Pore-scale observations of natural hydrate-bearing sediments via pressure core sub-coring and micro-CT scanning.

Both intra-pore hydrate morphology and inter-pore hydrate distribution influence the physical properties of hydrate-bearing sediments, yet there has been no pore-scale observations of hydrate habit under pressure in preserved pressure core samples so far. We present for the first time a pore-scale micro-CT study of natural hydrate-bearing cores that were acquired from Green Canyon Block 955 in UT-GOM2-1 Expedition and preserved within hydrate pressure-temperature stability conditions throughout sub-sampling and imaging processes. Measured hydrate saturation in the sub-samples, taken from units expected to have in-situ saturation of 80% or more, ranges from 3 ± 1% to 56 ± 11% as interpreted from micro-CT images. Pore-scale observations of gas hydrate in the sub-samples suggest that hydrate in silty sediments at the Gulf of Mexico is pore-invasive rather than particle displacive, and hydrate particles in these natural water-saturated samples are pore-filling with no evidence of grain-coating. Hydrate can form a connected 3D network and provide mechanical support for the sediments even without cementation. The technical breakthrough to directly visualize particle-level hydrate pore habits in natural sediments reported here sheds light on future investigations of pressure- and temperature-sensitive processes including hydrate-bearing sediments, dissolved gases, and other biochemical processes in the deep-sea environment.

Prevalence of focal lamina cribrosa defects in eyes with pachychoroid disease spectrum.

AIM: To determine the prevalence of focal lamina cribrosa (LC) defect among patients with pachychoroid disease spectrum (PDS) in the absence of peripapillary retinoschisis. METHODS: This retrospective, cross-sectional study comprised of 180 patients with PDS, including polypoidal choroidal vasculopathy (PCV), central serous chorioretinopathy, and pachychoroidal neovasculopathy. Medical records and optic nerve head evaluations conducted using spectral-domain optical coherence tomography with enhanced depth imaging were reviewed. As a control group, 236 patients who underwent ophthalmologic evaluation for vitreous floaters, without obvious ocular disease, were also included. RESULTS: The mean age of the PDS group, which included 118 male patients (65.6%), was 57.4±11.1y. There was no significant difference between the two groups in age (P=0.710) or sex (P=0.248). Six patients (3.3%) in the PDS group and none in the control group showed focal LC defect (P=0.318). Among the six patients with focal LC defect in the PDS group, four eyes had PCV, one eye was the fellow eye of a PCV eye, and one eye had pachychoroidal neovasculopathy. CONCLUSION: Focal LC defect can be defected in patients with PDS in the absence of peripapillary retinoschisis. However, the prevalence of focal LC defect was not different significantly between PDS patients and those who did not have PDS.

Changes in peripapillary and subfoveal choroidal thickness in patients with central retinal vein occlusion.

PURPOSE: We sought to evaluate changes of mean peripapillary choroidal thickness (PCT) and subfoveal choroidal thickness (SFCT) over 12 months in patients with unilateral central retinal vein occlusion (CRVO). METHODS: Our retrospective, observational study included 19 patients with treatment-naïve, unilateral CRVO who completed at least 12 months of follow-up period. Mean PCT and mean SFCT in CRVO-affected eyes and unaffected contralateral eyes were measured at each follow-up visit, and then compared. Differences between baseline and 12 months (ΔSFCT and ΔPCT) and percentage changes (ΔSFCT or ΔPCT/baseline×100%) were determined. We also investigated the predictive factors for visual outcome in the CRVO-affected eyes. RESULTS: In the CRVO-affected eyes, mean PCT was 146.7±41.9 µm at baseline, and 106.5±24.2 µm at 12 months (P < 0.001). Mean PCT of the contralateral eyes was 129.8±42.6 µm at baseline and 124.6±39.7 µm at 12 months (P = 0.089). Mean SFCT of CRVO-affected eyes was 225.8±77.9 µm at baseline, and 199.4±66.6 µm at 12 months (P = 0.009). Mean SFCT of the contralateral eyes was 218.4±83.0 µm at baseline, and 208.4±78.1 µm at 12 months (P = 0.089). Δ PCT was -41.6±25.3 µm in the CRVO-affected eyes, and -5.2±5.8 µm in the contralateral eyes (P<0.001). % PCT was -24.9±14.0% in the CRVO-affected eyes, and -4.0±0.4% in the contralateral eyes (P = 0.001). Δ SFCT was -26.4±24.6 µm in the CRVO-affected eyes, and -9.5±16.7µm in the contralateral eyes (P = 0.016). % SFCT was -10.4±9.8% in the CRVO-affected eyes, and -3.4±6.4% in the contralateral eyes (P = 0.015). Among the various factors, BCVA at baseline (ß = 0.797, P = 0.001) and % SFCT (ß = 0.712, P = 0.001) were significantly associated with visual outcome at 12 months in the CRVO-affected eyes. CONCLUSION: Both peripapillary and subfoveal choroidal thickness reduced significantly over 12 months in the CRVO-affected eyes, but not in the contralateral eyes. In addition, the absolute reduction amount and reduction ratio of PCT and SFCT were significantly greater in the CRVO-affected eyes than the contralateral eyes.

Long-term treatment response after intravitreal bevacizumab injections for patients with central serous chorioretinopathy.

PURPOSE: To investigate long-term treatment response after intravitreal bevacizumab injections (IVBIs) for central serous chorioretinopathy (CSC). METHODS: This retrospective, interventional study investigated the medical records of 45 eyes of 44 patients with CSC who underwent IBVIs and completed at least 2-year follow-up period. Complete resolution (CR) was defined as complete resolution of subretinal fluid at least 3 months after the last IVBI. Thick-choroid CSC was defined as mean subfoveal choroidal thickness more than 300.0 µm. The main outcome measure was long-term treatment outcome after IVBIs in patients with CSC. RESULTS: Thirty-five patients (79.5%) were male, and their mean age was 45.5 ± 9.6 years. The mean follow-up period was 35.1 ± 11.5 months. Twenty-two eyes (48.9%) had acute CSC, and 40 eyes (88.9%) achieved CR. Twenty eyes (50.0%) developed recurrence, the mean number of IVBIs to achieve the first CR was not significantly different between eyes with and without recurrences (2.6 ± 1.6 vs. 2.9 ± 1.9; P = 0.658). Thick-choroid CSC was significantly difference between the eyes with and without recurrence (17 eyes, 85.0% vs. eyes, 50.0%; P = 0.020). Among the baseline characteristics, serous pigment epithelial detachment (B = - 2.580, P = 0.032) and thick-choroid (B = 1.980, P = 0.019) were significantly associated with recurrence. CONCLUSION: Eyes with CSC treated with IVBI and achieving complete resolution of subretinal fluid have 50% chance of recurrence in the long term. Thinner choroid and serous pigment epithelial detachment appear protective for recurrences.

Focal lamina cribrosa defects and significant peripapillary choroidal thinning in patients with unilateral branch retinal vein occlusion.

PURPOSE: To investigate the prevalence of focal lamina cribrosa (LC) defects in patients with unilateral branch retinal vein occlusion (BRVO) and to compare ocular characteristics between eyes with and without focal LC defect and those eyes with normal-tension glaucoma (NTG). METHODS: This retrospective, cross-sectional study included 121 patients. Thirty-nine patients had unilateral BRVO (BRVO group), 36 patients had NTG (NTG group), and 36 patients had vitreous floaters, but no other ocular diseases (control group). In addition to baseline characteristics such as age, sex, refractive errors, the ocular characteristics such as peripapillary choroidal thickness (PCT), retinal nerve fiber layer thickness, and subfoveal choroidal thickness were retrospectively analyzed. RESULTS: Focal LC defects were detected in 20 eyes of 14 patients (38.9%) in the BRVO group, 24 eyes of 15 patients (41.7%) in the NTG group, and none in the control group (P<0.001). In the BRVO-affected eyes, the mean PCT was 102.7±31.1 µm in the eyes with focal LC defects, and 163.1±70.1 µm in the eyes without LC defects (P = 0.009). In the BRVO-affected eyes, the mean PCT was 102.7±31.1 µm in the eyes with focal LC defects, and 163.1±70.1 µm in the eyes without LC defects (P = 0.009). In the NTG group, the mean PCT was 133.1±48.9 µm in the eyes with focal LC defects and 170.8±81.9 µm in those without (P = 0.042). The other baseline and ocular characteristics were not significantly different between the eyes with and without focal LC defects in both the BRVO group and the NTG group. CONCLUSIONS: About 40% of the patients with unilateral BRVO had focal LC defect in the BRVO-affected eyes and unaffected fellow eyes, similar prevalence to the patients with NTG. The mean PCT was significantly thinner in the eyes with focal LC defect than those without in the patients with BRVO and those with NTG, suggesting possible pathophysiologic correlation between these two diseases.

Clinical characteristics of asymptomatic Terson syndrome in the patients with aneurysmal subarachnoid hemorrhage.

AIM: To investigate clinical characteristics of asymptomatic Terson syndrome and its clinical impact in patients with aneurysmal subarachnoid hemorrhage (SAH). METHODS: This retrospective, interventional study included 31 patients with aneurysmal SAH, and the medical records were reviewed. In addition to baseline characteristics of the study population such as age, sex, and underlying medical history, multi-modal imaging analysis, including fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), were also reviewed. Glasgow Coma Scale (GCS), Hunt-Hess (HH) grade, and Fisher scale at the time of admission, and functional outcome by using modified Rankin Scale (mRS) at 6mo were compared. RESULTS: Of the 31 patients, 10 patients (32.3%) were diagnosed with Terson syndrome. All the patients with Terson syndrome did not report visual symptoms at the time of ophthalmologic screening. FA showed microvascular changes of retinal capillaries and varying degrees of disc leakage. SD-OCT allowed intuitive anatomical localization of multi-layered retinal hemorrhages and assessment of ellipsoid zone integrity. The patients with Terson syndrome showed significantly worse GCS (P=0.047) and HH grade (P=0.025) than those without, except Ficher scale (P=0.385). There was no significant difference in the mRS (P=0.250) at 6mo. Among baseline factors, the HH grade was the only significant factor associated with Terson syndrome (B=1.079, P=0.016). CONCLUSION: In our study, 32.3% of the patients have Terson syndrome without visual symptoms. The baseline HH grade is significantly correlated with Terson syndrome, and there is no significant difference in the functional outcome between the patients with and without Terson syndrome. Terson syndrome may develop without any visual symptoms as shown in our study, and ophthalmologic screening may be recommended to prevent further visual deterioration especially in the patients with poor HH grade at the time of aneurysmal SAH.

Rod Fracture Causing Relief of Back Pain That Developed After Adult Lumbar Degenerative Flat-Back Correction Surgery: A Case Report.

A 73-year-old woman underwent deformity correction surgery (anterior lumbar interbody fusion of L2-L3-L4-L5-S1, pedicle subtraction osteotomy at L4, and posterior screw fixation from T10 to the pelvis) due to lumbar degenerative flat-back. Following the operation, the patient experienced pain in her back and buttocks, for which she regularly took medications. She reported frequently feeling a heavy and stretched sensation of pain after the operation in those areas, which made her regret undergoing the operation. However, at 33 months postoperatively, she reported that one day, while getting up from a chair, she felt a crack in her back, which was followed by an improvement in her back and buttock pain; thereafter, she stopped taking pain medications. Follow-up radiography revealed a bilateral rod fracture at the L4-5 level on the right side and at the L3-4 level on the left side. The overall pelvic parameters, except pelvic incidence, slightly changed after the rod fracture. Therefore, the broken rod was replaced and another rod was added to the broken rod area; however, the changed pelvic parameters were not corrected further during the reoperation. Following the reoperation, the patient showed improvements and she no longer required pain medication.

Significant changes of the choroid in patients with ocular ischemic syndrome and symptomatic carotid artery stenosis.

PURPOSE: To evaluated the changes in choroidal vasculature in patients with ocular ischemic syndrome (OIS) and in the ipsilateral eyes of patients with symptomatic carotid artery stenosis (CAS). METHOD: A total of 50 patients (15 patients with OIS, 10 patients with symptomatic CAS, 25 patients of age-and sex-matched control group) were included, and the medical records were retrospectively reviewed. The mean subfoveal choroidal thickness (SFCT) of each eye was measured, and binary images of the choroid were evaluated to compare the mean choroidal area and the luminal area. RESULTS: The mean SFCT was 170.5±75.3 µm in the eyes with OIS, 154.8±62.9 µm in the ipsilateral eyes with symptomatic CAS, and 277.5±73.2 µm in the right eyes of the control group patients (P<0.001). The mean choroidal area was 494,478.6±181,846.2 µm2 in the eyes with OIS, 453,750.0±196,725.8 µm2 in the ipsilateral eyes with symptomatic CAS, and 720,520±281,319.5 µm2 in the control group eyes (P = 0.036). The mean luminal area was 333,185.7±112,665.9 µm2 in the eyes with OIS, 313,983.3±132,032.1 µm2 in the ipsilateral eyes with symptomatic CAS, and 480,325.0±185,112.6 µm2 in the control group eyes (P = 0.046). The mean SFCT, mean choroidal area, and mean luminal area were significantly smaller in the eyes with OIS (P = 0.017, P = 0.005, and P = 0.004, respectively), and those with symptomatic CAS (P = 0.020, P = 0.016, and P = 0.021, respectively) than in the unaffected contralateral eyes. There were no significant differences between the eyes in the control group (P = 0.984, P = 284, and P = 0.413, respectively). CONCLUSION: The mean SFCT, mean choroidal area, and mean luminal area were significantly thinner in the eyes with OIS and the ipsilateral eyes with symptomatic CAS, compared with the control group eyes. The eyes with OIS and those with symptomatic CAS had significantly thinner SFCT, and smaller choroidal area and luminal area than the unaffected contralateral eyes. Choroid may reflect the vascular status of the carotid artery, indicated by choroidal thinning and decreasing choroidal area, especially luminal area.

Sectoral changes of the peripapillary choroidal thickness in patients with unilateral branch retinal vein occlusion.

AIM: To investigate sectoral changes in the mean peripapillary choroidal thickness (PCT) in patients with unilateral branch retinal vein occlusion (BRVO). METHODS: This retrospective, interventional study included 41 patients with acute, unilateral BRVO without macular edema. All patients completed at least a 6-month follow-up period. The PCT was measured at eight locations (temporal, superotemporal, superior, superonasal, nasal, inferonasal, inferior, and inferotemporal). In addition to calculating the average of all locations, the peripapillary choroidal area was divided into four sectors: superior (average of superotemporal PCT, superior PCT, and superonasal PCT), temporal, inferior (average of inferotemporal PCT, inferior PCT, and inferonasal PCT), and nasal. RESULTS: In the BRVO-affected eyes, the mean PCT was 177.7±69.8 µm (range, 70.1-396.0 µm) at baseline and 127.8±54.8 µm (range, 56.4-312.1 µm) at 6mo (P<0.001). In the non-affected contralateral eyes, the mean PCT was 192.5±60.6 µm (range, 61.4-365.0 µm) at baseline and 165.9±61.1 µm (range, 56.8-326.8 µm) at 6mo (P<0.001). In sectoral analysis, the mean PCT in each sector was significantly reduced in over 6mo in the BRVO-affected eyes (all P<0.001). In the non-affected contralateral eyes, the mean PCT was not significantly changed in any sector over the 6-month follow-up period (superior sector, P=0.143; temporal sector, P=0.825; inferior sector, P=0.192; and nasal sector, P=0.599). CONCLUSION: Sectoral analysis shows that the mean PCTs in all sectors are reduced significantly over 6mo in the BRVO-affected eyes, but not in the non-affected contralateral eyes.

Integration of triaxial testing and pore-scale visualization of methane hydrate bearing sediments.

Understanding mechanical interactions between hydrate and hosting sediments is critical for evaluating formation stability and associated environmental impacts of hydrate-bearing sediments during gas production. While core-scale studies of hydrate-bearing sediments are readily available and some explanations of observed results rely on pore-scale behavior of hydrate, actual pore-scale observations supporting the larger-scale phenomena are rarely available for hydrate-bearing sediments, especially with methane as guest molecules. The primary reasons for the scarcity include the challenge of developing tools for small-scale testing apparatus and pore-scale visualization capability. We present a testing assembly that combines pore-scale visualization and triaxial test capability of methane hydrate-bearing sediments. This testing assembly allows temperature regulation and independent control of four pressures: influent and effluent pore pressure, confining pressure, and axial pressure. Axial and lateral effective stresses can be applied independently to a 9.5 mm diameter and 19 mm long specimen while the pore pressure and temperature are controlled to maintain the stability of methane hydrate. The testing assembly also includes an X-ray transparent beryllium core holder so that 3D computed tomography scanning can be conducted during the triaxial loading. This testing assembly permits pore-scale exploration of hydrate-sediment interaction in addition to the traditional stress-strain relationship. Exemplary outcomes are presented to demonstrate applications of the testing assembly on geomechanical property estimations of methane-hydrate bearing sediments.

Transforaminal Epiduroscopic Basivertebral Nerve Laser Ablation for Chronic Low Back Pain Associated with Modic Changes: A Preliminary Open-Label Study.

Background: Chronic low back pain (CLBP) arising from degenerative disc disease continues to be a challenging clinical and diagnostic problem whether treated with nonsurgical, pain intervention, or motion-preserving stabilization and arthrodesis. Methods: Fourteen patients with CLBP, greater than 6 months, unresponsive to at least 4 months of conservative care were enrolled. All patients were treated successfully following screening using MRI findings of Modic type I or II changes and positive confirmatory provocative discography to determine the affected levels. All patients underwent ablation of the basivertebral nerve (BVN) using 1414 nm Nd:YAG laser-assisted energy guided in a transforaminal epiduroscopic approach. Macnab's criteria and visual analog scale (VAS) score were collected retrospectively at each follow-up interval. Results: The mean age was 46 ± 9.95 years. The mean symptoms duration was 21.21 ± 21.87 months. The mean follow-up was 15.3 ± 2.67 months. The preoperative VAS score of 7.79 ± 0.97 changed to 1.92 ± 1.38, postoperatively (P < 0.01). As per Macnab's criteria, seven patients (50%) had excellent, six patients (42.85%) had good, and one patient (7.14%) had fair outcomes. Conclusion: The transforaminal epiduroscopic basivertebral nerve laser ablation (TEBLA) appears to be a promising option in carefully selected patients with CLBP associated with the Modic changes.

Full Endoscopic Lumbar Discectomy using the Calcification Floating Technique for Symptomatic Partially Calcified Lumbar Herniated Nucleus Pulposus.

BACKGROUND: Partially calcified lumbar herniated nucleus pulposus (HNP) can cause severe radiating pain and neurologic symptoms requiring surgical treatment. As it is not safe to enforce conventional endoscopic lumbar discectomy using trephine or burr to remove the partially calcified disc, we report a calcification floating technique using a working channel for the treatment of these cases. METHODS: We retrospectively analyzed 31 patients who underwent full endoscopic discectomy using this technique for partially calcified lumbar HNP between April 2009 and June 2013. Calcification floating technique was performed by inserting the working channel around the partially calcified HNP and then rotating the working channel around it to remove the lesion. We analyzed the outcomes with a Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and complication rate. RESULTS: The mean follow-up period was 26.58 ± 11.2 months. The interlaminar approach was used in 15 cases, and the transforaminal approach was used in 16 cases. The mean VAS of 8.19 ± 0.65 before surgery was decreased to 1.29 ± 0.69 at the last follow-up. The mean ODI score before surgery was decreased at the last follow-up, from 41.32 ± 2.87 to 9.87 ± 3.47. Mean operative duration was 45 ± 12 minutes per level. None of the patients required revision surgery or developed any major complication. CONCLUSIONS: Calcification floating technique is a safe and effective method for the treatment of partially calcified lumbar HNP.

Percutaneous Endoscopic Interlaminar Unilateral Ventral Dural Approach for Symptomatic Bilateral L5-S1 Herniated Nucleus Pulposus: Technical Note.

BACKGROUND: Percutaneous endoscopic lumbar diskectomy is a good treatment modality for lumbar disk herniation. However, when a patient complains of bilateral lower limb radicular pain with severe disk protrusion at the L5-S1 level, the transforaminal approach is often unable to resolve both lesions owing to anatomical limitations. It is also very difficult to resolve both lesions in an ipsilateral direction using the percutaneous interlaminar approach. We report our surgical technique and clinical results using a ventral dural approach of percutaneous endoscopic interlaminar lumbar diskectomy for L5-S1 herniated nucleus pulposus (HNP) in patients with bilateral radiculopathy due to a severe disk protrusion. METHODS: Twenty-seven patients with severe L5-S1 HNP complaining of back pain and bilateral lower limb pain were included in the study. The unilateral ventral dural approach of percutaneous full endoscopic interlaminar lumbar diskectomy technique was used. The visual analog scale (VAS) and Macnab criteria were used for clinical evaluation. All assessments were completed 1 day before surgery, 1 week after surgery, 6 months after surgery, and at final follow-up after surgery. RESULTS: The mean preoperative back and leg pain VAS scores decreased from 5.67 ± 0.78 and 7.81 ± 0.83 to 2.44 ± 0.58 and 2.26 ± 0.53 at 1 week, 1.78 ± 0.51 and 1.52 ± 0.58 at 6 months, and 1.56 ± 0.70 and 1.67 ± 0.96, respectively, at the final follow-up after surgery. With respect to the Macnab criteria, 51.85% of the results were excellent, 44.44% were good, and 3.70% were fair. Four cases recurred: three patients underwent conservative treatment and one patient operated with percutaneous endoscopic interlaminar lumbar diskectomy. CONCLUSION: According to the results of this study, the ventral dural approach of percutaneous full endoscopic interlaminar lumbar diskectomy in patients with L5-S1 HNP associated with bilateral lower limb pain due to a severely protruded HNP is a good option for a minimally invasive surgical approach.

Suprapedicular Circumferential Opening Technique of Percutaneous Endoscopic Transforaminal Lumbar Discectomy for High Grade Inferiorly Migrated Lumbar Disc Herniation.

PURPOSE: To evaluate the efficacy of suprapedicular circumferential opening technique (SCOT) of percutaneous endoscopic transforaminal lumbar discectomy (PETLD) for high grade inferiorly migrated lumbar disc herniation. MATERIAL AND METHODS: Eighteen consecutive patients who presented with back and leg pain with a single-level high grade inferiorly migrated lumbar disc herniation were included. High grade inferiorly migrated disc was removed by the SCOT through PETLD approach. Outcome evaluation was done with visual analog scale (VAS) and Mac Nab's criteria. RESULT: There were 14 males and 4 females. The mean age of patients was 53.3 ± 14.12 years. One, 4, and 13 patients had disc herniation at L1-2, L3-4, and L4-5 levels, respectively, on MRI, which correlated with clinical findings. The mean follow-up duration was 8.4 ± 4.31 months. According to Mac Nab's criteria, 9 patients (50%) reported excellent and the remaining 9 patients (50%) reported good outcomes. The mean preoperative and postoperative VAS for leg pain were 7.36 ± 0.73 and 1.45 ± 0.60, respectively (p < 0.001). Improvement in outcomes was maintained even at final follow-up. There was no complication. CONCLUSION: In this preliminary study we achieved good to excellent clinical results using the SCOT of PETLD for high grade inferiorly migrated lumbar disc herniation.

SIGNIFICANT REDUCTION OF PERIPAPILLARY CHOROIDAL THICKNESS IN PATIENTS WITH UNILATERAL BRANCH RETINAL VEIN OCCLUSION.

PURPOSE: To evaluate changes in peripapillary choroidal thickness in patients with branch retinal vein occlusion (BRVO) over 12 months, using spectral-domain optical coherence tomography with enhanced depth imaging. METHODS: This retrospective, interventional case series included 20 treatment-naive patients with unilateral BRVO with at least 12 months follow-up. The peripapillary choroidal thickness was measured over 12 months. RESULTS: In BRVO-affected eyes, the mean peripapillary choroidal thickness was 213.5 ± 51.7 µm (126.1[FIGURE DASH]326.9 µm) at baseline and 129.6 ± 39.3 µm (65.9[FIGURE DASH]197.1 µm) at 12 months. In nonaffected contralateral eyes, the mean peripapillary choroidal thickness was 194.1 ± 39.8 µm (158.5[FIGURE DASH]238.3 µm) at baseline and 156.6 ± 56.2 µm (125.9[FIGURE DASH]213.9 µm) at 12 months. The mean peripapillary choroidal thickness decreased significantly over 12 months in both BRVO-affected and nonaffected eyes (P < 0.001, both eyes). Although the mean peripapillary choroidal thickness was not significantly different between groups at baseline (P = 0.472), it was significantly lower in BRVO-affected eyes than in nonaffected eyes at 12 months (P = 0.036). CONCLUSION: Peripapillary choroidal thickness decreased significantly over 12 months in BRVO-affected eyes and nonaffected eyes in patients with unilateral BRVO.

SIGNIFICANT REDUCTION OF BOTH PERIPAPILLARY AND SUBFOVEAL CHOROIDAL THICKNESS AFTER PANRETINAL PHOTOCOAGULATION IN PATIENTS WITH TYPE 2 DIABETES.

PURPOSE: To evaluate changes in peripapillary choroidal thickness (PCT) and subfoveal choroidal thickness (SFCT) after panretinal photocoagulation (PRP) for diabetic retinopathy. METHODS: This retrospective interventional study included 59 treatment-naive eyes of 33 patients who underwent PRP and completed ≥12 months of follow-up. Peripapillary choroidal thickness and SFCT were measured at baseline and 1, 3, 6, and 12 months post-PRP. Differences between baseline and 12 months (ΔSFCT and ΔPCT) and percentage changes (ΔSFCT or ΔPCT/baseline × 100%) were determined. RESULTS: Mean SFCT was 287.7 ± 76.7 µm (139.0-469.0 µm) at baseline and 225.8 ± 62.0 µm (102.5-379.5 µm) 12 months post-PRP (P < 0.001). Mean PCT was 161.2 ± 16.5 µm (75.3-308.1 µm) at baseline and 128.4 ± 41.8 µm (73.0-212.9 µm) 12 months post-PRP (P < 0.001). ΔSFCT was -61.3 ± 28.7 µm (-139.5 to -17.0 µm), and %SFCT was 21.2 ± 7.2% (6.8% to 36.1%). ΔPCT was -36.4 ± 23.2 µm (-149.1 to 5.4 µm), and %PCT was 22.4 ± 12.0% (2.5% to 62.6%). Diabetic retinopathy severity was the only factor significantly correlated with %SFCT (ß = 0.500, P = 0.004) and %PCT (ß = 0.152, P = 0.024). CONCLUSION: Both PCT and SFCT reduced significantly after PRP. Diabetic retinopathy severity was significantly correlated with post-PRP changes of peripapillary and SFCT.

Functional Limitations Due to Stiffness After Long-Level Spinal Instrumented Fusion Surgery to Correct Lumbar Degenerative Flat Back.

STUDY DESIGN: A retrospective analysis of functional limitations due to stiffness after long-level spinal instrumented fusion surgery to correct lumbar degenerative flat back was performed. OBJECTIVE: To analysis the functional limitations in patients treated surgically for adult lumbar degenerative flat back (ALDFB) with long-level instrumented fusion to the sacrum or pelvis. SUMMARY OF BACKGROUND DATA: Long-level instrumented fusion for ALDFB decreases back pain and spinal deformity. On the contrary, this surgery considerably eliminates spinal range of motion. This may have the potential to impair function and ability to perform activities of daily living (ADLs). METHODS: Consecutive 44 patients who underwent long-level instrumented fusion to the sacrum or pelvis for ALDFB were retrospectively included in this study. All patients were followed up for a minimum of 13 months. The Lumbar Stiffness Disability Index for Korean Lifestyle and Oswestry Disability Index were administered and analyzed to assess the impact of spinal stiffness on daily living. Cohorts were defined based on the upper instrumented vertebrae (above T10 [group 1] or below L1 [group 2]) and lower instrumented vertebrae (S1 pedicle screw [group S] or iliac bolt screw [group I]). RESULTS: All patients showed deteriorated postoperative ADLs compared to preoperative values. Group 1 showed deterioration postoperatively compared to group 2. Group 1 showed deteriorated postoperative ADLs compared to preoperative values. In group 2, question 5 and 7 showed deterioration postoperatively compared to preoperative values, and question 2 and 10 showed improvement postoperatively compared to preoperative values. Group I showed deterioration postoperatively compared to group S. CONCLUSION: This study will hopefully allow surgeons to provide patients with ALDFB with a more informed explanation of expected surgery effects on specific ADLs. LEVEL OF EVIDENCE: 3.

Lumbar chronic subdural hematoma mimicking an intradural extramedullary tumor: A case report.

BACKGROUND: Chronic spinal subdural hematomas are extremely rare with only 28 cases reported in the literature. Nevertheless, they should be considered among the differential diagnoses for spinal intradural/extramedullary lesions. CASE REPORT: A 65-year-old male presented with progressive back pain and right S1 radiculopathy. Magnetic resonance imaging scan revealed a right-sided posterolateral intradural/extramedullary lesion at the L5-S1 level. It was hyperintense on T1 and hypointense on T2-weighted images; on the short TI inversion recovery sequence it was hyperintense. The lesion was excised through a right L5 hemilaminectomy, and the patient was neurologically intact postoperatively. Histopathology revealed a chronic subdural hematoma. CONCLUSION: Chronic spinal subdural hematoma can mimic intradural extramedullary spinal tumors even in the absence of trauma and/or coagulopathies.

Intraoperatively Observed Lacrimal Obstructive Features and Surgical Outcomes in External Dacryocystorhinostomy.

PURPOSE: To analyze the features of lacrimal drainage system obstruction confirmed during external dacryocystorhinostomy surgeries and report the surgical outcomes. METHODS: We reviewed the medical records of a total of 769 cases who underwent external dacryocystorhinostomy for primary lacrimal drainage obstruction between 2005 and 2014. Data about detailed location and extent of obstruction were collected intraoperatively. The sites of obstruction were classified into nasolacrimal duct obstruction (NLDO), common canalicular obstruction (CCO), and canalicular obstruction. Lacrimal sac mucosa and lumen were grossly inspected, and the frequency of lacrimal sac changes, such as significant inflammation or fibrosis, was analyzed in cases of CCO or canalicular obstruction. The surgical success rate was also evaluated including effect of lacrimal sac status in the CCO and canalicular obstruction groups. RESULTS: Of 769 cases, primary NLDO with patent canaliculi was diagnosed intraoperatively in 432 cases (56.2%), CCO in 253 (32.9%), and canalicular obstruction in 84 (10.9%). Of 253 cases with CCO, 122 (48.2%) showed clear lacrimal sac lumen, and the other 131 (51.8%) showed significant inflammation or fibrosis of the lacrimal sac. In cases with canalicular obstruction, 35 of 84 (41.7%) showed a clear lacrimal sac, and the other 49 cases (58.3%) cases revealed mucosal changes of the lacrimal sac. The functional success rate was 87.5% for primary NLDO, 75.5% for CCO, and 72.6% for canalicular obstruction. In the CCO group, the functional success rate was lower in cases with significant lacrimal sac change (p = 0.044). CONCLUSIONS: Even in patients with CCO or canalicular obstruction, a large number of cases have lacrimal sac changes, and those changes were associated with lower functional success rate.