Lisch spots in neurofibromatosis type 1

Rajesh C Saxena; Sandeep Saxena

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ORIGINAL ARTICLE

Year : 1991 | Volume : 39 | Issue : 4 | Page : 179-180

Lisch spots in neurofibromatosis type 1

Rajesh C Saxena, Sandeep Saxena
Dept. of Ophthalmology King George's Medical College, Lucknow, India

Correspondence Address:
Rajesh C Saxena
G-19 River Bank Colony Lucknow. 226 018 (U.P)
India

Source of Support: None, Conflict of Interest: None

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PMID: 1810882

Abstract

The eyes of 28 patients of Neurofibromatosis type 1 were examined. Lisch spots were present in all the patients above 20 years. Their clinical appearance is being presented as seen in Indian subjects.

How to cite this article:
Saxena RC, Saxena S. Lisch spots in neurofibromatosis type 1. Indian J Ophthalmol 1991;39:179-80

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Saxena RC, Saxena S. Lisch spots in neurofibromatosis type 1. Indian J Ophthalmol [serial online] 1991 [cited 2023 Jun 10];39:179-80. Available from: https://journals.lww.com/ijo/pages/default.aspx/text.asp?1991/39/4/179/24427

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Introduction

Neurofibromatosis was first comprehensively described by von Recklinghausen in 1882^[1]. Three forms are recognised : von Recklinghausen or peripheral neurofibromatosis, central neurofibromatosis and segmental neurofibromatosis^[2]. Von Recklinghausen neurofibromatosis (Neurofibromatosis type 1) is an autosomal dominant disorder with a high mutation rate and a prevalence of around 30/100000 of the population^[3] . Diagnosis is made on the basis of major defining features of the disease - Cafe au lait spots and cutaneous neurofibromas^[4]. Abnormalities of the iris in neurofibromatosis were first reported by Waardenburg in 1918^[5]. Iris nodules were reported by Lisch in 1937^[6]sub . Histologically they have been shown to be melanocytic hamartomas ^[7],[8] and therefore embryonically they are probably of neural crest origin as are the cafe au lait spots and the cutaneous neurofibromas. We herewith report, the incidence of Lisch spots in patients with neurofibromatosis type 1, their clinical presentation in Indian subjects and their role in making the diagnosis.

Material and methods

Following our case report^[9], a total number of 28 patients of neurofibromatosis type 1 were examined. The criteria used for the diagnosis are shown in [Table - 1]. A detailed ophthalmological examination included visual acuity, examination of the cornea and the iris and both direct and indirect ophthalmoscope.

Results

Out of these 28 patients, 20 were males and 8 were females. The age of the patients ranged from 2 years to 56 years. In 60.7% of the patients (17 out of 28) Lisch spots were present and were bilateral in 95.3% (16 out of 17). The age distribution of the patients with Lisch spots is shown in [Figure - 1]. The Lisch spots were multiple, variable in number and involved any part of the iris surface. They had both a flat as well as a nodular dome shaped appearance. None of the spots had pigmentation but all of them were pale in colour on brown irides. We observed two tvpes of presentation. one clearly discrete^[9] whereas the other confluent, where more spots appeared to coalesce together [Figure - 2]. None of the cases showed any sign of inflammation, neovascularisation or secondary rise of intraocular tension. All the patients aged above 20 years showed Lisch spots.

Discussion

Iris involvement in neurofibromatosis is regarded as rare by some authors^[10],[11]. However the incidence of Lisch spots as reported in various series ranges from 30% of 97% in patients overall ^{[4],[12],[17]} and from 95% to 100% in posttpubertal or adult patients^[4],[15],18] Lewis and Riccardi^[16] correlated presence of Lisch nodules to age whereas Zehavi, Romano and Goodman^[13] correlated their presence directly to the severity of skin manifestation of the disease.

In our series of 28 patients with neurofibromatosis type 1 Lisch spots were found in 60.7%. However, they were found in all the patients above the age of 20 years. Their bilateral presentation was observed in 95.3%. Multiplicity of the spots was a characteristic feature. They were seen involving any part of the iris surface. These spots were invariably flat, except in two cases where they were nodular. In another case both flat as well as nodular spots were seen. We observed typically two distinct types of clinical presentations of these spots; "discrete" and "confluent". None of the patients in our series had brown pigmentation of the Lisch nodules as described by Huson, Jones and Beck^[4], perhaps because the colour of the iris in Indians differs from those of that in the west.

In conclusion, we have observed that Lisch spots are a characteristic associated finding of Neurofibromatosis type 1. In adults, if bilateral "discrete" or "confluent" spots on the iris are seen in the absence of inflammation or secondary rise of intraocular tension, they are highly suggestive of Neurofibromatosis[18].

References

1.	Von Recklinghausen FD. Ueber die multiplen Fibrome der haut and ihre Beziehung zu den multiplen Neuromen. Berlin. Hirschwald. 1982.
2.	Riccardi VM Neurofibromatosis: A clinical, pathological and genetic study of multiple neurofibromatosis. Springfield. Illinois. Thomas 1956.
3.	Crowe FW, Schull WT. Neel JV. A clinical, pathological and genetic study of multiple neurofibromatosis. Springfield. Illinois. Thomas 1956.
4.	Huson S, Jones D, Beck L. Ophthalmic manifestations of neurofibromatosis. Br. J. Ophthalmol. 1987:71 (3): 235-8.
5.	Waardenburg PJ. Heterochromie en melanosis. Ned Tijdschr Geneeskd. 1918.2 : 1453-8.
6.	Lisch K. Ueber Beteiligung der Augen, insbenson dere das Vorkommen von irisknotchen der Neurofibrmatose (Recklinghausen). Z. Augenheilkd 1937. 93:137-43.
7.	Goldstein I, Wexler D. Melanosis uveae and melanoma of the iris in neurofibromatosis (Recklinghausen). Arch. Ophthalmol. 1930. 3:288.96.
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14.	Ma QY. Zeng LH. Chen YZ, Wu LY. Mao WS. Iris nodules, ocular findings and blood grouping in neurofibromatosis. Yen Ko Hsueh Pao. 1989 5 (3-4) : 113-7.
15.	Huson SM. Harper PS, Compston DA. von Recklinghausen neurofibromatosis. A clinical and population study in south east Wales. Brain. 1988. 111:1355-81.
16.	Lewis RA, Riccardi VM. Von Recklinghausen neurofibromatosis. Incidence of iris hamartomas. Ophthalmology. 1981. 88(4):384-54.
17.	Fl"ueler U, Boltshauser E, Kilchhofer A. Iris hamartomata as diagnostic criterion in neurofibromatosis. Neuropediatrics. 1986. 17(4):183-5.
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