# Ophthalmic Manifestation in Neurofibromatosisosis Type 2
## 4 Discussion
Corneal involvement was characterized by superficial punctate keratitis (two patients 14.3%), corneal leukoma (two patients 14.3%), and corneal pannus (one patient 7.1%). A post-surgical lagophthalmos, due to the removal of acoustic nerve neurinomas, was responsible for all these clinical conditions, as the incomplete closure of the eyelid rim determined corneal epithelial suffering. One of our patients presented papilledema, due to increased intracranial pressure (7.1%). [PERSON] et al. described in their paper a 30% prevalence of optic disk edema, mostly caused by intracranial tumors or optic disk sheath meningiomas. The lowering of intracranial pressure, thanks to the surgical removal of cancerous masses, is not always sufficient to revert the progressive optic neuropathy. In these cases, patients can develop optic disk atrophy with irreversible loss of vision [9]. In the literature, papilledema is described in a small percentage of NF2 patients (<10%). The most frequent cerebral neoplasms associated with swelling of the optic disk are tumors in the posterior fossa, cranial nerve schwannomas, or large supratentorial meningiomas [26]. Our patient was diagnosed with multiple intra and extra-axial large and recurrent meningiomas, which required numerous surgical procedures. Among our cohort, we also identified one case of retinal hamartoma (7.1%) in a patient with a moderate form of NF2. The lesion had a nasal peripapillary localization and was observable both during the fundoscopic examination and by OCT imaging. In the literature, retinal hamartomas have been reported with a variable frequency of 6-22% in NF2 patients [27]. These findings can be observed at the fundoscopic examination as whitish lesions, often involving the juxta papillary or macular area. OCT images are helpful to better characterize the extension and depth of such lesions. Retinal hamartomas are not specifically linked to NF2 but can be observed in other phakomatoses as well. Moreover, the prevalence of retinal hamartomas is higher in severe forms of NF2, often leading to a diagnosis based on ocular findings [28]. [PERSON] et al. suggested that the presence of retinal hamartomas can be considered a clinical indicator of intermediate/severe forms of this pathology [5]. Furthermore, a frequent association between pigment epithelial and retinal hamartomas has been described [9; 29]. Many of the reported manifestations can affect visual acuity. Within our sample, ERMs showed the greatest impact on BCVA, mainly when the fovea was involved, as we observed in one of our patients who had a BCVA of 0.03. Other causes of visual impairment in our NF2 patients were corneal opacities and cataracts. Regarding ocular motility, in 2008, in a retrospective study, [PERSON] observed strabismus in more than half of patients with NF2, mostly determined by cranial nerve palsy (III-IV-VI) [30]. In the available literature, many studies identified ocular motility disorders in NF2 patients. [PERSON] et al. retrospectively reviewed 83 patients affected by genetically characterized NF2. They diagnosed partial third nerve palsy in three children with severe mutation. Neuroimaging confirmed a third nerve schwannoma in all cases. Moreover, one patient developed a partial fourth nerve palsy [10]. [PERSON] et al. carried out a retrospective study of 73 NF2 patients. Different kinds of ocular motility disorders were identified in 52% of patients. About 22% of these patients presented cranial nerve palsy, due, in most cases, to intracranial tumors, and 26% showed concomitant strabismus, mainly horizontal [30]. [PERSON] et al. conducted a cross-sectional study on 49 NF2 patients, identifying oculomotor and abducens nerve palsy in six patients and concomitant strabismus in three patients [31]. [PERSON] et al. identified monocular elevator paresis in four patients out of 29 affected by NF2, with dysfunction of both the superior rectus and inferior oblique muscles [25]. [PERSON] et al.