Assessment the neurodegenaration process of post-geniculate optic pathway in thalamic tumors using optical coherence tomography: Post-geniculate optic pathway in thalamic tumors.

PURPOSE: To investigate the effect of thalamic tumors related to post-geniculate optic pathway and those of microsurgical removal on neurodegeneration process of visual pathway using OCT. METHODS: This cross-sectional study included 30 eyes of 15 patients with thalamic tumors and data compiled from 45 eyes of 45 healthy participants. The analysis of variables was divided into ipsilateral and contralateral eye depends on the laterality of brain tumors. The data gained at baseline, postoperative 3rd and postoperative 6th month period was analyzed in One-Way Repeated Measures ANOVA. RESULTS: The mean superior quadrant retinal nerve fiber layer (RNFL) thickness of ipsilateral eye was significantly thicker (p = 0.02), while inferior hemifield ganglion cell-inner plexiform layer (GC-IPL) thickness of contralateral eye was significantly higher compared to control groups (p = 0.02). Significant negative correlations were found between the mean preop. mean deviation (MD) and tumor volume and time interval between initial diagnosis and surgery (r = - 0.730, p = 0.002 and r = - 0.680, p = 0.005, respectively) in the ipsilateral eye. In repeated measure analysis, there was no unfavourable effect of thalamic microsurgery on peripapillary average RNFL thickness on both ipsilateral and contralateral eyes (Ipsilateral eye; f (1.5,21.7) 0.76 p = 0.51 and contralateral eye; f (1.4,20.4) 0.42 p = 0.59). CONCLUSION: This study suggests that thalamic tumors affecting post-geniculate optic pathway may lead to significant increase in RNFL and GC-IPL thicknesses and changes in VF parameters. Timely intervention in thalamic tumors may prevent irreversible loss of retinal axons secondary to neurodegeneration process.

Changes in the peripapillary and subfoveal choroidal vascularity index after transsphenoidal surgery for pituitary macroadenoma.

PURPOSE: To investigate the changes in peripapillary and subfoveal choroidal vascular indexes (CVI) before and after pituitary macroadenoma surgery by using a binarization method. METHOD: In this cross-sectional study, we examined 17 eyes in 9 patients with pituitary macroadenomas who had undergone transsphenoidal pituitary surgery due to chiasmal compression. We also compiled data from 17of in 17 healthy subjects. ImageJ 1.51 software processing (National Institutes of Health, Bethesda, Maryland, USA) was used for binarization of optical coherence tomography scans. The CVI was computed as the ratio of luminal area to total choroidal areal. The CVI, OCT and VF parameters were analyzed in One-Way Repeated Measures ANOVA to determine significant changes in measurements during the postoperative course. RESULTS: The mean peripapillary inferior and temporal quadrant CVIs were significantly lower in the eyes of patients with pituitary macroadenoma compared to controls (46.0 ± 0.03 versus. 42.8 ± 0.04, p = 0.02; 45.8 ± 0.03 Versus. 42.3 ± 0.04, p = 0.02). In repeated measure analysis, there was a significant effect of transsphenoidal microscobic pituitary surgery on peripapillary inferior quadrant CVI and BCVA, F(1.3, 21.5) = 6.62, p = 0.01 and F (1.8, 29.7) = 7.8, p < 0.005, respectively. CONCLUSION: This study suggests that PMa with chiasmal compression may lead to significant changes in the peripapillary CVI. Pituitary surgery had a favorable significant effect on peripapillary choroidal vascular network and BCVA. Furthermore, optical coherence tomography is a helpful technique for quantifying the alterations of peripapillary CVI during the preoperative and postoperative course.

Does the novel coronavirus use the ocular surface as an entrance into the body or as an infection site? / O novo coronavírus usa a superfície ocular como porta de entrada no corpo ou como local de infecção?

ABSTRACT This study attempts to review whether the coronavirus disease-2019 (COVID-19) is transmitted through the ocular surface and examine the symptoms and signs of ocular disease. Considering that COVID-19 is transmitted by airborne droplets and close contact with infected individuals, we will also review the conditions to which eye clinics and ophthalmologists should pay attention to prevent the transmission of the disease. Although some researchers have argued that COVID-19 transmission cannot occur through the ocular surface, most of them are of the opinion that the ocular surface is a potential pathway of transmission. Until date, ocular signs and symptoms have been rarely reported in the COVID-19 patients. However, there are case reports of conjunctivitis as the first, and rarely, the only clinical symptom of the disease. In addition, low coronavirus RNA positivity can be detected in the ocular surface samples. Further laboratory and clinical investigations are needed to ascertain whether the ocular surface is one of the potential transmission pathways through which severe acute respiratory syndrome-coronavirus 2 can gain entry into the human body.

RESUMO Rever se o COVID- 19 é transmitido através da su perfície ocular e seus sintomas e sinais na doença ocular. Dado que o COVID-19 é transmitido por gotículas de ar e contato próximo, também analisaremos, também, as condições às quais os oftalmologistas e as clínicas oftalmológicas devem prestar atenção a fim de evitar a transmissão da doença. Embora alguns autores tenham argumentado que a transmissão de COVID-19 não pode ocorrer através da superfície ocular, a maioria dos autores acredita que a superfície ocular é uma via potencial de transmissão. Até à data, foram notificados, muito raramente, sinais e sintomas oculares em doentes com COVID- 19. No entanto, há relatos de casos de conjuntivite como sendo, raramente, o primeiro e único sintoma clínico da doença. Além disso, a baixa positividade do RNA coronavírus pode ser detectada nas amostras da superfície ocular. São necessárias mais investigações clínicas laboratoriais sobre se a superfície ocular é uma das vias de transmissão através das quais o SARS-COV-2 penetra no corpo humano.

Does the novel coronavirus use the ocular surface as an entrance into the body or as an infection site?

This study attempts to review whether the coronavirus disease-2019 (COVID-19) is transmitted through the ocular surface and examine the symptoms and signs of ocular disease. Considering that COVID-19 is transmitted by airborne droplets and close contact with infected individuals, we will also review the conditions to which eye clinics and ophthalmologists should pay attention to prevent the transmission of the disease. Although some researchers have argued that COVID-19 transmission cannot occur through the ocular surface, most of them are of the opinion that the ocular surface is a potential pathway of transmission. Until date, ocular signs and symptoms have been rarely reported in the COVID-19 patients. However, there are case reports of conjunctivitis as the first, and rarely, the only clinical symptom of the disease. In addition, low coronavirus RNA positivity can be detected in the ocular surface samples. Further laboratory and clinical investigations are needed to ascertain whether the ocular surface is one of the potential transmission pathways through which severe acute respiratory syndrome-coronavirus 2 can gain entry into the human body.

How do intracranial tumors associated with visual pathways affect quadrant and sectoral based optical coherence tomography measurements: The effect of intracranial tumors on RNFL and GC-IPL thickness.

AIM: To investigate the quantitative sectoral and regional changes of retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) thickness in different types of intracranial tumors associated with visual pathways. METHODS: This comparative retrospective study included 58 eyes of 30 patients with intracranial tumors and the data of 62 eyes of 31 healthy subjects. The RNFL and GCIPL thicknesses were analyzed using spectral-domain optical coherence tomography (OCT). The tumors were classified into ones that affect pre-geniculate and post-geniculate pathway. RESULTS: The mean RNFL thickness in temporal quadrant was significantly thinner in eyes with intracranial tumors affecting the pre-geniculate optic pathway compared to controls (p = 0.04). In contrast, the mean superior quadrant RNFL thickness was significantly thicker in eyes with brain tumors associated with post-geniculate optic pathway (p = 0.01). The mean GC-IPL thicknesses of the inner ring superotemporal, superonasal, inferotemporal and inferionasal sectors and outer ring superonasal and inferonasal sectors were significantly thinner in eyes with intracranial tumors affecting the pre-geniculate optic pathway compared to control eyes (p = 0.02, p = 0.001, p = 0.02, p = 0.003, p = 0.008 and p = 0.03 respectively). CONCLUSION: The results of this study showed that significant changes can be seen in the different RNFL quadrants and GC-IPL sectors in eyes with intracranial tumors affecting pre-geniculate or post-geniculate optic pathway. OCT is a very useful imaging technique to quantify these structural changes which take place during the neurodegeneration process of visual pathways in intracranial tumors.

Extramacular Retinal Hole Following Intravitreal Dexamethasone Implant: Case Report

The intravitreal dexamethasone implant Ozurdex is indicated for the treatment of macular edema due to diabetes and branch retinal vein occlusion. While the most common ocular side effects are elevated intraocular pressure and cataract formation, rare complications related to the injection have been reported. We present a case with extramacular retinal hole after Ozurdex injection.

Diode laser transscleral cyclophotocoagulation for the treatment of refractory glaucoma after penetrating keratoplasty.

PURPOSE: To evaluate the effect and safety of diode laser transscleral cyclophotocoagulation (TSCPC) in eyes with refractory glaucoma after penetrating keratoplasty (PK). METHODS: Diode laser TSCPC was performed on 32 eyes of 32 patients with secondary glaucoma after penetrating keratoplasty. The mean follow-up period was 11.4 +/- 3.8 months (range, 6-20 months). The intraocular pressure (IOP), number of glaucoma medications, graft status, side effects, and complications of the procedure were all recorded during the follow-up period. The treatment was considered successful if after one cyclodiode treatment the IOP could be reduced to or below 22 mmHg with or without medication. The success rate of the diode laser treatment was analyzed by the Kaplan-Meier survival analysis method during the 6th and 12th months of the follow-up period and the end of the study. The decrease in drug requirement after laser treatment was analyzed by the Wilcoxon nonparametric test. Statistical significance was set at p < 0.05. RESULTS: During the follow-up period, diode laser TSCPC reduced the IOP significantly. Our cumulative success rate was 56% at the end of the study. Cyclodiode treatment resulted in an IOP less than 22 mmHg in 97% of the eyes on the 6th month and 72% of the eyes on the 12th month with or without medication. The total retreatment rate of the study was 44%. More than one treatment was necessary, 8 times in the 1st month, 9 times in the 3rd month, 5 times in the 6th month and 3 times in the 12th month. The average number of antiglaucomatous drugs used was 2.8 before surgery and 1.2 after the 12th month follow-up period (p < 0.05). No eyes with graft failure after treatment were present. Visual acuity improved (> 2 Snellen lines of acuity) in two eyes and remained the same in the others. No serious side effects such as phthisis bulbi or hypotonia were observed. CONCLUSIONS: Diode laser TSCPC appears to be a safe and effective procedure for the treatment of uncontrolled glaucoma secondary to penetrating keratoplasty.

Microvascular blood flow of the optic nerve head and peripapillary retina in unilateral exfoliation syndrome.

PURPOSE: To measure microvascular blood flow in patients with unilateral exfoliation syndrome (XFS) without glaucoma or ocular hypertension and to compare the values in the eyes with clinically detected exfoliation, their nonexfoliative fellow eyes of the same patients and control eyes. METHODS: Twenty-two patients with clinically detected unilateral XFS and 30 age-matched healthy subjects were included in this study. Group 1 consisted of 22 eyes with clinical XFS, and the nonexfoliative fellow eyes of the same patients formed Group 2. The control group (Group 3) comprised te randomly selected eyes of 30 age-matched healthy subjects. Ocular blood flow values (volume, flow and velocity) were recorded from the opti nerve head (ONH) and peripapillary retina (PPR) using the Heidelberg retinal flowmeter (HRF). The difference between the three groups were compared statistically. RESULTS: The mean values of blood flow obtained from the ONH and PPR in eyes with clinically detected exfoliation (Group 1) and their nonexfoliative fellow eyes (Group 2) were both significantly lower than the values for the control eyes (Group 3). The differences in ocular blood flow between the eyes with exfoliation and the nonexfoliative fellow eyes were not statistically significant [one-way analysis of variance (ANOVA), Dunnett's T3 test, p >/= 0.05]. CONCLUSION: These findings suggest that the eyes with clinically detected unilateral XFS were associated with reduced blood flow values in both the ONH and the PPR. The nonexfoliative fellow eyes also have lower blood flow values than the control eyes.