Corneal nerves have a significant role in maintaining corneal sensation and ocular surface health. Dry eye disease is accompanied by reduced corneal nerve density, resulting in a compromised ocular surface and reduced tear function. Although dry eye disease (DED) has an inflammatory component, not all patients respond to conventional, topical anti-inflammatory agents, particularly when the corneal nerves are compromised.^1,2

Cryopreserved amniotic membrane is rich in nerve growth factor and has a potent anti-inflammatory effect. It has been used successfully to treat DED with secondary ocular surface involvement.^3-5

Based on this knowledge, a clinical trial was designed to evaluate the efficacy of cryopreserved self-retained amniotic membrane in restoring corneal nerve density and improving corneal sensitivity in patients with DED.⁶

STUDY OBJECTIVE AND DESIGN

This prospective, controlled study compared self-retained amniotic membrane (PROKERA® Slim), with conventional treatment in patients with moderate to severe dry eye disease (Dry Eye Workshop [DEWS] scores from 2 to 4). Patients were randomly assigned to receive PROKERA Slim (the treatment group) or conventional maximum medical therapy (the control group). The study evaluated changes in clinical signs and symptoms, corneal topography, corneal sensitivity, and corneal nerve density using in vivo confocal microscopy at baseline, 1 month, and 3 months. Analyses were masked.

STUDY RESULTS

Seventeen patients completed the 1- and 3-month follow-up visits. Dry eye signs and symptoms were evaluated at both visits using pain score, the Standardized Patient Evaluation of Eye Dryness (SPEED) Questionnaire, corneal staining, tear breakup time, and DEWS score.

Across the board, all parameters in the treatment group showed statistically significant improvement compared with the control group. The corneal surface showed prominent staining and breakup of the light reflex before PROKERA Slim was applied (Figure 1). Following treatment, the corneal surface showed significant improvement, with decreased staining and a clear, crisp light reflex.

Confocal microscopy showed a statistically significant increase in corneal nerve density in the treated group as well as statistically significant improvements in corneal sensitivity at both time points. Corneal topography showed improved patterns and consistent improvement of higher-order aberrations in the treatment group.

CONCLUSION

The research showed placement of self-retained cryopreserved amniotic membrane is a promising treatment modality for patients with dry eye and ocular surface involvement. It suppresses inflammation, thereby accelerating the recovery of the ocular surface with a lasting effect. ●

REFERENCES

1. Dana MR, et al. Adv Exp Med Biol. 2002;506:729-738.
2. Benítez del Castillo JM, et al. Invest Ophthalmol Vis Sci. 2004;45:3030-3035.
3. Touhami A, et al. Invest Ophthalmol Vis Sci. 2002;43:987-994.
4. Cheng A, et al. Ocul Surf. 2016;14:56-63.
5. Sheha H, et al. Ocular Surface Disorders. JP Medical, London;2013:325-329.
6. John T, et al. J Ophthalmol. 2017;2017:644918.