Pattern Dystrophy: An Imprecise Diagnosis in the Age of Precision Medicine

Electrophysiological Evaluation of Macular Dystrophies

Macular dystrophies are a heterogeneous group of genetic disorders that often severely threatens the bilateral central vision of the affected patient. While advances in molecular genetics have been instrumental in the understanding and diagnosis of these disorders, there remains significant phenotypical variation among patients within any particular subset of macular dystrophies. Electrophysiological testing remains a vital tool not only to characterize vision loss for differential diagnosis but also to understand the pathophysiology of these disorders and to monitor the treatment effect, potentially leading to therapeutic advances. This review summarizes the application of electrophysiological testing in macular dystrophies, including Stargardt disease, bestrophinopathies, X-linked retinoschisis, Sorsby fundus dystrophy, Doyne honeycomb retina dystrophy, autosomal dominant drusen, occult macular dystrophy, North Carolina macular dystrophy, pattern dystrophy, and central areolar choroidal dystrophy.

Prevalence and Dose Dependency Analysis of Pentosan Polysulfate Sodium Maculopathy

PURPOSE

We describe a retrospective cohort study investigating the prevalence of pentosan polysulfate sodium (PPS) maculopathy in patients with PPS exposure, as well as the relationship between cumulative PPS exposure and the presence of PPS-maculopathy.

METHODS

Patients were identified through review of the electronic medical record system. Available diagnostic imaging was reviewed for signs of PPS-maculopathy. Patients were also contacted to determine cumulative exposure.

RESULTS

Of the 335 identified eligible patient records, 84 had sufficient diagnostic imaging. Sixteen patients had definitive signs of PPS-maculopathy, 6 had likely signs of PPS-maculopathy, and 62 had no signs. The mean cumulative PPS exposure and standard error of the mean (SEM) for patients with any signs of PPS-maculopathy was 1946.0 g (396.0 g), significantly higher than the mean cumulative PPS exposure for patients without such signs of 782.3 g (105.3 g). No significant difference in BCVA was noted. The odds ratio (OR, 95% confidence interval (95% CI)) of PPS-maculopathy was significantly elevated in patients with cumulative PPS exposures of 1500-2000 g [OR 4.72 (0.856-26.02 95% CI)] and greater than 2000 g [OR 28.33 (2.388-336.1, 95% CI)]. Logistic regression analysis confirmed a positive dose response relationship.

CONCLUSIONS

We describe the concerning incidence of PPS-maculopathy in a multispecialty ophthalmology practice's patient population and investigate the dose-dependency of PPS-maculopathy. Patients with PPS-maculopathy were shown to have a higher average exposure to PPS than those without the maculopathy. Patients with cumulative PPS exposures greater than 1500 g were shown to have an increased risk of PPS-maculopathy.

Age-Related Macular Degeneration Masquerade: A Review of Pentosan Polysulfate Maculopathy and Implications for Clinical Practice

ABSTRACT

Pentosan polysulfate (PPS) sodium (Elmiron) is the only Food and Drug Administration (FDA)-approved oral medication to treat interstitial cystitis, also known as bladder pain syndrome. A symptomatic pigmentary maculopathy associated with PPS was reported in 2018. Since then, recognition of this unique drug toxicity has increased rapidly. This potentially sight-threatening side effect prompted the FDA in June 2020 to update the label for PPS to warn about "retinal pigmentary changes." A challenging feature of pentosan maculopathy is its ability to mimic many other retinal conditions, including inherited retinal dystrophies such as pattern dystrophy, mitochondrially inherited diabetes and deafness, and Stargardt disease, and age-related macular degeneration. In this review, we discuss the history of PPS maculopathy and its implications for thousands of at-risk interstitial cystitis patients. We use published literature and an illustrative case from our institution to highlight the importance of diagnosing PPS maculopathy. We also compare PPS maculopathy to age-related macular degeneration, explain why differentiating between the 2 is clinically important, and highlight avenues for further research. Finally, we highlight the paucity of data on patients of color and why this lack of understanding may impact patient care.

Acquired Vitelliform Macular Degeneration: Characteristics and Challenges of Managing Subretinal Fluid

Purpose

To highlight diagnostic challenges in patients with acquired vitelliform macular degeneration (AVMD) with subretinal fluid (SRF) and to examine the characteristics of image findings in patients with AVMD.

Methods

In this retrospective review, the electronic medical record of 22 eyes of 16 patients with AVMD was studied. The rates of SRF, drusen, pigment epithelial detachment (PED), and patient clinical information such as age, length of follow-up, and best-corrected visual acuity (BCVA) were assessed.

Results

The mean age at diagnosis with AVMD was 72 years with a mean follow-up time of 29 months. Median BCVA 20/33 at presentation and 20/33 at final follow-up. Drusen was found in 13 of 22 eyes (59.1%), PEDs in 4 of 22 eyes (18.2%), and SRF in 10 of 22 eyes (45.5%) at some point during their follow-up. Of the 10 eyes with SRF, 70% were center involving, and recurrence occurred in 40%, all in the same location as the initial presentation of SRF. Three eyes received an anti-vascular endothelial growth factor injection for SRF. In 66% of cases receiving an injection, the fluid later relapsed and remitted without further injections during the course of follow-up.

Conclusion

AVMD occurs in the same demographic as age-related macular degeneration (AMD) and has many common features. SRF in AVMD tends to be center involving and recurs usually in the same location as its origin. The use of anti-VEGF injections did not seem to improve SRF in contrast to the SRF seen in wet AMD. Proper differentiation of AVMD may prevent unnecessary long-term treatment with intravitreal anti-VEGF injections.

Progression of Subclinical Pachychoroid Neovasculopathy to an Active Neovascularization in the Presence of Acquired Vitelliform Lesions

We describe a unique case of bilateral acquired vitelliform lesions in a 67-year-old-female with pachychoroid associated with subretinal fluid in the right eye (OD) and a nonexudative choroidal neovascular membrane (CNVM) in the left eye (OS). Multimodal imaging performed at baseline and over the ensuing two years showed an increase in the OS vitelliform lesions with a concurrent transformation of quiescent CNVM to an exudative form. Further studies are warranted to gain better insight into the etiopathogenesis of these vitelliform lesions in pachychoroid and their potential role in instigating CNVM activation.

Clinical and molecular findings in patients with pattern dystrophy

Purposes: To study the clinical and genetic background of a series of Italian patients affected by pattern dystrophy (PD).Methods: We reviewed patients with a clinical diagnosis of PD examined at the Eye Clinic in Florence from 2012 to 2019. We took into consideration patients with a standard ophthalmological examination, personal and familial ophthalmological history, fundus imaging, and molecular genetic analysis of genes PRPH2 and BEST1. We labelled patients with BEST1 and PRPH2 mutations as m-PD group (mutated) whereas patients with no mutations in these 2 genes as nm-PD group (non-mutated).Results: Seventy-seven PD patients were assessed (average age 59.7 ± 14.2, range 31-88 years). Fifty patients were placed in the nm-PD group and 27 in the m-PD. Pathogenic BEST1 and PRPH2 mutations were detected in 7% and 22% of PD patients, respectively. In total, we reported 1 BEST1 and 8 PRPH2 novel mutations. Ten patients were characterized by drusen in the nm-PD group whereas in no patients in the m-PD group drusen were detected at the fundus.Conclusions: An important proportion of patients affected by PD showed BEST1 or PRPH2 mutations. Patients affected by drusen represent a different sub-phenotype. Genetic examination is recommended for a correct clinical management.

Pentosan polysulfate maculopathy

Pentosan polysulfate sodium (PPS), a semisynthetic sulfated polysaccharide, is the only FDA-approved oral therapy for interstitial cystitis. Recent studies have described a progressive, vision-threatening macular condition associated with long-term PPS use. We reviewed all publications concerning PPS maculopathy to consolidate known clinical features and to evaluate the strength of this association. Current literature supports a strong dose-dependent association between PPS exposure and a progressive maculopathy impacting the retinal pigment epithelium (RPE) and RPE-photoreceptor interface that may worsen even after drug cessation. Initial symptoms may include prolonged dark adaptation and difficulty reading with relative visual acuity preservation. Fundus examination often shows macular pigment clumps corresponding to lesions of focal RPE thickening. Fundus autofluorescence most clearly depicts the condition, with a distinctive pattern of hypo- and hyperautofluorescent spots in the posterior pole that sometimes extends to the retinal periphery. Many cases also show a characteristic peripapillary hypoautofluorescent halo. Near infrared reflectance may aid in early detection. RPE atrophy, cystoid macular edema, and macular neovascularization may also occur, potentially resulting in loss of central acuity. This newly described association implies significant public health risk. Ophthalmologists should screen PPS users with multimodal retinal imaging, and prescribers should minimize dose and duration of PPS use.

Stargardt disease masquerades

PURPOSE OF REVIEW

Stargardt disease is the most common inherited macular dystrophy but has a wide clinical spectrum, and several inherited macular dystrophies have phenotypic similarities that can make clinical diagnosis challenging. This review seeks to highlight key clinical and multimodal imaging features to aid clinicians in accurate diagnosis.

RECENT FINDINGS

Multimodal imaging has provided additional information to aid in the diagnosis of Stargardt disease and its masquerades. These data from multimodal imaging are important to correlate with findings from clinical examination to help support the clinical diagnosis or guide molecular investigations.

SUMMARY

This review highlights the key similarities and differences, in history, clinical examination and multimodal imaging, to help distinguish between Stargardt disease and other macular dystrophies. These findings can help direct a focused molecular analysis for accurate diagnosis, which is critical in the era of gene and stem cell therapies.

Update on maculopathy secondary to pentosan polysulfate toxicity

PURPOSE OF REVIEW

The aim of the present review is to provide a comprehensive summary of available knowledge regarding toxic maculopathy secondary to pentosan polysulfate sodium (PPS).

RECENT FINDINGS

PPS toxicity was described in 2018, and additional studies characterize it as dysfunction of the retinal pigment epithelium centered on the posterior pole, which can progress despite drug cessation. Requisite exposure can be as little as 0.325 kg and 2.25 years but averages closer to 1-2 kg and 10-15 years. Multimodal imaging should include near-infrared reflectance, optical coherence tomography, and fundus autofluorescence. Cross-sectional studies demonstrate evidence correlating cumulative dosing and the likelihood/severity of maculopathy. Early estimates of prevalence range from 12.7 to 41.7% depending on dosing, with overall rates around 20%.

SUMMARY

Reasonable evidence associates maculopathy with extended exposure to PPS, with an average reported incidence of around 20% in patients with long-term exposures. Patients with unexplained retinal pigment epithelium changes and difficulty with dark adaptation should be questioned regarding PPS exposure, and patients with known exposure to PPS should be examined. Further research is needed to refine screening protocols. Currently, providers should consider baseline examination and examination at 5 years and/or 500 g of exposure followed by yearly screening.

Visual Function in Pentosan Polysulfate Sodium Maculopathy

Purpose

Individuals with pentosan polysulfate sodium (PPS) maculopathy commonly report symptoms of prolonged dark adaptation and difficulty reading. We hypothesize that PPS maculopathy causes degradation of visual function not fully captured with visual acuity testing.

Methods

Subjects with PPS maculopathy underwent multimodal evaluation of retinal structure and function. Structural changes were graded as moderate or advanced. Patient-reported visual function was assessed with the National Eye Institute Visual Function Questionnaire 39 (NEI-VFQ-39) and Low Luminance Questionnaire (LLQ). Objective functional evaluations included Early Treatment of Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), Pelli-Robson contrast sensitivity, mesopic microperimetry, and dark adaptometry. Functional testing results were correlated with structural disease category.

Results

Thirteen patients (26 eyes), median age 62 years (range, 37-76), completed the study. Median ETDRS letter score was 82 (Snellen equivalent 20/25). Median NEI-VFQ-39 and LLQ composite scores were 65 (range, 33-88) and 41 (range, 20-92), respectively. Median contrast sensitivity was 1.65 (range, 0.15-1.95), and median mesopic microperimetry average thresholds and percent reduced thresholds were 26 decibels (range, 0.4-28.6) and 21.6% (range, 0-100%), respectively. Median rod intercept time was 14.1 minutes (range, 4.4-20.0). Eyes with advanced disease based on retinal structure had significantly worse retinal function for several testing modalities.

Conclusions

PPS maculopathy causes considerable visual function degradation that is not fully captured with BCVA testing. There was good correlation between other measures of visual function and disease severity. These findings deepen our concern regarding this patient safety issue.

Association of macular disease with long-term use of pentosan polysulfate sodium: findings from a US cohort

BACKGROUND/AIMS

A series at a single clinical centre recently demonstrated an association between the interstitial cystitis drug pentosan polysulfate sodium (PPS) and a vision-threatening pigmentary maculopathy. The aim of this study was to determine if an association exists between PPS use and macular disease in a large national cohort.

METHODS

A retrospective, matched cohort study using data from a large US medical claims database from 2002 to 2016 was performed. A total of 3012 and 1604 PPS users were compared with 15 060 and 8017 matched controls at 5 and 7 years, respectively. The primary outcome measures included (1) any new diagnosis of a hereditary or secondary pigmentary maculopathy (atypical maculopathy outcome), and (2) any new diagnosis of dry age-related macular degeneration (AMD) or drusen in addition to the aforementioned diagnoses (atypical maculopathy+AMD outcome).

RESULTS

At the 5-year and 7-year follow-up, 9 (0.3%) and 10 (0.6%) PPS patients progressed to the atypical maculopathy outcome compared with 32 (0.2%) and 25 (0.3%) control patients, respectively. 103 (3.4%) and 87 (5.4%) PPS patients developed the atypical maculopathy+AMD outcome compared with 440 (2.9%) and 328 (4.1%) control patients at 5 and 7 years, respectively. At 5 years, multivariate analysis showed no significant association (p>0.13). At 7 years, PPS users had significantly increased odds of having the atypical maculopathy+AMD outcome (OR=1.41, 95% CI 1.09 to 1.83, p=0.009).

CONCLUSIONS

PPS exposure was associated with a new diagnosis of macular disease at the 7-year follow-up in a large national cohort.

Phenotypic Spectrum of Pentosan Polysulfate Sodium-Associated Maculopathy: A Multicenter Study

Importance

A unique pigmentary maculopathy was recently described in 6 patients with long-term exposure to pentosan polysulfate sodium (PPS), a long-standing oral therapy for interstitial cystitis.

Objective

To characterize the exposure characteristics and clinical manifestations of PPS-associated maculopathy.

Design, Setting, and Participants

In this multi-institutional case series, medical records of patients who exhibited the characteristic maculopathy in the setting of prior PPS exposure were retrospectively reviewed. Data were collected from August 1, 2012, to October 1, 2018, and data were analyzed from October 2018 to January 2019.

Main Outcomes and Measures

Drug exposure, visual acuity, and retinal imaging characteristics.

Results

Of the 35 included patients (70 eyes), 34 (97%) were female, and the median (range) age was 60 (37-79) years. The median (range) duration of PPS intake was 15 (3-22) years, and the median (range) cumulative exposure was 1.61 (0.44-4.31) kg. The leading visual symptoms were metamorphopsia, blurred vision, and prolonged dark adaptation. Median (range) logMAR visual acuity of all eyes was 0.10 (-0.12 to 1.18). Fundus examination often revealed hyperpigmented macular spots (34 of 64 eyes [53%]) with interspersed pale-yellow deposits, although less commonly in eyes that exhibited retinal pigment epithelial atrophy (6 of 26 eyes [23%]; P < .001). Optical coherence tomography showed foci of retinal pigment epithelium elevation or thickening associated with hyperreflectance on near-infrared reflectance imaging. Fundus autofluorescence imaging typically revealed a symmetric, confluent pattern of hyperautofluorescent and hypoautofluorescent spots that involved the fovea in all eyes and extended to the retinal periphery in 24 eyes (36%). Longitudinal evaluation demonstrated dynamic changes in pigmentary abnormalities.

Conclusions and Relevance

These findings suggest that PPS-associated maculopathy is a vision-threatening condition that can manifest in the setting of long-term exposure to the drug. Multimodal imaging posits a distinctive clinical phenotype, characterized in this cohort by dynamic alterations within the retinal pigment epithelium and at the retinal pigment epithelium-photoreceptor interface. Ongoing work might explore causality and direct screening guidelines.