unilateral pigmentary degeneration of the retina associated with heterochromia iridis

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Page 1: Unilateral pigmentary degeneration of the retina associated with heterochromia iridis

Graefe's Arch Clin Exp Ophthalmol (1998)236:940±944 � Springer-Verlag 1998 S H O R T C O M M U N I C A T I O N

Salvatore GrisantiMichael DiestelhorstJulia LebekPeter WalterKlaus Heimann

Unilateral pigmentary degenerationof the retina associated with heterochromia iridis

Received: 30 January 1998Revised version received: 6 April 1998Accepted: 7 April 1998

S. Grisanti ()) ´ M. Diestelhorst ´ J. LebekP. Walter ´ K. HeimannDepartment for Vitreoretinal Surgery,University Eye Clinic Cologne,Joseph-Stelzmann-Strasse 9,D-50931 Cologne, Germany

Abstract l Background: For thepast 5 years, a 56-year-old patient hasbeen displaying monocular progres-sive pigmentary changes in the lefteye. Heterochromy of the left eyehas been known since childhood. Theother eye is clinically and function-ally normal. The patient was adoptedand he has no children. Therefore,we have no family history.l Methods: The patient wasexamined clinically and by meansof electroretinography, electroocu-lography, perimetry, computertomography, pulsatile ocular bloodflow (POBF) measurement,serology and Doppler sonography.l Results: Electrophysiology dis-played a considerable reduction ofscotopic and photopic ERGs, a re-

duced dark-through, and a reducedlight-rise in the left eye, whereas thefellow eye was normal. The visualfield was limited to 5 deg around thefixation point, and a peripheralcrescent-shaped arch encircled thetemporal-inferior quadrant concomi-tant to the pigmentary changes.By computer tomography andDoppler sonography a vascular af-fection was excluded. The left eyedisplayed lower POBF values. Allserological tests were found negative.l Conclusion: The clinical pictureand negative exclusion criteria indi-cate a unilateral retinitis pigmentosa.However, with regard to the literaturean unequivocal diagnosis can only bemade upon hereditary evidence.

Introduction

In 1865 Pedraglia described a case of retinitis pigmentosaªin its absolutely typical formº that affected only one eye;the other eye was normal [17]. The histological examina-tion of this patient's eyes 25 years later revealed a markeddegeneration of the retina, most pronounced in the outerlayer, with widespread pigmentation in the affected eye.The clinically normal fellow eye displayed no histopath-ological changes [6]. However, retinitis pigmentosa haslong been recognized as a bilateral tapetoretinal heredo-degeneration with symmetry of development as a com-mon characteristic [3]. Therefore, since Pedraglia's initialreport and the subsequent accumulation of more similarobservations there has been controversy regarding the truenature of a unilateral tapetoretinal heredodegeneration.

This question will not be resolved here, but the present re-port is the first illustration of a case of unilateral pigmen-tary degeneration of the retina associated with heterochro-mia iridis.

In 1952 Francois and Verriest proposed several criteriato rule out cases of pseudoretinitis pigmentosa [8]: (a) theophthalmoscopic appearance and functional changes typ-ical of a tapetoretinal dystrophy in the affected eye; (b)absence of pigmentary degeneration and normal electro-retinogram in the fellow eye; exclusion of (c) an inflam-matory or (d) a vascular cause in the affected eye; (e) aminimum 5-year period of observation to exclude a de-layed onset in the unaffected eye; (f) hereditary evidenceof tapetoretinal degeneration. Extensive examinationswere performed in the present case. Though exogenouscauses for the unilateral affection could not be identified,unequivocal diagnosis of a unilateral primary tapetoreti-

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nal degeneration fails due to the absence of hereditary ev-idence.

Materials and methods

In addition to the routine ophthalmologic examinations the follow-ing tests were performed: Peripheral fields were tested in the Gold-mann projection perimeter. Target specifications are indicated inFig. 3. Computerized perimetry was performed using the 30±2 fieldprogramm of a Humphrey field analyzer. Dark adaptation was mea-sured with a Goldmann-Weekers adaptometer. The electroretinogra-phy and -oculography were performed according to recommendedstandards [15, 16]. For scotoscopic conditions the triple-flash ERG

was also applied [1]. Visual evoked potentials were elicited byblack-and-white checkerboard reversals. Color vision was testedboth with Ishihara plates and the Farnsworth-Munsell 15-hue test.Pulsatile ocular blood flow (POBF) rates were recorded accordingto previous reports using the Langham system [14, 17, 20]. In addi-tion to routine examinations, serological testing included exclusionof syphilis, toxoplasmosis and borreliosis. Neurological work-up in-cluded computer tomography of the skull and Doppler sonographyof the carotids.

Results

The 56-year-old male patient was initially examined oph-thalmologically in 1992 with a complaint of progressivevisual field loss in his left eye. He also reported hemeral-opia since his early youth. Heterochromia of the left eyehad been known since childhood. The patient's familyhistory could not be analyzed, since he was adopted andhas no children.

The examination of the patient revealed a visual acuityof 20/20 in the right eye. The best corrected visual acuity

a

a

b

b

Fig. 1 Photography of the anterior segment demonstrates a a normalright eye and b heterochromia iridis of the affected left eye

Fig. 2a, b Composite fundus photography. a The right eye dis-played no pathological changes. No pigmentary disturbance is evi-dent. b The left eye from the same patient revealed pigmentarychanges ranging from bone corpuscle appearance to confluent pig-ment clumps

1a, b

2a, b

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of the left eye was 16/20. Applanation tonometry revealedan intraocular pressure of 17 mmHg in each eye. The ad-nexa revealed no abnormalities. Cornea, lens and vitreouswere clear. The iris of the left eye displayed pigmentarychanges (Fig. 1).

Fundoscopic examination of the right eye (Fig. 2a) re-vealed a normal disk, macula and vessels. No pigmentarydisturbances were found in the periphery. Fundoscopicexamination of the left eye (Fig. 2b) revealed a waxy-col-ored disc with peripapillary atrophy, attenuation of the ar-terioles, and a pigmentation disturbance of the superotem-poral region, which had an atrophic appearance with easyvisible choroidal vessels. The altered pigmentation ex-tended in a crescent from the disc and varied from typicalpigment deposits of bone corpuscle shape to more conflu-ent deposits.

Peripheral visual field examination on the Goldmannperimeter was normal for the right eye, but revealed a se-vere loss in the left eye (Fig. 3a). The visual field of theleft eye was limited to 5 deg around the fixation point,and a peripheral crescent-shaped arch encircled the tem-

Fig. 3 a Goldmann peripheralvisual fields and b Humphreyautomated 30-2 visual fields forthe right (OD) and left (OS) eye

Fig. 4 Goldmann-Weekers dark adaptation curves for the right(OD) and left (OS) eye in relation to the reference level (normalrange)

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poral-inferior quadrant. The arcuate scotoma extendingboth into the nasal and inferior periphery was concomitantwith the pigmentary changes. Computerized perimetrydone using a Humphrey field analyzer on the 30-deg fieldshowed normal levels for the right eye. In the left eyewere found absolute scotomas, corroborating the manualexamination (Fig. 3b). During a period of 5 years the vi-sual field loss was slowly progressive.

Dark-adaptation curves were significantly elevated inthe left eye, but the right eye displayed subnormal levelstoo (Fig. 4).

Scotopic and photopic ERGs were within normal lim-its in the right eye, but electroretinography of the affectedleft eye was almost extinguished for all stimulus condi-tions (Fig. 5a). Electrooculography displayed normal val-ues for the right eye. In the left eye the dark-through val-ues were reduced and the light peak was nearly absent(Fig. 5b).

Color vision examination using the Farnsworth-Mun-sell 15-hue test showed slightly subnormal findings inboth eyes with no evidence of a systematic color visiondefect.

A Doppler investigation of the carotids and transcrani-al Doppler sonography showed no significant vascularimpairment. POBF testing revealed a normal flow ratefor the right eye (721 �l/min). The flow rate in the lefteye was reduced to 537 �l/min.

Computer tomography of the skull excluded expansiveprocesses in the optic nerve region. Intracerebral struc-tures were normal. Neurological examination was unre-markable. Visually evoked cortical potentials were nor-mal for both eyes.

Serum analysis revealed no abnormalities. The resultsof tests, including syphilis, toxoplasmosis and borreliosis,were all negative.

Discussion

Since Pedraglia's initial account in 1865 [17] more than100 cases of unilateral pigmentary retinopathy have accu-mulated, leading to controversy over the authenticity ofan unilateral form of retinitis pigmentosa.

In view of the fact that several factors may lead to afundus appearance similar to retinitis pigmentosa, Fran-çois and Verriest introduced criteria to rule out cases ofpseudoretinitis pigmentosa [8]. Among the possible caus-es for pseudoretinitis pigmentosa, previous inflammatorydiseases, trauma, drugs and vascular changes must beconsidered [4]. Concerning the first possibility, we want-ed to exclude Fuchs' heterochromic cyclitis (FHC), whichis associated with pigmentary changes of the iris. In thepresent case the heterochromia iridis, which may alsobe termed iris bicolor, seems to be due to pigment in-crease in the anterior stroma (Fig. 1). This is not typicalfor FHC, which is characterized by stromal atrophy withthe pigmented stromal layers showing through. Thoughthe etiology of FHC is unknown, it can occur in combina-tion with a number of different ocular conditions [13], in-cluding ocular toxoplasmosis [5, 19] and retinitis pigmen-tosa [7, 9]. Toxoplasmosis itself has been found to be re-sponsible for some cases of unilateral pigmentary degen-eration of the retina. In our case serological testing fortoxoplasmosis was negative. A negative result was also

Fig. 5 a Electroretinogram. From top to bottom: Scotopic triple-flash ERG (0.01, 0.03, 0.1, 0.2 cds/m2 flash luminance, flashes elic-ited at 0, 140, and 420 ms of a Hz stimulus cycle, 20 averages); stan-dard response (2.4 cds/m2); oscillatory potentials (2.4 cds/m2); pho-topic ERG (5 cds/m2 after 10 min light adaptation); photopic 31 Hzflicker ERG (5 cds/m2). b Electrooculogram. Horizontal bar indi-cates dark period. Normal EOG in the right eye (OD), reduced darktrough and missing light peak in the affected left eye (OS)

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obtained for borreliosis and syphilis, which are postulatedas possible causes for pseudoretinitis pigmentosa [10].Optic disc vasculitis has been described to induce retinitispigmentosa-related changes [12]. However, in that casethe onset of disease associated with papillitis and macularedema was quite dramatic. Our patient's history evincedno acute symptoms, and no signs of vasculitis could befound in the unaffected areas of the diseased left eye orin the fellow eye.

The patient reported no ocular trauma, retinal detach-ment or uveal effusion. Though blunt ocular trauma inchildhood cannot be excluded, we found no other changesof the left eye, such as angle recession or contusional ro-sette of the lens, indicating previous contusion.

Several drugs, such as thioridazine, chloroquine andhydroxychloroquine, may cause pigmentary changes ofthe retina [2, 21]. Our patient denied the use of any rele-vant drugs. There was also no topical use of prostaglandinderivatives, recently found to induce pigmentary changesof the iris [18].

Vascular abnormalities may also occasionally inducepigmentary changes [4, 11]. Doppler examination of thecarotids in this patient revealed no significant impairment.The POBF test demonstrated a diminished flow rate in theaffected eye. This result, however, more likely representsa secondary effect of the retinal changes than a primaryvascular affection.

Though the dark-adaptation curve of the seeminglyunaffected eye was slightly subnormal, the general view

is that electrophysiological tests provide the most sensi-tive tool, especially to detect occult abnormalities ofthe `normal' eye. The present case displays highly patho-logical results for the affected left eye, in contrast tocompletely unremarkable values for the right eye. Anasymmetric variant of the bilateral form of retinitis pig-mentosa can not be excluded, but the knowledge of pig-mentary changes for more than 5 years and the advancedage of the patient make a delayed onset of a bilateral af-fection very unlikely. This case is unusual in that pig-mentary changes have been found both in the retinaand the iris. On the basis of the present study it is not pos-sible to state whether there is a single pathomechanismfor the two conditions.

Refinement in diagnostic methods and technologymade a significant contribution to define and monitor thisatypical form of retinal pigmentary degeneration. Howev-er, a unilateral degenerative process pertaining to a pairedorgan causes doubts and will remain widely debated untilfurther studies elucidate the etiology and pathogenesis.Nevertheless, it is important for the integrity of the unaf-fected eye to exclude any presumably treatable disease re-sponsible for the unilateral changes. On the basis of pre-vious data, until hereditary evidence is obtained, the diag-nosis remains tapetoretinal degeneration with the appear-ance of unilateral retinitis pigmentosa.

Acknowledgements This study was supported by the DeutscheForschungsgemeinschaft (HE 840/7-1).

References

1. Bartz-Schmidt KU, Brunner R, Esser P,Lüke L, Walter P, Sickel W (1996) Thetriple flash electroretinogram and itssignificance in vascular diseases.Graefe's Arch Clin Exp Ophthalmol234:604±611

2. Bernstein HV, Ginsberg J (1986) Thepathology of chloroquine retinopathy.Arch Ophthalmol 155:98±116

3. Biro I (1963) Symmetrical developmentof pigmentation as a specific feature offundus pattern in retinitis pigmentosa.Am J Ophthalmol 55:1176±1179

4. Carr RE, Siegel IM (1973) Unilateralretinitis pigmentosa. Arch Ophthalmol90:21±26

5. De Abreu MT, Belfort R, Hirata P(1982) Fuchs' heterochromic cyclitisand ocular toxoplasmosis. Am JOphthalmol 93:739±744

6. Deutschmann R (1891) Einseitigetypische Retinitis pigmentosa mitpathologisch anatomischen Befund.Beitr Augenheilkd 1:69

7. François J, Mastilovic B (1961) L'het-erochromie Fuchs' associØe aux heredo-degenØrescences choriorØtiniennes. AnnOculist 94:385

8. François J, Verriest G (1952) Retino-pathie pigmentaire unilaterale. Oph-thalmologica 124:65±87

9. Galixto N, Maia JAC (1974) Fuchsheterochromic cyclitis. 22nd ConciliumOphthalmol Paris, Acta 2:503

10. Heckenlively JR (1988) Simplex retini-tis pigmentosa. Nonhereditary pigmentretinopathies. In: Heckenlively JR (ed)Retinitis pigmentosa. Lippincott, Phila-delphia, pp 188±197

11. Hollenhorst RW, Svien H, Benoit CF(1954) Unilateral blindness occurringduring anesthesia for neurosurgical op-eration. Arch Ophthalmol 52:819±830

12. Laatikainen L, Mustonen E (1992)Asymetry of retinitis pigmentosa ± re-lated to initial optic disc vasculitis. ActaOphthalmol 70:543±548

13. La Hey E, de Jong PTVM, Kjilstra A(1994) Fuchs' heterochromic cyclitis:review of the literature on the pathoge-netic mechanisms. Br J Ophthalmol78:307±312

14. Langham ME, To'Mey KF (1978) Aclinical procedure for the measurementsof the ocular pulse-pressure relationshipand the ophthalmic arterial pressure.Exp Eye Res 27:7±25

15. Marmor MF, Zrenner E (1993) Standardfor clinical electrooculography. ArchOphthalmol 111:601±604

16. Marmor MF, Zrenner E (1995) Standardfor clinical electroretinography. DocOphthalmol 89:199±210

17. Pedraglia (1865) Retinitis pigmentosa.Klin Monatsbl Augenheilkd3:114±117

18. Selen G, Stjernschutz J (1997)Prostaglandin-induced iridial pigment inprimates. Surv Ophthalmol 41[Suppl 2]:125±128

19. Silveira C, Belfort R, Nussenblatt R,Farah M, Takahashi W, Imamura P,Burnier M (1989) Unilateral pigmentaryretinopathy associated with ocular tox-oplasmosis. Am J Ophthalmol 107:682±684

20. Silver DM, Farell RA, Langham ME,O'Brien V, Schilder P (1989) Estima-tion of pulsatile ocular blood flow fromintraocular pressure. Acta Ophthalmol67 [Suppl 191]:25±29

21. Weekley RD (1960) Pigmentary reti-nopathy in patients receiving high dosesof a new phenothiazine. ArchOphthalmol 64:63±68