Evaluation of changes in corneal volume, volume and angle of anterior chamber in keratoconus patients using Pentacam after CXL

Introduction and Objective:

Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet-A (UVA) is a new technique of mechanical stability of the cornea and prevention of keratoconus progression. The present study aimed at the evaluation of the changes in the corneal volume (CV), volume, and the angle of anterior chamber in keratoconus patients using the Pentacam after CXL.

Methods:

This prospective study was performed on 48 eyes of 24 patients (including 12 men, 17–33 years old) with progressive keratoconus undergoing CXL treatment at collagen cross-linking Imam Khomeini Hospital in Ahvaz in 2019. The CV (CV) and anterior chamber parameters such as anterior chamber volume (ACV) and anterior chamber angle (ACA) were measured using the Pentacam before CXL and at 6 and 12 months after CXL. Also, all of the patients were evaluated in terms of best-corrected visual acuity (BCVA), during the follow-up.

Results:

The pre-CXL values of BCVA was significantly lower than the post-CXL values in 6 and 12 months (0.18 ± 0.11, 0.15 ± 0.10, and 0.11 ± 0.10, respectively, P < 0.0001). In general, there was a significant improvement in the BCVA (P < 0.0001), a significant decrease in the CV (P = 0.001), and a significant increase in the ACV (P < 0.0001), and angle (P < 0.0001) 6 and 12 months after CXL.

Conclusion:

It seems that CXL has a positive effect on the anterior chamber parameters (ACV and ACA) and CV after 6 months and 1 year in the treatment of keratoconus patients. In addition, the visual acuity improves after CXL. Finally, further studies with a higher sample size and longer follow-up periods are recommended.

Effect of capsular tension ring implantation on predicted refractive error after cataract surgery in patients with pseudoexfoliation syndrome

AIM

To investigate the effect of capsular tension ring (CTR) implantation on predicted refractive error after cataract surgery in patients with pseudoexfoliation (PEX) syndrome.

METHODS

This double-blind randomized clinical trial was conducted on 60 patients with PEX syndrome referring to Imam Khomeini Hospital affiliated to Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran, for undergoing cataract surgery. The study population was divided into two groups, namely CTR group (n=30) and non-CTR group (control group; n=30). The refractive error and anterior chamber depth (ACD) were measured 1wk, 1mo, and 3mo after phacoemulsification (PE) surgery.

RESULTS

The results indicated no statistically significant difference between the two groups in terms of predicted refractive error (obtained by subtracting preoperative predicted refractive error from actual postoperative refractive error) 1wk (P=0.47), 1mo (P=0.30), and 3mo (P=0.06) after the PE surgery. Regarding the CTR group, the changes of ACD was statistically significant 1 and 3mo after the PE surgery, compared to those obtained 1wk post-surgery (P=0.005).

CONCLUSION

The CTR implantation in PEX cataractous patients without zonulysis has no statistically significant effect on the predicted refraction and ACD changes after PE. The predicted refraction error has a hyperopic shift in both groups. The results reveal the unnecessary of calculating modified IOL in CTR implantation.

Prevention of Corneal Neovascularization; a Preliminary Experimental Study in Rabbits

The purpose of this study was to compare the effects of propranolol, timolol and bevacizumab with betamethasone to prevent corneal neovascularization (CNV) in rabbits. This study was performed on 28 male rabbits. CNV was induced by three 7-0 silk sutures 2 mm long and 1 mm distal to the limbus. Animals were randomly divided into 4 groups of propranolol + betamethasone, timolol + betamethasone and bevacizumab + betamethasone and betamethasone alone. Eye drops were started from the first day of study. On 7^th, 14^th, 21^st, 28^th, 35^th and 42^nd days, vascular progression, time of neovascularization and vascular area were evaluated and compared with the control group (betamethasone alone). There was a significant reduction in the area of ​​neovascularization in the timolol and bevacizumab groups compared to the control group (P-value = 0.05, P=0.047, respectively). Also, regarding vascular progression, there was a significant decrease in the timolol and bevacizumab groups (P-value = 0.014, P=0.002, respectively). Regarding delayed onset of neovascularization, there was a significant difference in the timolol and bevacizumab group in rabbits (P-value = 0.04, P=0.00, respectively). In conclusion, the use of timolol and bevacizumab drops besides betamethasone can delay neovascularization and decrease the length of corneal vascularization in rabbits.

Imaging Mouse Prostate Gland by 3 Tesla Clinical MRI System

In vivo detection of prostate tumor in animal model will facilitate the investigations that deal with the efficacy of different treatment strategies in different experimental settings. Recently higher field strength dedicated animal MRI system has been used successfully to detect mouse prostate glands and its lesions, however, usefulness of clinical system has not been utilized to its fullest extent. In this short communication we show the advantages and disadvantages of different in vivo imaging parameters of MRI to acquire images of the mouse prostate gland using clinical strength MRI systems.