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ABSTRACT
The age-related trend values and the normal intraocular pressure (IOP) increase curve from birth through the 16th year of life were studied in 460 subjects with a noncontact tonometer (Keeler Pulsair, Keeler, Ltd, Windsor, Berks, UK). Much lower values than in adults were recorded in subjects up to the age of 3 or 4 years. This finding leads us to believe that in the treatment of infantile glaucoma IOP should be kept within the age physiologic levels, in an attempt to prevent visual field loss and optic atrophy.
INTRODUCTION
In the evaluation of medical and/or surgical treatment of glaucoma, it is important to ascertain the physiologic values of the intraocular pressure IOP).
In adults, several factors (body weight, blood pressure, sleep, breathing, excitability, etc) have been identified that affect eye pressure to various degrees. Pressure values from 15 to 17 mm Hg, with fluctuations of 2 to 4 mm Hg over 24 hours, are considered normal in adults, and the maximum acceptable value is generally 21 mm Hg. There may, however, be abnormally high IOPs without glaucoma; also, the resistance to the effects of pathologic IOP is an individual factor.
In children, few studies of the physiologic values of IOP have been done, and case records are limited. Additionally, in the 1st years of life, most authors have recorded IOP using general anesthesia, when the relaxation of extraocular muscles causes a reduction of pressure values in the deep stage of anesthesia, whereas an increased pressure level is possible in the induction stage. In such circumstances, the mean values recorded with an applanation tonometer have been from 11 to 14.7 mm Hg,1 9.56 ± 2.66 mm Hg,2 and 7.7 mm Hg.3
The few studies performed in awake children report values of 11.4 ± 2.4 mm Hg in newborns4 and 8.4 ± 0.6 mm Hg in infants younger than 4 months.5 Ricci et al,6 using a Digilab 30 D pneumotonometer, found values of 20.71 ± 1.9 mm Hg and 20.61 ±1.7 mm Hg in the right and left eye, respectively, in 100 full-term newborns and slightly lower values in a group of premature infants.
A trend of increasing IOP values was recorded by Rossazza and Wa,3 who reported a mean pressure value of 1...