A quantitative sonoelastography evaluation of ocular and periocular elasticity after intravitreal ranibizumab injection.

PURPOSE: We evaluated changes in ocular and periocular elasticity by ultrasound (US) elastography in intravitreal ranibizumab-treated eyes and the healthy fellow eyes of patients with neovascular AMD. METHODS: The study was performed on 52 eyes of 26 volunteers who ranged in age from 59 to 89 (mean 72±7.78) years old. The study group consisted of the patients with neovascular AMD treated with intravitreal ranibizumab. The fellow eyes (without choroidal neovascularization) of the study group were selected as the control group. All patients were examined with sonoelastography before intravitreal injection and at 1day, 1week, and 1month after intravitreal injection. All images were acquired with a Toshiba Aplio 500 ultrasound system (Tokyo, Japan) including software with a combined autocorrelation method and a multifrequency linear probe. The elastography values of the anterior vitreous (AV), posterior vitreous (PV), retina-choroid-sclera complex (RCS), retrobulbar fat tissue (RF), optic nerve head (ONH) and retrobulbar optic nerve (RON) were measured in each eye. RESULTS: There were 13 male (50%) and 13 female (50%) participants in our study. Anterior vitreous, posterior vitreous, RCS, retrobulbar fat tissue, ONH, and RON US elastography values were similar in both groups (P˃0.05 for all). On the other hand, there was a positive correlation between the difference between baseline and 1-month PV sonoelastography values and age (r=0.47, P=0.035). CONCLUSION: A single dose intravitreal Ranibizumab (Lucentis®, Genentech, USA) injection does not alter the elasticity of ocular and periocular structures.

Comparison of photoreceptor outer segment length in diabetic and idiopathic epiretinal membranes.

PURPOSE: Idiopathic and diabetic epiretinal membranes (ERMs) differ significantly in terms of macular morphology. Our aim was to compare the photoreceptor outer segment (PROS) length in diabetic and idiopathic ERMs before and after surgery. METHODS: Fifty-two eyes of 50 patients who underwent pars plana vitrectomy (PPV) due to idiopathic and diabetic ERMs were included in this retrospective case series. All of the patients underwent ERM and internal limiting membrane (ILM) removal. The patients had been followed up 6 months postoperatively. Spectral-domain optical coherence tomography (OCT) was used to measure the PROS length, overall PR length and central foveal thickness (CFT). RESULTS: The PROS length, overall PR length, and CFT were statistically significantly lower at all the postoperative visits when compared to preoperative values in both the idiopathic and diabetic ERM groups (P<0.001). The amount of decrease in PROS and overall PR length were similar in both groups after surgery (P>0.05). There was no relation between amount of PROS length change and visual acuity gain in both groups (P>0.05). CONCLUSIONS: Postoperative change of PROS length was similar in idiopathic and diabetic ERMs. PROS length change may not be an indicator of postoperative visual acuity.

Effects of coronary artery bypass grafting surgery on retinal vascular caliber, ocular pulse amplitude and retinal thickness measurements.

AIM: The retina and ocular vasculature are vulnerable to alterations in systemic hemodynamics, such as in open heart surgeries. Our aim was to investigate retinal vascular caliber (RVC), ocular pulse amplitude (OPA), peripapillary retinal nerve fiber layer (RNFL) and macular thickness in coronary artery bypass grafting (CABG) surgery patients. METHODS: Twenty-six patients who had a history of CABG surgery and 26 age-sex-matched healthy participants were recruited for this prospective, cross-sectional and comparative study. The RVC, peripapillary RNFL and macular thickness measurements were taken with spectral-domain optical coherence tomography. The OPA, a surrogate of pulsatile ocular blood flow, was measured with the Pascal dynamic contour tonometer. RESULTS: There were no statistically significant differences between the CABG surgery patients and the controls with regard to RVC, OPA, peripapillary RNFL thickness and macular thickness measurements (p>0.05). CONCLUSIONS: CABG surgery does not affect retinal structures and pulsatile ocular blood flow in the long-term follow-up.

Chorio-retinal thickness measurements in patients with acromegaly.

PURPOSE: To compare choroidal, foveal, and peripapillary retinal thickness between patients with acromegaly and healthy adults. METHODS: This prospective, cross-sectional, and comparative study included 30 patients with acromegaly (study group) and 30 healthy subjects (control group). The subfoveal choroidal thickness (SFCT), foveal thickness, and peripapillary retinal nerve fibre layer thickness were measured with spectral domain optical coherence tomography. RESULTS: The mean SFCT in the study group and in the control eyes was 374.4±98.1 and 308.6±77.3 µm, respectively (P<0.001). The mean thinnest foveal thickness value was 233.2±22.4 µm in the acromegaly group and 222.8±13.9 µm in the control group (P=0.003). The mean peripapillary retinal nerve fibre layer thickness did not differ significantly between the groups (P=0.34). CONCLUSION: The SFCT and foveal thickness were significantly higher in patients with acromegaly, whereas peripapillary retinal nerve fibre layer thickness was similar between the groups.

Choroidal changes after cardiopulmonary bypass.

AIM: Choroid, which is the vascular tissue responsible for blood supply to the outer parts of the retina, might be affected by hemodynamic events. We aimed to reveal choroidal thickness and ocular pulse amplitude changes after cardiopulmonary bypass in which gross hemodynamic alterations occur. METHODS: Forty-two eyes of 42 patients who underwent heart surgery with cardiopulmonary bypass were examined in this prospective, cross-sectional case series. The spectral domain optical coherence tomography (Spectralis, Heidelberg, Germany) was used to analyze sub-foveal choroidal thickness. The ocular pulse amplitude, the surrogate of gross choroidal blood flow, was measured with the Pascal dynamic contour tonometer (Pascal DCT, Swiss Microtechnology AG, Port, Switzerland).. The intraocular pressure was also measured with this tonometer. The examinations were performed pre-operatively and post-operatively at the first week and first month. RESULTS: The mean age of the patients was 58.8 ± 12.4 years. The mean sub-foveal choroidal thickness and ocular pulse amplitude values did not change statistically significantly after the operations at the follow-up visits (p>0.05). Also, there were no important correlations between cardiopulmonary bypass time and mean sub-foveal choroidal thickness and ocular pulse amplitude changes at the post-operative first week (p>0.05). The intraocular pressure values were decreased markedly at the control visits (p<0.05). CONCLUSIONS: Sub-foveal choroidal thickness and ocular pulse amplitude are unchanged, while intraocular pressure decreases one week and one month after cardiopulmonary bypass.

Vertical muscle transposition augmented with lateral fixation (Foster) suture for Duane syndrome and sixth nerve palsy.

PURPOSE: To report the postoperative results of full-tendon vertical rectus transposition (VRT) augmented with lateral fixation suture for the treatment of type 1 Duane syndrome and sixth nerve palsy and to determine whether there was a decrease in the effect of the Foster suture over time. METHODS: This retrospective, consecutive case series included patients who underwent a full-tendon VRT transposition with lateral fixation for type 1 Duane syndrome or sixth nerve palsy. The primary outcome measures included deviation, abnormal head posture(AHP), abduction deficiency, and postoperative binocular single visual field (BSVF). RESULTS: Eighty-seven patients (87 eyes: 40 eyes with Duane syndrome and 47 eyes with sixth nerve palsy) were included in this study. In Duane syndrome patients, the deviation was reduced by a mean of 95%, the AHP was eliminated in 86% of patients, the abduction was improved by 42%, and a useful BSVF of ≈ 67% of normal was achieved at 1 year post operation. In sixth nerve palsy patients, the deviation was reduced by 99%, the abduction was improved by 59%, and a useful BSVF of ≈ 71% of normal was achieved at 1 year post operation. In both groups, the improvements in deviation angle and abduction were stable postoperatively. Sixteen patients needed reoperation for undercorrection. CONCLUSION: VRT surgery with posterior fixation is an effective treatment method for complete sixth nerve palsy and Duane syndrome with esotropia, AHP, and abduction deficiency. The procedure carries a small risk of reoperation for undercorrection. The effect of the Foster suture did not decline over time.

Modelling the transmission dynamics of Theileria annulata: model structure and validation for the Turkish context.

A mathematical model that describes the transmission dynamics of Theileria annulata is proposed that consists of 2 host components: the Hyalomma tick population and a compartmental model of T. annulata infection in the cattle population. The model was parameterized using data describing tick infestation and the infection status of cattle in Turkey from 2006 to 2008. The tick attachment rates are highly seasonal and because of the temporal separation of infectious and susceptible ticks virtually all ticks are infected by carrier cattle, so that annual peaks of disease in cattle do not impact on infection in the Hyalomma tick population. The impact of intervention measures that target the tick population both on the host and in the environment and their impact on the transmission of T. annulata were investigated. Interventions that have a limited 'one-off' impact and interventions that have a more permanent impact were both considered. The results from the model show the importance of targeting ticks during the period when they have left their first host as nymphs but have yet to feed on their second host.

The effects of posterior continuous curvilinear capsulorhexis on contrast sensitivity.

PURPOSE: We aimed at evaluating the effects of posterior continuous curvilinear capsulorhexis (PCCC) on contrast sensitivity. MATERIALS AND METHODS: In this prospective, randomized, bilateral clinical study, 40 eyes of 20 patients who underwent bilateral cataract surgery were included. The phacoemulsification machine, viscoelastic substances, surgical tools, and intraocular lenses (IOLs) were the same for both eyes. The only difference was that we conducted the PCCC procedure before IOL implantation to one of the eyes of the patients. The selection of the eye that underwent the PCCC procedure was decided randomly. RESULTS: The mean photopic contrast sensitivity values at spatial frequencies of 1.5, 3, 6, 12, and 18 cpd (cycles per degree) were 41.55, 59.90, 61.25, 32.35, and 9.75, respectively, and for the control group these values were 39.05, 56.60, 57.95, 29.80, and 8.75, respectively. The mean mesopic contrast sensitivity values at special frequencies of 1.5, 3, 6, 12, and 18 cpd were 41.20, 54.75, 55.55, 31.70, and 9.00, respectively, and for the control group these values were 38.35, 51.70, 52.15, 30.05, and 8.00, respectively. The mean contrast sensitivity values of the eyes that underwent the PCCC procedure were slightly better than the fellow eyes at all spatial frequencies, but the difference was statistically insignificant (P>0.05). CONCLUSIONS: In early post-operative period, the PCCC procedure exerts some positive effects on contrast sensitivity although these effects are statistically insignificant.