Fluctuation of Intraocular Pressure and Vascular Factors Are Associated With the Development of Epiretinal Membrane in Glaucoma

The spectrum of microcystic macular edema: Pathogenetic insights, clinical entities, and functional prognosis

Microcystic macular edema (MME) is the presence of small cystoid abnormalities localized in the inner nuclear layer of the retina. First identified in the context of multiple sclerosis, successive reports highlighted the presence of microcystic changes in several optic nerve conditions, such as neuromyelitis optica, optic atrophy from several etiologies, medical retinal diseases such as age-related macular degeneration and diabetic retinopathy, and in the postoperative period after epiretinal membrane peeling. Generally, these cysts are not associated with vascular leakage, unlike the more conventional types of macular edema from vascular origin. A number of theories have been proposed to explain these findings: the suspect of neuronal loss as causative finding made the hypothesis of retrograde trans-synaptic degeneration likely, more recently flanked by theories including the presence of vitreomacular traction and Müller cells dysfunction. We gather all the insights regarding the pathogenesis, epidemiology and functional impact of MME.

Premacular membranes and glaucoma: a review of clinical and therapeutic considerations

PURPOSE

Primary epiretinal, or more precisely termed pre macular membranes (PMM) and glaucomatous optic neuropathy are both common conditions affecting a predominantly elderly population. There are several relevant clinical and pathological considerations when they are both diagnosed in the same eye.

METHODS

We systematically searched the literature to review the challenges clinicians must address when dealing with patients with co-existing PMM and glaucoma.

RESULTS

Although the current literature is limited there appears to be a link between the occurrence of glaucomatous optic neuropathy and idiopathic PMM. The presence of PMM can confound glaucomatous progression detection on optical coherence tomography (OCT). Vitrectomy and membrane peeling may improve vision in some patients with co-existing disease but there may be an increased risk of glaucoma progression particularly in eyes with advanced glaucoma and more extensive neuronal loss. Peeling of the retinal inner limiting membrane in addition to PMM peeling may result in an increased risk of visual loss. Inner nuclear layer hypo-reflective spaces on OCT are particularly prevalent in eyes with glaucoma and PMM and may be a negative prognostic sign for outcome.

CONCLUSION

Patients should be counseled regarding the guarded prognosis, and careful consideration given to the benefits of PMM surgery. Further research is needed to guide clinical practice.

VISUAL ACUITY LOSS AFTER VITRECTOMY FOR EPIRETINAL MEMBRANE IN EYES WITH GLAUCOMA

PURPOSE

To investigate the incidence and predictors of visual acuity loss after surgery for epiretinal membrane in glaucomatous eyes.

METHODS

A prospective cohort study examining visual acuity and central visual fields (VFs, Humphrey 10-2) at baseline and 3, 6, and 12 months after vitrectomy with internal limiting membrane peeling for epiretinal membrane in the glaucoma (47 eyes of 43 patients) and control (46 eyes of 46 patients) groups. Visual acuity and VF tests were repeated for ≥1.5 years only for the glaucoma group. Factors associated with substantial visual acuity loss (>0.2 logarithm of the minimal angle of resolution [approximately >2 lines on the Snellen chart] from baseline) were determined using a Cox proportional hazards model.

RESULTS

Until 1 year postoperatively, no substantial visual acuity loss occurred and postoperative visual acuity improved significantly and similarly in both groups ( P < 0.001 vs. baseline, P > 0.15 between 2 groups). Substantial visual acuity loss occurred in 8 eyes (17%) with glaucoma ≥1.5 years postoperatively, which was associated with worse preoperative VF mean deviation and 1-year mean decrease in postoperative VF mean deviation (hazard ratio = 0.83-0.72; P = 0.018, <0.001, respectively).

CONCLUSION

Substantial visual acuity loss occurred long after epiretinal membrane surgery in eyes with glaucoma, which was associated with worse preoperative central VFs and greater central VF deterioration during the first postoperative year.

Multi-functional, conformal systems with ultrathin crystalline-silicon-based bioelectronics for characterization of intraocular pressure and ocular surface temperature

Technologies that established in vivo evaluations of soft-tissue biomechanics and temperature are essential to biological research and clinical diagnostics, particularly for a wide range of eye-related diseases such as glaucoma. Of importance are advanced bioelectronic devices for high-precise monitoring of intraocular pressure (IOP) and various ocular temperatures, as clinically proven uses for glaucoma diagnosis. Existing characterization methods are temporary, single point, and lack microscale resolution, failing to measure continuous IOP fluctuation across the long-term period. Here, this work presents a multi-functional smart contact lens, capable of rapidly capturing IOP fluctuation and ocular surface temperature (OST) for assistance for clinical use. The microscale device design is programmable and determined by finite element analysis simulation, with detailed experiments of ex vivo porcine eyeballs. Such compact bioelectronics can provide high-precise measurement with sensitivity of 0.03% mmHg-1 and 1.2 Ω °C-1 in the range of Δ2∼50 mmHg and 30-50 °C, respectively. In vivo tests of bio-integration with a living rabbit can evaluate real-time IOP fluctuation and OST, as of biocompatibility assessments verified through cellular and animal experiments. The resultant bioelectronic devices for continuous precise characterization of living eyeballs can offer broad utility for hospital diagnosis of a wide range of eye-related disorders.

Thicker Inner Nuclear Layer as a Predictor of Glaucoma Progression and the Impact of Intraocular Pressure Fluctuation

Background: Thickening of the inner nuclear layer (INL) or microcystic macular changes has been reported to be implicated in glaucoma patients, but their potential impact on disease progression remains unclear. We investigated the relationship between baseline microcystic macular edema in the INL or INL thickness and subsequent visual field (VF) progression in glaucoma patients. Methods: This retrospective observational study included primary open-angle glaucoma with follow-up exceeding 3 years. We identified macular cystic changes through Spectralis optical coherence tomography and measured the INL thickness using automated segmentation. Glaucoma progression was determined using the Guided Progression Analysis program of the Humphrey filed analyzer, calculating the mean deviation (MD) changes (dB/year). Results: Microcystic macular changes were observed in 12 (7.5%) of 162 patients. Patients with microcystic macular change had thicker INL thickness than those without it (p = 0.010). Progressors had a higher probability of having microcystic macular changes and a thicker average INL thickness than nonprogressors (p = 0.003, p = 0.019). Thicker INL thickness was associated with faster VF progression based on MD slope (dB/year) in the multivariate regression analysis (p = 0.045). Additionally, greater intraocular pressure (IOP) fluctuation was found to be associated with both a thicker INL and the presence of microcystic changes in the multivariate regression analysis (p = 0.003, 0.028). Conclusions: Increased macular INL thickness indicative of INL changes was linked to subsequent VF progression in glaucoma patients. These findings suggest that retinal inner nuclear change could serve as an indicator of progressive glaucoma.

Long-Term Intraocular Pressure Fluctuation and Epiretinal Membrane in Patients with Glaucoma or Glaucoma Suspect

Background: A relationship between glaucoma and epiretinal membrane (ERM) has been suggested previously. We investigated the association between intraocular pressure (IOP) fluctuation and idiopathic ERM in patients with glaucoma or glaucoma suspect. Methods: Among patients with glaucoma or glaucoma suspect, data from 43 patients with ERM and 41 patients without ERM were reviewed and analyzed in this retrospective study. The long-term fluctuation of IOP was defined based on the standard deviation of IOP across all visits. Results: Patients with ERM were older and had a higher SD of IOP and a higher proportion of having a history of cataract surgery and greater macular thickness (p = 0.018, 0.049, 0.013, and <0.001, respectively). In multiple logistic regression analysis, the high-IOP-fluctuation group was associated with the presence of ERM (p = 0.047). Among patients with ERM, eyes with stage-3 or -4 ERM had worse visual field defects based on mean deviation than those with stage-1 or -2 ERM (p = 0.025). Conclusions: Long-term IOP fluctuation was associated with idiopathic ERM in patients with glaucoma or glaucoma suspect. Idiopathic ERM could serve as a biomarker for long-term IOP fluctuation in glaucoma patients, particularly in clinics where measuring long-term IOP fluctuation during the first visit is not feasible due to its time-consuming nature.

Evaluation of New and Preexisting Epiretinal Membranes Following Glaucoma Filtration Surgery

Secondary epiretinal membranes (ERMs) can develop from various causes, including those associated with glaucoma treatments such as trabeculectomy (TLE) and EX-PRESS (EXP) insertion surgery. This study aimed to investigate the occurrence of new ERMs and changes in preexisting ERMs following TLE or EXP insertion. Between April 2018 and March 2019, 102 and 74 eyes that underwent primary and standalone TLE and EXP insertion, respectively, were evaluated. Of these, 48 eyes were included in the TLE group and 32 eyes were included in the EXP group. Optical coherence tomography (OCT) was used to assess preoperative and postoperative ERMs. In the TLE group, postoperative ERMs were observed in one (case 1) (3%) out of 34 eyes without preexisting ERMs and in one (case 2) (7%) out of 14 eyes with preexisting ERMs, showing an increase in ERM stage. In the EXP group, postoperative ERMs were observed in one (case 3) (5%) out of 22 eyes without preexisting ERMs and in one (case 4) (10%) out of 10 eyes with preexisting ERMs, showing a decrease in the ERM stage. Case 1 was a 58-year-old man with primary open-angle glaucoma (POAG) in the left eye who underwent TLE. Although no preoperative ERMs were observed, postoperative ERM was noted at the three-month follow-up. Case 2 was a 49-year-old man with POAG in the right eye who underwent TLE. Although ERM was observed preoperatively, ERM progressed at six months postoperatively. Case 3 was a 59-year-old woman with POAG in the right eye who underwent EXP insertion. No preoperative ERMs were observed, but an ERM was noted at the 15-month follow-up. Case 4 was a 72-year-old woman with steroid-induced glaucoma in the right eye who underwent EXP insertion surgery. A preoperative ERM was present, and the foveal pit was absent; however, the foveal pit was observed at the 12-month follow-up. Despite the low incidence of ERMs, filtration surgery may be associated with ERM development and the progression or regression of preexisting ERMs.