Are pachymetric and tonometric asymmetry related?

Abstract

Abstract Purpose: Goldmann applanation tonometry readings are affected by central corneal thickness. We have determined the level of pachymetric and tonometric asymmetry in normal, diabetic, ocular hypertensives and diabetic ocular hypertensive patients, and the relationship between both asymmetries. Methods: Four groups, one of 77 normal patients (N), one of 59 type II diabetic patients (DM), one of 74 patients with ocular hypertension (OHT), and one group of 61 type II diabetic ocular hypertensive patients (DMOHT) have been included. Ocular exploration, including ultrasound pachymetry, has been performed in all of them. Time from diagnosis and current treatment are also recorded. Interocular differences are analyzed by the SPSS 14.0 program using ANOVA and Pearson tests. Results: The pachymetric asymmetry between groups is not significant (ANOVA P < 0,072). The difference between pachymetric assymetry in diabetic patients (DM+DMOHT) 6,83±5,45μ and non‐diabetic patients (N+OHT) 5,50±5,01μ is statistically significant (P < 0.037). This difference is not significant between ocular hypertensives (OHT+DMOHT) and ocular normotensives (N+DM) (P < 0,982). There is not linear correlation between pachymetric and tonometric asymmetry in the whole sample (r = 0,003). Pachymetric asymmetry correlates with time from diagnosis, and asymmetry is bigger under treatment with insuline, and in retinal proliferative stages. IOP asymmetry correlates with time from diagnosis, is bigger for insuline treated patients and is similar through the different stages of retinopathy. Conclusions: Pachymetric asymmetry is not related to tonometric asymmetry in this study. Diabetic patients showed bigger pachymetric asymmetry than non diabetic patients, but is not related to tonometric asymmetry.