Ex-PRESS shunt combined with ab-interno peripheral iridectomy: A new surgical procedure for iridocorneal endothelial syndrome

Purpose

Iridocorneal endothelial (ICE) syndrome may cause refractory glaucoma due to progressive synechial closure or membrane formation at the anterior chamber angle. Filtration surgeries are often required but are associated with a higher rate of surgical failure or complications than other types of glaucoma. Herein, we report a new and effective surgical procedure for glaucoma secondary to ICE syndrome: Ex-PRESS shunt combined with ab-interno peripheral iridectomy using a small-gauge vitreous cutter.

Methods

Three patients with ICE syndrome who underwent surgery were included. Intraoperatively, an ab-interno peripheral iridectomy was performed using a small-gauge vitreous cutter through a corneal incision in the superior-nasal or superior-temporal quadrants to create space for the insertion of Ex-PRESS shunt free from the iris tissue. The shunt was inserted under the scleral flap. The first patient underwent combined cataract surgery, whereas patients 2 (pseudophakia) and 3 (phakia) underwent Ex-PRESS alone.

Results

No intraoperative complications were observed. The intraocular pressure remained stable until the final postoperative visits at approximately 7, 4, and 1 year in Cases 1, 2, and 3, respectively. Case 2, with mild preoperative corneal edema due to graft failure in Descemet's stripping automated endothelial keratoplasty (DSAEK), underwent reDSAEK 6 months postoperatively.

Conclusions and importance

Ex-PRESS shunt combined with ab-interno peripheral iridectomy using a small-gauge vitreous cutter may be a safe and effective surgical procedure in patients with ICE syndrome, regardless of the lens status.

Comparing Surgical Outcomes in Neovascular Glaucoma between Tube and Trabeculectomy: A Multicenter Study

OBJECTIVE

To compare the surgical outcomes between Baerveldt glaucoma implant (BGI) surgery and trabeculectomy with mitomycin C for patients with neovascular glaucoma (NVG).

DESIGN

Retrospective clinical cohort study at 5 clinical centers in Japan.

PARTICIPANTS

Patients treated with trabeculectomy or BGI for NVG between April 1, 2012, and December 31, 2019, at 5 clinical centers were recruited.

METHODS

The inclusion criteria were age ≥ 20 years and having NVG. The exclusion criteria were eyes with no light perception vision and with previous tube-shunt surgery. If both eyes in the same patient satisfied the inclusion criteria, the eye that was treated first was investigated. We included 100 eyes undergoing BGI surgery and 204 eyes undergoing trabeculectomy.

MAIN OUTCOME MEASURES

The primary outcome was surgical success or failure, with failure being defined according to 3 criteria: < 20% reduction of the preoperative intraocular pressure (IOP) or criterion A (IOP > 21 mmHg), criterion B (IOP > 17 mmHg), or criterion C (IOP > 14 mmHg). Cases of reoperation, a loss of light perception vision, or hypotony were also considered failures.

RESULTS

The probability of success was significantly higher in patients undergoing BGI surgery than in those receiving trabeculectomy for criteria A (P < 0.01) and B (P = 0.01). Trabeculectomy was significantly associated with surgical failure in the multivariable analysis for criterion A (hazard ratio, 1.70) and criterion B (hazard ratio, 1.50). The overall incidence of postoperative complications was similar between the 2 groups. Reoperations for glaucoma were required significantly more frequently in the trabeculectomy group than in the BGI surgery group (20.1 % vs. 5.0%; P < 0.01).

CONCLUSIONS

Baerveldt glaucoma implant surgery had a higher success rate compared with trabeculectomy in patients with NVG for a target IOP < 21 mmHg or < 17 mmHg. The rates of postoperative complications were similar between both surgical procedures. Additional glaucoma surgery was required more frequently after trabeculectomy than after BGI surgery.

Predicting Lifetime Transition Risk of Severe Visual Field Defects Using Monte Carlo Simulation in Japanese Patients with Primary Open-Angle Glaucoma

Purpose

To maintain visual fields and quality of life over a lifetime, medical practice must be conducted taking into consideration not only visual field progression but also future visual field changes that occur over the patients’ expected lifespan. The purpose of this study is to investigate the feasibility of establishing a model that predicts prognosis, estimating the proportion of glaucoma patients with severe visual field defects.

Patients and Methods

The data of 191 patients with primary open-angle glaucoma, with a predominance of normal-tension glaucoma, were used for this study. The model was developed based on patients’ backgrounds and risk factors, using Monte Carlo simulation. A “severe visual field defect” was defined as ≤-20 dB. The mean deviation (MD) value for 10,000 virtual patients in each simulation pattern (144 patterns) was calculated using a predictive formula to estimate the MD slope, and the effects of risk factors and intraocular pressure (IOP) reduction on the proportion of patients with severe visual field defects were evaluated.

Results

Younger age, later-stage disease, more severe glaucomatous structural abnormalities and the presence of disc hemorrhage were associated with an increase in the progression rate of patients with severe visual field defects. Conversely, lower IOP was associated with a decrease in this rate.

Conclusion

Combining regression analysis with Monte Carlo simulation could be a useful method for developing predictive models of prognosis in glaucoma patients.

The Effect of Brimonidine 0.1% on Disc Hemorrhage in Primary Open-Angle Glaucoma Patients

Background

This retrospective study evaluated the effect of adjunctive administration of brimonidine 0.1% on disc hemorrhage (DH) in patients with primary open-angle glaucoma or normal-tension glaucoma who were already treated with other anti-glaucoma drugs.

Methods

Patients with DH, before adjunctive therapy with brimonidine, were enrolled. Subjects were excluded if their treatment regimen was changed within 1 year after initiation of adjunctive therapy with brimonidine. We investigated the frequency of DH and intraocular pressure (IOP). Both parameters were compared before and after adjunctive administration of brimonidine.

Results

The frequency of DH before and after brimonidine administration was 0.67±0.68 and 0.31±0.72 times/year, respectively, with a significant decrease (P=0.01), and the mean IOP before and after brimonidine administration was 12.5±1.9 and 11.2±2.2 mmHg, respectively, (P=0.0006) with a significant reduction after adjunctive administration.

Conclusion

The results of this study supported the hypothesis that the frequency of DH is reduced by brimonidine alongside lowering of IOP.

Is high myopia a risk factor for visual field progression or disk hemorrhage in primary open-angle glaucoma?

Purpose

The purpose of this study was to clarify differences between highly myopic and non-myopic primary open-angle glaucoma (POAG) patients, including normal-tension glaucoma patients.

Patients and methods

A total of 269 POAG patients were divided into two groups: patients with ≥26.5 mm of axial length (highly myopic group) and patients with <24.0 mm of axial length (non-myopic group).

Results

We analyzed 53 highly myopic and 93 non-myopic POAG patients. Age at first visit of the highly myopic group was significantly less than that of the non-myopic group (P<0.0001). Baseline intraocular pressures (IOPs) showed no significant differences. Follow-up IOPs of the non-myopic group were significantly lower than those of the highly myopic group (P=0.0009). According to the mean deviation definition of progression, the cumulative probability of non-progression of visual field (VF) loss was significantly greater in the highly myopic group (10-year survival rate, 73.7%±6.8%) than in the non-myopic group (10-year survival rate, 46.3%±5.8%; log-rank test, P=0.0142). The occurrence of disk hemorrhage (DH) in the non-myopic group (1.60±3.04) was significantly greater than that in the highly myopic group (0.93±2.13, P=0.0311). The cumulative probability of DH was significantly lower in the highly myopic group (10-year survival rate, 26.4%±5.4%) than in the non-myopic group (10-year survival rate, 47.2%±6.6%, P=0.0413).

Conclusion

Highly myopic POAG is considered as a combination of myopic optic neuropathy and glaucomatous optic neuropathy (GON). If GON is predominant, it has frequent DH and more progressive VF loss. However, when the myopic optic neuropathy is predominant, it has less DH and less progressive VF loss.

Neural retinal contribution to the slow negative potential of the canine electroretinogram

To establish the normal waveform of the electrical responses from canine eyes, electroretinograms and the light peak were recorded in hybrid and beagle dogs under general anesthesia and artificial ventilation. The neural retinal and retinal pigment epithelial components were pharmacologically isolated by intravitreal glutamate injection and systemic sodium iodate administration, respectively. The a- and b-waves elicited by either flash or rectangular stimuli, the oscillatory potentials elicited by flash stimuli and the light peak elicited either by a single maintained illumination or by repetitive stimuli were almost identical with those of other vertebrates thus far studied. In contrast, in response to rectangular (several-second duration) stimuli, the c-wave was usually absent and was replaced by a slow cornea-negative potential that had a time course similar to that of the c-wave in other species. This slow negative potential was elicited at such low stimulus intensities that the a-wave was absent, was deepened by an intravenous administration of sodium iodate, was not affected by an intravitreal injection of sodium glutamate and was shallowed during the light peak. These results suggest that the slow negative potential that replaces the c-wave consists of large slow PIII, small retinal pigment epithelial c-wave and negligible contribution from the late photoreceptor potential and the dc component of the PII.

Spatial tuning loss of pattern reversal visual evoked response in optic nerve disease

We compared the pattern reversal visual evoked response (PVER) amplitude-check size functions from 25 eyes (25 normal subjects; visual acuities > or = 20/20) with those from 32 eyes (22 patients; visual acuities 20/15 to 20/50; mean, 20/25.5) with mild optic nerve disease to determine if spatial tuning loss of the PVER occurs in the presence of optic nerve dysfunction. The steady-state PVER was recorded with five check sizes (range, 160 to 10 minutes of arc). To analyze the PVER amplitude-check size function, we calculated the difference between the maximum and minimum PVER amplitudes and then calculated the area of spatial tuning (the area under the function). Values were significantly smaller in patients than in normal subjects (1.81 +/- 1.27 microV versus 5.73 +/- 3.27 microV; F = 41.24, p = 0.0001; 3.87 +/- 2.70 area units versus 12.57 +/- 7.60 area units; F = 38.62, p = 0.0001). There was no shift in the distribution of peak check sizes. Results suggest that a spatial tuning loss occurs in optic nerve disease. The shape of the function, including the area of spatial tuning, appears to be a sensitive indicator of early or mild optic nerve dysfunction.

Spatial frequency sweep pattern reversal VER acuity vs Snellen visual acuity: effect of optical defocus

The effect of artificially induced image defocusing on visual acuities (VAs) measured by spatial frequency sweep pattern reversal visual evoked response (SPVER) and Snellen measurement was studied in six normal subjects. The steady-state SPVER was recorded using vertical gratings of 10 different spatial frequencies ranging from 0.52 to 30.36 c/deg. The SPVER acuity was compared with Snellen acuity (SA) measured under the same conditions of optical defocus. With moderate defocusing [< + 1.0 diopter (D), VA > 20/40], the SPVER acuities were equal to or poorer than the SAs. With more defocus (> + 1.5 D, VA < 20/70), the SPVER acuities became better than the SAs. The discrepancies between the SA and SPVER acuities may be the result of the influence of the parafoveal area on the SPVER at lower visual acuity levels.

Pattern-reversal visual-evoked response in bull's eye maculopathy associated with Stargardt's disease

Using steady-state pattern-reversal visual-evoked response (PVER), we studied the macular function in patients with bull's eye maculopathy. The results were correlated with fluorescein angiography. Study patients with an established (25 eyes of 14 patients) and a suspected (8 eyes of 4 patients) diagnosis of Stargardt's disease with bull's eye maculopathy were divided into group G (good vision group: 15 eyes with visual acuity of 20/40 or better) and group P (poor vision group: 18 eyes with visual acuity of 20/50 or worse). The diameters of the atrophic area and the normal or less affected central area of the bull's eye were measured form the fluorescein angiograms. The mean diameter of the central area in group G (2.0 degrees) was significantly larger than that in group P (0.6 degrees; d.f. = 17, p = 0.0227). The PVER amplitudes were reduced in the patient groups with all check sizes and the amplitude-check size functions were flat. Amplitude differences were observed between the patient groups with the 20' checks (d.f. = 17, p = 0.0638), probably due to the difference in the mean central diameters (2.0 degrees vs. 0.6 degrees). Patients with a perifoveal abnormality can have an abnormal PVER despite relatively good visual acuity. We also recorded the PVER in 7 normal controls tested with simulated ring-shaped scotomas, the sizes of which matched the mean diameters of the scotomas in the patient groups (7.0 degrees x 0.6 degrees and 7.0 degrees x 2.0 degrees). The controls also showed markedly reduced responses with all check sizes.(ABSTRACT TRUNCATED AT 250 WORDS)

Stargardt's disease/fundus flavimaculatus: psychophysical and electrophysiologic results

Retinal functions were analyzed psychophysically and electrophysiologically in 73 patients (146 eyes) with Stargardt's disease/fundus flavimaculatus. Patients were classified into types 1, 2, 3, and 4; patients with type 3 were subdivided into 3E and 3L (early and late onset of initial symptoms). Most had visual acuity (VA) of 20/200 or greater at initial testing. VA declined 0.25 octave/year during follow-up (mean, 6.1 years). Four of 16 patients (25%) older than 40 years had VA of 20/200 or less in the stronger eye. Psychophysical tests (flicker profile, central scotoma, dark adaptation) showed variable degrees of abnormalities. Electrophysiological tests showed significant photopic b-wave amplitude decreases, particularly in type 3E (42.2% of normal). The electro-oculogram light peak/dark trough ratio was abnormal in 60 of 132 eyes (45.5%), especially in type 3E (25 of 34 eyes, 73.5%). Visual prognosis and overall visual function varied depending upon disease type, location of retinal lesions, and age of onset. In Type 3E, overall retinal function was poorest and accompanied by the most severe decline of central vision and function in the surrounding macula.

Correlating visual acuity and electrooculogram recordings in Best's disease

The visual function in 54 eyes of 27 patients with Best's disease was analyzed by retrospectively examining the Snellen visual acuities and the electrooculogram (EOG). Visual acuities, generally well maintained in most patients, were 20/40 (0.5) or better in 41 of 54 (75.9%) eyes, and showed no correlation with age. Those in the cicatricial stage had worse visual acuities than those in the previtelliform stage. The EOG was abnormal in 47 eyes (87.0%) with a subnormal light peak/dark trough (Lp/Dt) ratio less than 1.85. Seven eyes (13.0%) with an Lp/Dt ratio 1.85 or higher had significantly smaller Dt values compared with those with a low Lp/Dt ratio. The Lp/Dt ratio did not correlate with patient age or disease stage. No correlation existed between visual acuities and Lp/Dt ratios. The Lp/Dt ratio did not reflect the severity of the macular lesions. The results indicate that not only a low Lp/Dt ratio but also a low dark trough value in cases with a normal Lp/Dt ratio are helpful in diagnosing Best's disease.