Consider axial length as an important parameter for your surgical decision in childhood glaucoma patients

Primary congenital glaucoma leads to blindness if not treated adequate. Typical symptoms are epiphora, photophobia and blepharospasm. The elevated pressure leads to buphthalmos (globe enlargement), corneal edema, ruptures of the Descemet’s membrane (Haab’s striae), and to glaucomatous optic disc changes. When deciding on a surgical procedure the IOP is the most important factor to consider. However, IOP may be measured false too low (deep anaesthesia) or false too high (thick cornea, anterior segment dysgenesis with different biomechanics of the globe, anaesthetics such as ketamine). Therefore, it is important to include axial length development in the decision for or against surgery.

Axial length (AL) growth is one of the most reliable signs for glaucoma progression in the young patient. It can be measured in the office or during EUA (examination under anesthesia). However, one needs to know normal AL growth to differentiate pathologic growth. Sampaolesi estimated that at one month of age the 5th percentile and 95th percentile of normal AL are 17.25 mm and 20.25 mm, respectively and it increases mostly during 1st and 2nd years. Increase in AL outside normal limits for age or asymmetrical increase compared to fellow-eye suggest poorly controlled IOP. Stabilization of the AL measurements performed within a 3-4 months intervals is considered a good response to glaucoma surgery. Thus, it is of paramount importance to take basal and follow-up AL measurements in children with congenital glaucoma, especially in the first 3 years of age.

Contributors: Esther Hoffmann and Zeynep Aktas

References:
1. Sampaolesi R, Caruso R. Ocular echometry in the diagnosis of congenital glaucoma. Arch Ophthalmol 1982; 100: 574-577.
2. Hoffmann EM, Aghayeva F, Schuster AK, Pfeiffer N, Karsten M, Schweiger S, Pirlich N, Wagner FM, Chronopoulos P, Grehn F. Results of childhood glaucoma surgery over a long-term period. Acta Ophthalmol. 2022 Mar;100(2):e448-e454.
3. Wagner FM, Schuster AK, Grehn F, Urbanek L, Pfeiffer N, Stingl JV, Hoffmann EM. Twenty-Years of Experience in Childhood Glaucoma Surgery. J Clin Med. 2021 Dec 8;10(24):5720.
4. Alshigari R, Freidi A, Souru C, Edward DP, Malik R. Risk Factors for Blindness in Children With Primary Congenital Glaucoma-Follow-up of a Registry Cohort. Am J Ophthalmol. 2021 Apr;224:238-245.

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