Technical difficulties of adequate assessment of intraocular pressure in a patient with glaucoma in the long term after corneal refractive surgery (clinical case)

Abstract

PURPOSE. To demonstrate a clinical case involving difficulties in adequate assessment of intraocular pressure (IOP) in a patient with glaucoma in the long term after LASIK.METHODS. The study describes the case of patient M. of 58 years old with complaints about decreased distance vision in the right eye during the last year. In 2004 the patient underwent LASIK for moderate myopia. In 2018, asymmetry in the parameters of optic nerve head (size of the optic cup to the optic disc ratio (C/D ratio) was revealed: in the right eye — up to 0.7, narrowing of the visual field from nasal to fixation point; in the left eye — 0.5, visual fields without abnormalities. The IOP measured using the Maklakov method in both eyes corresponded to the average statistical norm — 22 mm Hg. The following diagnosis was established: IIA primary open-angle glaucoma in the right eye, IA primary open-angle glaucoma in the left eye. One-time instillations of latanoprost 0.005% eye drops solution was indicated for both eyes. In subsequent years the IOP was 18–20 mm Hg. After 4 years, the IOP according to the Maklakov method: OD — 18 mm Hg; OS — 21 mm Hg (on the hypotensive regimen — instillations of latanoprost 0.005% eye drops solution). In the right eye: C/D ratio 0.85–0.9 with absolute scotoma in the Bjerrum area 5–15° from fixation; in the left eye: C/D ratio 0.9 with neuro retinal rim loss from below, with absolute scotoma in the blind spot area. The stages of primary open-angle glaucoma were ascertained: IIIA in the right eye, IIA in the left eye.RESULTS. Selective laser trabeculoplasty was performed. Brimonidine 0.1% solution was added due to the lack of complete stabilization of the IOP level on a single instillation of latanoprost 0.005%, after that IOP decreased to 19 mm Hg in both eyes.CONCLUSION. It is necessary to carefully assess the condition of the structures of the optic nerve head in patients after LASIK, regardless of the statistically normal IOP values.