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Contact Lens Spectrum

Article

GP INSIGHTS

Neurotrophic Dry Eye Treatment

By: MELANIE FROGOZO, OD, FAAO
Contact Lens Spectrum July 1, 2023 Vol 38, Issue July 2023 Page(s): 13

THE LACRIMAL FUNCTIONAL unit controls the production, delivery, and clearance of tears (Rosenthal and Borsook, 2016). The neural component of the lacrimal functional unit is a reflexive loop starting at the corneal innervation, which is provided by the ophthalmic branch of the trigeminal nerve. This afferent pathway connects to secretory and motor efferent nerves, which aid in tear production and blinking. The efferent pathways end at the accessory lacrimal glands, conjunctival goblet cells, and meibomian glands (Pflugfelder and Stern, 2020).

Damage to the innervation of the lacrimal functional unit, because of either surgery or disease, results in decreased tear secretion and surface epithelial barrier disruption (Dua et al, 2018). Consequently, neuropathic pain, altered tear composition, and inflammation occur (Rosenthal and Borsook, 2016).

Denervation to the cornea may also cause neurotrophic keratitis (NK) (Bonini et al, 2003; Dua et al, 2018). This is a corneal degenerative disease characterized by trigeminal nerve impairment, reduced corneal sensitivity, spontaneous epithelial breakdown, and corneal ulceration (Rosenthal and Borsook, 2016). The Mackie classification scheme grades NK in three stages (Semeraro et al, 2014).

  • Stage 1 is characterized by epithelial irregularities, such as punctate keratopathy, hyperplasia, and superficial vascularization, and potentially by the presence of rose bengal staining to conjunctival epithelium.
  • Stage 2 is characterized by persistent epithelial defects (PEDs), folds in Descemet’s membrane, and in some cases an inflammatory reaction in the anterior chamber.
  • Stage 3 is characterized by corneal ulcers with progression to perforation or stromal melting.

The goal of NK treatment is preserving surface integrity. Thus, those who have NK may benefit from therapeutic scleral lenses. The design of a scleral lens creates vault over the cornea while landing on the sclera conjunctival tissue. A fluid reservoir constantly hydrates the cornea, which promotes the healing process and prevents further surface desiccation (Harthan and Shorter, 2018). The large-diameter lens protects the ocular surface from the shearing forces of the eyelids. Last, the GP lens design corrects irregular astigmatism due to the corneal abnormalities (Harthan and Shorter, 2018) of NK.

To aid scleral lens therapy for NK, topical medications may be added into the lens vault (He et al, 2018). Autologous (from patients) or allogenic (from adult donors) serum may be placed within the scleral lens before application.

Blood serum contains metabolically active substances such as growth factors that promote cellular proliferation and migration (Bradley et al, 2008). Besides NK, blood serum drops have been used to treat ocular surface disorders, such as dry eye disease, ocular surface burn, recurrent corneal erosion, and limbal stem cell deficiency (Bernabei et al, 2019).

Take, for example, the case of a 5-year-old female with a history of stage 2 NK in the right eye from stroke. Her PED resolved after the application of a scleral lens medicated with daily installation in the lens vault of allogenic serum tears donated by her mother (Figure 1). The patient’s resolution to stage 1 NK has been stable for the past two years (Figure 2). CLS

Figure 1. Young patients can wear scleral lenses with topical medication in the bowl of the lens for healing.Photo courtesy of Melanie Frogozo, OD.
Figure 1. Young patients can wear scleral lenses with topical medication in the bowl of the lens for healing.Photo courtesy of Melanie Frogozo, OD.

Figure 2. Stage 1 NK can be therapeutically treated with scleral lenses. Photo courtesy of Melanie Frogozo, OD.
Figure 2. Stage 1 NK can be therapeutically treated with scleral lenses. Photo courtesy of Melanie Frogozo, OD.

References

  1. Dua HS, Said DG, Messmer EM. Neurotrophic keratopathy. Prog Retin Eye Res. 2018 Sep;66:107-131.
  2. Rosenthal P, Borsook D. Ocular neuropathic pain. Br J Ophthalmol. 2016 Jan;100:128-134.
  3. Bonini S, Rama P, Olzi D, Lambiase A. Neurotrophic keratitis. Eye (Lond). 2003 Nov;17:989-95.
  4. Pflugfelder SC, Stern ME. Biological functions of tear film. Exp Eye Res. 2020 Aug;197:108115.
  5. Semeraro F, Forbice E, Romano V, et al. Neurotrophic keratitis. Ophthalmologica. 2014;231:191-197.
  6. Harthan JS, Shorter E. Therapeutic uses of scleral contact lenses for ocular surface disease: patient selection and special considerations. Clin Optom (Auckl). 2018 Jul;10:65-74.
  7. He X, Donaldson KE, Perez VL, Sotomayor P. Case Series: Overnight Wear of Scleral Lens for Persistent Epithelial Defects. Optom Vis Sci. 2018 Jan;95;70-75.
  8. Bradley JC, Bradley RH, Mccartney DL, Mannis MJ. Clin Exp Ophthalmol. 2008 Nov;36:717-20.
  9. Bernabei F, Roda M, Buzzi M, Pellegrini M, Giannaccare G, Versura P. Blood-Based Treatments for Severe Dry Eye Disease: The Need of a Consensus. J Clin Med. 2019 Sep;8:1478.

Dr. Frogozo is the owner of Alamo Eye Care in San Antonio, TX, where she directs the Contact Lens Institute. She is a consultant to CooperVision and Lentechs. You can contact her at contactlensinstitutesa@gmail.com.

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