Eyes Wide Open – A Case of Nocturnal Lagophthalmos

In late 2012 I was asked to provide an opinion in regard to a clinical presentation of a 43 year-old female with a history of maintenance insomnia, irritability and intermittent soft snoring.

Standard physical and biochemical examinations were unremarkable and there were no issues related to general health and wellbeing, diet or sleep hygiene.

A laboratory based diagnostic sleep study was also largely unremarkable with no evidence of snoring, other respiratory events, or limb movements. The only clinical flags were a somewhat elevated arousal index and increased REM and slow wave sleep latency. Of greatest interest was the finding that the patient slept with her eyes open! This was also substantiated by her bed partner who remarked that he found her continual nocturnal gaze ‘disconcerting’. The inability to close the eyelids during sleep is a recognised disorder known as Nocturnal Lagophthalmos (NL).

Nocturnal Lagophthalmos is found in approximately 5% of the adult population. 1 NL is associated with poor quality, fragmented sleep, daytime sensations of dry irritated eyes, and the presence of crustiness or ‘sleep’ in the eyes upon waking in the morning. The condition often runs in families but is noticeably less common in children when compared to adults.

Eyelid closure appears to be important for the initiation and maintenance of sleep by reducing visual input to the cortex and by protecting the cornea against exposure.

NL is easily missed during regular clinical examination, however the implications of a missed diagnosis may become serious. In addition to poor sleep, corneal irritation and abrasion (or at worst, corneal damage – exposure keratopathy), and blepharitis (swelling or inflammation of the eyelids) can occur.

NL is frequently caused by a malfunction of the eyelid preventing full closure. There may be physiological, congenital, traumatic, or infectious causes which underlie the various presentations of NL. 2

Although the condition is poorly understood, a tripartite typology of the disorder has been suggested based upon putative pathophysiological findings.1

1) Palpebral insufficiency (reduced separation between the upper and lower eyelids, eye muscle dysfunction, or disturbance of motor innervation from the seventh cranial nerve)

2) Proptosis or excessive ocular surface exposure

3) Idiopathic

Treatment of NL is frequently multimodal with concurrent management of symptoms and treatment of the distal cause. Treatment options may include: eyelid taping, surgical correction of mechanical causes, external or implanted eyelid weights (gold or platinum) and topical remedies.1

Returning to our patient in question, an ophthalmologic exam revealed dysfunction of the levator palpebrae muscle which  resulted in  the incomplete closure of the eyelids during sleep. The resultant corneal exposure and irritation appeared to be a factor in producing nocturnal arousals and fragmented, unrefreshing sleep. Possible treatment options included surgical management, gold eyelid implants, eyelid taping and topical remedies. The latter two options were pursued and the patient has reported an improvement in sleep quality with less eye irritation. A formal follow-up sleep study to objectively evaluate the effectiveness of these remedies is pending.

Finally, given the relatively poor understanding of this disorder, further research is required to properly understand the relationship of NL to sleep quantity and quality. Ophthalmologists should be mindful of sleep-associated eye disorders and refer patients for formal sleep studies where appropriate.

Craig Little

References:

  1. Latkany R, Lock B, Speaker, M. Nocturnal Lagophthalmos: An overview and classification. Ocul Surf.  2006; 4: 44-53
  2. Tsai SH, Yeh LJ, Wu CH, Liao SL. Nocturnal Lagophthalmos. In J Geront. 2009; 3(2): 89-95