Effectiveness of diagnosis and early treatment of ocular motility alterations in premature infants

Objective: Prematurity often results in important developmental sequelae of brain structures, particularly those involved in processing visual information, such as the optic nerve, primary visual cortex and visuomotor integration areas. The aim of this study is to analyse the functionality of the sensory and motor pathways of the visual system by means of an orthoptic-ophthalmological assessment. Materials and methods: In this retrospective study, 151 records were examined, covering a period from 2000 to 2020, of preterm patients with gestational age < 32 weeks and birth weight ≤ 1,500 g up to an average age of about 8 years, referred to the Centre for Paediatric Ophthalmology and Strabology of the Ophthalmology Clinic of the Policlinico Umberto I, La Sapienza University of Rome, who underwent a complete ophthalmological and orthoptic assessment including the following tests measurement of ocular deviations according to the Hirschberg method, Lang I-II test, Titmus Stereotest, objective convergence assessment and ocular motility examination. Results: From the charts reviewed, 24.5% (37/151) of patients had Retinopathy of the Premature (ROP); while 38% of the whole sample (57/151) had strabismic amblyopia, of the latter only 31.5% (18/57) had ROP. In 8% of patients (12/151) the stereoscopic sense was absent, in 45% (8/151) stereopsis was gross (> 60 seconds of arc). In addition, 20.52 % (31/151) had a manifest eye deviation. 7.28% (11/151) had hypermetropia in the right eye (RE); 7.95% (12/151) hypermetropia in the left eye (OS); 3.31% of the patients (5/151) had myopia in the RE; 2% (3/151), myopia in the left eye (LE). In addition, the study of ocular motility revealed varying degrees of alteration poorly correlated with prematurity status. Conclusion: It was found that amblyopia, stereopsis and objective convergence are more affected by ROP than strabismus, refractive defects and ocular motility, indicating that premature children are particularly susceptible to ophthalmological and orthoptical alterations.