Intraocular Pressure of Premature Newborns – A 2 Year Follow up

Document Type : Original Article


1 Department of Ophthalmology, University Hospital, Stara Zagora, Bulgaria

2 Department of Neonatology, University Hospital, Stara Zagora, Bulgaria



Background: The intraocular pressure (IOP) ranges of premature newborns are not the same as those in full-term newborns and adult population. There are no unified standards for IOP in infants, much less premature newborn. Research on the topic is very conflicting and needs to be expanded upon. To assess IOP in premature and full-term newborns and factors influencing it.
Methods: Using a hand-held rebound tonometer, IOP was measured in 548 eyes of 274 preterm infants (gestational age ranging from 26 to 32 weeks) shortly after birth and at weekly intervals for one month.
Results: The mean gestational age for premature newborns was 30.23±2.34 weeks (25-35 weeks), for full-term newborn it was 39.19±0.91 weeks (37-41 weeks). Mean IOP values in preterm infants were 21.95±4.36 mmHg (ranging from 11.1 to 32 mmHg), while for full-term were 13.5±2.9 (from 10.5 to 25.1 mmHg). At the end of the first month the mean IOP decreased to 17.66 ± 2.21 mm Hg (P < .001) for preterm newborns, while not changing in a statistically significant way for the full-term ones (P>0.5). Central corneal thickness was found to be among the major factors associated with increased IOP (P<.001).
Conclusion: Measured values of IOP are well outside the normal range for newborns. There is a tendency for decreasing IOP observed during the first month screening which decreases the value of the initial findings. The exact causes of the decrease of IOP are not completely clear up to this point. Use of eyelid speculum needs to be avoided to prevent artificial increase of IOP.


  1. Gulati S, Andrews CA, Apkarian AO, Musch DC, Lee PP, Stein JD. Effect of gestational age and birth weight on the risk of strabismus among premature infants. JAMA Pediatr. 2014;168(9):850-856.
  2. Larsson EK, Rydberg AC, Holmström GE. A population-based study of the refractive outcome in 10-year-old preterm and full-term children. Arch Ophthalmol. 2003;121(10):1430-1436. 
  3. O'Connor AR, Wilson CM, Fielder AR. Ophthalmological problems associated with preterm birth. Eye (Lond). 2007;21(10):1254-1260.
  4. Thiagarajah C, Kern M, Jones L. Case series of neonates with concomitant retinopathy of prematurity and congenital glaucoma. Investig Ophthalmol Vis Sci. 2006;47(13):720.
  5. Senthil S, Balijepalli P, Garudadri C, Jalali S. Clinical presentation and management outcomes of coexistent congenital glaucoma and retinopathy of prematurity. J Glaucoma. 2019;28(1):20-26.
  6. Dragosloveanu CDM, Potop V, Coviltir V, Dinu V, Păsărică M, Ducan IL, et al. Prematurity-risk factor or coincidence in congenital glaucoma? Medicina (Kaunas). 2022;58(3):334.
  7. Nakakura S, Terao E, Kuroda N, Fujio S, Hirose Y, Tabuchi A, et al. A case report on premature twins: primary congenital glaucoma or large cupping disks mimicking primary congenital glaucoma? Cureus. 2021;13(8):e17108.
  8. Ricci B. Intraocular pressure in premature babies in the first month of life. J AAPOS. 1999;3(2):125-127. 
  9. Gandhi PD, Gürses-Özden R, Liebmann JM, Ritch R. Attempted eyelid closure affects intraocular pressure measurement. Am J Ophthalmol. 2001;131(4):417-420.
  10. Iester M, Mermoud A, Achache F, Roy S. New Tonopen XL: comparison with the Goldmann tonometer. Eye (Lond). 2001;15(Pt 1):52-58.
  11. McKee EC, Ely AL, Duncan JE, Dosunmu EO, Freedman SF. A comparison of Icare PRO and Tono-Pen XL tonometers in anesthetized children. J AAPOS. 2015;19(4):332-337. 
  12. Haus AH, Jonescu-Cuypers C, Seitz B, Kaesmann-Kellner B. Comparison between intraocular pressure measurements with ICare rebound tonometry and tonopen XL tonometry in premature infants. Invest Ophthalmol Vis Sci. 2008;49(13):712-712.
  13. Yıldırım N, Sahin A, Basmak H, Bal C. Effect of central corneal thickness and radius of the corneal curvature on intraocular pressure measured with the tonopen and noncontact tonometer in healthy schoolchildren. J Pediatr Ophthalmol Strabismus. 2007;44:216–222.
  14. Neuburger M, Maier P, Böhringer D, Reinhard T, F Jordan J. The impact of corneal edema on intraocular pressure measurements using goldmann applanation tonometry, Tono-Pen XL, iCare, and ORA: an in vitro model. J Glaucoma. 2013;22:584–590.
  15. Uva MG, Reibaldi M, Longo A, Avitabile T, Gagliano C, Scollo D, et al. Intraocular pressure and central corneal thickness in premature and full-term newborns. J AAPOS. 2011;15(4):367-369. 
  16. Musarella MA, Morin JD. Anterior segment and intraocular pressure measurements of the unanesthetized premature infant. Metab Pediatr Syst Ophthalmol (1985). 1985;8(2-3):53-60.
  17. Muslubas IB, Oral AY, Cabi C, Caliskan S. Assessment of the central corneal thickness and intraocular pressure in premature and full-term newborns. Indian J Ophthalmol. 2014;62(5):561-564.
  18. Erginturk Acar D, Acar U, Ozdemir O, Tunay ZO. Determination of normal values of intraocular pressure and central corneal thickness in healthy premature infants-a prospective longitudinal study. J AAPOS. 2016;20(3):239-242.
  19. Ng PC, Tam BS, Lee CH, Wong SP, Lam HS, Kwok AK, et al. A longitudinal study to establish the normative value and to evaluate perinatal factors affecting intraocular pressure in preterm infants. Invest Ophthalmol Vis Sci. 2008;49(1):87-92.
  20. Kirwan C, O'Keefe M, Fitzsimon S. Central corneal thickness and corneal diameter in premature infants. Acta Ophthalmol Scand. 2005;83(6):751-753.
  21. Autzen T, Bjørnstrøm L. Central corneal thickness in premature babies. Acta Ophthalmol (Copenh). 1991;69(2):251-252.
  22. Epley K, Tychsen L, Lueder G. The effect of an eyelid speculum on intraocular pressure measurement in children. Am J Ophthalmol. 2002;134(6):926-927.
  23. Çiçek A, Bayram N, Alabay B, Vural E. The effect of an eyelid speculum on intraocular pressure measurement in newborns. J Pediatr Ophthalmol Strabismus. 2022;59(1):13-16.
  24. Mikhail M, Sabri K, Levin AV. Effect of anesthesia on intraocular pressure measurement in children. Surv Ophthalmol. 2017;62(5):648-658.