Comparison of standard and low dose intraoperative mitomycin C in prevention of corneal haze after photorefractive keratectomy

This study aimed to compare two doses of Mitomycin C in reducing haze formation after photorefractive keratectomy. 170 eyes of 85 patients enrolled; in each patient one eye randomly assigned to be treated by low dose intraoperative MMC [LDMMC] and other eye by standard dose MMC [SDMMC]. Then the patients were followed up to 6 months and refraction, Uncorrected Distant Visual Acuity [UCDVA], Best Corrected Distant Visual Acuity [BCDVA] and haze formation submitted in each postoperative exam. The mean preoperative refraction in LDMMC eyes was -3.08 [SD 1.65] sphere and 0.92 [SD 0.88] cylinder. These values for SDMMC eyes were -3.25 [SD 1.80] sphere and 0.81 [SD 0.84] cylinder. Mean postoperative sphere in LDMMC group was -0.132 [SD 0.503] and -0.138 [SD 0.484] in 3 and 6 months after PRK. These results was -0.041 [SD 0.501] and -0.076 [SD 0.489] for SDMMC group. Mean postoperative cylinder 3 and 6 month after PRK was 0.435 [SD 0.218] and 0.423 [SD 0.255]. In LDMMC group and 0.435 [SD 0.247] and 0.426 [SD 0.261] in SDMMC group. In third month 14 eyes in LDMMC group presented with grade 1 score of clinical haze. From these eyes only 2 still had this haze after 6 month. 7 eyes in SDMMC group had grade 1 clinical haze at third month. but no clinical haze was seen at the end of 6[th] month. The results of the two doses of Mitomycin C were not significant. We suggest to use the lower dose to reduce its side effects

25 Hydroxyvitamin D concentrations in patients with optic neuritis as a clinically isolated syndrome and healthy controls

The onset of multiple sclerosis in the majority of the cases occurs as a clinically isolated syndrome [CIS]. We sought to assess serum levels of 25-hydroxyvitamin D [25-OHD] in CIS patients and healthy controls. In this cross-sectional study 40 patients [36 women and 4 men] with CIS manifesting as a single isolated optic neuritis and 40 Age- and sex-matched healthy controls [35 women and 5 men] were enrolled between late October 2010 and early March 2011. General vitamin D deficiency was defined as serum 25-OHD levels of lower than 20 ng/ml and was classified as mild [15 < 25-OHD <20 ng/ml], moderate [8 < 25-OHD <15 ng/ml], and severe [25- OHD <8 ng/ml]. We found no difference in the median interquartile range [IQR] between CIS patients and controls [17.95 [10.40- 29.13] vs. 17.00 [12.25-31.00]; P=0.57]. However, when stratified by the levels of deficiency, among CIS patients a significantly higher proportion had severe vitamin D deficiency in comparison to healthy controls [20% vs. 2.5%; P=0.034]. Nevertheless, the frequency of general [62.5% vs. 60%, P=0.82], mild [25% vs. 30%, P=0.80], and moderate [17.5% vs. 27.5%, P=0.42] vitamin D deficiency were not different between the two groups. Our findings do not indicate any significant difference of serum 25-OHD between CIS patients and healthy controls. However, in our series severe vitamin D deficiency was more frequent among CIS patients.

Anti-aquaporin-4 IgG in patients presenting with unilateral optic neuritis: a cohort study

Optic neuritis [ON] can be the first presentation of multiple sclerosis [MS] or neuromyelitis optica [NMO]. Anti-aquaporin-4 IgG [AQP4 IgG] is a highly specific and moderately sensitive biomarker for NMO. This study was designed to assess the rate of seropositivity for AQP4 IgG, and the short-term outcome of patients presenting with single isolated ON [SION]. A cohort of 41 consecutive patients experiencing severe [< 20 / 200] SION [not fulfilling the diagnostic criteria for MS or NMO], was prospectively recruited. Blood sampling was carried out immediately after the diagnosis of ON, and AQP4 IgG was tested qualitatively, using an indirect immunofluorescence kit. After clinical and paraclinical investigations, all the patients were followed up for a short-term period of at least 18 months. The seroprevalence among the initial ON patients was 9.7% [4 / 41]. The short-term conversion rate to MS and NMO was estimated to be about 7.3 and 4.9%, respectively. The conversion rate to NMO in initially seropositive patients was greater than that for the whole cohort [2/4 [50%] vs. 2/41 [4.9%]; P = 0.035; Odds ratio: 19.5, 95% confidence interval: 1.73 to 219.50]. AQP4 IgG seropositive SION patients were more likely to develop NMO in comparison to the total SION population. Further studies, with a longer follow-up period and larger sample sizes are warranted to assess the clinical and prognostic value of assessing AQP4 IgG in SION

Stereoacuity following LASIK

To evaluate the effect of laser in situ keratomileusis [LASIK] on stereoacuity [SA]. This prospective study includes 200 patients scheduled for LASIK. SA was evaluated preoperatively and one week, one month and three months postoperatively using the Random Dot test. Patients with preoperative SA worse than 480 sec/arc were excluded from the study. The study included 138 female [69%] and 62 male [31%] subjects. Spherical equivalent was -0.5 to -12.0 D. Mean preoperative SA was 124.80 +/- 124.64 [range 480-15] sec/arc which deteriorated to 138.30 +/- 126.48 sec/arc one week after surgery [P=0.158] but improved to 111.30 +/- 112.15 sec/arc [P=0.002] one month and 103.65 + 112.20 sec/arc [P = 0.001] three months postoperatively. Overall, stereoacuity decreased in 9.5%, increased in 32.5% and remained unchanged in 58% of patients [P = 0.007]. Patients with anisometropia had worse SA; eventually, SA increased in 5 non-amblyopic anisometropic patients. Despite the overall improvement in mean SA after LASIK, a minority of patients experienced decreased SA. Anisometropic patients without amblyopia seem to have a chance for improved SA after LASIK

Remifentanil-ketamine versus fentanyl-ketamine sedation in patients undergoing phacoemulsification with topical anesthesia: comparison of intraocular pressure changes and sedation quality

Narcotics and sedatives can reduce intraocular pressure. This study was performed to evaluate the effect of remifentanil plus ketamine on intraocular pressure and sedation quality in comparison with fentanyl plus ketamine during and after operation in patients undergoing phacoemulsification with topical anesthesia. Forty four patients were randomized into two groups to receive either a continuous infusion of remifentanil [0.2 micro g/kg/min for 4 min and then 0.1 micro g/kg/min: Group R, n=22] or bolus intravenous fentanyl [1.5 micro g/kg: Group F, n=22] for sedation. Patients in both groups received low dose ketamine [0.15 mg/kg] intravenously. Topical anesthesia was performed using tetracaine 0.5% eye drop in both eyes. Intraocular pressure was measured in non-operative eye before sedation [baseline], 2 minutes after sedation, before intraocular lens insertion, at the end of operation and 15 minutes after the end of operation using Schiotz tonometer. Sedation, cooperation, satisfaction and pain scores and also postoperative nausea and vomiting were recorded in all patients. Surgeon satisfaction scores were evaluated at the end of operation. The intraocular pressure did not differ significantly between the two groups throughout the study. The mean [SD] intraocular pressures 2 minutes after sedation, before intraocular lens insertion, at the end of operation and 15 minutes after the end of operation in recovery room were all less than that of baseline in both groups, but the baseline value was decreased only significantly [P<0.05] in recovery room [13.75 [3.46] to 11.91 [3.43] in group R, respectively and 13.74 [3.05] to 11.57 [2.33] in group F, respectively]. The incidence of postoperative nausea and vomiting in group R was higher than that of group F [7 patients in group R and no patient in group F, P=0.009]. Combination of remifentanil infusion and intravenous ketamine did not offer any advantages over the combination of intravenous fentanyl and ketamine in order to prevent intraocular pressure rising during phacoemulsification. The lower incidence of postoperative nausea and vomiting and higher rate of appropriate sedation in fentanyl group suggested fentanyl as a more suitable medication for systemic sedation compared with remifentanil