Successful reversal of neuropathic eye pain by treatment of occult ocular surface disease: Case series and implications

Abstract

Purpose: To report the successful approach to managing neuropathic dry eye-like pain (NP) in three consecutive patients described as severe: 1) "burning fire," "burning acid," and "horrible burning pain" with hyperalgesia and allodynia, 2) refractory to topical anesthetic (TA), and 3) without surface hyperemia nor vital staining.

Observations: Two of three patients' pain was reversed with significant symptom relief within 48 hours by identification of occult obstructive Meibomian gland dysfunction (o-MGD) and treatment using Meibomian gland probing (MGP) with intraductal steroid lavage (MGP_(s)) and aqueous tear deficiency (ATD) treated with punctal thermocautery (PO). The third patient's pain was reversed within one week after treatment of superior conjunctivochalasis (CCh) using amniotic membrane surface reconstruction and ATD using PO with subsequent MGP and MGP_(s) for o-MGD.

Conclusions and importance: It has been generally thought that central (NP) is strongly suggested by triad of 1) severe chronic burning pain with hyperalgesia and allodynia, 2) refractory to TA with 3) minimal signs. In this three-case series, treatment of occult surface disease consistently led to symptom reversal. Results may represent salutary effect of successful treatment to suppress nociceptive inflammation leading to reversal of central NP. Alternatively, the current triad of diagnostic criteria may be unable to differentiate centralized NP from peripheral sensitization alone, thereby requiring rigorous examination to uncover occult, yet treatable, surface disease to restore eye comfort and reverse psychosocial sequelae when possible. Furthermore, rigorous targeting of surface disease in patients with this pain triad may obviate unnecessary systemic treatments with associated risks of serious side effects.

Keywords: Conjunctivochalasis; Dry eye; Meibomian gland dysfunction; Meibomian gland probing; Neuropathic pain; Ocular surface disease.

Fig. 1

Case 1 Exam Findings. (A) Superotemporal CCh (bracket) left eye with upper lid mobilization and secondary irritation plus 1+ superior bulbar hyperemia (asterisk) which rapidly increased to 3+ severity (not shown). (B) Infrared-Meibography showing advanced MG atrophy with proximal (asterisk), whole gland (arrow head) and discontinuous (arrow) atrophy. (C) CFM of left upper lid MG orifice showing periductal fibrosis with flattening of external duct wall (brackets).

Fig. 2

Schematic Flow Diagram of Reversal of Apparent Central Neuropathic Pain for Case 1 After Treatment of Occult Surface Disease These cases suggest a reversibility of neuropathic pain refractory to topical anesthetic by uncovering and reversing persistent tear, surface and Meibomian gland abnormalities. Persistent nociceptive (physiologic) inflammation and pain, which is relieved with topical anesthetic (TA) (1), may lead to (2) neuropathic pain (NP). NP can be thought of as peripheral sensitization with hypersensitive peripheral nerves that do respond to TA with resolution of pain (3). With chronicity, peripheral sensitization progresses to central sensitization (4) which is considered refractory to TA with resultant persistent pain (5). This case series shows that treatment of occult surface disease can lead to reversal of apparent centralized NP (6a,b), perhaps by suppressing long standing occult nociceptive inflammation. Alternatively, the functional somatosensory test of persistent pain after TA, as well as a disconnect between symptoms and signs, are not sufficiently specific to differentiate central from peripheral sensitization.