Guest Editorial

Introduction

Vernal Keratoconjunctivitis is a type 1 hypersensitivity reaction, with the resultant allergic
reaction affecting chiefly conjunctiva and cornea. The corneal complications like shield ulcer, keratoconus, and limbal stem cell deficiency result in visual debility and also reduces the quality of life in the long run.

VKC usually affects the individuals living in Sub Saharan desert areas, 1 with dry climate, the incidence increases in summers, although it is perennial is 23% individuals. 2 The distribution of VKC varies in the different geographical areas, and in India, the distribution is similar to tropical countries and mixed type is the most common. 3 Lack of general consensus, high expectations of patients and parents an easy over the counter availability of steroids, results indiscriminate use of high potency steroids, which leads to complications like cataract and glaucoma, the incidence of cataract and glaucoma in VKC can be as high as 6 % 3 and 5.5 % 4 respectively.

Etiopathogenesis

VKC, as mentioned earlier, is a type 1 hypersensitivity reaction, and involves complex
immunological reaction, which is most commonly triggered by the exposure to pollens, smoke, dust, which are further engulfed by macrophages, following this there is activation of B cells which further produce IgE antibodies, these antibodies bind to the mast cells, so whenever there is exposure to allergens these bind to IgE on the surface of mast cells, leading to its degranulation and this releases histamine, and other mediators of inflammation also there is activation of eosinophils, which further release eosinophil peroxidase, eosinophil cationic protein, and eosinophil major basic protein, all these inflammatory mediators have cytotoxic effects on corneal epithelium. 5

Clinical features

VKC usually affects young males and is characterized by itching, watering, mucoid ropy
discharge, on examination there is a characteristic presence of cobblestone papilla, in the limbal conjunctiva one can see the presence of limbal papilla, also known as Horner Tranta spots, corneal involvement in the initial stages can be in the form of microerosions, these can convert to further macro erosions, leading to exposure of Bowman’s membrane, and the formation of shield ulcer. Limbal stem cell deficiency, corneal neovascularization, and keratoconus are the corneal complications seen in chronic cases.

Management

The various treatment options available for VKC include mast cell stabilizers, antihistaminics, dual action drugs, steroids, non-steroidal anti-inflammatory drugs and steroid sparing agents like cyclosporine and tacrolimus. Mechanism of action of the various drugs used in VKC has been summarized in Table 1. In order to prevent the treatment-related complications arising due to the long term use of high potency steroids, it is important to have a grading system for VKC and tailoring the management
accordingly.

Various treatment algorithms have been suggested for VKC by Sachetti et al, 6 Bonini et al 7 and Gokhale et al. 8Gokhale et al, 8 have classified VKC as mild, moderate and severe according to corneal involvement, in which the mild form has only papillae, with no corneal involvement, moderate form of the disease also had corneal involvement in the form of corneal microerosions, and severe form of VKC also had corneal involvement in the form of macro erosions. The mild form of VKC should be treated only with antiallergens like antihistaminic agents, mast cell stabilizers or dual action drugs.

In the moderate form of VKC, low potency steroids like fluorometholone along with antiallergen drugs should be prescribed. The low potency steroids can be started as four times per day and must be tapered in the next four weeks. 9 In severe and chronic forms of VKC, where long term use of steroids is needed, it is important to make a choice of steroid sparing agents like cyclosporine and tacrolimus.

Besides medical management, it is important that patients and parents are counseled about the disease course and the chronic nature of the disease. Patients must also be told to avoid frequent rubbing of the eyes so as to prevent complications like keratoconus, and it is also important to avoid triggering factors like dust and pollens, cold compress and lubricants can also be advised as they are believed to dilute the allergen. A simplified management protocol has been given in Table 2.

Conclusion

Hence, the successful management of VKC is possible only when there is a better understanding of the seriousness of the disease. There should be a proper grading system so as the management becomes simplified, and the use of high potency steroids is minimized.

Proper counseling and supportive measures are equally important, and one must prefer steroid-sparing agents in chronic cases.

References

1) Stephan JT, Ian AC, Mark W, David Y. Limbal vernal keratoconjuctivitis in the tropics. Rev Int Trachome. 1988;3(4):53–71

2) Kumar S. Vernal keratoconjunctivitis: a major review. Acta Ophthalmol (Copenh).
2009;87(2):133-147.

3) Saboo US, Jain M, Reddy JC, Sangwan VS. Demographic and clinical profile of vernal
keratoconjunctivitis at a tertiary eye care center in India. Indian J Ophthalmol 2013; 61:486-9.

4) Ang M, Ti SE, Loh R, et al. Steroid-induced ocular hypertension in Asian children with severe vernal keratoconjunctivitis. Clin Ophthalmol. 2012;6:1253–1258.

5) Leonardi, A. (2002). Vernal keratoconjunctivitis: pathogenesis and treatment. Progress in Retinal and Eye Research, 21(3), 319–339

6) Sacchetti M, Lambiase A, Mantelli F, Deligianni V, Leonardi A, Bonini S. Tailored approach to the treatment of vernal keratoconjunctivitis. Ophthalmology 2010;117:1294-9.

7) Bonini S, Sacchetti M, Mantelli F, Lambiase A. Clinical grading of vernal
keratoconjunctivitis. Curr Opin Allergy Clin Immunol. 2007;7(5):436-441.

8) Gokhale NS. Systematic approach to managing vernal keratoconjunctivitis in clinical
practice: Severity grading system and a treatment algorithm. Indian J Ophthalmol.
2016;64(2):145-148.

9) Singhal D,  Sahay P ,  Maharana PK , Raj N, Sharma N,  Titiyal JS .Vernal Keratoconjunctivitis. Surv Ophthalmol. 2018 Dec.12