Dust HAZE phenomenon is one of the atmospheric phenomena which leaves negative environmental impacts and it is one of the most important environmental challenges in West and South-West of Asia, particularly in Iran. This phenomenon related to desertification processes and occurs in arid and semi-arid regions of the world. Remote sensing is science and technique to obtain information from geographic phenomena without any contact with them. To detect the phenomenon of dust HAZE the images with wide coverage and high frequency are needed therefore the images related to MODIS sensor is suitable for study of dust HAZE phenomenon due to high spectral bands. The main objectives of this research was identification the sources generating dust HAZE entering the West and South West of Iran and monitoring the movement of dust HAZE.In this research the source of two occurrence of dust HAZE phenomenon related to 2011 which has occurred in areas of West and South West of Iran was identified with the help of satellite images and using thermal and visible bands of MODIS sensor and Ackerman index.Then monitoring was carried out and synoptic analysis to identify the movement of dust HAZE from its source to Iran was done By using500 hectopascal geopotential height synoptic data, sea level pressure and 500and 100 hectopascal wind direction maps. Finally, its movement from the source to Iran was monitored by using GIS and Spatial Analysis Tools.

According to article 50 of the constitution, environmental protection is a public duty, and all people and agencies are obligated to do so. One of the factors that threatens the environment is the phenomenon of HAZE that has affected many provinces of Iran in the past decade and today threatens the right to life of citizens and even many animal species. On the other hand, considering that many countries face this environmental risk, in addition to domestic actions, joint actions of countries should not be ignored. For this reason, in recent years, laws and agreements have been introduced at national, regional and international levels, but they have not been able to affect the management of HAZE phenomenon. In addition, measures must be taken within the country that prevent or minimize the penetration of HAZE phenomenon, These measures have been mentioned in laws such as the Clean Air Act, the Environmental Protection and Improvement Act, and the Executive Regulations on Combating the HAZE phenomenon, but unfortunately they have always faced challenges,Therefore, in this study, while emphasizing international actions, these challenges and limitations have been addressed and solutions have been proposed to eliminate them in order to manage HAZE phenomenon.

Determinants of early onset HAZE were retrospectively explored in patients who had been undergone laser-assisted sub-epithelial keratectomy (LASEK) in a private eye clinic. The technique included creating an epithelial flap following 20 seconds exposure to 20% alcohol. ‘Optimized’ ablation profile was used by Allegretto laser (Wavelight Technologie). Following repositioning of the flap, a single-brand bandage contact lens was used. For eyes with a spherical equivalent of more than 3 diopters, intraoperative mitomycin C (MMC) was used for 20-30 seconds. Patients were visited at day 1, day 4, week 3, month 3, month 6, and year 1 postoperatively….

Purpose: To study the effect of prophylactic application of mitomycin-C on regression and corneal HAZE formation after photorefractive keratectomy (PRK) for high myopia.Methods: Fifty-four eyes of 28 high myopic patients were enrolled in this prospective study. All eyes underwent PRK with application of 0.02% mitomycin-C for two minutes and irrigation with 15-20 ml of normal saline. Follow-up visits were scheduled for the first 7 days and 1,3 and 6 months after surgery. Hanna grading (in the scale of 0 to 4+) was used to assess corneal HAZE.Results: Mean spherical equivalent refraction (SE) was -7.08 ± 1.11 diopters (D), preoperatively. All eyes were examined on the first 7 days and one month after surgery; 48 eyes (88.9%) were evaluated 3 and 6 months post-surgery. Six months after surgery, all eyes had uncorrected visual acuity (UCVA) of 20/40 or better and 37 eyes (77.1 %) achieved UCVA of 20/20 or better, 45 eyes (93.7%) had SE within ±1.00D of emmetropia. One month postoperatively, 2 eyes (3.7%) had grade 0.5 HAZE, while at 3 and 6 months after surgery no visited eye had HAZE at all. There was no decrease in best corrected visual acuity after 6 months. In spatial frequencies of 6 and 12 cycle/degree, contrast sensitivity decreased immediately after PRK but increased to the preoperative values by the 6th postoperative month.Conclusions: Mitomycin-C can prevent the development of corneal HAZE when treating high myopia with PRK. In patients with insufficient corneal thickness for laser in situ keratomileusis (LASIK), mitomycin-C makes a useful adjunct to PRK to provide an alternative treatment for myopia. However, further research with longer follow-up is suggested.

Purpose: To determine the effect of a topical steroid (betamethasone 0.1%) on refractive and visual outcomes and corneal HAZE after photorefractive keratectomy (PRK) for correcting low to moderate myopia and astigmatism using a 6.0 mm ablation diameter. Participants and methods: A prospective, single masked, randomized clinical trial was conducted on 130 eyes of 70 patients who had excimer laser PRK for correction of myopia and astigmatism ranging from -1.75 to -6.75 (-4.54±1.26) in eyes treated with topical steroids and -1.12 to -6.50 (-4.15±1.26) in eyes without steroid therapy. Sixty-two eyes of 34 patients were treated with topical betamethasone 0.1% eye drops starting 6 times daily and tapered over 6 weeks. Sixty-eight eyes of 36 patients received no steroid therapy. The patients were observed for at least 6 months after PRK. Results: There was no statistically significant difference between the steroid and control groups regarding pre-operative refraction, but the difference in post-operative refraction was statistically significant (P<0.05). Steroid-induced complications occurred in 4.4% of the eyes. The corneal HAZE score was statistically different at all stages between the groups (P<0.05 at 1 week, 1 month, 3 months and 6 months’ post-operatively). Furthermore, no regression during 6 months, follow up was detected in either group with refractive error ≤-4D myopia (SE). Conclusion: Considering potential steroid side effects, better outcome in the control group, and abscence of regression or more than +1 corneal haziness, routine steroid administration in PRK for patients with ≤-4D (SE) myopic refractive error, seems to be unnecessary.

Purpose: To study the effect of prophylactic application of mitomycin-C on regression and corneal HAZE after photorefractive keratectomy (PRK) for high myopia. Methods: Fifty-four eyes of 28 high myopic patients were enrolled in this prospective study. All eyes underwent PRK followed by 0.02% mitomycin-C application for two minutes, washed with 15 to 20 ml of normal saline afterwards. All eyes were examined thoroughly on the first 7 days and one month after surgery, 48 eyes (88.9%) were evaluated at 3 and 6 months postoperatively. Hanna grading (in the scale of 0 to 4+) was used for assessment of corneal HAZE. Results: Mean spherical equivalent refraction (SE) was –7.08±1.11 diopters (D), preoperatively. Six months after surgery, 37 eyes (77.1%) achieved uncorrected visual acuity (UCVA) of 20/20 or better and all eyes had an UCVA of 20/40 or better. At 6 months postoperatively, 45 (93.7%) of eyes had SE within ± 1.00D of emmetropia. One month postoperatively, 2 eyes (3.7%) had grade 0.5+ of HAZE, while at 3 and 6 months after surgery no visited eye had HAZE at all. There was no decrease in bestcorrected visual acuity after 6 months. In spatial frequencies of 6 and 12 cycle per degree contrast sensitivity decreased immediately after PRK and increased 1.5 lines by the 6th postoperative month compared to preoperative data. Conclusions: Mitomycin-C can prevent corneal HAZE in treating high myopia with PRK. PRK+ mitomycin-C can be considered as an alternative method for treatment of myopic patients in whom corneal thickness is inadequate for laser in situ keratomileusis (LASIK). However, the results should be confirmed in longer follow-ups.