
- |
Retinal folds |
No follow-up |
N/A |
|
6 |
2009 |
Asian |
Cohen et al. |
Am J Ophthalmol |
OD |
19 |
M |
20/20 |
Central RPE atrophy/ transmission defects |
- |
- |
20/20 |
|
7 |
|
White |
|
|
OD |
36 |
F |
20/32 |
Central atrophy, ERM |
ERM, retinal folds |
- |
20/32 |
|
8 |
|
White |
|
|
OS |
18 |
M |
20/40 |
Central RPE atrophy/ transmission defects |
Torturous vessels |
- |
20/40 |
|
9 |
|
White |
|
|
OD |
42 |
|
20/400 |
Central atrophy, transmission defects, cystic irregular retinal surface, localised detachment |
|
|
20/400 |
|
10 |
|
White |
|
|
OD |
16 |
F |
20/25 |
Central RPE atrophy/ transmission defects |
Vascular tortuosity, retinal folds |
|
20/25 |
|
11 |
2012 |
- |
Renz et al. |
Arch Ophthalmol |
OD/OS |
35 |
F |
20/25 |
Outer retinal thinning, attenuated IS/OS |
- |
Lost to follow up |
N/A |
|
12 |
2014 |
- |
Shioyama et al. |
Case Rep Ophthalmol |
OS |
8 |
M |
20/20 |
Subfoveal CNV |
Progression/ treatment resistantCNVM |
SITA /Bevacizumab |
20/50 |
|
13 |
2017 |
- |
Yamasaki et al. |
Retina Cases Brief Rep |
OS |
8 |
M |
20/20 |
Attenuated IS/OS junction, choroidal thinning |
Mild progression of atrophic lesion over 2 years |
- |
20/20 |
|
14 |
2018 |
- |
Krohn et al. |
Acta Ophthalmol |
OS |
21 |
M |
20/20 |
Disorganized retinal architecture, Foveal RPE atrophy |
Progressive RPE atrophy over 10 years |
- |
20/100 |
|
15 |
2019 |
African-American |
Florakis et al. |
Retina Cases Brief Rep |
OS |
47 |
M |
20/20 |
RPE hyperplasia, shallow RPE detachment, thinned outer retina. |
- |
- |
20/20 |
|
16 |
2019 |
White |
Gar-Or et al. |
Retina Cases Brief Rep |
OS |
30 |
F |
20/25 |
Hyporeflective subretinal mass originating from RPE with subretinal fluid |
Presumed RPE tumour |
Ranibizumab + aflibercept intravitreally lead to reduction in subfoveal/ subretinal fluid |
20/20 |
|
17 |
2019 |
- |
Preziosa et al. |
Retina Cases Brief Rep |
OS |
51 |
F |
20/200 |
RPE hyperplasia with atrophy and subfoveal PED |
CNVM |
2 injections of bevacizumab |
20/50 |
|
18 |
2020 |
- |
Riga et al. |
Ocul Oncol Pathol |
OS |
52 |
M |
20/40 |
ERM, retinal tortuosity and folds, RPE atrophy |
Progressive atrophy over 8 years |
- |
20/200 |
|
19 |
2020 |
Chinese |
Ding et al. |
BMC Ophthalmol |
OS |
10 |
F |
20/25 |
Thinned out ellipsoid zone, irregular RPE-Bruch’s complex. Inhomogeneous signals of outer segments of photoreceptors at the fovea. |
- |
- |
20/25 |
|
20 |
2020 |
- |
Sekeryapan Gediz et al. |
Turk J Ophthalmol |
OD |
32 |
M |
20/32 |
Retinal folds, CNV with SRF |
Retinal folds, CNV |
Bevacizumab |
20/20 |
|
21 |
2020 |
- |
Diafas et al. |
Am J Ophthalmol Case Rep |
|
16 |
F |
Counting Fingers at 1 meter |
Localized tractional detachment with macular hole |
TRD with FTMH |
PPV with ERM-ILM peel |
20/32 |
|
22 |
2021 |
- |
Handa et al. |
Can J Ophthalmol |
OS |
16 |
F |
20/30 |
RPE loss with hypertransmission+ RPE thickening |
- |
- |
N/A |
|
23 |
2022 |
Chinese |
Zhu et al. |
BMC Ophthalmol |
OD |
51 |
M |
14/20 |
Cystic changes, disorganised architecture, ERM, CNVM |
CNV, ERM |
- |
N/A |
|
24 |
|
|
|
|
OD |
39 |
M |
20/25 |
Abnormal RPE, cystic changes, subretinal hyperreflectivity |
- |
- |
N/A |
Figure 2: Spectral-domain optical coherence tomography (SD-OCT): Retinal pigment epithelium (RPE) hyperplasia with choroidal hyperreflectivity secondary to hyper-transmission effect.
Spectral-domain optical coherence tomography (SD-OCT) revealed distorted outer retinal layers. The ellipsoid and interdigitation zones were thinned out. The RPE-Bruch’s membrane complex showed hyperplastic changes throughout the lesion giving hypertransmission on OCT (Figure 2). There was no fluid, blood, or exudates seen in the scans.
The FAF and OCT scans of the fellow-eye were unremarkable. The patient was diagnosed as having right-eye URPED with good vision. He was counselled about the nature of his disease and the need for its long-term follow-up.
DISCUSSION
The pale appearance surrounded by fringe-like margins, marked hypo-autofluorescence on FAF along with thinned-out interdigitation and ellipsoid zones on OCT in this patient were consistent with the findings of Cohen et al.1 The triangular area of a gravitational tract on FAF suggested a now resolved accumulation of fluid (Figure 1). Whether this was a separate event or was secondary to the URPED lesion remained a query.
The disease does not show a preference towards gender. Literature showed middle-aged people being affected more than young (Table I). The aetiology of this condition remains unidentified. It was hypothesised by Renz et al. that an infection, inflammation, or an autoimmune condition could play a role. With the word dysgenesis, they suggested that it should be a bilateral disease and reported a bilateral variant of URPED in 2012.4 This was one of its kind and no other bilateral cases have been reported since then.
Despite its distinctive features, it is important to consider other differentials. Acute zonal occult outer retinopathy (AZOOR) may appear as a whitish discoid lesion but the fringe-like margins of URPED can differentiate the two. Combined hamartoma of the retina and RPE (CHRRPE) is another entity of which URPED is a forme fruste variant. It can present as a raised lesion with retinal disorganisation. Furthermore, clinical manifestations, age at presentation, and FFA features may differ from URPED. Choroidal osteoma, a benign ossifying intraocular tumour, has smooth delineating margins as opposed to URPED along with a prominent elevated mass, which is not seen in URPED.
The prognosis of the disease seems good unless complications such as choroidal neovascular or epiretinal membranes, retinal detachment, and foveal atrophy develop.2 Gal-Or et al. reported a presumed intraocular tumour from an existing URPED lesion.5
However, there are certain limitations to this case. There was a lack of the fundus fluorescein angiography (FFA) information as the patient could not financially afford further tests. Further long-term follow-up was also needed as the disease is reported to progress slowly and gradually.
PATIENT’S CONSENT:
A written informed consent was taken from the patient.
COMPETING INTEREST:
The authors declared no competing interest.
AUTHORS’ CONTRIBUTION:
HQ: Prepared the draft.
RS: Revised the draft and provided critical feedback.
Both authors approved the final version.
REFERENCES