Peripapillary retinal splitting visualized on OCT in glaucoma and glaucoma suspect patients

Peripapillary fluid: Obvious and not so obvious!

Intraretinal or subretinal fluid in the peripapillary area can be clinically visualized in conditions such as peripapillary choroidal neovascularization, optic disc pit maculopathy, and optic nerve head tumors and granulomas. Optical coherence tomography (OCT) helps to visualize peripapillary fluid in many other chorioretinal conditions such as peripapillary pachychoroid syndrome, posterior uveitis, central retinal vein occlusion, malignant hypertension, hypotonic maculopathy as well as neuro-ophthalmological conditions such as glaucoma, microcystic macular edema and disc edema due papilledema, non-arteritic anterior ischemic optic neuropathy, neuroretinitis, and diabetic papillopathy. Often, the differential diagnosis of peripapillary fluid is a bit tricky and may lead to misdiagnosis and improper management. We describe a diagnostic algorithm for peripapillary fluid on OCT and outline the salient features and management of these conditions.

Optical coherence tomographic findings of glaucomatous eyes with papillomacular retinoschisis

OBJECTIVES

To investigate the relationship between the shape of the optic nerve head (ONH) margin detected by optical coherence tomography (OCT) and the clinical characteristics of glaucomatous eyes with papillomacular retinoschisis (PMRS).

METHODS

The medical record of patients with a PMRS in a glaucomatous eye were reviewed. The eyes were placed into two groups determined by the shape of the ONH margin in the OCT images; eyes with an externally oblique ONH margin (Group 1) and eyes with an internally oblique ONH margin (Group 2). We compared the clinical characteristics of the PMRS of these two groups.

RESULTS

We studied 31 eyes of 29 patients with PMRS and glaucoma with 24 eyes in Group 1 and 7 eyes in Group 2. The optic nerve fibre layer schisis on the lamina cribrosa (LC), beta zone, and gamma zone, and found that the LC defects were detected significantly more frequently in Group 1 than in Group 2 eyes (P < 0.05). A retinal nerve fibre schisis was observed around the ONH significantly more frequently in Group 2 than in Group 1 eyes (P < 0.01).

CONCLUSION

The cases of glaucoma-associated PMRS could be classified into two groups according to the obliquity of the ONH. They had differences in the findings of OCT and FA. The possibility that the mechanism of PMRS development is different in both groups is suggested.

SPONTANEOUS RESOLUTION OF RETINOSCHISIS IN THE SETTING OF NARROW-ANGLE GLAUCOMA: A CASE REPORT

PURPOSE

To present a rare case of retinoschisis in the setting of narrow-angle glaucoma that demonstrated spontaneous resolution with conservative management.

METHODS

Case report presentation from the Vitreous Retina Macula Specialists of Toronto in December 2020.

RESULTS

A 65-year-old woman with previous bilateral laser peripheral iridotomies for narrow-angle glaucoma was referred to a tertiary retina clinic for the assessment of query macular edema in the left eye. The patient presented with a blunted foveal reflex in the left eye, and optical coherence tomography imaging demonstrated diffuse retinoschisis of outer retinal layers in the peripapillary region and nasal macula. The patient elected for conservative management, and by 10-month follow-up, her retinoschisis resolved spontaneously.

CONCLUSION

Only seven cases of retinoschisis in the setting of narrow-angle glaucoma have been identified in the literature. This is the first case in this setting to demonstrate spontaneous resolution with conservative management. Although laser peripheral iridotomies have been shown to resolve retinoschisis in narrow-angle glaucoma patients, clinicians should be aware of a conservative management approach to yield a positive improvement in retinal integrity.

Peripapillary Retinoschisis as a Manifestation of Ocular Hypotony

The aim of this case report was to present an unusual case of peripapillary retinoschisis (PPRS) associated with ocular hypotony after glaucoma surgery. It refers to a 78-year-old man with primary open-angle glaucoma who developed PPRS while hypotonous. Optical coherence tomography of the peripapillary and the macular area of the right eye revealed PPRS temporally and nasally to the optic disc, more prominent at the level of the outer nuclear layer and less so at the inner nuclear layer. The PPRS completely regressed after 1 month of treatment and restoration of intraocular pressure to normal levels. This case report highlights the fact that PPRS in glaucoma patients may present in the setting of ocular hypotony and appears to resolve when the hypotony is successfully managed. Hydrostatic pressure gradient across retinal vasculature that allows movement of fluid into the extracellular spaces is a potential mechanism for the development of PPRS in ocular hypotony.

Non-vasogenic cystoid maculopathies

Besides cystoid macular edema due to a blood-retinal barrier breakdown, another type of macular cystoid spaces referred to as non-vasogenic cystoid maculopathies (NVCM) may be detected on optical coherence tomography but not on fluorescein angiography. Various causes may disrupt retinal cell cohesion or impair retinal pigment epithelium (RPE) and Müller cell functions in the maintenance of retinal dehydration, resulting in cystoid spaces formation. Tractional causes include vitreomacular traction, epiretinal membranes and myopic foveoschisis. Surgical treatment does not always allow cystoid space resorption. In inherited retinal dystrophies, cystoid spaces may be part of the disease as in X-linked retinoschisis or enhanced S-cone syndrome, or occur occasionally as in bestrophinopathies, retinitis pigmentosa and allied diseases, congenital microphthalmia, choroideremia, gyrate atrophy and Bietti crystalline dystrophy. In macular telangiectasia type 2, cystoid spaces and cavitations do not depend on the fluid leakage from telangiectasia. Various causes affecting RPE function may result in NVCM such as chronic central serous chorioretinopathy and paraneoplastic syndromes. Non-exudative age macular degeneration may also be complicated by intraretinal cystoid spaces in the absence of fluorescein leakage. In these diseases, cystoid spaces occur in a context of retinal cell loss. Various causes of optic atrophy, including open-angle glaucoma, result in microcystoid spaces in the inner nuclear layer due to a retrograde transsynaptic degeneration. Lastly, drug toxicity may also induce cystoid maculopathy. Identifying NVCM on multimodal imaging, including fluorescein angiography if needed, allows guiding the diagnosis of the causative disease and choosing adequate treatment when available.

Structural Abnormalities in the Papillary and Peripapillary Areas and Corresponding Visual Field Defects in Eyes With Pathologic Myopia

Purpose

To identify structural abnormalities in the papillary and peripapillary area in eyes with pathologic myopia (PM) and normal IOP and to determine their relationship to visual field (VF) defects.

Methods

One hundred eight eyes of 70 patients with PM were retrospectively studied. The disc-centered swept source optical coherence tomographic images and the Goldmann VF recorded within 1 year of the optical coherence tomographic examination were analyzed. Four structural abnormalities were identified: lamina cribrosa (LC) defects, ridge protrusions, intrachoroidal cavitations (ICC), and prelaminar schisis. The correspondence of the VF defects with the structural abnormalities was assessed.

Results

The mean age, axial length, and optic disc area of the 108 eyes were 58.7 ± 10.0 years, 31.1 ± 2.4 mm, and 4.7 ± 2.2 mm2, respectively. Eighty-five of the 108 eyes (78.7%) had at least one abnormality and 49.4% (42/85) had two or more abnormalities. LC defects, ridge protrusions, ICC, and prelaminar schisis were detected in 47.2%, 33.3%, 21.3%, and 30.6% of the eyes, respectively. VF defects at the corresponding areas of these structural abnormalities were seen in 63% of the eyes with LC defects, 39% of the eyes with ridge protrusions, and 21% of the eyes with ICC.

Conclusions

Four kinds of structural abnormalities with corresponding VF defects are commonly observed in the papillary and peripapillary region of eyes with PM. The presence of these abnormalities suggests a possibility of functional damage.

Performance evaluation of various deep learning based models for effective glaucoma evaluation using optical coherence tomography images

Glaucoma is the dominant reason for irreversible blindness worldwide, and its best remedy is early and timely detection. Optical coherence tomography has come to be the most commonly used imaging modality in detecting glaucomatous damage in recent years. Deep Learning using Optical Coherence Tomography Modality helps in predicting glaucoma more accurately and less tediously. This experimental study aims to perform glaucoma prediction using eight different ImageNet models from Optical Coherence Tomography of Glaucoma. A thorough investigation is performed to evaluate these models' performances on various efficiency metrics, which will help discover the best performing model. Every net is tested on three different optimizers, namely Adam, Root Mean Squared Propagation, and Stochastic Gradient Descent, to find the best relevant results. An attempt has been made to improvise the performance of models using transfer learning and fine-tuning. The work presented in this study was initially trained and tested on a private database that consists of 4220 images (2110 normal optical coherence tomography and 2110 glaucoma optical coherence tomography). Based on the results, the four best-performing models are shortlisted. Later, these models are tested on the well-recognized standard public Mendeley dataset. Experimental results illustrate that VGG16 using the Root Mean Squared Propagation Optimizer attains auspicious performance with 95.68% accuracy. The proposed work concludes that different ImageNet models are a good alternative as a computer-based automatic glaucoma screening system. This fully automated system has a lot of potential to tell the difference between normal Optical Coherence Tomography and glaucomatous Optical Coherence Tomography automatically. The proposed system helps in efficiently detecting this retinal infection in suspected patients for better diagnosis to avoid vision loss and also decreases senior ophthalmologists' (experts) precious time and involvement.

Clinical Features of Advanced Glaucoma With Optic Nerve Head Prelaminar Schisis

PURPOSE

To investigate the clinical characteristics of optic nerve head (ONH) prelaminar schisis in eyes with advanced glaucoma.

DESIGN

Cross-sectional study.

METHODS

One hundred sixteen eyes with advanced glaucoma (30-2 mean deviation <-12 dB) were included. ONH prelaminar schisis was identified using the spectral-domain optical coherence tomography independently by 2 evaluators and only eyes that reached consensus for the presence of ONH prelaminar schisis were included. Bruch membrane opening-minimum rim width (BMO-MRW), thickness and depth of lamina cribrosa (LC), peripapillary retinal nerve fiber layer (RNFL) thickness, macular thickness (total, RNFL, ganglion cell layer, inner plexiform layer), and peripapillary and subfoveal choroidal thickness were additionally obtained. Clinical characteristics were compared between the 2 groups based on the presence of ONH prelaminar schisis.

RESULTS

ONH prelaminar schisis was identified in 48 of 116 eyes. Multivariate logistic regression analysis revealed that short axial length, thin and deep LC, and thick macula were associated with the presence of ONH prelaminar schisis. When the structure-function relationships were determined, macular structural parameters tended to have a better relationship with functional parameters than the BMO-MRW and peripapillary RNFL thickness parameters in eyes with ONH prelaminar schisis.

CONCLUSIONS

The ONH prelaminar schisis was associated with thin and deep LC, short axial length, and generally thick macula. In patients with this features, the macular measurements, rather than peripapillary or ONH measurements, better predict the functional status of the eye. Our findings may have significant clinical implications for management of advanced glaucoma eyes with and without ONH prelaminar schisis.

The Progression of Peripapillary Retinoschisis May Indicate the Progression of Glaucoma

Purpose

To identify the temporal correlation between the increase in peripapillary retinoschisis (PPRS) and glaucoma progression during PPRS fluctuation.

Methods

We performed a comparative clinical timeline analysis for PPRS and glaucomatous progression in eyes with PPRS. In particular, the interval between the increase in PPRS extent and glaucoma progression was analyzed. Temporal correlation was defined when the interval was less than one year between glaucoma progression and PPRS increase, including both de novo development and an increase in the amount of retinoschisis on serial optical coherence tomography.

Results

We included 33 eyes of 30 patients, with an average follow-up period of 7.5 ± 3.0 years and a total of 253 glaucoma examinations. Glaucoma progression was observed in 21 of 33 eyes; 19 (90.5%) of the 21 eyes with glaucoma progression and 29 (74.4%) of the 39 episodes of PPRS increase showed temporal correlation. The de novo development of PPRS during the follow-up period over baseline PPRS was more frequently observed in the glaucoma progression group than in the no-progression group (P = 0.006).

Conclusions

In glaucomatous eyes with PPRS, the increase in PPRS temporally correlated with glaucoma progression. Possible glaucoma progression may be considered around the time of increase and de novo development of PPRS.

Evaluation of peripapillary atrophy in early open-angle glaucoma using autofluorescence combined with optical coherence tomography

PURPOSE

To quantitatively analyze α-zone and β-zone peripapillary atrophy (PPA) in patients having early primary open-angle glaucoma (POAG) using fundus autofluorescence (FAF) in conjunction with spectral domain optical coherence tomography, colored photography and perimetry.

DESIGN

This is an observational cross-sectional case-control study.

METHODS

This study included 100 eyes (54 patients) of early to moderate POAG and 100 normal eyes (50 subjects). Ophthalmological examination, OCT for the optic nerve and FAF were performed. The extent of α-PPA and β-PPA was measured.

RESULTS

The extent of α-PPA and β-PPA as measured by FAF had higher values in POAG group as compared to control group (p values 0.003 and ≤ 0.001 for the total nasal and temporal extents, respectively). However, the nasal alpha and temporal beta zones showed more values in POAG patients as compared to normal controls (p values 0.002 and 0.024). The difference between the total extents of either zones alone was not significant. B-scan OCT was able to positively detect both zones. Detecting the alpha zone was significantly higher in the control group, while beta zone detection was significantly higher in the POAG group (p values ≤ 0.001).

CONCLUSION

The sensitivity of alpha zone detection was equal using colored photographs, FAF and B-scan OCT. FAF showed superior results in estimating the beta zone extent although OCT was more accurate in the anatomical delineation of Bruch's membrane and RPE termination. The nasal alpha and temporal beta zone extents could be taken as early indices for evaluating early glaucomatous optic neuropathy.

Factors Determining the Morphology of Peripapillary Retinoschisis

Purpose

We conducted cross-sectional examinations to determine the frequency of peripapillary retinoschisis (PRS) in eyes with glaucoma and suspected glaucoma and analyzed the pathogenesis of PRS by using spectral-domain optical coherence tomography (SD-OCT).

Patients and Methods

In 1516 cases involving glaucoma and suspected glaucoma, we retrospectively reviewed the disc and macular volume scans obtained by SD-OCT and categorized PRS into two groups based on whether the retinoschisis was closer to the optic nerve over the Bruch’s membrane opening (BMO) (ahead group) or did not go past the BMO (behind group) and then compared the characteristics between both groups.

Results

The total frequency of PRS was 1.49% (20/1342 eyes) in primary open-angle glaucoma (POAG) eyes and 0.59% (10/1687 eyes) in glaucoma suspects. In the behind group, PRS was mostly detected in the inner layers of the retina (retinal nerve fiber layer: 30.9%, ganglion cell layer: 21.8%, inner plexiform layer: 7.3%). However, in the ahead group, PRS was detected in the outer layers (inner nuclear layer: 10%, outer plexiform layer: 20%, outer nuclear layer: 50%). In addition, the eyes in the ahead group had significantly greater axial lengths and significantly smaller spherical equivalent values. These two differences suggest that the pulling force of the vitreous traction may play an important role in PRS only in the behind group and that the scleral stretching force may play a role in the development of PRS in the ahead group.

Conclusion

The frequency of PRS in patients with POAG is higher than that in patients with suspected glaucoma. Both forms of PRS are affected by posterior vitreous detachment and axial length elongation. Careful follow-up is required to assess the development of PRS in glaucoma suspects. The pathogenesis of PRS has been elucidated to some degree by classifying the morphological condition of the PRS and BMO.

Long-term follow-up of adult patient with neurofibromatosis type 1 with retinal astrocytic hamartoma using spectral-domain optical coherence tomography: a review of the literature and a report of a case

Background: Retinal astrocytic hamartoma (RAH) is a tumor that can be sporadic or in the context of tuberous sclerosis complex (TSC) and has been reported to be associated with neurofibromatosis type 1 (NF1) in a few cases.Patient and methods: A 65-year-old male patient with NF1 was referred for ophthalmological evaluation. Comprehensive examination, near-infrared reflectance (NIR), spectral-domain optical coherence tomography (SDOCT), fluorescein angiography (FFA), and indocyanine green angiography (ICGA) were carried out. The follow-up of the patient was at 4 and 7 years.Results: Best-corrected visual acuity (BCVA) was 20/20 in both eyes. Anterior segment examination revealed bilateral Lisch nodules. Fundus examination was unremarkable but at NIR and SDOCT the patient presented choroidal hamartoma, microvascular retinal alterations, and enlarged choroidal vessels in both eyes. NIR also revealed an unusual area of peripapillary hyporeflectivity in the right eye. On SDOCT, this corresponded to an elevated peripapillary mass characterized by intralesional optically empty cavities in the retinal nerve fiber layer (RNFL) and ganglion cell layer-inner plexiform layer (GCL-IPL), diagnosed as a RAH. Four years later, BCVA was 20/25 with a retinal schisis departing from the lesion to the macula. At 7 years, BCVA was stable at 20/25, the lesion was smaller, and there was a slight reduction of the schisis.Conclusion: RAH is a rare finding in NF1 and the translucent type has not been previously reported. RAH in NF1 has a peripapillary location and demonstrates clinically unpredictable behavior; thus, close monitoring with multimodal imaging is advisable.

Effect of partial posterior vitreous detachment on spectral-domain optical coherence tomography retinal nerve fibre layer thickness measurements

Background/aims

To assess the effect of partial posterior vitreous detachment (pPVD) on spectral-domain optical coherence tomography (OCT) peripapillary retinal nerve fibre layer thickness (RNFL) measurements.

Methods

Spectral-domain OCT RNFL thickness measurements were obtained from 684 consecutive patients who were seen in the Massachusetts Eye and Ear Glaucoma Service. Of these patients, we compared RNFL thickness measurements between 101 eyes of 101 glaucoma suspects who met inclusion criteria (55 eyes with and 46 eyes without pPVD).

Results

Among all 684 patients, 253 (37%) had pPVD in at least one eye. Among a subset of 101 eyes of 101 glaucoma suspects, average RNFL thickness was greater in eyes with compared to eyes without pPVD (p=0.02). Measurements were significantly greater in the inferior (p=0.004) and superior quadrants (p=0.008), but not in the nasal (p=0.10) and temporal quadrants (p=0.25). The difference in average RNFL thickness remained significant (p=0.05) even when corrected for expected age-related decline in RNFL thickness.

Conclusion

Over a third of patients were found on peripapillary spectral-domain OCT to have a pPVD, which was associated with greater RNFL thickness measurements. Judicious clinical interpretation of this finding on spectral-domain OCT RNFL thickness scans should be factored into the assessment of glaucoma suspects.

Peripapillary Retinoschisis in Glaucoma: Association With Progression and OCT Signs of Müller Cell Involvement

Purpose

To examine demographic and clinical factors associated with glaucomatous peripapillary retinoschisis (PPRS) and assess its association with glaucoma progression.

Methods

Using a case control study design and longitudinal data from a cohort of 166 subjects with a diagnosis of glaucoma or glaucoma suspect, we compared functional, structural, clinical, and demographic characteristics between PPRS cases and controls.

Results

The frequency of PPRS was 6.0% (12 eyes from 10/166 subjects) with two eyes having PPRS in different sectors for a total of 15 retinoschisis events. There were no significant differences (P > 0.05) in age, sex, visual acuity, central corneal thickness, intraocular pressure, or presence of vitreous adhesion between PPRS and controls. However, eyes with PPRS tended to have a higher cup-to-disc ratio (P = 0.06), thinner RNFL (P = 0.02), and worse visual field mean deviation (MD, P = 0.06) than controls. The rate of RNFL thinning was faster in PPRS (average: −2.8%/year; range: −7.4% to 0.0%/year) than controls (−1.3%/year; range: −4.4% to 0.6%/year; P = 0.021). The rate of visual field MD change was faster in PPRS (−0.49 dB/year; range: −2.0 to 0.9 dB/year) than controls (−0.06 dB/year; range: −0.8 to 0.3 dB/year; P = 0.030). OCT scans showed hyperreflective structures spanning the PPRS whose morphology and spacing (50 ± 7 μm) are consistent with Müller glia, causing signal attenuation casting “shadows” onto distal retina.

Conclusions

This is the first report showing that glaucomatous PPRS is associated with a faster overall rate of RNFL thinning and visual field deterioration and to specifically identify OCT signs of Müller cell involvement.