Characteristics of Bacterial Biofilm Formation in Nasolacrimal Silicone Tubes Post-dacryocystorhinostomy.

PURPOSE: To examine the biofilm formation characteristics of bacteria identified at the genus level in samples obtained from silicone tubes after dacryocystorhinostomy surgery. METHODS: In the study involving consecutive patients who underwent dacryocystorhinostomy surgery at Ankara Bilkent City Hospital and whose silicone tubes were removed six months after surgery, between January 2023 and May 2023; the tubes were placed in glycerol-PBS (phosphate buffered saline) solution and cultured on descriptive selective media at the genus level. The biofilm-forming properties of the obtained isolates were examined in solid-air and liquid-air interphases. Salmonella Typhimurium ATCC SL1344 strain was used as the control bacterium. RESULTS: As a result of the analysis of the samples taken from the patients, Pseudomonas spp. was identified in three of the samples, Staphylococcus spp. in five of the samples, and Streptococcus spp. in one of the samples. Among these samples, except for the bacteria identified in samples one and five, the rest were found to be strong biofilm producers. In all strong biofilm producers, the maximum biofilm production time was determined as 72 h and the incubation temperature was 37°C. The presence of cellulose and amyloid proteins in biofilm matrix structures is identified. Swimming and swarming motilities were observed in all bacterial samples. CONCLUSION: Since biofilms are considered potential factors in the pathogenesis of infectious and inflammatory diseases, they are a subject that needs to be thoroughly investigated. In our study, although there were no clinical infections in any of the patients, biofilm formation was detected in the patient samples. The fact that the bacteria exhibited moderate to strong biofilm formation characteristics suggests that these microorganisms could be persistent infectious agents.

Is Intravitreal Injection of Recombinant Tissue Plasminogen Activator Effective for the Treatment of Refractory Diabetic Macular Edema in Patients With Posterior Vitreous Detachment?

OBJECTIVE: To determine whether intravitreal injection of recombinant tissue plasminogen activator (rTPA) is effective for the treatment of refractory diabetic macular edema (DME) in patients who already had posterior vitreous detachment (PVD). METHODS: It is a retrospective chart review of the patients with refractory DME and PVD. The efficacy of intravitreal injection of rTPA was assessed based on the changes in central macular thickness (CMT) and best-corrected visual acuity (BCVA) in these patients. RESULTS: Nine eyes of nine patients as the study group and 14 eyes of the 14 patients as the control group were examined. Before the injections, the mean CMT was 470.0± 107.6 in the study group, compared to 536.2± 150.5 in the control group, with no statistical significance (p=0.403). The statistical analysis revealed no significant differences in the mean changes in CMT from baseline to one and three months after injections between the study and control groups (p=0.439, p=0.781, respectively). Likewise, no statistically significant disparities were observed in the mean pre-injection BCVA between the study group (0.877± 0.349) and the control group (0.950± 0.300) (p=0.415). Additionally, after three months of injection, there were no significant changes in the mean BCVA of the study group (0.844± 0.304) and the control group (0.864± 0.253) (p=0.512). CONCLUSION: This study showed that rTPA has no effect on changes in CMT and BCVA in patients who had refractory DME and PVD at the same time. This may suggest that the improvement in CMT in previous studies may be due to the induction of PVD.

Repair of eyelid margin defects with diagonal tarsal suture technique.

PURPOSE: Evaluation of the results of diagonal suture technique in full-thickness eyelid margin repair in the early recovery period. MATERIALS AND METHODS: In this study, full-thickness eyelid margin repair cases using a diagonal suture technique between February 2016 and March 2020 were reviewed retrospectively. Cases due to trauma were not included in the study. Patients were evaluated on the 1st, 6th and 30th day following surgery. The demographic information of the patients, the surgery performed, the level of the lid margin (normal healing, notching), and the presence of tissue reaction (edema, redness, tissue separation, abscess formation) were recorded. RESULTS: Nine (47.4%) out of 19 patients were female and 10 (52.6%) were male. Their ages ranged from 56 to 83 (median: 66). Of the 19 surgeries performed, 14 were Quickert, 3 were pentagon excision, and 2 were Lazy-T. Edema was observed in 3 cases (15.8%) on the first day. Tissue reaction was not observed in any of the cases in neither the first week nor the first month. Although the lid margin healed properly in each case, notching was observed on the inner surface of the lid margin on the 1st and 6th postoperative days in 1 (5.3%) patient. During the 30th-day follow-up visit, it was observed that the notching had decreased. CONCLUSION: The advantages of diagonal suture technique are having no sutures that may touch the cornea at the lid margin and resulting in a better cosmetic appearance in the early postoperative period. It is an easy, effective and reliable method to apply.

Comparison of Ganglion Cell and Retinal Nerve Fiber Layer Thickness in Pigment Dispersion Syndrome, Pigmentary Glaucoma, and Healthy Subjects with Spectral-domain OCT.

PURPOSE: To evaluate the ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL) thickness in pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) with RTVue spectral domain optical coherence tomography (SD-OCT). METHODS: A total of 102 subjects were enrolled: 29 with PDS, 18 with PG, and 55 normal subjects. Full ophthalmic examination including visual field analysis was performed. SD-OCT was used to analyze GCC superior, GCC inferior, and average RNFL thickness. To compare the discrimination capabilities, the areas under the receiver operating characteristic curves were assessed. RESULTS: Superior GCC, inferior GCC, and RNFL thickness values of patients with PG were statistically signicantly lower than those of patients with PDS (p < 0.001) and healthy individuals (p < 0.001 for all). No statistically significant difference was found between PDS and normal subjects in same parameters (p > 0.05). CONCLUSIONS: The SD-OCT-derived GCC and RNFL thickness parameters can be useful to discriminate PG from both PDS and normal subjects.

The effect of intravitreal bevacizumab as a pretreatment of vitrectomy for diabetic vitreous hemorrhage on recurrent hemorrhage.

PURPOSE: This study was constructed to compare the rate of rehemorrhage in patients with diabetic vitreous hemorrhage (VH) undergoing pars plana vitrectomy (PPV) with versus without preoperative intravitreal bevacizumab (IVB) injection. METHODS: It is a retrospective chart review of all patients who had undergone PPV for diabetic VH from January 2008 to January 2011. Patients who had undergone IVB injection before PPV were assigned to Group 1; the others were assigned to Group 2. Postoperative VH was the main outcome. RESULTS: A total of 65 eyes of 60 patients (19 eyes in Group 1 and 46 eyes in Group 2) were examined. Postoperative VH occured in three eyes (15.8%) in Group 1 and in 13 eyes (28.3%) in Group 2, but this was not statistically significant (p: 0.347). CONCLUSION: Further studies to evaluate the effect of IVB on postoperative VH are needed.