The Intraocular Pressure Measured by Different Tonometers in Corneal Edema

The Variation of the Intraocular Pressure Measured by Different Tonometers in Patients With Clinical Corneal Edema

The investigators conduct this study to access the effect of corneal edema (the investigators are particularly interested in those who have the clinical central corneal edema) on the variation of intraocular pressure values measured by 3 commercial-available tonometers compare to the current gold standard tonometer; Goldmann applanation tonometer.

Previous published articles reported on the effect of corneal edema on the accuracy of tonometry were performed in enucleated cadaver eyes, or contact lens-induced corneal edema eyes. Thus, it remains unclear as to how the clinical corneal edema that is found in routine clinical practice will affect the variation of intraocular pressure measurement using the standard Goldmann applanation tonometer and other more modern tonometers such as the dynamic contour tonometer, the iCare, and the Tonopen.

Inclusion Criteria:

• Age more than 18 year-old
• Patients who have a clinical central corneal edema after clear cornea phacoemulsification and intraocular lens implantation
• Agree to participate in the study and willing to sign an informed consent

Exclusion Criteria:

• Combined phacoemulsification and trabeculectomy
• Clear cornea phacoemulsification that has suture on the cornea
• Previous history of intraocular surgery, ocular trauma prior to phacoemulsification
• Vitrectomized eye
• History of glaucoma or ocular hypertension or using IOP lowering medication
• History of diabetic retinopathy staged as severe non-proliferative or worse
• Pregnant or breast-feeding women
• History of refractive surgery or any keratoplastic procedure
• Corneal opacities or diseases making no suitable tonometry
• Severe dry eye syndrome
• Wears contact lenses
• Astigmatism higher than 2.5 diopters
• Microphthalmos or buphthalmos
• Subjects with having poor or eccentric fixation or nystagmus
• Excessive eye squeezing
• Known allergy to topical anesthesia
• Known allergy to fluorescein solution