This study provided a rare prospective evaluation on the how ocular adnexal features and prosthesis handling affect the discharge produced by anophthalmic sockets.
Abnormal tear film and mucus production are common problems for patients with anophthalmic sockets, yet there is limited literature on the topic. This prospective study attempted to address this issue, and is noteworthy for using the normal eye in each patient as the control.
Study design
The study enrolled 50 subjects more than 6 years of age. Each had worn a prosthesis at least 6 months and had healthy fellow eyes. The study excluded patients with concomitant systemic diseases, conditions requiring medicated drops, ill-fitting prostheses, socket complications or previous trauma to the adnexal structures. Subjects filled out questionnaires on discharge characteristics and underwent 2 checkups with 2 examiners masked to each other’s findings.
Outcomes
Overall, anophthalmic sockets displayed significantly lower tear production and higher rate of lacrimal tear drainage obstruction compared with the normal socket. In addition, 86% of patients had frequent to very frequent discharge and 58% had Meibomian gland dysfunction (MGD). The authors suggest that treatment of MGD and aqueous tear deficiency may address the seemingly contradictory symptoms of inadequate tear production and discharge.
Anophthalmic sockets with some degree of lagophthalmos (80% of subjects) had higher frequencies of discharge and prosthesis removal, and those with lower eyelid laxity (46%) showed significantly longer dye disappearance time compared with those without laxity. Lacrimal system obstruction was found in 54% of anophthalmic sockets, most commonly in the form of incomplete obstruction of the punctum, canaliculus and/or common canaliculus.
The authors found that subjects with frequent prosthesis removal (more than once per month) had a significantly higher frequency of discharge than subjects with less frequent prosthesis removal (96.6% vs. 70%, P=0.02). Frequent removal was also associated with significantly greater lagophthalmos (P=0.02) and blinking rate (P=0.04), whereas color and volume of discharge were similar between these 2 groups.
Interestingly, discharge characteristics and frequency of prosthesis removal did not appear to be impacted by lacrimal blockage, tear production or subject age. In addition, tear film measurements were not significantly different between obstructed and open lacrimal systems.
Clinical Significance
These results raise interesting questions, notably the apparent disconnect between lacrimal obstruction and tear production with discharge. The prevalence of tear film impairment in anophthalmic sockets (75% of cases) suggests punctal occlusion may benefit these patients, yet previous studies have shown it improve symptoms and discharge in only 60% of cases. Why so many anophthalmic sockets display some type of lacrimal duct obstruction is also unknown.
Because lagophthalmos—which affects evaporative properties in the eye—was positively associated with discharge production, the authors hypothesize that socket irregularities play a role in the pathophysiology of discharge. Additionally, they posited that the increase in discharge from frequent prosthesis removal may be due to related trauma and inflammation to the conjunctiva and eyelid, or the introduction of more gram-negative bacteria into the socket. However, a causal relationship cannot yet be established, and perhaps it is the increased discharge production that led to more frequent removal in some patients. Nevertheless, the authors suggest that less frequent prosthesis removal could be recommended for subjects with discharge. The provocative findings necessitate further studies.