Ocular Pulse Amplitude in Non-Diabetic Patients with End Stage Renal Disease and Normal Individuals Using Dynamic Contour Tonometry.

INTRODUCTION: Ocular Pulse Amplitude (OPA) is the fluctuation of IOP with the cardiac cycle which is equal to the difference between systolic and diastolic IOP. These variations in IOP are thought to be caused by the blood volume that is pumped into the eye, mainly the choroidal bed during each cardiac cycle. In patients with end stage renal disease (ESRD), Choroidal perfusion has been found to be reduced as determined by Indocyanine Green Angiography (ICG) which is an invasive procedure. OPA is recorded by Dynamic Contour Tonometer (DCT) which represents a potential new technology for measuring choroidal blood flow indirectly & non-invasively especially in patients with suspected compromise in perfusion as in ESRD. In this study we postulate that measurement of OPA can be used to assess the choroidal perfusion inpatients with ESRD. OBJECTIVES: To measure OPA in non-diabetic patients with ESRD on hemodialysis and to compare it with that of OPA in age matched normal individuals. MATERIALS & METHODS: It was a prospective Cross-sectional study and was done in a clinical set up during the period of January 2013 to October 2013. OPA among 44exposed and 44 non exposed individuals were measured using Dynamic Contour Tonometry (DCT) and analysis done. RESULTS: The mean OPA in non diabetic patients with ESRD was 1.945mm Hg (CI:1.847 - 2.043) and the mean OPA in age matched normals was 2.16mm Hg (CI: 2.08- 2.24). CONCLUSION: OPA in non diabetic ESRD patients was statistically significantly lower than that of age matched normals (p=0.03). There was no correlation between OPA and other parameters like age, gender, intraocular pressure, blood pressure or serumcreatinine levels.

Correlation between ocular parameters and amplitude of accommodation.

AIM: To study the relationship between ocular parameters and amplitude of accommodation (AA) in the peri-presbyopic age group (35-50 years). MATERIALS AND METHODS: Three hundred and sixteen right eyes of consecutive patients in the age group 35-50 years, who attended our outpatient clinic, were studied. Emmetropes, hypermetropes and myopes with best-corrected visual acuity of 20/20, J1 in both eyes were included. The AA was calculated by measuring the near point of accommodation. The axial length (AL), central anterior chamber depth (CACD) and lens thickness (LT) were also measured. RESULTS: There was moderate correlation (Pearson's correlation coefficient r = 0.56) between AL and AA as well as between CACD and AA (r = 0.53) in myopes in the age group 35-39 years. In the other age groups and the groups taken as a whole, there was no correlation. In hypermetropes and emmetropes, there was no correlation between AA and the above ocular parameters. No significant correlation existed between LT and AA across different age groups and refractive errors. CONCLUSION: There was no significant correlation between AA and ocular parameters like anterior chamber depth, AL and LT.

Amplitude of accommodation and its relation to refractive errors.

AIMS: To evaluate the relationship between amplitude of accommodation and refractive errors in the peri-presbyopic age group. MATERIALS AND METHODS: Three hundred and sixteen right eyes of 316 consecutive patients in the age group 35-50 years who attended our outpatient clinic were studied. Emmetropes, hypermetropes and myopes with best-corrected visual acuity of 6/6 J1 in both eyes were included. The amplitude of accommodation (AA) was calculated by measuring the near point of accommodation (NPA). In patients with more than +/- 2 diopter sphere correction for distance, the NPA was also measured using appropriate soft contact lenses. RESULTS: There was a statistically significant difference in AA between myopes and hypermetropes (P < 0.005) and between myopes and emmetropes (P < 0.005) in the 35-39 year age group. In the 40-44 year age group, there was a significant difference in AA between emmetropes and hypermetropes (P < 0.0001), emmetropes and myopes (P < 0.01) and hypermetropes and myopes (P < 0.0001). In patients above 45 years of age there was no significant difference (P > 0.5). CONCLUSION: Our study showed higher amplitude of accommodation among myopes between 35 and 44 years compared to emmetropes and hypermetropes.