Determination of the retinal toxicity of intravitreal colistin in rabbit eyes.

PURPOSE: To determine the possible adverse effects and safe dose range of intravitreal colistin, an antibiotic, after its intravitreal application. METHODS: Twenty eyes of 20 adult male and female New Zealand white rabbits were selected. Various concentrations of colistin were prepared. In each rabbit, 0.1 mL of colistin solution or saline solution was injected intravitreally into the right eye. Electroretinographic recordings were taken before and 2 weeks after injection. Histopathological examination was made using a light microscope following enucleation and fixation procedures. In histopathologic cross-sections, the differences between drug-injected eyes and control eyes were evaluated. RESULTS: Electroretinographic examination showed a decrease of 30% as a significant value in the a and b wave amplitudes of the rabbits that injected 400 µg/0.1 ml and higher concentrations. Histological examination revealed histiocytic infiltration, histiocytic vacuoles, inflammation, and retinal degeneration in rabbit eyes given 400 µg/0.1 ml, 800 µg/0.1 ml, and 1.6 mg/0.1 ml concentrations of colistin. CONCLUSION: Based on our findings, the safe concentration of colistin is 0.2 mg/0.1 ml. Administration of 0.4 mg/0.1 ml was associated with cataract development, electrophysiological depression, and pathological changes in retinal layers.

Comparison of Biomicroscopy and Light Microscopy Findings in Demodex Diagnosis in Patients With Chronic Blepharitis.

OBJECTIVES: We aimed to compare the results of biomicroscopic examination and light microscopy in the diagnosis of Demodex infestation in chronic blepharitis cases. METHODS: The study was performed with retrospective data and included patients with chronic blepharitis and who were admitted to the Medipol University Ophthalmology Outpatient Clinic. Biomicroscopic evaluation was performed intentionally under 40x magnification to investigate the presence of Demodex ectoparasites. Three or four pieces of eyelashes were obtained from all cases with epilation technique, and Demodex parasites were examined under ×100 and ×400 magnifications with light microscopy. The presence of one or more Demodex parasites in the examined area under light microscopy was considered to be positive for infestation. We calculated sensitivity, specificity, false-positive rate, false-negative rate, and positive and negative predictive values of biomicroscopic examination compared with those of positive light microscopy. RESULTS: Of the 255 subjects included in the study, 134 (52.5%) were men and 121 (47.5%) were women. The mean age was 43.9±11.9 years. Of the 255 chronic blepharitis cases, 130 (51%) presented Demodex infestation on light microscopy. We calculated the sensitivity, specificity, false-positive rate, false-negative rate, positive predictive value, and negative predictive value and were found to be 83.07%, 90.4%, 9.6%, 16.9%, 90%, and 83.7%, respectively, for the biomicroscopic examination. CONCLUSIONS: Careful biomicroscopic examination can be time-efficient and cost-effective, and the need for more advanced and invasive procedures for the identification of Demodex in patients with chronic blepharitis can be reduced.

Investigation of Demodex Parasite Existence in Treatment-Resistant Chronic Blepharitis Cases.

OBJECTIVE: Demodex acari is an obligate ectoparasite, and it is usually located in the human hair follicles, eyelash roots, and sebaceous glands. The aim of this study was to investigate the presence of Demodex infestation in chronic blepharitis cases that are resistant to therapy. METHODS: Patients who were admitted at the Istanbul Medipol University School of Medicine Hospital with a diagnosis of chronic blepharitis were included. All cases received conventional therapy at least three times. Three or four eyelash samples from patients with blepharitis were collected and examined under light microscopy. For the diagnosis, the presence of one or more Demodex parasites at 10× and 40× magnification by a light microscope was considered as positive for infestation. RESULTS: Overall, 153 cases were included in the study. Of the cases, 79 (51.6%) were males and 74 (48.4%) were females. The mean age was 43.1±9.7 years. The presence of D. acari in the follicles of the eyelashes in patients with chronic blepharitis was found in 69 (45.1%) cases. CONCLUSION: D. acari should be considered in patients with chronic blepharitis, especially in treatment-resistant cases. We believe that it would be useful to search for the parasite in patients with blepharitis prior to treatment on a routine basis.

A CASE OF CONE DYSTROPHY ASSOCIATED WITH CHOROIDAL NEOVASCULARIZATION.

PURPOSE: To report a case of choroidal neovascularization (CNV) in a patient with cone dystrophy (CD). METHODS: Case report. RESULTS: A 20-year-old woman presented with diminished vision in her right eye. Fundus examination showed perifoveal retinal pigment epithelial changes and retinal hemorrhage consistent with subretinal CNV in the right eye, and mild retinal pigment epithelial changes with a dull foveal reflex in the left eye. Optical coherence tomography analysis and fundus fluorescein angiography also confirmed the subfoveal CNV in the right eye. Electroretinography showed decreased amplitudes in photopic and 30-Hz flicker tests in both eyes, which confirmed cone dystrophy. A single intravitreal ranibizumab injection resolved the edema and stabilized the CNV during the follow-up of 6 months. CONCLUSION: Cone dystrophy is an inherited ocular disorder characterized by loss of cone photoreceptors. Association of CNV has been reported in patients with fundus flavimaculatus, best dystrophy, gyrate atrophy, choroideremia, retinitis pigmentosa, adult-onset foveomacular vitelliform dystrophy, Sorsby macular dystrophy, Bietti crystalline dystrophy, and myotonic dystrophy-related macular dystrophy. We report a case of a patient with CD in whom CNV developed in one eye and responded to a single ranibizumab injection.

A Rare Complication After Septoplasty: Visual Loss Due to Right Retinal Artery Spasm.

Septoplasty is a commonly used procedure for correcting septal cartilage deformities. Hemorrhage, abscesses, scaling, adhesions, and scar tissue are often seen after the operation of the septoplasty, but temporary or permanent visual loss due to local anesthetic use has been reported very rarely in the literature. The authors also aimed to present a female patient with retinal artery spasm in the right eye after septoplasty in this article. A 27-year-old female patient was admitted to the authors' clinic with long-standing nasal obstruction and postnasal drip. There was no feature in her history and also no sign other than nasal septal deviation on physical examination. The patient was informed about the operation and the operation was planned. Emergency eye consultation was requested after the patient said that the right eye of the patient had never seen in the postoperative wake-up hall. Examination by an ophthalmologist; mild exotropia and total loss of vision in the right eye (including loss of light reflex) was detected. The light reaction in the affected eye was negative and indirect reaction was positive. After enlargement of the pupil, fundus examination revealed that the right posterior pole region (inside of the macula and vessel arches) was pale and no central retinal artery pulsation was observed. The patient was diagnosed with central retinal artery occlusion and emergency intervention was performed. The right eye massage, paracentesis, and hyperbaric oxygen therapy returned to the patient's visual function.

Changes in Anterior Chamber Depth after Combined Phacovitrectomy.

OBJECTIVES: To evaluate changes in anterior chamber depth (ACD) and postoperative refractive outcomes after combined phacovitrectomy. MATERIALS AND METHODS: This study included 10 eyes of 10 patients that underwent combined phacovitrectomy (study group) and 14 eyes of 14 patients that underwent phacoemulsification surgery (control group) at Istanbul Medipol University Ophthalmology Department. Preoperative and 3-month postoperative best corrected visual acuity (BCVA), ACD, change in ACD and refractive outcomes were compared between the two groups. RESULTS: Preoperative ACD, postoperative ACD at 3 months and change in ACD were similar between two groups (p=0.403, p=0.886, p=0.841). Postoperative mean refractive outcomes were 0.22±0.51 diopter in the phacovitrectomy group and -0.39±0.53 diopter in the phacoemulsification group (p=0.019). BCVA was increased in both groups (p=0.001). CONCLUSION: Postoperative refractive outcomes in eyes that underwent combined phacovitrectomy are different from those in eyes that underwent only phacoemulsification surgery. This is important in determining preoperative intraocular lens power before combined phacovitrectomy.

Acute retrobulbar haemorrhage: An ophthalmologic emergency for the emergency physician.

Acute retrobulbar haemorrhage (ARBH) is a rare ophthalmic emergency observed following blunt eye trauma. Multiple trauma and loss of consciousness can hide symptoms of ARBH. Rapid diagnosis and immediate lateral canthotomy and cantholysis must be performed to prevent permanent visual loss in patients. Medical treatment can be added to surgical therapy. Lateral canthotomy and cantholysis are simple procedures that can be performed by emergency physicians. In this report, it was aimed to present a case with post-traumatic ARBH and provide general knowledge about the diagnosis, follow-up and treatment of ARBH.

Comparison of Pattern Electroretinography and Optical Coherence Tomography Parameters in Patients with Primary Open-Angle Glaucoma and Ocular Hypertension.

OBJECTIVES: To investigate the correlation of visual field (VF), pattern electroretinography (PERG) and Fourier domain optical coherence tomography (FD-OCT) results in patients with ocular hypertension (OHT) and early primary open-angle glaucoma (POAG). MATERIALS AND METHODS: The study included 72 eyes of 37 patients with early POAG, 76 eyes of 38 patients with OHT, and 60 eyes of 30 controls. All subjects underwent full ophthalmologic examination, VF assessment with 24-2 Humphrey standard automated perimetry (Swedish Interactive Thresholding Algorithm (SITA)-Standard), retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness measurement with FD-OCT, and PERG P50 and N95 wave latency and amplitude measurements with electroretinography (Nihon Kohden). RESULTS: With the exception of the nasal quadrant, all GCC parameters and RNFL results were significantly lower in the POAG group compared to the OHT and control groups. There was no statistically significant difference between the OHT and control group. PERG amplitudes were lower in the POAG and OHT groups than in the control group. Reduction in N95 amplitude was greater than that of P50 amplitude. No difference was detected in PERG latencies among groups. GCC was significantly correlated with VF and RNFL in the POAG group. CONCLUSION: Significant thinning of the GCC and RNFL occurs in addition to VF pathologies in patients with early POAG, and these examinations should be concomitantly evaluated. During diagnostic assessment of patients with early POAG, GCC and RNFL analysis by FD-OCT are highly effective. GCC is as reliable as RNLF in the early diagnosis of glaucoma and there is a highly significant correlation between them. Dysfunction of ganglion cells in patients with OHT may be detected earlier using PERG amplitude analysis.

Effect of intracameral carbachol given during cataract surgery on macular thickness.

To evaluate the effect of intracameral carbachol on foveal thickness in patients who underwent uneventful cataract surgery. This retrospective study included two groups: the study group patients (group 1, n = 47 eyes) had uneventful cataract surgery and received only carbachol 0.01 % for miosis; the control group patients (group 2, n = 49 eyes) had uneventful cataract surgery without carbachol or any intracameral medication(s). The groups were compared for foveal thickness after cataract surgery. All phacoemulsification plus intraocular lens implantation surgeries were performed under local anesthesia via temporal clear corneal tunnel incisions. Mean values and standard deviations were calculated for preoperative and postoperative visual acuity (VA) and foveal thickness (FT) at 1 and 4 weeks. Optical coherence tomography was used for the FT measurements, with the MM6 map program. The patients in the study and control groups had a mean age of 57.78 ± 9.07 and 59.72 ± 8.96, respectively (p = 0.355). All eyes had a significant improvement in VA. In the study group, the mean FT at the visits before and 1 and 4 weeks after surgery was 216.87 ± 21.06, 228.81 ± 30.52, and 222.94 ± 29.91 µm, respectively. For the control group, the mean FT, before and 1 and 4 weeks after surgery, was 222.53 ± 17.66, 231.67 ± 23.08, and 225.41 ± 22.59 µm, respectively. Intracameral carbachol 0.01 % had no effect on foveal thickness in patients who underwent uneventful cataract surgery.

Comparison of fixed combinations of dorzolamide/timolol and brimonidine/timolol in patients with primary open-angle glaucoma.

To compare the short-term effectiveness and ocular side-effects of fixed combinations of dorzolamide/timolol (DTFC) and brimonidine/timolol (BTFC) in patients with primary open-angle glaucoma (POAG). Forty-two eyes of 42 patients newly diagnosed with primary open-angle glaucoma were assessed prospectively. One of the two eyes was chosen randomly and treated with DTFC (2 × 1) for 4 weeks. The treatment was then stopped to allow a 4-week wash-out period. Following the wash-out period, the same eye was treated with BTFC (2 × 1) for 4 weeks. Intraocular pressure (IOP) values were measured before and after each treatment at 0800, 1,200 and 1,600 h. Tear function test results and ocular side-effects were also recorded. The mean baseline IOP values for DTFC and BTFC were 24.1 ± 1.8 and 24.6 ± 2.4 mmHg, respectively. The mean IOP values after 4 weeks of treatment with DTFC or BTFC were 17.1 ± 2.9 and 16.9 ± 2.5 mmHg, respectively. Both medications reduced IOP values significantly (P = 0.0000). The effectiveness of both medications was similar (P = 0.7363). Both combinations significantly reduced the amount of tear secretion and tear break-up time (P = 0.0000). Eye burning was more common with DTFC than with BTFC (P = 0.0182). Other adverse effects were observed at similar rates for both combinations. This study demonstrated that the IOP-reducing effects of DTFC and BTFC in patients with POAG are similar. The side-effect profile of BTFC is similar to that of DTFC. Lower occurrence of a burning sensation may improve patient compliance in the BTFC group.

Foveal and parafoveal retinal thickness in healthy pregnant women in their last trimester.

PURPOSE: The inspection of foveal and parafoveal thickness in healthy pregnant women in the last trimester. MATERIALS AND METHODS: This study included 40 healthy pregnant women in their last trimester (study group: 40 women, 80 eyes) and 37 nonpregnant women (control group: 37 women, 74 eyes). Visual acuity, intraocular pressure, slit lamp examination of anterior and posterior segments, and visual field examination with automated perimetry were performed in both groups. Foveal and parafoveal thickness in the four quadrants (upper, nasal, temporal, and inferior parafoveal) and peripapillary retinal nerve fiber layer were measured by optical coherence tomography. There were no systemic or ocular problems in either group. Findings were analyzed with statistical software. A P value <0.05 was considered statistically significant. RESULTS: Mean foveal and parafoveal thicknesses in the study group were: foveal 236.12 ± 27.28 µm, upper quadrant 321.31 ± 12.28 µm, temporal quadrant 307.0 ± 12.05 µm, inferior quadrant 317.0 ± 10.58 µm, and nasal quadrant 313.62 ± 14.51 µm. Mean foveal and parafoveal thicknesses in the control group were: foveal 224.62 ± 21.19 µm, upper quadrant 311.62 ± 12.71 µm, temporal quadrant 296.87 ± 13.78 µm, inferior quadrant 305.43 ± 13.25 µm, and nasal quadrant 304.93 ± 13.44 µm. Mean retinal nerve fiber layer thicknesses in the study and control group were 110 ± 12.4 µm and 108 ± 13.1 µm, respectively. CONCLUSION: Mean retinal thickness in pregnant women was higher than control group in all measurements. Statistically significant difference in thickness was only found in upper, temporal, and inferior parafoveal areas.

Intravitreal bevacizumab for macular edema due to branch retinal vein occlusion: 12-month results.

PURPOSE: To present the functional and anatomic changes after intravitreal bevacizumab in eyes with macular edema (ME) due to branch retinal vein occlusion (BRVO). DESIGN: The study was a retrospective study. MATERIALS AND METHODS: The study included 31 patients with ME due to BRVO. We compared the examination findings of patients with ME before and after intravitreal bevacizumab therapy at 12 months. The study included patients who had macular edema secondary to BRVO treated with bevacizumab. The therapy was started in the first week after occlusion. The initial therapy was three intravitreal bevacizumab injections at monthly intervals with 1.25/0.05 mL bevacizumab. Patients with a baseline visual acuity less than 0.5 (logarithm of the minimum angle of resolution [logMAR] 0.30), central macular thickness (CMT) more than 290 µm, and no neovascularization were included. Patients with diabetes mellitus or a history of intravitreal triamcinolone or grid laser photocoagulation therapy or ischemic BRVO were excluded. The retreatment criteria were as follows: increased CMT more than 100 µm combined with a loss of visual acuity of five or more letters. The statistical analysis of this study was carried out by paired samples t-test (SPSS). A P value of less than 0.05 was considered to be statistically significant. RESULTS: This retrospective study included 33 eyes of 31 patients (20 women, 11 men; mean age was 55.30 ± 9.62 years (range 36-75 years). Patients received a mean of 5.3 injections during 12 months of follow-up. The best corrected visual acuity increased from 0.66 ± 0.20 (logMAR) at baseline to 0.22 ± 0.13 (logMAR) (t = 15.42; P < 0.001) at month 12. The CMT decreased from 494.15 ± 104.16 µm at baseline to 261.79 ± 45.36 µm at month 12 (- 232.36 ± 109.98 µm); P < 0.001). No bevacizumab-related systemic or ocular adverse effects following intravitreal drug injections were observed. The majority of patients required reinjection(s) treatment for ME (84.9%). CONCLUSION: Intravitreal therapy using bevacizumab appears to be an effective primary treatment option for ME due to BRVO. No serious ophthalmologic or systemic side effects were observed for intravitreal bevacizumab therapy. The main disadvantage of bevacizumab therapy is the requirement of multiple injections in order to maintain visual and anatomic improvements.