Varun Ranganathan, MC Optom

Clinical Optometrist

An OCULAR Interface Exclusive

Keywords: Dry eye, Serum eye drops, Ocular Surface disorder, Bioengineered transplant, Artificial Intelligence in Eyecare.

Keratoconjunctivitis sicca, commonly known as dry eye, is a multifactorial condition with various presentations and symptoms ¹. It is usually characterised by discomfort and visual disturbance but has the potential to damage the ocular surface. Hyperosmolarity is considered as the most common factor in all types of dry eye, and it acts as a stimulus for ocular surface inflammation ².

Conventional treatment options for dry eye usually include prescribing ocular lubricants and if Meibomian Gland Dysfunction (MGD) is present warm compresses are advised alongside. However, newer treatment options offer longstanding relief for people suffering from chronic dry eyes.

Corticosteroids:

Unpreserved topical corticosteroids reduce the inflammatory response and improve symptoms of ocular irritation. They work by inhibiting inflammatory cytokines and other mediators ³. These are prescribed as short-term use only since long-term use can lead to an increase in intraocular pressure and can also cause cataracts.

Cyclosporine:

Topical cyclosporine eye drop was first developed to increase tear production. It is a fungal derivative peptide and works by reducing the inflammatory response of the eye ⁴. They also improve conjunctival goblet cell density and ocular surface integrity ⁵. Unlike side-effects of long-term use of corticosteroids, cyclosporine is much safer. However, its efficacy on severe dry eyes has not been studied fully.

Serum eye drops:

Autologous serum eye drops have gained a lot of popularity in treating dry eyes and have been successfully used for many years. The blood serum has the same pH levels and osmolarity as tears and they promote epithelial healing ⁶. They have higher concentrations of epitheliotropic factors like epidermal growth factor and transforming growth factor more than in natural tears ⁷.

Scope for the future:

A recent proposal for treatment of severe dry eye caused by aqueous deficiency is about transplant of bioengineered human lacrimal gland ⁸. In this recent study, cadavers were used for the transplant and the patency of the lacrimal gland was tested using hematoxylin which is a dye used universally in microscopic procedures. The study showed that the procedure is feasible within the ischemic window. However more robust methods and its long-term viability in live humans will be needed before it is clinically approved.

Conjunctival goblet cells are responsible for secreting mucin to the tear film and mucin layer of tear film is directly in contact with the epithelial layer of the cornea. Inflammatory cytokines inhibit the goblet cells and compromise the protective function of the tears and damage the ocular surface ⁹. Goblet cells are also found in lungs and intestine, and they are also stratified in structure ¹⁰. Transplant of autologous goblet cells from lungs or intestine in cases of severe dry eye can be a viable option in healthy individuals and Artificial Intelligence can be used to study the mechanism and determine the success rate to a greater accuracy.

References:

1. Mondal H, Kim HJ, Mohanto N, Jee JP. A Review on Dry Eye Disease Treatment: Recent Progress, Diagnostics, and Future Perspectives. Pharmaceutics. 2023 Mar 19;15(3):990. doi: 10.3390/pharmaceutics15030990. PMID: 36986851; PMCID: PMC10051136.
2. Bhavsar AS, Bhavsar SG, Jain SM. A review on recent advances in dry eye: Pathogenesis and management. Oman J Ophthalmol. 2011 May;4(2):50-6. doi: 10.4103/0974-620X.83653. PMID: 21897618; PMCID: PMC3160069.
3. Bielory B.P., O’Brien T.P., Bielory L. Management of seasonal allergic conjunctivitis: Guide to therapy. Acta Ophthalmol. 2012;90:399–407. doi: 10.1111/j.1755-3768.2011.02272.x.
4. J. Petcher, H. P. Weber, and A. Rueegger, “Crystal and molecular structure of an iodo derivative of the cyclic undecapeptide cyclosporin A,” Helvetica Chimica Acta, vol. 59, no. 5, pp. 1480–1488, 1976.
5. Periman LM, Mah FS, Karpecki PM. A Review of the Mechanism of Action of Cyclosporine A: The Role of Cyclosporine A in Dry Eye Disease and Recent Formulation Developments. Clin Ophthalmol. 2020 Dec 2;14:4187-4200. doi: 10.2147/OPTH.S279051. PMID: 33299295; PMCID: PMC7719434.
6. Vazirani J, Sridhar U, Gokhale N, Doddigarla VR, Sharma S, Basu S. Autologous serum eye drops in dry eye disease: Preferred practice pattern guidelines. Indian J Ophthalmol. 2023 Apr;71(4):1357-1363. doi: 10.4103/IJO.IJO_2756_22. PMID: 37026267; PMCID: PMC10276663.
7. Geerling G, Maclennan S, Hartwig D. Autologous serum eye drops for ocular surface disorders. Br J Ophthalmol. 2004;88:1467–74.
8. Holtmann C, Roth M, Filler T, Bergmann AK, Hänggi D, Muhammad S, Borrelli M, Geerling G. Microvascular anastomosis of the human lacrimal gland: a concept study towards transplantation of the human lacrimal gland. Graefes Arch Clin Exp Ophthalmol. 2023 May;261(5):1443-1450. doi: 10.1007/s00417-022-05933-x. Epub 2022 Dec 7. PMID: 36477647; PMCID: PMC10148775.
9. Contreras-Ruiz, A. Ghosh-Mitra, M. A. Shatos, D. A. Dartt, S. Masli, “Modulation of Conjunctival Goblet Cell Function by Inflammatory Cytokines”, Mediators of Inflammation, vol. 2013, Article ID 636812, 11 pages, 2013. https://doi.org/10.1155/2013/636812
10. Gipson IK. Goblet cells of the conjunctiva: A review of recent findings. Prog Retin Eye Res. 2016 Sep;54:49-63. doi: 10.1016/j.preteyeres.2016.04.005. Epub 2016 Apr 16. PMID: 27091323; PMCID: PMC4992623.

Author Name : Varun Ranganathan