Case of paediatric steroid‐induced glaucoma showing extremely fast progression with deformation of lamina cribrosa

The ocular-hypertensive response to steroids is reported to be of greater frequency and severity in children than in adults. However, there have as yet been no observations of accompanying structural changes to the deep optic nerve head in paediatric steroid-induced glaucoma. This clinical picture illustrates a paediatric case showing unexpectedly fast progression, despite a relatively well-controlled intraocular pressure, with special emphasis on the longitudinal structural alteration of the lamina cribrosa. An eight-year-old East Asian female patient presented with a one-week history of right-eye conjunctival injection. Her visual acuity was 6/6 bilaterally, and the Goldmann applanation tonometry-measured intraocular pressure was 15 mmHg in both eyes. She was diagnosed with anterior uveitis in both eyes, and treated with 1% prednisolone eye drops four times per day. All laboratory tests for underlying systemic diseases showed normal results. Two weeks later, anterior segment inflammation was significantly improved, although intraocular pressures were greatly increased, to 34 mmHg in both eyes. Her central corneal thickness was 0.542 mm in both eyes. Anti-glaucoma medications, 2% dorzolamide/0.5% timolol fixed-combination was initiated. After five days, her intraocular pressure returned to normal, and maintained < 16 mmHg subsequently. Her uveitis, meanwhile, was worsening, despite oral methotrexate. Vitritis was noted, in response to which, the patient was given a bilateral subconjunctival dexamethasone injection. One month later, no inflammation was observed, and intraocular pressures were maintained between 20 and 23 mmHg until five months after the injection. Nine months after the injection (December 2017), the patient’s intraocular pressure gradually reached 26 mmHg in both eyes. The deep optic nerve head and retinal nerve fibre layer evaluations showed unexpectedly large changes relative to the results of August 2017 (Figures 1 and 2): greatly increased cup-to-disc ratio (from 0.75 to 0.99 in both eyes), substantially reduced retinal nerve fibre layer thickness (−55 per cent in the right eye and −30 per cent in the left eye) and significant posterior displacement of the lamina cribrosa (−529 μm in the right eye and −516 μm in the left eye). The lamina cribrosa is known as the primary site of glaucoma pathogenesis. Lamina cribrosa deformation can cause kinking of the retinal ganglion cell axons in laminar pores, thereby blocking axonal flow and accelerating glaucomatous damage. The degree of lamina cribrosa deformation, for a given intraocular pressure and cerebrospinal fluid pressure, is a function of the mechanical properties of the lamina cribrosa tissue. Previous studies have demonstrated greater lamina cribrosa compliance in younger individuals; therefore, great dynamic change in lamina cribrosa morphology is to be expected, as in the present case. The lamina cribrosa, from the earliest glaucoma stage, not only deforms, but also remodels itself in response to the altered biomechanical environment. In the present case, biomechanical changes in the lamina cribrosa would have already begun by the time of initial intraocular pressure peak. Thereafter, glaucomatous damage progressed slowly, but at some point beyond the critical level – even with the only moderate degree of intraocular pressure elevation – the vulnerable lamina cribrosa structure might have undergone much greater and more rapid deformation, resulting in accelerated damage. This case highlights the importance, in paediatric steroid-induced glaucoma, of strict intraocular pressure control and regular evaluation of accompanying structural change in the deep optic nerve head.