A recent study published in Cornea evaluated the effect of autologous serum (AS) tears at a 50% concentration in patients with refractory dry eye disease (DED) due to Sjögren’s syndrome (SS).
Give me some background.
Managing DED in patients with severe dry eye secondary to an autoimmune condition such as SS can be challenging.
Why: Immune-mediated DED is thought to stem from insufficient tear production due to immunologic destruction of the main and accessory lacrimal glands—resulting in an unhealthy tear film with missing essential components.
A previous study demonstrated that AS tears at a 20% concentration had short-term benefits for various DED conditions, though the optimal concentration for treating severe immune-based DED remains uncertain.
Now talk about the study.
In this double-blinded randomized study, investigators included 20 eyes of 10 patients (mean age 61.4 years, 100% female) with severe immune-mediated DED between June 2021 and May 2023.
- Patients were then randomized into two cohorts: AS tears 50% or artificial tears
Note: The dosage of eye drops was four times a day for both the control and intervention groups.
Tell me more.
Changes in ocular surface metrics were assessed before treatment and at 1, 2, and 3 months after treatment using objective tests for DED and confocal microscopy, including:
- Tear stability
- Ocular surface staining
- Morphology of the corneal sub-basal nerves
The microbiological safety of the used AS tears 50% was investigated using Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS).
- To note: MALDI-TOF MS is a rapid and robust method for identifying microorganisms in samples.
Findings?
At the 3-month follow-up, the AS tears 50% group exhibited significant improvements in (P<0.05):
- Tear breakup time (TBUT): 4-second improvement
- Schirmer test scores: 3.15 mm improvement
- Visual acuity (VA): From 0.18 logMAR at month 1 to 0.11 logMAR at month 3
- Confocal microscopy parameters of corneal nerve health:
- 4.75 n/mm2 increase in nerve fiber density
- 5.02 n/mm2 increase in nerve branch density
- 2.16 mm/mm2 increase in nerve fiber length
In addition: Corneal nerve regeneration correlated with increased tear stability and decreased ocular surface staining.
Anything else?
Microbiological analyses identified Gram-negative bacteria in the AS tears after use—emphasizing the need for meticulous handling and storage practices.
Throughout the duration of the study, no adverse events were reported.
Expert opinion?
“An intriguing observation from our study was the positive correlation between corneal nerve regeneration and clinical signs of DED improvement, suggesting that the morphological integrity of the corneal nerves plays a crucial role in alleviating the symptoms of DED,” the study authors noted.
Limitations?
These included:
- The inability to investigate any variations in patient-reported symptomatic relief after the use of AS tears 50%
- The Ocular Surface Disease Index (OSDI) survey was only implemented at the screening visit
Take home.
These findings suggest that treating immune-mediated DED with AS tears at a 50% concentration notably enhanced:
- Ocular surface health
- Tear stability
- VA
Further: This study affirmed the regenerative effects of AS tears on corneal nerves in severe DED and supported the therapeutic potential of higher-concentration AS tears in DED management.
However: Strict protocols for handling the AS tears are required to mitigate contamination risks and ensure patient safety.