AUTOFLUORESCENCE CHARACTERISTICS OF CONGENITAL HYPERTROPHY OF THE RETINAL PIGMENT EPITHELIUM Beatriz S. Takahashi, MD, Claudia Brue`, MD, Richard F. Spaide, MD
Purpose: To report the autofluorescence features of congenital hypertrophy of the retinal pigment epithelium (CHRPE). Methods: Four patients with CHRPE were evaluated using autofluorescence in a camera-based system. Results: All CHRPE lesions studied had well demarcated borders and were hypoautofluorescent. Presence of a hypopigmented halo and lacunae did not alter the homogeneous hypofluorescence. Conclusion: Hypoautofluorescence confirmed the known absence of lipofuscin in the retinal pigment epithelium cells of CHRPE lesions. Autofluorescence imaging may provide useful information in evaluating pigmented lesions of the fundus. RETINAL CASES & BRIEF REPORTS 2:259 –261, 2008
From the Vitreous, Retina, Macula Consultants of New York, and the LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear, and Throat Hospital, New York, New York.
adulthood. Choroidal melanomas and nevi have specific autofluorescence findings, offering the possibility that fundus autofluorescence can be used to differentiate CHRPE lesions from other pigmented lesions in the fundus.
L
esions in congenital hypertrophy of the retinal pigment epithelium (CHRPE) are generally flat and solitary and have well demarcated borders. Colors vary from grayish brown to black, and it is usually surrounded by a hypopigmented halo. It is an asymptomatic and benign lesion, but CHRPE may mimic other pigmented lesions in appearance such as ocular nevi and melanomas. The histopathology of CHRPE suggests that while the retinal pigment epithelium (RPE) cells are hypertrophic, they do not participate in photoreceptor outer segment turnover. The overlying photoreceptor cells are degenerated,1 the hypertrophied RPE cells do not contain lipofuscin,2,3 and there is an absolute scotoma within the lesion in
Methods The patients in this study were examined at a private referral practice. Each patient underwent distance visual acuity measurement, general ophthalmic examination that included slit-lamp biomicroscopy and indirect ophthalmoscopy, and fundus photography. Fundus photography used 50° fields of the posterior pole and the area with the lesion being studied using a Topcon TRC 50IX fundus camera (Topcon, Paramus, NJ). The autofluorescence filters had an excitation bandwidth of 535 nm to 580 nm, and the barrier filter was 615 nm to 715 nm.4 Results
Supported by The Macula Foundation, Inc. (New York, NY). The authors have no financial interest related to this work. Dr. Claudia Brue` is currently affiliated with the University Politecnica delle Marche, Ancona, Italy. Reprint requests: Richard Spaide, MD, Vitreous, Retina, Macula Consultants of New York, 460 Park Avenue, 5th Floor, New York, NY 10022; e-mail: [email protected]
Four patients were included in this study; three patients were male and one was female. Mean age of the patients was 45.75 years (range, 28 – 68 years). All CHRPE lesions had well demarcated borders (Fig. 1) 259
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Fig. 1. Color fundus photograph of congenital hypertrophy of the retinal pigment epithelium (A) with the corresponding large hypoautofluorescent area shown in the autofluorescence photograph (B).
and showed homogeneous hypoautofluorescence (Fig. 2) even if there were depigmented halos or lacunae. One patient had a choroidal nevus temporal to the macula and a CHRPE temporal to the nevus. Although the CHRPE was hypoautofluorescent, the nevus showed very subtle hypoautofluorescence compared with normal fundus (Fig. 3). Discussion The lack of an autofluorescence signal in CHRPE is consistent with the absence of lipofuscin within the RPE cells seen histopathologically. Even though the RPE is thickened in this abnormality, this layer is not functional in terms of outer segment turnover,2,3 accounting for the apparent absence of lipofuscin. The development and continual presence of viable photoreceptor outer segments depend on normally functioning RPE cells.5,6 The lack of photoreceptors over and lipofuscin in the affected RPE cells may indicate that the photoreceptors never developed correctly in the first place or alternately became atrophic from inadequate support by the
hypertrophied RPE cells. Hypopigmented lacunae within the CHRPE lack RPE cells,1,3 with only basement membrane being present, which may explain the hypoautofluorescence in the absence of any visible pigment within the lesions. Choroidal melanomas may have areas of increased autofluorescence associated with orange pigment, which has the histopathologic correlate of lipofuscin in overlying macrophages, or if there is chronic subretinal fluid. Choroidal nevi display the same range of autofluorescence abnormalities as melanomas, except most choroidal nevi have neither overlying orange pigment nor subretinal fluid.4,7 The presence of chronic subretinal fluid may lead to secondary RPE changes and inhibition of phagocytosis of shed outer segments, both of which may cause autofluorescence abnormalities. CHRPE may be mistaken for other pigmented lesions.8 The differentiation of choroidal melanocytic lesions is dependent on diagnostic data available to the clinician, and autofluorescence photography offers supplemental information not obtainable by other means.
Fig. 2. Congenital hypertrophy of the retinal pigment epithelium shown on a color photograph (A) has a hypopigmented halo around the dark lesion, but the whole lesion looks homogeneously hypoautofluorescent (B).
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Fig. 3. Color photograph of the left eye demonstrates a gray flat choroidal nevus inferotemporal to the macula (A) and a large congenital hypertrophy of the retinal pigment epithelium (CHRPE) on the temporal periphery. The nevus shows a minimal decrease in autofluorescence, while the CHRPE lesion is hypoautofluorescent (B).
Key words: autofluorescence, congenital hypertrophy of the retinal pigment epithelium.
4. 5.
References 1. 2.
3.
Buetner H. Congenital hypertrophy of the retinal pigment epithelium. Am J Ophthalmol 1975;79:177–189. Parsons MA, Rennie IG, Rundle PA, et al. Congenital hypertrophy of retinal pigment epithelium: a clinico-pathological case report. Br J Ophthalmol 2005;89:920–921. Lloyd WC 3rd, Eagle RC Jr, Shields JA, et al. Congenital hypertrophy of the retinal pigment epithelium. Electron microscopic and morphometric observations. Ophthalmology 1990; 97:1052–1060.
6.
7. 8.
Holz FG, Schmitz-Valkenberg S, Spaide RF, Bird AC. Atlas of Fundus Autofluorescence Imaging. New York: Springer; 2007. Stiemke MM, Landers RA, al-Ubaidi MR, et al. Photoreceptor outer segment development in Xenopus laevis: influence of the pigment epithelium. Dev Biol 1994;162:169–180. Lin N, Fan W, Sheedlo HJ, et al. Photoreceptor repair in response to RPE transplants in RCS rats: outer segment regeneration. Curr Eye Res 1996;15:1069–1077. Gunduz K, Pulido JS, Bakri SJ, et al. Fundus autofluorescence in choroidal melanocytic lesions. Retina 2007;27:681–687. Shields CL, Mashayekhi A, Ho T, et al. Solitary congenital hypertrophy of the retinal pigment epithelium. Clinical features and frequency of enlargement in 330 patients. Ophthalmology 2003;110:1968–1976.
Purpose: To report the autofluorescence features of congenital hypertrophy of the retinal pigment epithelium (CHRPE). Methods: Four patients with CHRPE were evaluated using autofluorescence in a camera-based system. Results: All CHRPE lesions studied had well demarcated borders and were hypoautofluorescent. Presence of a hypopigmented halo and lacunae did not alter the homogeneous hypofluorescence. Conclusion: Hypoautofluorescence confirmed the known absence of lipofuscin in the retinal pigment epithelium cells of CHRPE lesions. Autofluorescence imaging may provide useful information in evaluating pigmented lesions of the fundus. RETINAL CASES & BRIEF REPORTS 2:259 –261, 2008
From the Vitreous, Retina, Macula Consultants of New York, and the LuEsther T. Mertz Retinal Research Center, Manhattan Eye, Ear, and Throat Hospital, New York, New York.
adulthood. Choroidal melanomas and nevi have specific autofluorescence findings, offering the possibility that fundus autofluorescence can be used to differentiate CHRPE lesions from other pigmented lesions in the fundus.
L
esions in congenital hypertrophy of the retinal pigment epithelium (CHRPE) are generally flat and solitary and have well demarcated borders. Colors vary from grayish brown to black, and it is usually surrounded by a hypopigmented halo. It is an asymptomatic and benign lesion, but CHRPE may mimic other pigmented lesions in appearance such as ocular nevi and melanomas. The histopathology of CHRPE suggests that while the retinal pigment epithelium (RPE) cells are hypertrophic, they do not participate in photoreceptor outer segment turnover. The overlying photoreceptor cells are degenerated,1 the hypertrophied RPE cells do not contain lipofuscin,2,3 and there is an absolute scotoma within the lesion in
Methods The patients in this study were examined at a private referral practice. Each patient underwent distance visual acuity measurement, general ophthalmic examination that included slit-lamp biomicroscopy and indirect ophthalmoscopy, and fundus photography. Fundus photography used 50° fields of the posterior pole and the area with the lesion being studied using a Topcon TRC 50IX fundus camera (Topcon, Paramus, NJ). The autofluorescence filters had an excitation bandwidth of 535 nm to 580 nm, and the barrier filter was 615 nm to 715 nm.4 Results
Supported by The Macula Foundation, Inc. (New York, NY). The authors have no financial interest related to this work. Dr. Claudia Brue` is currently affiliated with the University Politecnica delle Marche, Ancona, Italy. Reprint requests: Richard Spaide, MD, Vitreous, Retina, Macula Consultants of New York, 460 Park Avenue, 5th Floor, New York, NY 10022; e-mail: [email protected]
Four patients were included in this study; three patients were male and one was female. Mean age of the patients was 45.75 years (range, 28 – 68 years). All CHRPE lesions had well demarcated borders (Fig. 1) 259
RETINAL CASES & BRIEF REPORTSℜ
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2008
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VOLUME 2
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NUMBER 4
Fig. 1. Color fundus photograph of congenital hypertrophy of the retinal pigment epithelium (A) with the corresponding large hypoautofluorescent area shown in the autofluorescence photograph (B).
and showed homogeneous hypoautofluorescence (Fig. 2) even if there were depigmented halos or lacunae. One patient had a choroidal nevus temporal to the macula and a CHRPE temporal to the nevus. Although the CHRPE was hypoautofluorescent, the nevus showed very subtle hypoautofluorescence compared with normal fundus (Fig. 3). Discussion The lack of an autofluorescence signal in CHRPE is consistent with the absence of lipofuscin within the RPE cells seen histopathologically. Even though the RPE is thickened in this abnormality, this layer is not functional in terms of outer segment turnover,2,3 accounting for the apparent absence of lipofuscin. The development and continual presence of viable photoreceptor outer segments depend on normally functioning RPE cells.5,6 The lack of photoreceptors over and lipofuscin in the affected RPE cells may indicate that the photoreceptors never developed correctly in the first place or alternately became atrophic from inadequate support by the
hypertrophied RPE cells. Hypopigmented lacunae within the CHRPE lack RPE cells,1,3 with only basement membrane being present, which may explain the hypoautofluorescence in the absence of any visible pigment within the lesions. Choroidal melanomas may have areas of increased autofluorescence associated with orange pigment, which has the histopathologic correlate of lipofuscin in overlying macrophages, or if there is chronic subretinal fluid. Choroidal nevi display the same range of autofluorescence abnormalities as melanomas, except most choroidal nevi have neither overlying orange pigment nor subretinal fluid.4,7 The presence of chronic subretinal fluid may lead to secondary RPE changes and inhibition of phagocytosis of shed outer segments, both of which may cause autofluorescence abnormalities. CHRPE may be mistaken for other pigmented lesions.8 The differentiation of choroidal melanocytic lesions is dependent on diagnostic data available to the clinician, and autofluorescence photography offers supplemental information not obtainable by other means.
Fig. 2. Congenital hypertrophy of the retinal pigment epithelium shown on a color photograph (A) has a hypopigmented halo around the dark lesion, but the whole lesion looks homogeneously hypoautofluorescent (B).
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Fig. 3. Color photograph of the left eye demonstrates a gray flat choroidal nevus inferotemporal to the macula (A) and a large congenital hypertrophy of the retinal pigment epithelium (CHRPE) on the temporal periphery. The nevus shows a minimal decrease in autofluorescence, while the CHRPE lesion is hypoautofluorescent (B).
Key words: autofluorescence, congenital hypertrophy of the retinal pigment epithelium.
4. 5.
References 1. 2.
3.
Buetner H. Congenital hypertrophy of the retinal pigment epithelium. Am J Ophthalmol 1975;79:177–189. Parsons MA, Rennie IG, Rundle PA, et al. Congenital hypertrophy of retinal pigment epithelium: a clinico-pathological case report. Br J Ophthalmol 2005;89:920–921. Lloyd WC 3rd, Eagle RC Jr, Shields JA, et al. Congenital hypertrophy of the retinal pigment epithelium. Electron microscopic and morphometric observations. Ophthalmology 1990; 97:1052–1060.
6.
7. 8.
Holz FG, Schmitz-Valkenberg S, Spaide RF, Bird AC. Atlas of Fundus Autofluorescence Imaging. New York: Springer; 2007. Stiemke MM, Landers RA, al-Ubaidi MR, et al. Photoreceptor outer segment development in Xenopus laevis: influence of the pigment epithelium. Dev Biol 1994;162:169–180. Lin N, Fan W, Sheedlo HJ, et al. Photoreceptor repair in response to RPE transplants in RCS rats: outer segment regeneration. Curr Eye Res 1996;15:1069–1077. Gunduz K, Pulido JS, Bakri SJ, et al. Fundus autofluorescence in choroidal melanocytic lesions. Retina 2007;27:681–687. Shields CL, Mashayekhi A, Ho T, et al. Solitary congenital hypertrophy of the retinal pigment epithelium. Clinical features and frequency of enlargement in 330 patients. Ophthalmology 2003;110:1968–1976.
