Abstract
Purpose :
Central corneal thickness (CCT) has important implications in the surgical and clinical management of ocular diseases, such as glaucoma. Goldmann applanation tonometry (GAT) is the standard of care in the measurement of intraocular pressure and is typically performed prior to ancillary testing such as CCT pachymetry. We aimed to determine the effect of GAT on the reliability of contact- and non-contact modality CCT pachymetry measurements.
Methods :
Participants with no ophthalmic diagnoses, prior ocular surgeries, contact lens use for 24 hours, or best-corrected visual acuity worse than 20/20 were recruited for CCT measurement before and after GAT IOP measurement. Contact ultrasound pachymeter (Pachmate2, DGH Technology, Exton, PA, USA) and non-contact optical low-coherence reflectometer (OCLR) (Lenstar LS 900, Haag-Streit Diagnostics, Koeniz, Switzerland) CCT measurements were taken 5 min before and 5 min after GAT between 15:00 and 18:00 on different days.
Results :
CCT measurements (n=1,274) were collected from 26 participants with a mean age of26.3 (SD 7.3), female 77%, mean refraction spherical equivalent: minus 0.8 D (SD 1.4), and race of Black (3), White (9), Hispanic (6), and Other (3). Contact pachymetry appeared to show greater CCT thickness and wider standard deviations before compared with after GAT (+2.3 µm, SD +0.5), whereas noncontact pachymetry modalities showed minimal difference in CCT (-0.5 µm) after GAT and SD showed no change. IOP measurements taken after contact ultrasound pachymetry were less (13.1 mmHg, SD:2.75) than noncontact OCLR biometry (14.1 mm Hg, SD:3.02) (ns, p=0.088).
Conclusions :
Non contact central corneal thickness measurement is superior to contact measurement and not affected by Goldmann applanation tonometry. This should be considered in planning refractive or cataract surgery where central corneal thickness measurement is paramount in surgical decision making.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.