Treatment of chronic macular edema with acetazolamide

Acetazolamide Challenge Changes Outer Retina Bioenergy-Linked and Anatomical OCT Biomarkers Depending on Mouse Strain

Purpose

The purpose of this study was to test the hypothesis that optical coherence tomography (OCT) bioenergy-linked and anatomical biomarkers are responsive to an acetazolamide (ACZ) provocation.

Methods

C57BL/6J mice (B6J, a strain with relatively inefficient mitochondria) and 129S6/ev mice (S6, a strain with relatively efficient mitochondria) were given a single IP injection of ACZ (carbonic anhydrase inhibitor) or vehicle. In each mouse, the Mitochondrial Configuration within Photoreceptors based on the profile shape Aspect Ratio (MCP/AR) index was determined from the hyper-reflective band immediately posterior to the external limiting membrane (ELM). In addition, we tested for ACZ-induced acidification by measuring contraction of the external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness; the hyporeflective band (HB) signal intensity at the photoreceptor tips was also examined. Finally, the nuclear layer thickness was measured.

Results

In response to ACZ, MCP/AR was greater-than-vehicle in B6J mice and lower-than-vehicle in S6 mice. ACZ-treated B6J and S6 mice both showed ELM-RPE contraction compared to vehicle-treated mice, consistent with dehydration in response to subretinal space acidification. The HB intensity at the photoreceptor tips and the outer nuclear layer thickness (B6J and S6), as well as the inner nuclear layer thickness of B6J mice, were all lower than vehicle following ACZ.

Conclusions

Photoreceptor respiratory efficacy can be evaluated in vivo based on distinct rod mitochondria responses to subretinal space acidification measured with OCT biomarkers and an ACZ challenge, supporting and extending our previous findings measured with light-dark conditions.

Topical Dorzolamide as Adjunctive Treatment With Intravitreal Bevacizumab in Bilateral Diabetic Macular Edema

BACKGROUND

 Intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents is accepted as the gold standard treatment for center-involving diabetic macular edema (CI-DME). Adjunctive administration of topical dorzolamide may enhance the therapeutic effects of anti-VEGF agents. In this study, we compared the efficacy of topical dorzolamide plus intravitreal injection of bevacizumab (IVB) versus IVB alone in patients with bilateral DME.

METHODS

This prospective, randomized contralateral eye study was carried out in a tertiary referral ophthalmology center, Al-Zahra Eye Hospital, Zahedan, Iran, between April 2021 and April 2022. This study included 50 eyes of 25 patients with bilateral DME. All eyes received three consecutive monthly injections of IVB. For each patient, one eye was randomized to instill dorzolamide eye drops three times a day as an intervention, and the other received artificial tear drops as a placebo. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) were evaluated before starting treatment and then monthly for the first three months.

RESULTS

Among 25 included patients, the average age was 56.64 ± 7.97 years, and 48% were female. BCVA did not improve significantly in any groups (P > 0.05). No significant difference was observed in terms of BCVA between the intervention and control groups (P > 0.05). The present study showed a decrease in CMT in both study groups (P < 0.05). At month 3, the decrease in mean CMT from baseline was significantly higher in eyes receiving topical dorzolamide compared to the control group (-88.92 ± 82.90 vs. -37.64 ± 86.16 µM, respectively; P = 0.037). IOP decreased significantly only in eyes receiving dorzolamide (P < 0.001).

CONCLUSIONS

The results of the present study indicate that adjunctive administration of topical dorzolamide has a beneficial effect on CMT reduction from baseline, but it did not have an additive effect on BCVA improvement compared to IVB monotherapy.

Drug Repurposing Analysis for Colorectal Cancer through Network Medicine Framework: Novel Candidate Drugs and Small Molecules

This study aimed to reveal the drug-repurposing candidates for colorectal cancer (CRC) via drug-repurposing methods and network biology approaches. A novel, differentially co-expressed, highly interconnected, and co-regulated prognostic gene module was identified for CRC. Based on the gene module, polyethylene glycol (PEG), gallic acid, pyrazole, cordycepin, phenothiazine, pantoprazole, cysteamine, indisulam, valinomycin, trametinib, BRD-K81473043, AZD8055, dovitinib, BRD-A17065207, and tyrphostin AG1478 presented as drugs and small molecule candidates previously studied in the CRC. Lornoxicam, suxamethonium, oprelvekin, sirukumab, levetiracetam, sulpiride, NVP-TAE684, AS605240, 480743.cdx, HDAC6 inhibitor ISOX, BRD-K03829970, and L-6307 are proposed as novel drugs and small molecule candidates for CRC.

Central serous chorioretinopathy: updates in the pathogenesis, diagnosis and therapeutic strategies

Central serous chorioretinopathy (CSCR), first described by Albrecht von Graefe in 1866, is characterized by focal serous detachment of the neural retina and/or retinal pigment epithelium (RPE) in the posterior pole. CSCR is the first ever described pachychoroid disease. Most recently, hypothetical venous overload choroidopathy is also proposed due to its distinguished morphological and pathological characteristics, including choroidal thickening, choriocapillaris hyperpermeability, remodelling, and intervortex venous anastomoses. Identification of genetic variants is necessary to comprehend the pathophysiology of CSCR. The novel multimodality imaging platforms, including the ultra-widefield imaging system, flavoprotein fluorescence, fluorescence lifetime imaging ophthalmoscopy, and multispectral imaging system, have been used for diagnosing and managing CSCR. Half-dose photodynamic therapy (PDT) remains the mainstay of clinical practice, with about 95% of patients with chronic CSCR improving to visual acuity (VA) of 20/30 or better. The use of oral eplerenone for routine clinical care remains controversial, and long-term randomized clinical trials are warranted to investigate its efficacy in acute and chronic CSCR. While CSCR has generally been recognized as a self-limiting disease with good prognosis, the underlying pathogenesis is still not fully understood, and treatments are often not fully effective. With new evidence emerging about pachydrusen being a disease precursor in both CSCR and polypoidal choroidal vasculopathy (PCV), it would be interesting to investigate whether CSCR can be a precursor to PCV. In this review, we highlighted the currently available evidence on the pathogenesis, diagnosis, multimodality imaging features, and management strategies, including recent findings related to CSCR.

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.

Management of Cystoid Macular Edema in Retinitis Pigmentosa: A Systematic Review and Meta-Analysis

Background

To date, various treatments for cystoid macular edema (CME) in retinitis pigmentosa (RP) have been reported. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of current treatments for RP-CME.

Methods

PubMed, Embase and the Cochrane library were searched from inception to August 2021. ClinicalTrials.gov, WHO ICTRP and ISRCTN were also searched for relevant studies. Only studies published in English were included. The RoB 2 tool was used to evaluate the risk of bias of randomized controlled trials (RCTs), and the MINORS scale was used to assess the methodological quality of non-RCTs. Review manager (Revman) was used to pool the data. The primary outcomes included the change of central macular thickness (CMT) and best-corrected visual acuity (BCVA) from baseline. The secondary outcomes included fluorescein angiography (FA) leakage, rebound of CME and adverse effects.

Results

Thirty-two studies were included in the current systematic review and 7 studies were used for meta-analysis. Treatments for RP-CME included oral and topical carbonic anhydrase inhibitors (CAIs), systematic and local steroids, anti-VEGF therapy, NSAIDS, grid LASER photocoagulation, subliminal micropulse LASER, vitrectomy, lutein supplement and oral minocycline. CAIs and local steroids were proved to be effective in reducing CMT. The effects of anti-VEGF reagents varied among studies. Regarding other treatments, only one study for each method fitted the inclusion criteria, so the evidence was very limited.

Conclusion

Topical CAIs, oral CAIs and local steroids are effective in treating RP-CME. However, due to the overall inferior design and small patient number of the included studies, the quality of evidence was poor. Systematic steroids, LASER, NSAIDS and vitrectomy may also be effective, nevertheless, considering the limited number of studies, no conclusion could be drawn regarding these treatments. More well-designed and conducted studies are needed in this field.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021273979, identifier CRD42021273979.

Acute Serous Retinal Detachment after the Same Operating Session of Uncomplicated Cataract Surgeries: A Case Series

PURPOSE

To report four cases of acute serous retinal detachment (ASRD) after the same operating session of uncomplicated cataract surgeries.

METHODS

In this case series, data of patients who developed ASRD after uncomplicated phacoemulsification with intraocular lens implantation during the same operating session were collected. Diagnosis was made on the first postoperative day, when all patients had a very low best-corrected visual acuity (BCVA), despite a good aspect of the anterior segment, without significant keratopathy and with only trace cells in the anterior chamber. Spectral-domain optic coherence tomography (SD-OCT) revealed serous retinal detachment with subretinal fluid accumulation in the macular area. Patients received a parabulbar injection of 40 mg/mL triamquinolone in addition to usual the postoperative topical treatment of 0.1% dexamethasone and 0.3% netilmicin eye drops. Patients were examined postoperatively on days 1, 3, 7, and 1 month. BCVA and central foveal thickness (CFT) measured by SD-OCT were evaluated at each visit. A relationship between demographics, preoperative ocular conditions, systemic diseases, parameters of surgery, and the development of ASRD was analyzed.

RESULTS

After a single operating session of 10 uneventful cataract surgeries, operated by the same expert surgeon, on postoperative day 1, ASRD was detected in 4 patients (3 male, 1 female; mean age 71 ± 4.1 years). Preoperatively, the mean BCVA was 0.6 ± 0.1 decimals and mean CFT was 191.3 ± 13.7 µm. On the first postoperative day, mean BCVA was 0.01 ± 0.1 decimals, and all eyes had serous retinal detachment, with a mean CFT of 682.0 ± 97.4 µm. On the following visits, BCVA improved and CFT reduced significantly. On day 7, BCVA was at least 0.7 decimals in all eyes, with complete reabsorption of subretinal fluid. At 1 month, mean BCVA was 1.0 ± 0.0 decimals and no eye had recurrence of serous retinal detachment, with a mean CFT of 202.3 ± 26.7 µm. No relevant data were found on other parameters investigated.

CONCLUSION

Acute serous retinal detachment is a rare event that can occur after uncomplicated phacoemulsification, which in our cases, resolved in a few days without recurrence.

Aquaporin 4 in Traumatic Brain Injury: From Molecular Pathways to Therapeutic Target

Traumatic brain injury (TBI) is known as an acute degenerative pathology of the central nervous system, and has been shown to increase brain aquaporin 4 (AQP4) expression. Various molecular mechanisms affect AQP4 expression, including neuronal high mobility group box 1, forkhead box O3a, vascular endothelial growth factor, hypoxia-inducible factor-1 α (HIF-1 α) sirtuin 2, NF-κB, Malat1, nerve growth factor and Angiotensin II receptor type 1. In addition, inhibition of AQP4 with FK-506, MK-801 (indirectly by targeting N-methyl-D-aspartate receptor), inactivation of adenosine A2A receptor, levetiracetam, adjudin, progesterone, estrogen, V1aR inhibitor, hypertonic saline, erythropoietin, poloxamer 188, brilliant blue G, HIF-1alpha inhibitor, normobaric oxygen therapy, astaxanthin, epigallocatechin-3-gallate, sesamin, thaliporphine, magnesium, prebiotic fiber, resveratrol and omega-3, as well as AQP4 gene silencing lead to reduced edema upon TBI. This review summarizes current knowledge and evidence on the relationship between AQP4 and TBI, and the potential mechanisms involved.

Childhood cone-rod dystrophy with macular cyst formation in ABCA4 mutation identified by serial spectral-domain optical coherence tomography

Cone-rod dystrophy (CORD) is a type of progressive hereditary retinal dystrophies that causes cone predominant photoreceptor degeneration characterized by wide genotypic and phenotypic heterogeneity. Macular cyst (MC) occurs very infrequently in the pediatric age group and has rarely been described in CORD. We report a case of young-onset CORD that was affected by an isolated ABCA4 mutation complicated by the development of MC. Through serial spectral-domain ocular coherence tomography MC has been observed to persist for 24 months before its resolution, followed by retinal thinning and macular atrophy with corresponding visual acuity decline. The formation of MC and visual acuity appeared to be directly correlated in ABCA4-related CORD and its manifestation is invaluable in predicting eventual visual loss. We further speculate that dysfunctional outer blood-retinal barrier may play a role in the pathophysiology of MC development in CORD.

Current Management Options in Irvine-Gass Syndrome: A Systemized Review

Irvine-Gass syndrome (IGS) remains one of the most common complications following uneventful cataract surgery. In most cases, macular edema (ME) in IGS is benign, self-limiting, and resolves spontaneously without visual impairment; however, persistent edema and refractory cases may occur and potentially deteriorate visual function. Despite the relatively high prevalence of IGS, no solid management guidelines exist. We searched the PUBMED database for randomized clinical trials (RCT) or case series of at least 10 cases published since 2000 evaluating different treatment strategies in patients with cystoid macular edema (CME). The search revealed 28 papers that fulfilled the inclusion criteria with only seven RCTs. The scarceness of material makes it impossible to formulate strong recommendations for the treatment of IGS. Clinical practice and theoretical background support topical non-steroidal anti-inflammatory drugs (NSAIDs) as the first-line therapy. Invasive procedures, such as periocular steroids, intravitreal corticosteroids, and anti-vascular endothelial growth factor (anti-VEGF), are usually applied in prolonged or refractory cases. Results of novel applications of subthreshold micropulse laser (SML) are also promising and should be studied carefully in terms of the safety profile and cost effectiveness. Early initiation of invasive treatment for providing better functional results must be examined in further research.

Efficacy of topical dorzolamide 2% in diabetic cystoid macular edema

AIM

To study the effect of topical dorzolamide 2% on macular thickness reduction in diabetic cystoid macular edema (CME).

METHODS

This was a prospective, non-randomized, open study including eyes with diabetic macular edema (DME). All eyes received topical dorzolamide 2% three times daily for one month. Changes in best-corrected visual acuity (BCVA), and central macular thickness (CMT) by optical coherence tomography) were evaluated at 1wk, 1, and 3mo post-treatment.

RESULTS

Ninety-three eyes (84 patients) were included. Mean±SD (logMAR) BCVA improved significantly from 1.08±0.26 pretreatment to 0.66±0.24 at 1mo and 0.87±0.26 at 3mo post-treatment (P<0.001 both). The mean±SD CMT was significantly reduced from 535.27±97.4 µm at baseline to 357.43±125.8 µm at 1mo and 376.23±114.5 µm at 3mo post-treatment (P<0.001 both). No significant ocular or systemic side effects were recorded.

CONCLUSION

Topical dorzolamide 2% results in significant improvement of mean BCVA and reduction of mean CMT at 3mo post-treatment. It can be used as an effective, affordable, and safe therapy for treatment of non-refractory diabetic CME.

Linking the Presence of Macular Oedema to Structural and Functional Alterations in Retinitis Pigmentosa

OBJECTIVE

To investigate the association between the central retinal thickness (CRT), the retinal nerve fibre layer thickness (RNFL), and the functional alterations in retinitis pigmentosa (RP) patients.

METHODS

Forty-three patients with typical RP and nineteen age-matched controls, who underwent SD-OCT (macular and optic disc OCT protocols) and electrophysiology, were included. The RP group was divided into two subgroups: with clinical appearance of macular oedema (ME-RP; 30 eyes) and without macular oedema (no-ME; 44 eyes). Central retinal thickness OCT data were averaged in three zones (zone 1 [0°-3°], zone 2 [3°-8°], and zone 3 [8°-15°]) and were evaluated in relation to the RNFL thickness and electrophysiological data.

RESULTS

The ME-RP group showed increased CRT (zone 1) and RNFL thickness compared to the controls and no-ME-RP (p ≤ 0.002). The no-ME-RP group had reduced CRT thickness (all zones; p ≤ 0.018) compared to the controls and ME-RP, whereas the RNFL thickness in the no-ME-RP group was reduced only compared to the ME-RP group (p < 0.001). The ME-RP group showed significantly more attenuated functional responses than the no-ME-RP patients. A significant positive interaction was found between the CRT (zones 1 and 2) and the RNFL thickness within ME-RP (p ≤ 0.010). Significant negative interactions were found between CRT, RNFL thickness, and functional findings within ME-RP (p ≤ 0.049).

CONCLUSION

The presence of macular oedema correlated well with increased RNFL thickness and residual function in RP patients. Such association provides evidence of an underlying transneuronal mechanism of retinal degeneration. Simultaneous monitoring of CRT and RNFL thickness may help in the future to evaluate the progression of the disease and the efficacy of treatments in RP patients.

MICROSTRUCTURAL CHANGES IN CYSTOID MACULAR EDEMA IN RETINITIS PIGMENTOSA AFTER INTRAVITREAL DEXAMETHASONE IMPLANT INJECTION

PURPOSE

To evaluate microstructural changes in cystoid macular edema in retinitis pigmentosa after intravitreal dexamethasone implant injection.

METHODS

In an extended cohort of a randomized trial of intravitreal dexamethasone implant for the management of retinitis pigmentosa-associated cystoid macular edema, microstructural changes during six months after the treatment were evaluated using spectral-domain optical coherence tomography.

RESULTS

Forty-two eyes were included, and all had cystoid space in the inner nuclear layer (INL) at baseline. No eyes showed subretinal fluid, and 28.6% showed hyperreflective foci. Among 38 eyes with cystoid space both in the INL and outer nuclear layer/Henle's layer, 13 (34.2%) showed complete resolution and 12 (31.6%) showed cystoid space only in the INL at 2 months after injection, whereas others showed persistent cystoid space in both layers. After complete resolution, cystoid space recurrence was earlier in the INL than in the outer nuclear layer/Henle's layer. Multivariable analysis showed that greater cystoid space area in the INL and outer nuclear layer/Henle's layer, presence of macular leakage, and longer intact external limiting membrane at baseline were associated with greater cystoid space area decrease after the treatment.

CONCLUSION

Resolution and recurrence pattern of retinitis pigmentosa-associated cystoid macular edema after dexamethasone treatment showed that the INL is the primary layer of cystic change, and this suggests its pathogenesis is most likely caused by Müller cell dysfunction.

TOPICAL DORZOLAMIDE-TIMOLOL WITH INTRAVITREOUS ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR FOR RETINAL VEIN OCCLUSION: A PILOT STUDY

PURPOSE

To evaluate topical dorzolamide hydrochloride-timolol maleate as an adjunct therapy to intravitreous anti-vascular endothelial growth factor injections in eyes with retinal vein occlusion resistant to treatment.

METHODS

Retinal vein occlusion patients with a history of persistent macular edema, despite fixed-interval intravitreous anti-vascular endothelial growth factor injections, were enrolled between April 4, 2016, and June 4, 2017. On enrollment, patients were instructed to administer one drop of topical dorzolamide-timolol twice daily for the duration of the study. They were maintained on the same anti-vascular endothelial growth factor drug and same interval between injections as preenrollment for the subsequent two visits. Primary outcome measures were change in central foveal thickness, central subfield thickness, and thickest macular cut at the final study visit.

RESULTS

Eight patients (8 eyes) were eligible for enrollment and completed the study. There was a significant decrease in central foveal thickness (P = 0.02), central subfield thickness (P = 0.03), and thickest macular cut (P = 0.01) between the enrollment visit and the final visit. There was a decrease in mean (±SD) logarithm of the minimal angle of resolution from 0.52 (±0.35) (20/66, Snellen equivalent) at the enrollment visit to 0.41 (±0.35) (20/51, Snellen equivalent) at the final visit (P = 0.08).

CONCLUSION

Topical dorzolamide-timolol may have a beneficial anatomical and functional effect in eyes with macular edema secondary to retinal vein occlusion resistant to treatment.

Efficacy of Topical Carbonic Anhydrase Inhibitors in Reducing Duration of Chronic Central Serous Chorioretinopathy

Purpose

Topical carbonic anhydrase inhibitors (CAIs) can influence retinal fluid distribution, but their role in treating central serous chorioretinopathy (CSCR) has not been studied. We examined the efficacy of a topical CAI (dorzolamide) in treating chronic CSCR.

Methods

Prospective, nonrandomized, controlled intervention study of patients with chronic CSCR of at least 3 months duration. Observed controls (n = 15) were recruited consecutively from 2016 to 2017; treated cases (n = 18) were recruited from 2018 to 2019. Controls were observed without active intervention, whereas treated cases were treated with topical dorzolamide for 3 months. The study end points were change in central macular thickness (CMT), change in best corrected visual acuity (BCVA), and proportion of eyes achieving complete resolution of subretinal fluid (SRF). All end points were at 3 months.

Results

Treated patients who received topical CAI had greater reduction in CMT (−145.6 µm, 95% confidence interval [CI] −170.5 to −120.7) compared to observed controls (−45.1 µm, 95% CI −65.3 to −25.1) at the main study end point of 3 months (P = 0.015). A higher proportion of treated patients achieved complete resolution of SRF compared to observed controls (77.8% vs. 40.0%, P = 0.04) at 3 months. However, change in BCVA at 3 months was similar in both groups (P = 0.12).

Conclusions

Topical CAI resulted in more rapid reduction of CMT compared to observation. These results, if confirmed in other studies, suggest topical CAI may be a viable treatment option for patients with chronic CSCR.

Translational Relevance

Topical CAI is used to treat a number of retinal disorders, and may be a novel treatment option for chronic CSCR.

Current Pharmacological Treatment Options for Central Serous Chorioretinopathy: A Review

Central serous chorioretinopathy (CSC) is a common cause of visual impairment in patients generally aged 20 to 60 and it is characterized by acute or chronic neurosensory detachments of the retina. Although CSC resolves spontaneously in most cases, in some patients it may cause permanent visual impairment in the working population; for this reason, several approaches, including photodynamic therapy (PDT), subthreshold micropulse laser treatment and oral mineralocorticoid receptor antagonists, have been studied as first-line treatment options for CSC. To date, half-dose PDT has provided the most encouraging results in this regard, supported by large, multicenter, randomized clinical trials such as the “Prospective Randomized Controlled Treatment Trial for Chronic Central Serous Chorioretinopathy” (PLACE) trial; however, the role of novel possible non-invasive treatment options is attracting interest. This review article aims to discuss the current pharmacological treatment options investigated for the management of CSC, including aspirin, ketoconazole, beta blockers, rifampicin and many others. In particular, further evidence about oral mineralocorticoid receptor antagonists, firstly seen as promising non-invasive alternatives for treating CSC, will be provided and discussed in light of the recent “Eplerenone for chronic central serous chorioretinopathy in patients with active, previously untreated disease for more than 4 months” (VICI) trial results, which have largely resized their role as possible first-line oral treatment options for treating CSC.

Retinitis Pigmentosa and Retinal Degenerations: Deciphering Pathways and Targets for Drug Discovery and Development

Inherited retinal diseases (IRDs) are a group of retinopathies generally caused by genetic mutations. Retinitis pigmentosa (RP) represents one of the most studied IRDs. RP leads to intense vision loss or blindness resulting from the degeneration of photoreceptor cells. To date, RP is mainly treated with palliative supplementation of vitamin A and retinoids, gene therapies, or surgical interventions. Therefore, a pharmacologically based therapy is an urgent need requiring a medicinal chemistry approach, to validate molecular targets able to deal with retinal degeneration. This Review aims at outlining the recent research efforts in identifying new drug targets for RP, especially focusing on the neuroprotective role of the Wnt/β-catenin/GSK3β pathway and apoptosis modulators (in particular PARP-1) but also on growth factors such as VEGF and BDNF. Furthermore, the role of spatiotemporally expressed G protein-coupled receptors (GPR124) in the retina and the emerging function of histone deacetylase inhibitors in promoting retinal neuroprotection will be discussed.

RESPONSE OF INFLAMMATORY CYSTOID MACULAR EDEMA TO TREATMENT USING ORAL ACETAZOLAMIDE

PURPOSE

To determine the treatment effect of oral acetazolamide on refractory inflammatory macular edema.

METHODS

A retrospective review of identified patients with uveitic or pseudophakic macular edema treated using acetazolamide between 2007 and 2014. Visual acuity and central macular subfield thickness was determined at baseline and at first follow-up. Baseline optical coherence tomography features were analyzed as predictors of acetazolamide response.

RESULTS

Sixteen patients (19 eyes) of 61 screened met all criteria. Mean age was 57.9 years (19.7-81.1). The most common diagnosis was idiopathic uveitis (n = 6, 31.6%). Mean uveitis duration was 4.4 years (0.2-27.5). Average central macular subfield thickness decreased significantly (from 471.8 ± 110.6 μm to 358.3 ± 50.4 μm) (P < 0.0001). Average visual acuity (logarithm of the minimum angle of resolution) improved significantly from 20/54 (0.43 ± 0.25) to 20/37 (0.27 ± 0.16) (P = 0.003). Pretreatment optical coherence tomographies demonstrated intraretinal fluid (n = 19, 100%), subretinal fluid (n = 8, 42.1%), epiretinal membrane (n = 13, 68.3%), and vitreomacular traction (n = 1, 5.2%). No optical coherence tomography characteristic was predictive of a response to therapy.

CONCLUSION

There is a significant benefit to vision and central macular subfield thickness after acetazolamide treatment in patients with inflammatory macular edema. In patients with refractory inflammatory macular edema, treatment using acetazolamide can provide anatomical and visual benefit without corticosteroid-related adverse effects.

Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations

: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.

Oral medications for central serous chorioretinopathy: a literature review

Central serous chorioretinopathy (CSCR) is characterised by acute or chronic neurosensory detachments of the retina, usually in the posterior pole, with or without associated detachments of retinal pigment epithelium. Although the condition often resolves spontaneously, chronic and recurrent cases can lead to significant visual loss in the working population and it is thus increasingly recognised as an important public health issue. The uncertainty regarding the underlying cause of CSCR has led to a wide range of therapies being tried for this condition including photodynamic therapy, laser photocoagulation, anti-VEGF injections and a multitude of oral agents. This article aims to review the current evidence for oral agents that have been used for treatment of CSCR. A systematic literature search was conducted for articles published between 1980 to July 2018. A total of 73 articles were included. These studied the following oral medications: eplerenone, spironolactone, beta blockers, H. pylori agents, omeprazole, rifampicin, methotrexate, aspirin, acetazolamide, mifepristone, melatonin, finasteride, ketoconazole, antioxidants and curcumin phospholipid. Although none of the studies showed robust evidence of efficacy, the mineralocorticoid receptor antagonists, particularly eplerenone, appear to demonstrate the highest quality evidence for use in this condition. The review aims to give the reader an overview of the current available evidence for oral medications used in the treatment of CSCR in order to provide an evidence-based discussion with the patient and guide through possible options for treatment.

Fluid and solute transport across the retinal pigment epithelium: a theoretical model

The retina is composed of two main layers-the neuroretina and the retinal pigment epithelium (RPE)-that are separated by a potential gap termed the sub-retinal space (SRS). Accumulation of fluid in the SRS may result in a retinal detachment. A key function of the RPE is to prevent fluid accumulation in the SRS by actively pumping fluid from this space to the choroid. We have developed a mathematical model of this process that incorporates the transport of seven chemical species: Na⁺, K⁺, Cl^-, HCO3-, H⁺, CO₂ and H₂CO₃. This allows us to estimate solute and water fluxes and to understand the role of the different membrane ion channels. We have performed a global sensitivity analysis using the extended Fourier amplitude sensitivity test to investigate the relative importance of parameters in generating the model outputs. The model predicts that flow across the RPE is driven by an osmotic gradient in the cleft gap between adjacent cells. Moreover, the model estimates how water flux is modified in response to inhibition of membrane ion channels and carbonic anhydrase (CA). It provides a possible explanation for how CA inhibitors, which are used clinically to prevent fluid accumulation in the SRS, may be acting.

Effect of Acetazolamide on Choroidal Morphology in Central Serous Chorioretinopathy

PURPOSE

We sought to elucidate the influence of acetazolamide on choroidal structure changes during the treatment of central serous chorioretinopathy (CSC).

METHODS

This was a retrospective study of 45 eyes from 45 patients with acute CSC who were divided into an acetazolamide group (group 1, n = 20) and an observation group (group 2, n = 25). The main outcome measures were the changes in best-corrected visual acuity, subretinal fluid (SRF) height, subfoveal choroidal thickness (SFCT), and choroidal vascularity index (CVI) at one week, one month, two months, and three months, respectively.

RESULTS

Although statistical significance was not reached, best-corrected visual acuity improved in both groups at month 3 (from 0.06 ± 0.07 to 0.01 ± 0.03 in group 1 and 0.17 ± 0.24 to 0.09 ± 0.18 in group 2; p = 0.083 and 0.183, respectively). Separately, SRF height and CVI showed a significant decrease at three months in both groups (all p < 0.05), while a significant SRF height decrease was also noted in group 1 at one month (p = 0.038). In group 1, a significant decrease in the SFCT and CVI started at one week and one month (p = 0.021 and 0.008), respectively. However, in group 2, a significant decrease in the SFCT and CVI started at one month and two months (p = 0.005 and 0.015), respectively.

CONCLUSIONS

Acetazolamide has no effect on final functional or anatomical status at three months in eyes with CSC but does shorten the time for SRF absorption and accompanying choroidal structural changes.

Agents for the prevention and treatment of age-related macular degeneration and macular edema: a literature and patent review

Introduction: Macular degeneration (MD) and macular edema (ME) are ophthalmologic diseases affecting an increasing number of the aging population. Until recently, there were few therapeutic options for both conditions but the last two decades saw important advances. Areas covered: This review summarizes the agents used for the treatment of age-related MD (AMD), which include verteporfin, for photodynamic therapy, and anti-VEGF agents, the aptamer pegaptanib, the monoclonal antibodies (MAbs) ranibizumab (Lucentis®) and bevacizumab (Avastin®) and the fusion protein aflibercept (Eylea®). All these drugs are effective only for the wet form of AMD, whereas for the dry form there is no treatment available. ME is, on the other hand, treated with nonsteroidal anti-inflammatory drugs and carbonic anhydrase (CA) inhibitors. Recently, MAbs such as ranibizumab and bevacizumab were also shown to be effective for the management of the cystoid and diabetic ME. Expert opinion: There are important advances made in the field in the last years but longer-acting anti-VEGF agents or drugs with less ocular side effects are needed. Many such agents are in clinical development.

A RANDOMIZED PAIRED-EYE TRIAL OF INTRAVITREAL DEXAMETHASONE IMPLANT FOR CYSTOID MACULAR EDEMA IN RETINITIS PIGMENTOSA

PURPOSE

To evaluate the efficacy and safety of intravitreal dexamethasone (DEX) implant in retinitis pigmentosa patients with cystoid macular edema (CME).

METHODS

In this randomized, noncontrolled, paired-eye, single crossover clinical trial, one eye of retinitis pigmentosa patients with bilateral CME with central macular thickness of >250 µm was randomized to intravitreal DEX implant while the fellow eye was observed. Both eyes were started on topical dorzolamide. At Month 6, DEX implant was eligible for both eyes when CME was >250 µm. Patients were followed up until Month 12. Primary outcome measures were the central macular thickness and best-corrected visual acuity changes from baseline at Month 2.

RESULTS

Fourteen patients with bilateral RP-CME were included. Study eyes showed significant central macular thickness decrease (median, -147.5 µm; P = 0.001) and best-corrected visual acuity improvement (median, +6 letters; P = 0.001) at Month 2, but not at Month 6. Intravitreal DEX implant at Month 6 produced comparable efficacy to baseline treatment in 11 fellow eyes and 12 study eyes. Topical dorzolamide did not show significant therapeutic efficacy. During 12 months, elevated intraocular pressure of >21 mmHg and cataract progression were observed in 14.3% and 40.0% of study eyes.

CONCLUSION

Intravitreal DEX implant can both reduce macular thickness and improve vision in RP-CME, while repeated injection is required.

Update in treatment of uveitic macular edema

Macular edema (ME) represents the most common cause for visual loss among uveitis patients. The management of uveitic macular edema (UME) may be challenging, due to its often recalcitrant nature. Corticosteroids remain the mainstay of treatment, through their capability of effectively controlling inflammation and the associated ME. Topical steroids may be effective in milder cases of UME, particularly in edema associated with anterior uveitis. Posterior sub-Tenon and orbital floor steroids, as well as intravitreal steroids often induce rapid regression of UME, although this may be followed by recurrence of the pathology. Intra-vitreal corticosteroid implants provide sustained release of steroids facilitating regression of ME with less frequent injections. Topical nonsteroidal anti-inflammatory drugs may provide a safe alternative or adjuvant therapy to topical steroids in mild UME, predominantly in cases with underlying anterior uveitis. Immunomodulators including methotrexate, mycophenolate mofetil, tacrolimus, azathioprine, and cyclosporine, as well as biologic agents, notably the anti-tumor necrosis factor-α monoclonal antibodies adalimumab and infliximab, may accomplish the control of inflammation and associated ME in refractory cases, or enable the tapering of steroids. Newer biotherapies have demonstrated promising outcomes and may be considered in persisting cases of UME.

Central serous chorioretinopathy: Current update on management

Central serous chorioretinopathy (CSC), the fourth most common nonsurgical retinopathy with a usual self-limiting course, is known to present with persistent or recurrent form with distressing visual loss. Evolution of newer mutimodal imaging techniques have revolutionized the understanding about the pathophysiology of CSC, and hence the diagnosis and management. Multifactorial etiopathology of CSC promotes the use of multiple treatment modalities. With advances in investigative options, treatment options including conventional focal laser, micropulse laser, photodynamic therapy, and transpupillary thermotherapy are also advancing and refining. Medical management for CSC is also under evaluation with a wide spectrum of new drugs in vogue. However, standard of treatment is yet to be established through randomized clinical trials. This review article discusses the current approach to multimodal treatment options for CSC including conventional as well as newer therapeutic modalities.

Macular Grid Photocoagulation in Persistent Macular Edema Due to Central Retinal Vein Occlusion

AIM

Macular edema is still the main cause of poor visual prognosis in central retinal vein occlusion (CRVO). This study was designed to establish whether grid photocoagulation is effective in the management of this disorder.

METHODS

The records of 16 patients who had undergone macular grid photocoagulation for persistent macular edema due to CRVO were reviewed retrospectively. Pre-treatment visual acuity ranged from 20/400 to 20/40, and laser treatment was done six months or more after the onset of the disease.

RESULTS

Biomicroscopy and fluorescein angiography showed the improvement or disappearance of macular edema in 14/16 patients (87.5%). Improved visual acuity was observed in eight (50%) and no improvement or reduced vision in the other eight (50%). A poorer prognosis was statistically correlated with older age (p < 0.03), macular ischemia (p < 0.001), foveal avascular zone larger than 1/2 disc diameter (p < 0.05) and pigmentary clumps in the foveal area (p < 0.05). Laser treatment was ineffective for most patients with systemic vascular risk factors and pre-treatment visual acuity below 20/200.

CONCLUSION

Macular grid photocoagulation may be effective for drying up, or at least reducing, macular edema due to CRVO and some improvement of vision can be expected in half the cases.

Molecular genetics and emerging therapies for retinitis pigmentosa: Basic research and clinical perspectives

Retinitis Pigmentosa (RP) is a hereditary retinopathy that affects about 2.5 million people worldwide. It is characterized with progressive loss of rods and cones and causes severe visual dysfunction and eventual blindness in bilateral eyes. In addition to more than 3000 genetic mutations from about 70 genes, a wide genetic overlap with other types of retinal dystrophies has been reported with RP. This diversity of genetic pathophysiology makes treatment extremely challenging. Although therapeutic attempts have been made using various pharmacologic agents (neurotrophic factors, antioxidants, and anti-apoptotic agents), most are not targeted to the fundamental cause of RP, and their clinical efficacy has not been clearly proven. Current therapies for RP in ongoing or completed clinical trials include gene therapy, cell therapy, and retinal prostheses. Gene therapy, a strategy to correct the genetic defects using viral or non-viral vectors, has the potential to achieve definitive treatment by replacing or silencing a causative gene. Among many clinical trials of gene therapy for hereditary retinal diseases, a phase 3 clinical trial of voretigene neparvovec (AAV2-hRPE65v2, Luxturna) recently showed significant efficacy for RPE65-mediated inherited retinal dystrophy including Leber congenital amaurosis and RP. It is about to be approved as the first ocular gene therapy biologic product. Despite current limitations such as limited target genes and indicated patients, modest efficacy, and the invasive administration method, development in gene editing technology and novel gene delivery carriers make gene therapy a promising therapeutic modality for RP and other hereditary retinal dystrophies in the future.

Efficacy of carbonic anhydrase inhibitors in management of cystoid macular edema in retinitis pigmentosa: A meta-analysis

Background

Carbonic anhydrase inhibitors (CAI) are often used in the treatment of cystoid macular edema (CME) in retinitis pigmentosa (RP) patients. The aim of this meta-analysis is to gain a better understanding of the overall efficacy of CAI treatment.

Methods

Databases including PubMed, EMBASE, and Cochrane Library were searched to identify relevant studies. Eligible studies were clinical trials of patients with RP assigned topical or oral CAIs such as dorzolamide and acetazolamide. Changes in central macular thickness (CMT) by OCT in μm and best-corrected visual acuity (BCVA) in log MAR equivalents were extracted and results compared between baseline and after treatment.

Results

11 clinical reports were identified which included a total of 194 patients (358 eyes) available for analysis, with 59 patients (115 eyes) assigned oral CAI treatment and 135 patients (243 eyes) assigned topical CAI treatment. The combined results showed a significant reduction of macular edema, as calculated by baseline and final central macular thickness (CMT) based on OCT examination (46.02μm, 95%CI: -60.96, -31.08, I² = 65%). However, the effect on visual acuity was inconsistent across studies.

Conclusion

Based on non randomized controlled clinical studies, RP patients with CME who were treated with CAIs had better anatomical outcomes, but the effect on visual acuity was contradictory across studies. Multicenter prospective randomized controlled trials would be ideal to definitively test its clinical efficacy in RP patients.

[Usher syndrome: about a case]

Le syndrome d'Usher est une maladie génétique comportant une double atteinte sensorielle (auditive et visuelle) appelée surdicécité. Nous rapportons l'observation d'un patient de 50 ans, issue d'un mariage consanguin présentant une surdité congénitale avec une fonction vestibulaire normale et une rétinopathie pigmentaire responsable d'une baisse bilatérale de l'acuité visuelle apparue vers l'âge de 16 ans. Cette association compose le type 2 du syndrome d'Usher, affection rare de transmission autosomique récessive. La chirurgie de la cataracte a permis une amélioration de l'acuité visuelle chez ce patient.

Widening use of dexamethasone implant for the treatment of macular edema

Sustained-release intravitreal 0.7 mg dexamethasone (DEX) implant is approved in Europe for the treatment of macular edema related to diabetic retinopathy, branch retinal vein occlusion, central retinal vein occlusion, and non-infectious uveitis. The implant is formulated in a biodegradable copolymer to release the active ingredient within the vitreous chamber for up to 6 months after an intravitreal injection, allowing a prolonged interval of efficacy between injections with a good safety profile. Various other ocular pathologies with inflammatory etiopathogeneses associated with macular edema have been treated by DEX implant, including neovascular age-related macular degeneration, Irvine-Gass syndrome, vasoproliferative retinal tumors, retinal telangiectasia, Coats' disease, radiation maculopathy, retinitis pigmentosa, and macular edema secondary to scleral buckling and pars plana vitrectomy. We undertook a review to provide a comprehensive collection of all of the diseases that benefit from the use of the sustained-release DEX implant, alone or in combination with concomitant therapies. A MEDLINE search revealed lack of randomized controlled trials related to these indications. Therefore we included and analyzed all available studies (retrospective and prospective, comparative and non-comparative, randomized and nonrandomized, single center and multicenter, and case report). There are reports in the literature of the use of DEX implant across a range of macular edema-related pathologies, with their clinical experience supporting the use of DEX implant on a case-by-case basis with the aim of improving patient outcomes in many macular pathologies. As many of the reported macular pathologies are difficult to treat, a new treatment option that has a beneficial influence on the clinical course of the disease may be useful in clinical practice.

Treatment of cystic cavities in X-linked juvenile retinoschisis: The first sequential cross-over treatment regimen with dorzolamide

Purpose

To report the first sequential cross-over treatment with the longest ophthalmic follow-up in a case of X-linked juvenile retinoschisis (XLRS) successfully treated with topical dorzolamide.

Observations

A healthy 34 year-old man presented with one month history of decreased visual acuity in his left eye. Funduscopy was significant for a blunted and cystoid-like foveal reflex in both eyes. The macular OCT showed cystic foveal changes OU. The patient was diagnosed with XLRS and was observed. On two subsequent follow-ups, a significant decrease in the patient's visual acuity warranted the use of topical dorzolamide for treating the cystic foveal changes, which completely resolved two months post-treatment initiation.

Conclusion and importance

Previous reports showed the benefit of dorzolamide in treating foveal cystic cavities in XLRS. To our knowledge, this is the first case of XLRS demonstrating the benefits of topical dorzolamide based on a sequential cross-over treatment regimen. It may also represent a case with the longest ophthalmic follow-up providing, in consequence, long-term understanding of the natural history and complications of this rare disease After ruling out major causes of cystoid macular edema, XLRS patients presenting with worsening of their visual acuities due to larger cystic macular changes may benefit from an alternating ON/OFF regimen of topical dorzolamide, which offers a significant treatment advantage outweighing its well-known side effects. Our study consolidates the importance of “medication vacation” by showing its efficacy in providing anatomical and visual functional improvements in patients with chronic cystic macular changes.

The effect of oral acetazolamide on cystoid macular edema in hydroxychloroquine retinopathy: a case report

Background

Hydroxychloroquine (HCQ) retinopathy can accompany other retinal complications such as cystoid macular edema (CME), which leads to central visual loss. We report a case of CME with HCQ retinopathy that improved with the use of oral acetazolamide, and discussed the possible mechanisms of CME in HCQ retinopathy using multimodal imaging modalities.

Case presentation

A 62-year-old patient with systemic lupus erythematosus (SLE) and HCQ retinopathy developed bilateral CME with visual decline. Fluorescein angiography (FA) showed fluorescein leakage in the macular and midperipheral area. After treatment with oral acetazolamide (250 mg/day) for one month, CME was completely resolved, best corrected visual acuity (BCVA) improved from 20/50 to 20/25, and FA examination showed decreased dye leakage in the macular and midperipheral areas.

Conclusions

In cases of vision loss in HCQ retinopathy, it is important to consider not only progression of maculopathy, but also development of CME, which can be effectively treated with oral acetazolamide.

Novel mutations in CRB1 gene identified in a chinese pedigree with retinitis pigmentosa by targeted capture and next generation sequencing

PURPOSE

To detect the disease-causing gene in a Chinese pedigree with autosomal-recessive retinitis pigmentosa (ARRP).

METHODS

All subjects in this family underwent a complete ophthalmic examination. Targeted-capture next generation sequencing (NGS) was performed on the proband to detect variants. All variants were verified in the remaining family members by PCR amplification and Sanger sequencing.

RESULTS

All the affected subjects in this pedigree were diagnosed with retinitis pigmentosa (RP). The compound heterozygous c.138delA (p.Asp47IlefsX24) and c.1841G>T (p.Gly614Val) mutations in the Crumbs homolog 1 (CRB1) gene were identified in all the affected patients but not in the unaffected individuals in this family. These mutations were inherited from their parents, respectively.

CONCLUSION

The novel compound heterozygous mutations in CRB1 were identified in a Chinese pedigree with ARRP using targeted-capture next generation sequencing. After evaluating the significant heredity and impaired protein function, the compound heterozygous c.138delA (p.Asp47IlefsX24) and c.1841G>T (p.Gly614Val) mutations are the causal genes of early onset ARRP in this pedigree. To the best of our knowledge, there is no previous report regarding the compound mutations.

Topical carbonic anhydrase inhibitors in macular edema associated with Alström syndrome

BACKGROUND

Alström syndrome is a rare genetic ciliopathy caused by a mutation in the ALMS1 gene. The syndrome is characterized by cone-rod dystrophy, dilated myocardiopathy, childhood obesity and sensorineural hearing loss. To date, cystoid macular edema has not been reported.

METHODS

A female affected by Alström syndrome developed bilateral cystoid macular edema evidenced by optical coherence tomography. A topical carbonic anhydrase inhibitor was prescribed.

RESULTS

Complete resolution of the cystoid macular edema was achieved, though visual acuity did not improve.

CONCLUSIONS

Topical carbonic anhydrase inhibitors may have a role in the treatment of macular edema in syndromic retinal dystrophies such as Alström syndrome.

Effectiveness and safety of dexamethasone implants for postsurgical macular oedema including Irvine-Gass syndrome: the EPISODIC-2 study

AIM

To assess the effectiveness of intravitreal dexamethasone implants for treating postsurgical macular oedema (PSMO) including Irvine-Gass syndrome and determining the predictive factors of treatment response.

METHODS

Descriptive, observational, retrospective, consecutive, uncontrolled, multicentre, national case series. One hundred patients were included between April 2011 and June 2014, with a minimum of 1-year follow-up. Patients received dexamethasone implant 0.7 mg at baseline. Clinical characteristics, best-corrected visual acuity (BCVA), central subfield macular thickness (CSMT) and intraocular pressure were measured at each visit. The main outcome measure was the change in BCVA (Early Treatment of Diabetic Retinopathy Study (ETDRS) letters: L). An analysis of predictive factors of treatment response is also provided.

RESULTS

Mean improvement in BCVA was 9.6 (±10.6) L at month 6 and 10.3 (±10.7) L at month 12 (p<0.001). The proportion of eyes with gains in BCVA of 15 or more letters was 32.5% and 37.5% at months 6 and 12, respectively. The mean reduction in CSMT was 135.2 and 160.9 µm at months 6 and 12, respectively (p<0.001). Thirty-seven per cent of patients did not need a second injection after the first injection during follow-up. The presence of at least one PSMO risk factor decreases the probability of a gain in visual acuity (VA) ≥10 L (p=0.006). Initial VA ≤50 L at baseline and non-naïve status decrease the probability of having only one injection during follow-up (p=0.044).

CONCLUSIONS

The significant gain in BCVA from baseline achieved at month 6 was maintained at month 12 after intravitreal injection of dexamethasone implant. Naïve status seems to be a good predictive factor of treatment response.

Changes in morphology and visual function over time in mouse models of retinal degeneration: an SD-OCT, histology, and electroretinography study

PURPOSE

To examine the long-term natural course of retinal degeneration in rd10 and rd12 mice using serial spectral-domain optical coherence tomography (SD-OCT), electroretinography/electroretinograms (ERGs), and histological analysis.

METHODS

Photoreceptor layer thickness and the ability to visualize photoreceptor ellipsoid zones were analyzed using SD-OCT images, and these images were compared with hematoxylin and eosin-stained sections and electron microscopy images. The a- and b-wave amplitudes of the ERGs were analyzed.

RESULTS

In rd10 mice, the photoreceptor layer thickness rapidly decreased, and the photoreceptor ellipsoid zone was visible on SD-OCT images in 89 and 43 % of eyes of 21 and 33-day-old mice, respectively. In rd12 mice, the photoreceptor layer gradually thinned, and the ellipsoid zone remained visible in 92 % of eyes at 19 months. Electron microscopy revealed that photoreceptor degeneration had occurred on the inner side of the outer nuclear layer in 21-day-old rd10 and 7-month-old rd12 mice, possibly due to autophagy mechanisms. Scotopic ERGs of rd10 mice showed a diminished response at 21 days; at 33 days, no response was detectable. In rd12 mice, scotopic ERGs were undetectable at 28 days (stimulus intensity 3.0 cds/m(2)). Photopic ERGs were nearly undetectable in 28-day-old rd10 mice, but a small b-wave was still recordable in 13-month-old rd12 mice.

CONCLUSIONS

Our results demonstrate that visual function deteriorated with photoreceptor degeneration within 1 month in rd10 mice. In rd12 mice, however, the process of visual function deterioration and photoreceptor degeneration was still in progress at 13 months of age.

Design and development of sulfonylurea derivatives as zinc metalloenzyme modulators

Sulfonylurea derivatives are zinc metalloenzyme modulators.

Interventions for central serous chorioretinopathy: a network meta-analysis

BACKGROUND

Central serous chorioretinopathy (CSC) is characterized by serous detachment of the neural retina with dysfunction of the choroid and retinal pigment epithelium (RPE). The effects on the retina are usually self limited, although some people are left with irreversible vision loss due to progressive and permanent photoreceptor damage or RPE atrophy. There have been a variety of interventions used in CSC, including, but not limited to, laser treatment, photodynamic therapy (PDT), and intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents. However, it is not known whether these or other treatments offer significant advantages over observation or other interventions. At present there is no evidence-based consensus on the management of CSC. Due in large part to the propensity for CSC to resolve spontaneously or to follow a waxing and waning course, the most common initial approach to treatment is observation. It remains unclear whether this is the best approach with regard to safety and efficacy.

OBJECTIVES

To compare the relative effectiveness of interventions for central serous chorioretinopathy.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to February 2014), EMBASE (January 1980 to October 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 October 2015.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that compared any intervention for CSC with any other intervention for CSC or control.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We pooled data from all studies using a fixed-effect model. For interventions applied to the eye (i.e. not systemic interventions), we synthesized direct and indirect evidence in a network meta-analysis model.

MAIN RESULTS

We included 25 studies with 1098 participants (1098 eyes) and follow-up from 16 weeks to 12 years. Studies were conducted in Europe, North and South America, Middle East, and Asia. The trials were small (most trials enrolled fewer than 50 participants) and poorly reported; often it was unclear whether key aspects of the trial, such as allocation concealment, had been done. A substantial proportion of the trials were not masked.The studies considered a variety of treatments: anti-VEGF (ranibizumab, bevacizumab), PDT (full-dose, half-dose, 30%, low-fluence), laser treatment (argon, krypton and micropulse laser), beta-blockers, carbonic anhydrase inhibitors, Helicobactor pylori treatment, and nutritional supplements (Icaps, lutein); there were only one or two trials contributing data for each comparison. We downgraded for risk of bias and imprecision for most analyses, reflecting study limitations and imprecise estimates. Network meta-analysis (as planned in our protocol) did not help to resolve this uncertainty due to a lack of trials, and problems with intransitivity, particularly with respect to acute or chronic CSC.Low quality evidence from two trials suggested little difference in the effect of anti-VEGF (ranibizumab or bevacizumab) or observation on change in visual acuity at six months in acute CSC (mean difference (MD) 0.01 LogMAR (logarithm of the minimal angle of resolution), 95% confidence interval (CI) -0.02 to 0.03; 64 participants). CSC had resolved in all participants by six months. There were no significant adverse effects noted.Low quality evidence from one study (58 participants) suggested that half-dose PDT treatment of acute CSC probably results in a small improvement in vision (MD -0.10 logMAR, 95% CI -0.18 to -0.02), less recurrence (risk ratio (RR) 0.10, 95% CI 0.01 to 0.81) and less persistent CSC (RR 0.12, 95% CI 0.01 to 1.02) at 12 months compared to sham treatment. There were no significant adverse events noted.Low quality evidence from two trials (56 participants) comparing anti-VEGF to low-fluence PDT in chronic CSC found little evidence for any difference in visual acuity at 12 months (MD 0.03 logMAR, 95% CI -0.08 to 0.15). There was some evidence that more people in the anti-VEGF group had recurrent CSC compared to people treated with PDT but, due to inconsistency between trials, it was difficult to estimate an effect. More people in the anti-VEGF group had persistent CSC at 12 months (RR 6.19, 95% CI 1.61 to 23.81; 34 participants).Two small trials of micropulse laser, one in people with acute CSC and one in people with chronic CSC, provided low quality evidence that laser treatment may lead to better visual acuity (MD -0.20 logMAR, 95% CI -0.30 to -0.11; 45 participants). There were no significant adverse effects noted.Other comparisons were largely inconclusive.We identified 12 ongoing trials covering the following interventions: aflibercept and eplerenone in acute CSC; spironolactone, eplerenone, lutein, PDT, and micropulse laser in chronic CSC; and micropulse laser and oral mifepristone in two trials where type of CSC not clearly specified.

AUTHORS' CONCLUSIONS

CSC remains an enigmatic condition in large part due to a natural history of spontaneous improvement in a high proportion of people and also because no single treatment has provided overwhelming evidence of efficacy in published RCTs. While a number of interventions have been proposed as potentially efficacious, the quality of study design, execution of the study and the relatively small number of participants enrolled and followed to revealing endpoints limits the utility of existing data. It is not clear whether there is a clinically important benefit to treating acute CSC which often resolves spontaneously as part of its natural history. RCTs comparing individual treatments to the natural history would be valuable in identifying potential treatment groups for head-to-head comparison. Of the interventions studied to date, PDT or micropulse laser treatment appear the most promising for study in future trials.

Strong topical steroid, NSAID, and carbonic anhydrase inhibitor cocktail for treatment of cystoid macular edema

Purpose

To report the combination cocktail of strong steroid, non-steroidal anti-inflammatory drug (NSAID), and carbonic anhydrase inhibitor drops for treatment of cystoid macular edema.

Methods

This is a retrospective case series of patients with cystoid macular edema managed with a topical combination of strong steroid (difluprednate), NSAID, and carbonic anhydrase inhibitor drops. The patients were followed with optical coherence tomography and fluorescein angiography.

Results

In our six cases, resolution of the cystic edema with improvement in visual acuity was achieved with the use of a combination cocktail of drops. Leakage on fluorescein angiography and cystic edema on optical coherence tomography both responded to treatment with the topical cocktail of drops.

Conclusion

A topical cocktail of strong steroid, NSAID, and carbonic anhydrase inhibitor drops are effective for managing cystoid macular edema. Further studies comparing this combination with more invasive treatments should be undertaken to determine the efficacy of this cocktail over other treatment options.