Influence of involuntary eyelid spasms on corneal topographic and eyelid morphometric changes in patients with hemifacial spasm Teissy Osaki, 1 Midori H Osaki, 1 Tammy H Osaki, 1 Flavio E Hirai, 1 Nambi Nallasamy, 2 Mauro Campos 1 1 Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of São Paulo/ UNIFESP, São Paulo, SP, Brazil 2 Department of Ophthalmology, Duke University Eye Center, Durham, North Carolina, USA Correspondence to Dr Teissy H Osaki, Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Botucatu St, 821, 2nd Floor, São Paulo, SP 04023-062, Brazil; teissyosaki@yahoo.com.br Received 5 June 2015 Revised 18 September 2015 Accepted 10 October 2015 Published Online First 5 November 2015 To cite: Osaki T, Osaki MH, Osaki TH, et al. Br J Ophthalmol 2016;100: 963–970. ABSTRACT Background/aims In patients with hemifacial spasm (HFS), treatment relieves eyelid spasms on the affected side, thus changes in corneal topography and eyelid morphometry may be observed after treatment. We aimed to evaluate these parameters during a 4-month period in patients with HFS treated with botulinum toxin A (BTX-A). Methods This prospective study evaluated eyelid morphometric and corneal topographic changes in patients with HFS before onabotulinum toxin A application, and after 15 days and 2, 3 and 4 months. Results 24 patients were treated with BTX-A. On the normal side, the mean palpebral fissure height (PF), interpalpebral surface area (ISA), steep K and astigmatism values were 8.7±1.98 mm, 122.09± 39.37 mm 2 , 44.99±1.45 D and 0.9±0.64 D, respectively, before treatment. A statistically significant difference was not observed in these parameters after treatment (p>0.05). On the affected side, the mean PF, ISA, steep K and astigmatism were 5.5±1.77 mm, 67.68±28.49 mm 2 , 46.91±3.57 D and 2.63±2.46 D, respectively, before treatment. We observed a statistically significant (p<0.05) increase in the mean PF and ISA on the affected side 15 days (8.36±1.91 mm and 115.92 ±34.44 mm 2 , respectively), 2 months (8.18±1.80 mm and 112.22±33.57 mm 2 , respectively) and 3 months (7.27±1.65 mm and 95.48±27.80 mm 2 , respectively) after treatment. A statistically significant decrease in steep K and astigmatism was observed at 2 months (45.14±1.20 D and 1.01±0.58 D, respectively) and 3 months (45.64±1.77 D and 1.36±1.31 D, respectively) after treatment. Conclusions The results suggest that treatment with BTX-A in patients with HFS leads to eyelid and corneal changes on the affected eye that are significant during the known period of action of the toxin. Thus, caution should be taken when performing ophthalmological examination in patients with HFS, since it may vary according to BTX-A period of action. INTRODUCTION Hemifacial spasm (HFS) is characterised by tonic and clonic contractions of the muscles innervated by the ipsilateral facial nerve. Botulinum toxin A (BTX-A) is considered the medical treatment of choice for these patients and it acts by blocking the release of acetylcholine at the neuromuscular junc- tion. 1–5 Increased or altered pressure from the eyelids influences the shape of the corneal surface, leading to corneal topographic changes. 6–8 Patients with HFS present sustained abnormal eyelid tension on the cornea from involuntary eyelid spasms on the affected side. Treatment with BTX-A leads to temporary muscle paralysis and thus temporarily relieves the palpebral spasms. Therefore, different corneal topographic patterns are expected before and after treatment with BTX-A on the affected side. Furthermore, eyelid morphometric changes can also occur after treatment with BTX-A. Despite the efficacy of treatment with BTX-A for HFS, as well as the association between increased pressure from the eyelids leading to corneal topographic changes, being well established in the literature, to our knowledge, the evaluation of corneal topo- graphic and eyelid morphometric changes, during one complete BTX-A treatment cycle, has not been studied in these patients. Thus, questions related to possible changes in corneal parameters, especially in astigmatism values, remain unanswered in these patients. For example, the clinical significance of changes in astigmatism before and after BTX-A treatment, changes in astigmatism and their influ- ence in cataract surgery and intraocular lens (IOL) selection or even changes in visual acuity after BTX-A are some topics to be discussed. The purpose of this study was to investigate corneal topographic and eyelid morphometric changes and to evaluate possible correlations between corneal topography and eyelid morph- ology in patients with HFS treated with BTX-A during a 4-month period (period that corresponds to BTX-A duration of action). 259–12 MATERIALS AND METHODS After institutional review board approval and informed consent were obtained, 24 patients with moderate-to-severe HFS, according to Jankovic Rating Scale, 13 were recruited for this study. All subjects were treated in accordance with the tenets of the Declaration of Helsinki. Exclusion criteria included allergies to botulinum toxin or to any component of the drug, previous treatment with BTX-A fewer than 6 months prior, prior refractive, eyelid or intraocular surgery, patients with corneal surface-altering diseases, strabismus, contact lens wear, pregnancy, breastfeeding, patients with neuromuscular junction or peripheral neuropathic diseases and the use of aminoglycosides or other agents that could interfere with neuromuscular transmission. Data were collected from February 2013 to September 2014 at the Division of Ophthalmic Plastic and Reconstructive Surgery, Department of Osaki T, et al. Br J Ophthalmol 2016;100:963–970. doi:10.1136/bjophthalmol-2015-307272 963 Clinical science