Introduction: The orbital subarachnoid space surrounding the optic nerve is continuous with the circulation system for cerebrospinal fluid (CSF) and can be visualized by using magnetic resonance imaging (MRI). We hypothesized that the orbital subarachnoid space width (OSASW) is correlated with and can serve as a surrogate for intracranial pressure (ICP). Our aim was to develop a method for a noninvasive measurement of the intracranial CSF-pressure (CSF-P) based on MRI-assisted OSASW. Methods: The prospective observational comparative study included neurology patients who underwent lumbar CSF-P measurement and 3.0-Tesla orbital magnetic resonance imaging (MRI) for other clinical reasons. The width of the orbital subarachnoid space (OSASW) around the optic nerve was measured with MRI at 3, 9, and 15 mm behind the globe. The study population was randomly divided into a training group and a test group. After adjusting for body mass index (BMI) and mean arterial blood pressure (MABP), algorithms for the associations between CSF-P and OSASW were calculated in the training group. The algorithms were subsequently verified in the test group. Main outcome measures were the width of the orbital subarachnoid space (OSASW) and the lumbar cerebrospinal fluid pressure (CSF-P). Results: Seventy-two patients were included in the study. In the training group, the algorithms for the associations between CSF-P and OSASW were as follows: (a) CSF-P = 9.31 × OSASW (at 3 mm) + 0.48 × BMI + 0.14 × MABP-19.94; (b) CSF-P = 16.95 × OSASW (at 9 mm) + 0.39 × BMI + 0.14 × MABP-20.90; and (c) CSF-P = 17.54 × OSASW (at 15 mm) + 0.47 × BMI + 0.13 × MABP-21.52. Applying these algorithms in the independent test group, the measured lumbar CSF-P (13.6 ± 5.1 mm Hg) did not differ significantly from the calculated MRI-derived CSF-P (OSASW at 3 mm: 12.7 ± 4.2 mm Hg (P = 0.07); at 9 mm: 13.4 ± 5.1 mm Hg (P = 0.35); and at 15 mm: 14.0 ± 4.9 mm Hg (P = 0.87)). Intraclass correlation coefficients (ICCs) were higher for the CSF-P assessment based on OSASW at 9 mm and at 15 mm behind the globe (all ICCs, 0.87) than for OSASW measurements at 3 mm (ICC, 0.80). Conclusions: In patients with normal, moderately decreased or elevated ICP, MRI-assisted measurement of the OSASW appears to be useful for the noninvasive quantitative estimation of ICP, if BMI and MABP as contributing parameters are taken into account. Trial registration: Clinical trial registered with the Chinese Clinical Trial Registry: ChiCTR-OCC-11001271

The rising global prevalence of myopia is a growing concern for clinicians, as it predisposes patients to severe ocular pathologies including glaucoma. High myopia can be associated with clinical features that resemble glaucomatous damage, which make an accurate glaucoma diagnosis challenging, particularly among patients with normal intraocular pressures. These patients may also present with established visual field defects which can mimic glaucoma, and standard imaging technology is less useful in disease detection and monitoring due to the lack of normative data for these anatomically unique eyes. Progression over time remains the most critical factor in facilitating the detection of early glaucomatous changes, and thus careful longitudinal follow-up of high-risk myopic patients is the most important aspect of management. Here, we review our current understanding of the complex relationship between myopia and glaucoma, and the diagnostic challenges and limitations of current testing protocols including visual field, intraocular pressure, and imaging. Furthermore, we discuss the clinical findings of two highly myopic patients with suspected glaucoma.

To identify risk factors for surgical failure after gonioscopy-assisted transluminal trabeculotomy (GATT) in juvenile open-angle glaucoma (JOAG). Prospective, interventional case series. GATT was the initial surgery in 70 eyes of 70 patients with JOAG. Surgical success was defined as a postoperative intraocular pressure (IOP) of ≤21 mm Hg with at least a 20% reduction from preoperative IOP, with or without the use of antiglaucoma medication (qualified and complete success, respectively) at each postoperative visit. IOP spike was defined as IOP >30 mm Hg and an increase of at least 10 mm Hg from IOP before the spike, and then reduced to ≤21 mm Hg. The median age at the time of surgery was 19.3 years (range, 4.9-37.5 years) with a visual field mean deviation of -17.4 ± 10.6 dB. Mean IOP decreased from 31.3 ± 9.5 mm Hg preoperatively to 15.8 ± 2.7 at 12 months postoperatively. The complete and qualified success rates were 74.3% and 91.4%, respectively. An IOP spike occurred in 52 eyes (74%), with a median spike duration of 3.5 days (range, 1-21 days). Longer duration of IOP spike (P = .009) and older age at the time of surgery (P = .025) were both associated with worse surgical outcomes. Advanced disease was associated with prolonged IOP spike (P = .007). GATT provided excellent outcomes in patients with severe JOAG. Older age and longer duration of postoperative IOP spike are risk factors for failure. Severe cases are more likely to have longer durations of IOP spike. Frequent IOP monitoring during the early postoperative period is needed to detect IOP spikes in these patients.

AIM: To evaluate the ability of macular ganglion cell complex (GCC) thickness using Fourier domain optical coherence tomography (FD-OCT) to detect glaucoma in highly myopic eyes. METHODS: Cross-sectional study. A total of 114 participants, consecutively were enrolled. Macular GCC thickness and peripapillary retinal nerve fiber layer (RNFL) thickness were obtained with RTVue FD-OCT. Receiver operating characteristics curves were constructed for each measurement parameter, and areas under the curves (AUCs) were compared. RESULTS: Both the average GCC and average RNFL thickness showed negative correlations with axial length (rGCC=-0.404, P= 0.001; rRNFL=-0.561, P< 0.001). The largest AUCs from GCC, and RNFL parameters were 0.968 [global loss volume (GLV)], and 0.855 (average RNFL), respectively. GLV was significantly better for detecting high myopic glaucoma than average RNFL (P< 0.001). CONCLUSION: Macular GCC thickness has higher diagnostic power than peripapillary RNFL thickness to discriminate glaucoma patients from non-glaucoma subjects in high myopia.

To provide in vivo measurements of anterior chamber angle structures and their relationship with age as evaluated by high-frequency ultrasound biomicroscopy (UBM) in patients with primary congenital glaucoma (PCG) High-frequency UBM was done for 51 PCG eyes from 40 patients (aged from 3 to 96 months) and 11 unaffected contralateral eyes. Parameters, including the proportion of observable abnormal tissue membrane and Schlemm’s canal, the largest cross-sectional area (CSA) of Schlemm’s canal (SC), SC meridional diameter, trabecular-iris angle (TIA), trabecular meshwork (TM) thickness, iris thickness, ciliary process length, and corneal limbus thickness were compared between the two groups and their relationship with age was explored in PCG eyes. Abnormal tissue membrane was detected in 27.5% of PCG eyes and none in unaffected eyes. SC was observed in 73.1% of PGC eyes compared to 100% in unaffected eyes (P<0.001). The largest CSA of SC, SC meridional diameter, iris thickness, and corneal limbus thickness were all significantly smaller in PCG eyes compared to unaffected eyes (all P<0.05). TIA and ciliary process length in unaffected eyes were smaller than PCG eyes (both P<0.05). The largest CSA of SC, TM thickness, iris thickness, and ciliary process length were all significantly correlated to age in PCG eyes (P<0.05). The anatomical information evaluated by high-frequency UBM may provide glaucoma specialists a useful tool to aid in understanding the dysgenesis and changes with age of anterior chamber angle in PCG.

Background: To evaluate the safety and efficacy of gonioscopy-assisted transluminal trabeculotomy (GATT) in treating patients with open-angle glaucoma (OAG) who had failed prior incisional glaucoma surgery. Methods: A consecutive case series of OAG patients aged ≥ 18 who underwent GATT with previous failed glaucoma incision surgery was retrospectively analyzed. Main outcome measures included intraocular pressure (IOP), the number of glaucoma medications, surgical success rate, and occurrence of complications. Success was defined as an IOP of ≤ 21 mmHg and a reduction of IOP by 20% or more from baseline with (qualified success) or without (complete success) glaucoma medications. For eyes with preoperative IOP of < 21 mmHg on 3 or 4 glaucoma medications, postoperative IOP of ≤ 18 mmHg without any glaucoma medications was also defined as complete success. Results: Forty-four eyes of 35 patients (21 with juvenile-onset open-angle glaucoma and 14 with adult-onset primary open-angle glaucoma) with a median age of 38 years were included in this study. The proportion of eyes with 1 prior incisional glaucoma surgery was 79.5%, and the others had 2 prior surgeries. IOP decreased from 27.4 ± 8.8 mm Hg on 3.6 ± 0.7 medications preoperatively to 15.3 ± 2.7 mm Hg on 0.5 ± 0.9 medications at the 24-month visit (P < 0.001). The mean IOP and the number of glaucoma medications at each follow-up visit were lower than the baseline (all P < 0.001). At 24 months postoperatively, 82.1% of the eyes had IOP ≤ 18 mmHg (versus 15.9% preoperatively, P < 0.001), 56.4% reached IOP ≤ 15 mmHg (versus 4.6% preoperatively, P < 0.001), and 15.4% achieved IOP ≤ 12 mmHg (compared to none preoperatively, P = 0.009). While 95.5% of eyes took 3 or more medications preoperatively, 66.7% did not take glaucoma medication 24 months after GATT. Thirty-four (77.3%) eyes achieved IOP reduction greater than 20% on fewer medications. The complete and qualified success rates were 60.9% and 84.1%, respectively. No vision-threatening complications occurred. Conclusions: GATT was safe and effective in treating refractory OAG patients who failed prior incisional glaucoma surgery.