RESUMEN
Background: The accurate measurement of the horizontal corneal white-to-white [WTW] diameter is essential and has multiple applications in the field of ophthalmology whether medical or surgical. There are many means of measuring the horizontal white-to-white, which includes the Pentacam, the IOL Master and Manual Calipers. Both the Pentacam and Manual Calipers measure the external white-to-white diameter, whereas the IOL Master measures the internal white-to-white diameter
Objective: The aim of this study is to measure the accuracy of the Pentacam white-to-white camera in measuring the horizontal corneal WTW diameter in comparison to the Manual Calipers, which is considered to be the basic standard
Patients and Methods: The study was a cross sectional one, conducted at Maghrabi Eye Hospital, Cairo, Egypt. It was conducted in accordance with the ethical standards stated by the Ethical Committee of Ain Shams University. Informed consent was obtained from each participant following the explanation of the academic nature of the study
Results: Our study compared the accuracy of the Pentacam HR to the Manual Calipers and found a strong correlation between both methods regarding all parameters. A difference of 0.44 +/- 0.17 mm was found between the manual calipers and the Pentacam [HVID Automated] measurements and a lesser difference of 0.24 +/- 0.27 mm when comparing the manual calipers with the Pentacam manual digital calipers. On the other hand, the difference between the 2 methods of the Pentacam measurement used was 0.19 +/- 0.13 mm. All of which, showed a highly significant correlation
Conclusion: The Pentacam gives larger WTW measurements than the manual calipers as it relies on the gray scale analysis of the HVID in the iris image display
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Background: Diabetes Mellitus [DM] is a chronic metabolic disease with considerable morbidity and mortality. Diabetic retinopathy [DR] and diabetic macular edema [DME] are major complications of DM and are the principal cause of vision loss among the working age group in developed countries. Optical coherence tomography [OCT] uses low-coherence interferometry to provide noncontact and noninvasive optical biopsy of the tissue morphology of the retina, making it a useful tool for detecting and managing DME
Aim of the Work: To study the effect of controlled type II DM on visual acuity [VA] and macular changes by OCT. In addition, to correlate VA to macular parameters detected on OCT retinal examination
Patients and Methods: This is a retrospective case control study that included 30 eyes of 22 controlled type II diabetic patients [group1] and 30 eyes of 19, age and sex matched healthy subjects [group 2]. All diabetic patients were diagnosed as DME using OCT parameters. Correlation between central foveal thickness [CFT] and VA was done
Results: There were statistically significant differences in UCVA and BCVA between the 2 groups. The difference in the central foveal thickness [CFT] from ETDRS map of OCT between the 2 groups was statistically significant. There were statistically significant differences between CFT from ETDRS map and both UCVA and BCVA. Statistically significant differences were detected between CFT and both FBS and 2HPP levels. Furthermore, statistically significant differences were detected between BCVA and both FBS and RBS levels
Conclusion: Based on the data in our study, results pose a recommendation of regular follow up of three blood sugar-assessing parameters [FBS, 2HPP and RBS] and referring patients to ophthalmologists if abnormal values were detected
Recommendations: Using large sample size will give more valid results. In our study, we evaluated the structure of the fovea, further studies can evaluate structure using OCT and function by electrophysiology. OCT angiography also could be useful in scanning retinal vasculature
RESUMEN
Purpose: To evaluate the accuracy of SBK microkeratome in flap creation during myopic LASIK surgery using anterior segment optical coherence tomography [AS-OCT]
Design: A Prospective non-randomized noncomparative interventional clinical study
Methods: Flaps were created using the One Use-Plus SBK microkeratome [intended flap 90 micro m] in 40 eyes of 20 patients. Flap thickness was measured using AS-OCT one month after surgery
Results: The mean achieved central corneal flap thickness in both eyes was 88.67 +/- 7.19, 1.33 micro m thinner than the intended 90 micro m thickness [difference from intended thickness -1.33 +/- 7.19] with a p value of 0.067 which is statistically insignificant [p>0.05]. The mean achieved central corneal thickness in the right eye was 88.56 +/- 7.95 micro m [ranging from 70 micro m to 112micro m], 1.44 micro m thinner than the intended 90 micro m [difference from intended thickness -1.44 +/- 7.95] thickness with a p value of 0.206 which is statistically insignificant [ p>0.05]. The mean achieved central corneal flap thickness in the left eye was 88.78 +/- 6.41 micro m [ranging from 77micro m to 105 micro m] showing a difference from intended thickness of -1.22 +/- 6.41 micro m deviation from the intended thickness that is statistically insignificant [p value of 0.185, p>0.05]
Conclusion: Using the one use -plus SBK microkeratome is a safe, accurate and effective modality for creating a thinner SBK flap, hence increasing the available residual stromal bed and preserving corneal tissue. It has excellent predictability and reproducibility when it comes to flap thickness with minimal intra operative complication. There was several limitations to our study. The tool of measurement [AS-OCT], is that the boundaries between the flap and stroma become ambiguous with time, increasing the examiner's subjectivity