Journal of Ophthalmic and Optometric Sciences

Purpose: To investigate the relation between serum level of vitamin D and dry eye disease.
Patients and Methods:  In this cross-sectional case-control study, 40 patients with dry eye disease were enrolled.  Dry eye was diagnosed based on the slit lamp examination, tear meniscus height, tear break up time test, ocular surface disease index, and the results of Schirmer test. Forty age- and sex-matched healthy individuals served as controls. The serum level of vitamin D was measured and compared between patients with dry eye disease and controls.
Results:  The mean age was 44.92  ± 11.4 and 44.07  ± 11.29 years in the case and control groups, respectively (P = 0.739). The mean serum level of vitamin D was 21.18  ± 11.83 ng/dl in the case group and 20.54 ± 9.98 ng/dl in the control group (P = 0.793). Ocular surface disease index had a positive correlation with age (r = + 0.363, P < 0.0001), but a negative correlation with the serum level of vitamin D (r = - 0.480, P = 0.002). Other investigated variables failed to demonstrate association with the serum level of vitamin D and dry eye.
Conclusion: According to the present study results, no significant association between vitamin D deficiency and dry eye was detected. However, due to relatively small sample size in the present study further studies are recommended to better investigate this subject.

Key words: Dry eye; Vitamin D; Schirmer test; Tear.

Purpose: To study the possible effects of vibration on visual pathway using visual evoked potentials.

Patients and Methods: Fifty workers from a textile factory segment with machinery creating high levels of vibration were selected. The laborers had at least 6 years of experience in the factory segment where high vibrating machines were operating. The amplitude and latency of visual evoked potential, P100 peak was recorded for these selected workers and 50 age and sex matched controls from other sections of the factory.
Results The mean age was 27.5 ± 1.741 and 27.28 ± 1.641 in the case and control groups respectively. There was a statistically significant higher latency of the visual evoked potential, P100 peak in the case group compared to the control group (P < 0.001). No significant difference regarding the amplitude of visual evoked potential, P100 peak was observed between the two groups (P = 0.89).

Conclusion: Occupational vibration might have adverse effects on visual system, mainly visual pathway, causing increased latency of VEP; P100 peak measured using visual evoked potentials.

keywords: Vibration; Visual Pathways; Evoked Potentials, Visual.

Purpose: To evaluate the effect of intraocular pressure on topographic findings of donor corneas.

Materials and Methods: In the present study 37 intact enucleated globes were included. Desirable intraocular pressure was provided by fluid flowing into the globe using a needle inserted via the optic nerve connected to a balanced salt serum bottle. The Sim K and corneal astigmatism in different IOPs (0, 10, 20, 30, 40 and 50 mmHg) were measured using a topography cone (Zeiss-Humphery System, Atlas Version 10.1).

Results: Out of 37 globes studied, 26 globes (70.3 %) were from male and 11 globes (29.7 %) were from female donors. Donors were aged 25 to 45 years at time of death with the mean age of 37 years. The mean Sim K was not significantly different in different IOP levels (0 to 50 mmHg). The mean corneal astigmatism had a significant relation with IOP (P < 0.001) and decreased (IOP 0 mmHg to IOP 30 mmHg) then increased (IOP 30 mmHg to IOP 50 mmHg) when the IOP was changed. The minimum astigmatism was detected at IOP 30 mmHg (1.56 D) and the maximum was detected at IOP 0 mmHg (2.76 ± 1.73).
Conclusion: The mean Sim K of donor cornea does not significantly change in different IOP levels of enucleated globe, while the corneal astigmatism changes significantly.  It seems that keratometric readings from donor cornea might be used without caution about the IOP in enucleated globe.

Key words: Eye globe; IOP; Sim K; Astigmatism.

Purpose: To find the mean value of pupillary distance and to evaluate the effect of age, sex and refractive errors on this distance in an Iranian population.
Patients and Methods: In this study 703 individuals (403 women and 300 men) referred to the optometric department of Hazrat Khadijeh Clinic, Karaj, Iran, were selected. Subjects were divided into different age groups, pupillary distance was recorded after complete optometric examination, by a ruler while the patient was looking at target at a distance of 60 cm.
Results: The mean age of participants was 31.07 ± 16.63 years. The mean pupillary distance was 59.2 ± 3.88 mm. Refractive errors had no statistically significant effect on pupillary distance and this distance was significantly greater in men than women (P < 0.001). The pupillary distance also increased with age.
Conclusion: Similar to previous findings pupillary distance was affected by sex and age in an Iranian population. Refractive errors had no statistically significant effect on pupillary distance.

Keywords: Pupil; Age; Sex; Refractive Errors; Iran

Purpose: To compare peripapillary retinal nerve fiber layer thickness (RNFLT) between patients with multiple sclerosis (MS) and healthy controls using optical coherence tomography (OCT).  Patients and Methods: In this prospective case control study, peripapillary RNFLT of 120 eyes from 60 patients with multiple sclerosis (MS)  was compared to 120 eyes from 60 age and sex matched healthy controls using OCT.  The RNFLT in 4 peripapillary quadrants and the mean RNFLT of all four quadrants were compared between the case and control groups. The relation between MS variables such as age of onset, type and duration of disease, history of optic neuritis (ON) and other non-ocular episodes with RNFLT was evaluated in the case group.
Results: The mean RNFLT of all four quarters was significantly lower in patients with MS compared to the controls (P < 0.001). Also RNFLT was significantly lower in each of 4 quadrants (superior, temporal, inferior; P < 0.001, nasal P = 0.003). There was no significant relation between RNFLT, the age of onset of MS disease, and history of non-ocular episodes. RNFLT had a significant relation with duration of the disease (P < 0.001), the type of MS (P < 0.001), history of ON (P = 0.002), and the number of ON episodes (P = 0.021). 

Conclusion: We found that RNFLT decreases in MS patients and its reduction is related to the duration and type of disease as well as history and number of ON episodes. Therefore measuring RNFLT may help in estimating the progress of MS and can potentially be included as a part of patients’ follow up protocol.

Keywords: Multiple sclerosis;  Tomography; Optical Coherence;;Optic Neuritis; Retinal; Nerve Fibers

Transfusion dependent thalassemia is a hematological condition characterized by imbalance in synthesis of alpha and beta subunits of hemoglobin. The consequence of regular and repeated transfusions is iron deposition in different organs. In order to survive, these patients need iron chelator drugs. The oldest drug of this group is desferrioxamine which is administered subcutaneously or intravenously. Nowadays, oral iron chelator drugs, including deferiprone, deferasirox are in more widespread use since they are more convenience to use. In this review the ocular toxicity of these chelator drugs is discussed.

keywords: Ocular; Toxicity; Iron chelating agents; Thalassemia.

Photorefractive keratectomy (PRK) is a common procedure for correction of refractive errors. Corneal collagen crosslinking (CXL) is a procedure used to strengthen a weakened ectatic cornea and is mainly used as a therapeutic procedure in keratoconus (KC) patients, to prevent deterioration and improve visual acuity. PRK-CXL combination performed simultaneously or sequentially, has been suggested in KC patients to provide improved visual acuity, in addition to halting the ectatic progression. Our case was a patient with KCN and visual deterioration that underwent accelerated CXL with good results and 1 year later, his right eye was subjected to PRK due to anisometropia. The patient achieved an uncorrected visual acuity of 10/10 without any complications for both eyes. Our good results suggest that PRK-CXL combination might be considered for correction of decreased visual acuity and anisometropia in patients with KCN. However, more studies are required to further evaluate the surgical outcome and safety of this procedure.

Keywords: Keratoconus; Cross-Linking; Photorefractive Keratectomy; Surgery.

Objective: To report a case of anterior uveitis after subconjunctival mitomycin C injection in a patient with a history of trabeculectomy.

 Case Report: A 45 year old patient, with anterior uveitis in his right eye after postoperative injection of mitomycin C one month after trabeculectomy, was treated in Basir eye clinic, Tehran, Iran. The Patient had no history of previous ocular infection. Topical prednisolone and tropicamide drops were effective in improving vision and reducing pain in our case.

Conclusion: Anterior uveitis might happen after trabeculectomy surgery; however, in our case, it was more likely the result of mitomycin C administration one month after trabeculectomy. This should be considered as a differential diagnosis of postoperative bleb infections.

Keywords: Uveitis; Mitomycin C; Trabeculectomy.