[Color stability of dental composite materials after exposure to staining solutions: a spectrophotometer analysis]

The success rate of composite restorative materials depends very much on their color stability in the oral cavity. The purpose of this study was to investigate the color changes of four different brands of dental composite resin materials by using four staining solutions. A total of 128 disk-shaped specimens of 15-2 mm were prepared out of 4 composite resin materials. Two nanocomposites: Filtek supreme, Tetric Evoceram and two micro hybrid composites: Filtek Z250 and Tetric ceram, were prepared. The specimens were then divided into 4 groups of 8 specimens each and they were immersed in 4 staining solutions [Coffee, Tea, Cola, and Artificial Saliva] for 3 hours daily over a 24 day testing period. The color of specimens was measured with a spectrophotometer using CIELab color space relative to illuminant D65 at baseline and after staining. The color differences [delta E] were calculated. The delta E=3.3 was used as an acceptable value in subjective visual evaluations. Data was analyzed using ANOVA and Post-hoc test at significance level of 0.05. All tested materials showed unacceptable color change in coffee and tea groups [delta E>3.3]. The greatest color change was observed in Filtek supreme in coffee. The specimens in cola and artificial saliva didn't cause a notable color change clinically. Coffee and tea can significantly influence the discoloration of dental resin composite materials under investigation. The nanocomposite Filtek supreme color change was significantly more than other composites when exposed to coffee. Therefore, color stability of composite restorative materials depends very much on dietary habits

[Intravitreal bevacizumab [avastin] injection alone or combined with triamcinolone versus macular photocoagulation as primary treatment for diabetic macular edema; an interim analysis]

To report the efficacy of a single intravitreal injection of bevacizumab [IVB] alone or in combination with intravitreal triamcinolone acetonide [IVT] versus macular laser photocoagulation [MPC] as primary treatment for diabetic macular edema [DME]. This randomized three-arm clinical trial included 103 eyes of 97 patients with clinically significant DME and no previous treatment. The eyes were randomly assigned to one of the three study arms: the IVB group received 1.25 mg IVB [37 eyes], the IVB/IVT group received 1.25 mg IVB together with 2 mg IVT [33 eyes], and the MPC group underwent focal or modified grid laser photocoagulation [33 eyes]. Primary outcome measure was change in best-corrected visual acuity [BCVA]. Changes in BCVA [logMAR] at 12 weeks were -0.22 +/- 0.23, -0.13 +/- 0.31 and +0.08 +/- 0.31 in the IVB, IVB/IVT and MPC groups, respectively. The marginal regression model based on generalized estimating equation analysis demonstrated that changes in visual acuity was statistically significant in the IVB group at both 6 [P<0.001] and 12 [P=0.024] weeks but only at 6 weeks in the IVB/IVT group. Significant decrease in central macular thickness [CMT] was observed in the IVB and IVB/IVT groups at 6 weeks. Up to 12 weeks, IVB treatment in eyes with DME yielded better visual outcome than laser photocoagulation, although it was not associated with a significant decrease in CMT. IVT seemed to have no further beneficial effect in combination with IVB

[Ocular toxocariasis in a young man]

To present a case of ocular toxocariasis in a young male subject from the north of Iran. A 29-year-old man presented to our clinic with history of decreased vision in his left eye from 10 days before. He had a history of similar symptoms 2 years ago. Visual acuity in the left eye was counting fingers at 2 meters but relative afferent pupillary defect was negative. The right eye was normal on examination but the left eye showed mild anterior chamber reaction together with +3 to +4 cell in the anterior vitreous. Funduscopy in left eye disclosed posterior vitreous organization in the superonasal area of the retina. Serologic test study for toxocariasis was strongly positive. Ocular toxocariasis is a rare but severe cause of unilateral visual loss in young healthy persons

[Vitrectomy with internal limiting membrane peeling in acute central retinal vein occlusion presenting with low vision]

To evaluate the visual and anatomical outcomes of pars plana vitrectomy and indocyanine green [ICG] assisted internal limiting membrane [ILM] peeling in fresh central retinal vein occlusion [CRVO] with primary low vision. In a prospective interventional case series, 15 eyes of 15 patients with fresh CRVO [less than 3 months' duration] and presenting best-corrected visual acuity [BCVA] less than 20/200, underwent standard 3-port pars plana vitrectomy and ICG assisted ILM peeling. BCVA and central macular thickness [CMT] by optical coherence tomography [OCT] were evaluated 2 weeks and 1, 2, 4 and 6 months postoperatively and when needed thereafter. The patients included 8 male and 7 female subjects with mean age of 54.7 +/- 11.9 [range 29-75] years. Mean duration of symptoms at the time of surgery was 51.7 +/- 17.8 [range 26-85] days. CRVO was ischemic in 12 eyes [80%] and non-ischemic in 3 eyes [20%]. Patients were followed for 9.5 +/- 4.8 [range 6-23] months. Mean BCVA [logMAR] was 1.86 +/- 0.37 at presentation which improved to 1.65 +/- 0.40 at 2 weeks [P=0.23], 1.68 +/- 0.39 at one month [P=0.095], 1.60 +/- 0.46 at 2 months [P=0.069], 1.72 +/- 0.72 at 4 months [P=0.423], 1.58 +/- 0.69 at 6 months [P=0.140] and 1.42 +/- 0.37 at last visit [P=0.006]. Mean CMT was 605.5 +/- 279.2 +/- m preoperatively which was decreased to 527.4 +/- 274.3 microm at 2 weeks [P=0.371], 624.4 +/- 336.7 microm at one month [P=0.773], 546.4 +/- 344.9 microm at 2 months [P= 0.491], 343.3 +/- 256.9 microm at 4 months [P=0.250], 369.3 +/- 207.5 microm at 6 months [P=0.078] and 368.9 +/- 199.0 microm at final visit [P=0.03]. Pars plana vitrectomy with ILM peeling in patients with fresh CRVO and low presenting visual acuity [<20/200] may improve visual acuity and decrease in CMT in long-term follow-up, but does not seem to have any significant effect in comparison to the natural course of CRVO. Certain postoperative complications such as vitreous hemorrhage are relatively common requiring repeat vitreoretinal surgery. Therefore, we do not recommend this procedure for such patients

Causes and results of vitrectomy for spontaneous non-diabetic vitreous hemorrhage

To determine the visual and anatomical outcomes and complications of vitrectomy for non-traumatic non-diabetic vitreous hemorrhage [NDVH] and to report the causes of the condition among patients at Labbafinejad Medical Center, Tehran-Iran, from 1993 to 2003. Records of patients who underwent vitrectomy for non-traumatic NDVH with 6 months follow up were reviewed for demographic characteristics, causes of NDVH and results of surgery. Fifty eyes [54.2% right eyes] of 49 patients [51% male] with mean age of 62.7 +/- 10.3 years were enrolled in the study. Mean visual acuity [VA] was 2.36 +/- 0.52 LogMAR and relative afferent pupillary defect [RAPD] was positive in 91.7% of the eyes, preoperatively. Causes of non-traumatic NDVH detected intraoperatively were: branch retinal vein occlusion [56%], central retinal vein occlusion [16%], choroidal neovascularization [12%], and posterior vitreous detachment with break, Eales disease, familial exudative vitreoretinopathy, and Terson syndrome [each in 4%]. Mean VA increased significantly at 6th month [1.38 +/- 0.72 IogMAR] compared to preoperative value. [P<0.0001] The most common causes of decreased VA were: macular pigmentary derangement [26%], optic atrophy [16%], severe lens opacity [12%], and epiretinal membrane [8%]. Despite the statistically significant increase in mean VA following vitrectomy, underlying macular pathology limits significant improvement of central VA in most cases of non-traumatic NDVH

Clinical aspects and results of lensectomy in hereditary lens subluxation

To evaluate the clinical manifestations and results of lensectomy in patients with hereditary lens subluxation at Labbafinejad Medical Center, Tehran-Iran from 1996 to 2003. In an interventional case series, records of patients with hereditary lens subluxation who had undergone lensectomy were reviewed. Patients with at least 6 months of follow up were included. Background disease, best corrected visual acuity [BCVA] before and after surgery, intraocular pressure [IOP], and post-operative refraction and complications were evaluated. The study was performed on 87 eyes of 49 patients including 27 male and 22 female subjects. Mean follow up was 20 +/- 18 months. Marfan syndrome [79.5%], Weill-Marchesani syndrome [8.2%], simple ectopia lentis [8.2%], and homocystinuria [4.1%]. The most common indication for surgery was non-correctable refractive error [92.1%]. Mean BCVA was 1.13 LogMAR preoperatively which improved to 0.26 Log MAR post-operatively [P< 0.001]. BCVA better than 20/40 was achieved in 82.8% of cases after surgery. Angle-supported anterior chamber intraocular lens [AC IOL] was implanted in 85.1% of the eyes. Prophylactic band was applied in 63 eyes [72.4%]. Retinal detachment developed in four eyes, which was successfully treated. Lensectomy with implantation of angle-supported AC IOL in patients with hereditary subluxated lens will improve vision significantly without significant complications

Posterior lschemic optic neuropathy following percutaneous nephrolithotomy

To report a case of posterior ischemic optic neuropathy [PION] following percutaneous nephrolithotomy [PCNL]. A 57-year-old male who underwent PCNL because of renal stone was referred due to painless bilateral visual loss to the level of light perception immediately after the operation. The patient had history of diabetes mellitus, hyperlipidemia, and mild anemia. Ophthalmic examinations were unremarkable and optic discs were pink and without any sign of swelling. Visual fields were severely affected, but neuro-imaging was normal. Within three months, visual acuity and visual fields improved dramatically and optic discs became mildly pale. The clinical course was typical for PION. PION is a rare cause of severe visual loss following surgery. Severe blood loss, hypotension, anemia, and position of the patient during surgery are the most important risk factors. This is the first report of PION following PCNL. Urologists, ophthalmologists and anesthesiologist should be aware of this entity, and rare possibility should be discussed with the patient before surgery. Preventive measures against PION should also be taken

Eternal Weibull regression analysis for evaluation of the effects of different covariates on retinal redetachment following retinal detachment surgery

To evaluate the effect of age, sex, type of surgery, extent of retinal detachment [RD] vitreous incarceration in wound, and myopic degeneration on the rate of retinal redetachment following RD surgery using eternal Weibull regression analysis. We performed a survival analysis on a multi-center randomized controlled trial conducted on patients with pseudophakic or aphakic RD to compare the anatomic outcome of scleral buckling vs primary vitrectomy alone. Patients were examined one week and then 1, 2, 4 and 6 months after the operations. We applied modification to the survival, density and hazard function and considered the two-parameter Weibull distribution for survival times. Herein we evaluated the appropriateness of the modified model vs unmodified model with and without the effects of covariates. The mean survival time for the unmodified model was 2920 days confirming the eternal nature of the survivor function whereas the mean survival time for the modified model was 43.06 days. In the absence of covariates, the eternal proportion in the modified model was estimated to be 0.73. Taking the effects of covariates into account, the modified model revealed that the risk of redetachment is 76% higher among males than females and is almost 4 times greater in eyes with myopic degeneration, while this risk was 2.6 times for males and 2.7 times for those with myopia in the unmodified model. Moreover, vitreous incarceration in the wound played a significant role in the unmodified model whereas it had been set aside in the modified model. Comparing the two final models showed the superiority of modified model: -2 log L[m]- [-2 log L[um]] = 46.274 [P<0.001]. This study strongly suggests the benefit of using the modified over the unmodified model of eternal Weibull regression analysis in situations such as the present study in which some cases will have the event of interest whereas others will never have the event, given enough time

[Subretinal fibrosis and uveitis: a case report]

To report a case of subretinal fibrosis and uveitis [SFU] in a young man. Patient and findings: A 31 -year-old man presented with decreased vision without redness or pain or any systemic finding. Clinical findings included decreased visual acuity to 3 m CF and trace cell and flare in the anterior chamber and anterior vitreous. There were findings compatible with multifocal choroiditis that progressed to subretinal fibrosis in the macula in 3-4 months resulting in further decrease in visual acuity. In spite of many previous reports of SFU in women, it may occur in men. The patient should be followed carefully to detect early findings of subretinal fibrosis and to initiate appropriate treatment

[Effect of oral prednisolone on visual outcomes and complications after scleral buckling]

To evaluate the effect of oral prednisolone on visual outcome and complications of scleral buckling [SB] in patients with rhegmatogenous retinal detachment [RRD]. In a randomized double-blind placebo-controlled trial, patients with acute RRD who underwent SB were randomly divided into two groups. Oral prednisolone was administered for the treatment group and placebo for the control group. The two groups were compared for visual acuity [VA] , retinal detachment [RD], cystoid macular edema [CME], and proliferative vitreoretinopathy [PVR]. The trial was performed on 25 patients in the treatment group and 27 patients in the placebo group. Mean preoperative VA [LogMAR] was 1.46 +/- 0.81 overall, including 0.85 +/- 0.62 in location were equal in both group. [P=0.45] Significant PVR was seen in one eye in the treatment group and 3 eyes in the placebo group. [P=0.39]. Postoperative oral prednisolone does not seem to affect visual outcomes and complications of scleral buckling in phakic patients

[Acute myopia secondary to usage of topiramate: a case report]

Purpose: to present a case of acute myopia secondary to usage of Topiramate

Patient and findings: a 26-year-old female presented with 6-diopter myopia after two weeks of using topiramate for migraine headache. She improved after 3 days of cessation of this medicine

Conclusion: when a patient present with acute onset visual loss secondary to refractive error, history of drug usage can help for diagnosis