Brief Description
A 20-year-old female patient came for a routine ophthalmic evaluation. She had no ocular complaints. Best-corrected visual acuity was 6/6 in both eyes. Slit-lamp examination of the left eye is shown in Figure 1. Slit-lamp examination of the right eye also revealed similar findings. The posterior segment of both eyes was within normal limits.
Figure 1.
Slit-lamp photo of the left eye. Diffuse slit-lamp examination of the left eye showing multiple well-defined light brown elevations from the surface of the iris. Similar findings were seen in the right eye
Questions
What is the name of the finding seen in the slit-lamp photo?
What systemic condition is it commonly associated with?
What are the other ocular associations of this condition?
For answers please see page 124.
Answers for Clinical Quiz.
Answers
Slit-lamp photo shows multiple well-defined brown elevations projecting from the surface of the iris called Lisch nodules
Multiple and bilateral Lisch nodules are most commonly associated with neurofibromatosis Type 1 or Von Recklinghausen's disease, an autosomal dominant phakomatosis due to mutation in NF1 gene on chromosome 17
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The other ocular associations of this condition include:[1]
- Eyelid palpebral plexiform neurofibromas
- Conjunctival neurofibroma
- Hypertrophy of corneal intrastromal nerves “lignes grise”
- Glaucoma – congenital abnormality of the angle or secondary to involvement of angle by neurofibroma
- Choroidal nodules
- Retinal astrocytic hamartomas
- Optic nerve glioma.
Discussion
Lisch nodules are melanocytic hamartomas of the iris. Multiple and bilateral Lisch nodules are commonly associated with neurofibromatosis 1. They do not impair vision. They are well-defined, dome-shaped elevations, tan yellow or brown colored, projecting from the surface of the iris best identified by slit-lamp examination. They are visible in children after the age of 6 years, and the size and number increase with age (100% over 21 years of age).[2] It is important to differentiate them from nevi which are flat/minimally elevated, densely pigmented, blurred margins and iris mammillations which are regularly spaced, nipple-like protuberances which have a similar color to the underlying iris tissue.
Histology shows tightly packed dendritic or spindle-shaped melanocytes within the anterior layers of iris stroma which are normal uveal melanocytes and not nevus cells. Lisch nodule is a part of the diagnostic criteria of neurofibromatosis 1 which includes two or more of the following:[3]
Six or more cafe-au-lait macules over 5 mm in the greatest diameter in prepubertal individuals and over 15 mm in the greatest diameter in postpubertal individuals
Two or more neurofibromas of any type or one plexiform neurofibroma
Freckling in the axillary or inguinal region
Optic glioma
Two or more Lisch nodules (iris hamartomas)
A distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex, with or without pseudarthrosis
A first-degree relative (parent, sibling, or offspring) with neurofibromatosis Type 1 by the above criteria.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
- 1.Kinori M, Hodgson N, Zeid JL. Ophthalmic manifestations in neurofibromatosis type 1. Surv Ophthalmol. 2018;63:518–33. doi: 10.1016/j.survophthal.2017.10.007. [DOI] [PubMed] [Google Scholar]
- 2.Lubs ML, Bauer MS, Formas ME, Djokic B. Lisch nodules in neurofibromatosis type 1. N Engl J Med. 1991;324:1264–6. doi: 10.1056/NEJM199105023241807. [DOI] [PubMed] [Google Scholar]
- 3.Neurofibromatosis. Conference statement. National institutes of health consensus development conference. Arch Neurol. 1988;45:575–8. [PubMed] [Google Scholar]
