Sir,

This exceptionally rare bilateral fundus disorder was first described as choroiditis areata, in Iceland.1, 2 Later, it was renamed helicoidal peripapillary chorioretinal degeneration because of the lesion's resemblance to the propeller (helix) of an aeroplane.3 Today, in the light of modern genetics, we believe that it is more precise to use the term dystrophy than degeneration, because it is obviously a dominantly inherited disorder.4 A dominant form was recently mapped to chromosome 11p15.5 Finally, a novel TEAD1 mutation is recognized as the causative allele in helicoidal peripapillary degeneration.6

We have had an opportunity to study three cases of inherited helicoidal peripapillary chorioretinal degeneration: a father, daughter, and son. Although this particular disorder has mostly been observed in Scandinavia, this is the first known case presented in Serbia.

Case reports

Case one

A 20-year-old female patient experienced some visual disturbances as a child and was referred to an ophthalmologist 10 years ago. Unusual atrophic peripapillary change was noticed and helicoidal peripapillary atrophy was diagnosed. Visual acuity was 6/6 for the right eye and 6/12 for the left eye.

 At a routine check-up in July 2003, visual acuity had decreased to RE 6/9 with −1.75 D cyl axis 15° and LE 6/12 with −2.25 D cyl axis 170°. Intraocular pressure was normal. Discrete cataracts were observed (an unusual distribution in the anterior lens cortex) with very suggestive helicoidal peripapillary chorioretinal atrophy with tongues next to the fovea on both eyes. A fluorescein angiography was performed (Figure 1a, b).

Figure 1
figure 1

Case one: (a, b) Fluorescein angiograms show bilateral dystrophic peripapillar helicoidal lesions of retinal pigment epithelium and choriocapillaris, extending from the optic disc towards the periphery. On both fundi, atrophic tongues are close to the fovea. Case two: (c) A fluorescein angiogram of the right eye shows a dystrophic peripapillar triangular lesion, extending to the fovea. (d) A fluorescein angiogram of the left eye shows a dystrophic peripapillar lesion, resembling a starfish. Macula is spared. Case three: (e, f) Fluorescein angiograms show bilateral helicoidal peripapillary lesions. Clinical finding is very discrete, but fluorescein angiograms are impressive.

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Case two

Her 15-year-old brother had the same disorder, confirmed 7 years ago. His visual acuity was 6/9 with −0.75 D cyl axis 180° for both eyes, but the intraocular pressure was normal. He had no subjective visual problems. In addition to discrete central cataracts (in the anterior lens cortex), expressive helicoidal peripapillary chorioretinal atrophy was noticed. A fluorescein angiography was performed (Figure 1c, d).

Case three

The father, 45 years old, was also examined. His visual acuity was 6/6 with −0.50 D cyl axis 180° for both eyes. The intraocular pressure was within normal limits. Very discrete cataracts in the anterior portions of the lens were observed. A fundus examination showed only slight irregularity in colour and pigmentation around the disc. A fluorescein angiography was performed and a picture suggesting helicoidal peripapillary chorioretinal atrophy was observed (Figure 1e, f).

Comment

Helicoidal peripapillary chorioretinal degeneration is a rare autosomal dominant disorder characterized by peripapillary tongue-shaped patches of chorioretinal atrophy extending radially from the optic disc, with no inflammatory signs.1 Choroid and pigment epithelium are completely atrophic,7 but retinal vessels are not affected. One interesting hypothesis is that the peripapillary fundus lesions are the result of tearing and retraction of the retinal pigment epithelium and Bruch's membrane.8 We applied Sveinsson's9 findings, which led us to the conclusion that this disorder probably resulted from developmental anomalies of the choroid, the retinal pigment epithelium, or the short posterior ciliary arteries. A fluorescein angiography helped us to reach the correct diagnosis.

As mentioned earlier, this disorder has been described using various names: choroiditis areata,2 circumpapillary dysgenesis of the pigment epithelium,7 helicoidal peripapillary chorioretinal degeneration,3 or atrophia areata.4 Since there were no signs of inflammation in our cases, they differ specifically from serpiginous choroidopathy. Other differential diagnoses include angioid streaks, malignant myopia, paravenous retinochoroidal atrophy and radial lattice retinal degeneration.

There has been much confusion and misunderstanding concerning this phenomenon in medical literature to date, but our opinion is that the previously held position (that two variants of the disease exist) is questionable. In the congenital type (our cases), the atrophic peripapillary zone does seem generally to be stationary and probably does not seriously affect the macula during life. However, this is not a rule. The study of a large group of 26 affected individuals with autosomal dominant inheritance, pointed out poor visual acuity in later years.4 Recently, electrophysiological tests suggest that retinal dysfunction is focal rather than diffuse.10

Adult forms, described as separate entities in earlier literature,3 were probably variants of serpiginous choroidopathy, characterized by the fact that one eye was affected some time before the other, with atrophic tongues that may frequently affect the macula and thereby lead to deteriorated central vision.

Our cases have reasonable visual acuity, with minimal changes over several years. However, in the first case atrophic tongues on both eyes were very close to the fovea, so further careful examination is needed. The third case (father) was rather unusual since diagnosis could only possibly be performed by a fluorescein angiography.