Transfoveal Micropulse Laser Treatment of Central Serous Chorioretinopathy within Six Months of Disease Onset

Central serous chorioretinopathy: An evidence-based treatment guideline

Central serous chorioretinopathy (CSC) is a relatively common disease that causes vision loss due to macular subretinal fluid leakage and it is often associated with reduced vision-related quality of life. In CSC, the leakage of subretinal fluid through defects in the retinal pigment epithelial layer's outer blood-retina barrier appears to occur secondary to choroidal abnormalities and dysfunction. The treatment of CSC is currently the subject of controversy, although recent data obtained from several large randomized controlled trials provide a wealth of new information that can be used to establish a treatment algorithm. Here, we provide a comprehensive overview of our current understanding regarding the pathogenesis of CSC, current therapeutic strategies, and an evidence-based treatment guideline for CSC. In acute CSC, treatment can often be deferred for up to 3-4 months after diagnosis; however, early treatment with either half-dose or half-fluence photodynamic therapy (PDT) with the photosensitive dye verteporfin may be beneficial in selected cases. In chronic CSC, half-dose or half-fluence PDT, which targets the abnormal choroid, should be considered the preferred treatment. If PDT is unavailable, chronic CSC with focal, non-central leakage on angiography may be treated using conventional laser photocoagulation. CSC with concurrent macular neovascularization should be treated with half-dose/half-fluence PDT and/or intravitreal injections of an anti-vascular endothelial growth factor compound. Given the current shortage of verteporfin and the paucity of evidence supporting the efficacy of other treatment options, future studies-ideally, well-designed randomized controlled trials-are needed in order to evaluate new treatment options for CSC.

Crossover to PDT after the unsuccessful micropulse laser treatment of central serous chorioretinopathy

Purpose

Subthreshold micropulse laser (SML) and photodynamic therapy (PDT) are among the most effective therapeutic modalities applied to central serous chorioretinopathy (CSCR). This study aimed to evaluate the efficacy and durability of PDT in CSCR cases unresponsive to at least two SML treatments.

Methods

The study included 26 consecutive eyes of 24 patients (21 males and three females) with chronic CSCR. In all cases, a lack of reduction in subretinal fluid (SRF) levels was noted after at least two consecutive SML sessions. The parameters of best corrected visual acuity (BCVA) and spectral domain optical coherence tomography (SD-OCT) were evaluated at baseline and 1, 3 and 12 months post-PDT.

Results

The mean duration of symptoms in the group was 53.81 ± 39.48 months, the mean age of the patients was 49.26 ± 12.91 years, and the mean subfoveal choroidal thickness (SFCT) was 572.11 ± 116.21 mm. Complete resorption of SRF was observed in 21 out of 26 eyes (80.77%) at 1 month and sustained in 18 cases (69.23%) at 12 months. At 12 months, in the sustained group, BCVA improved significantly from 0.39 ± 0.18 to 0.19 ± 0.2 logMAR (P = 0.01), central subfoveal thickness (CST) reduced from 316.44 ± 75.83 mm to 197.67 ± 22.99 mm (P < 0.0001), and SFCT reduced from 579.28 mm to 446.78 mm (P < 0.0001).

Conclusions

PDT provides the opportunity for the successful treatment of CSCR unresponsive to SML treatment. Improvements are possible even in cases with a long duration of symptoms and significant alterations in retinal morphology. Thus, PDT should be considered for patients with prominently increased choroidal thickness.

Subthreshold laser treatment in retinal diseases: a mini review

PURPOSE

To summarize the mechanism and the clinical applications of subthreshold laser (STL) in retinal practice. Subthreshold or "non-destructive" laser includes all types of laser treatments that produce minimal or no damage to the tissues and no visible signs after application.

METHODS

A descriptive review of articles from literature databases (PubMed, Medline, Embase, Cochrane, Web of Science) published before August 2023, which discuss current STL treatments of retinal diseases.

RESULTS

This review provides evidence for STL as a treatment option for central serous chorioretinopathy, diabetic retinopathy, age-related macular degeneration, macular edema due to retinal vein occlusion, and other maculopathies. In most published reports, STL has shown a therapeutic effect without damage to the underlying tissue.

CONCLUSION

Subthreshold laser treatment has shown safety and efficacy in the management of some retinal and macular diseases. Stimulation of the retinal pigment epithelium without destroying adjacent neuroretina has been shown to be sufficient in inducing retinal repair in many clinical cases. Recent research and clinical studies continue to explore the mechanisms and improving therapeutic benefits of this technology as well as extend the range of retinal disorders treatable by this modality.

Micropulse Laser Therapy as an Integral Part of Eye Disease Management

Ocular diseases can significantly impact vision and quality of life through pathophysiological alterations to the structure of the eye. The management of these conditions often involves a combination of pharmaceutical interventions, surgical procedures, and laser therapy. Laser technology has revolutionized many medical fields, including ophthalmology, offering precise and targeted treatment options that solve some of the unmet needs of other therapeutic strategies. Conventional laser techniques, while effective, can generate excessive thermal energy, leading to collateral tissue damage and potential side effects. Compared to conventional laser techniques, micropulse laser therapy delivers laser energy in a pulsed manner, minimizing collateral damage while effectively treating target tissues. The present paper highlights the advantages of micropulse laser therapy over conventional laser treatments, presents the implications of applying these strategies to some of the most prevalent ocular diseases, and highlights several types and mechanisms of micropulse lasers. Although micropulse laser therapy shows great potential in the management of ocular diseases, further research is needed to optimize treatment protocols, evaluate long-term efficacy, and explore its role in combination therapies.

Functional Outcomes and Safety Profile of Trans-Foveal Subthreshold Micropulse Laser in Persistent Central Serous Chorioretinopathy

Our study evaluated visual function changes after subthreshold micropulse laser (SML) treatment in persistent central serous chorioretinopathy (CSC) and SML safety profile. We conducted a prospective study including 31 fovea-involving CSC patients. The natural course was observed for the first 3 months, SML was performed at 3 months, and SML effectiveness was observed at 6 months. At all three clinical visits, optical coherence tomography (OCT), best corrected visual acuity (BCVA), contrast sensitivity (CS) in five spatial frequencies (1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree (cpd)), microperimetry (MP), and multifocal electroretinography (mfERG) were performed. The SML safety profile was evaluated with functional and morphological parameters. In the cohort of all CSC patients treated with SML, the statistically significant average improvement was observed in BCVA (p = 0.007), CS-1.5 (p = 0.020), CS-3.0 (p = 0.050), CS-12.0 (p < 0.001), CS-18.0 (p = 0.002), CS (CS-A) (p < 0.001), MP in the central ring (MP-C) (p = 0.020), peripheral ring (MP-P) (p = 0.042), and average retinal sensitivity (MP-A) (p = 0.010). After the SML treatment, mean changes in mfERG amplitudes and implicit times in our cohort were not statistically significant. No morphological or functional adverse effects of SML treatment were observed. SML treatment in persistent CSC episodes leads to significant functional improvement and has an excellent safety profile.

Yellow Subthreshold Micropulse Laser in Retinal Diseases: An In-Depth Analysis and Review of the Literature

Yellow subthreshold micropulse laser (YSML) is a retinal laser capable of inducing a biologic response without causing thermal damage to the targeted tissue. The 577-nm YSML is delivered to the retina abiding by different protocols in which wavelength, power, duration, spot size and number of spots can be properly set to achieve the most effective and safe treatment response in various chorioretinal disorders. The ultrashort trains of power modulate the activation of the retinal pigment epithelium cells and intraretinal cells, such as Müller cells, causing no visible retinal scars. Subthreshold energy delivered by YSML stimulates the production of the heat-shock proteins, highly conserved molecules that protect cells against any sort of stress by blocking apoptotic and inflammatory pathways that cause cell damage. YSML treatment allows resorption of the subretinal fluid in central serous chorioretinopathy and intraretinal fluid in various conditions including diabetic macular edema, postoperative cystoid macular edema and other miscellaneous conditions. YSML also seems to modulate the development and progression of reticular pseudodrusen in dry age-related macular degeneration. The aim of this review is to discuss and summarize the safety and efficacy of YSML treatment in retinal diseases.

Comparing interventions for chronic central serous chorioretinopathy: A network meta-analysis

We compare efficacy of treatments for chronic central serous chorioretinopathy (CSCR) > 3 months. Four treatment classes were considered: photodynamic therapy (PDT), subthreshold laser therapies (SLT), mineralocorticoid receptor antagonists (MRA) and anti-vascular endothelial growth factor (anti-VEGF) agents. Pairwise and network meta-analyses of the primary outcomes (complete resolution of subretinal fluid (SRF), mean change in best corrected visual acuity (BCVA) (logMAR) and mean change in SRF) and secondary outcomes (mean change in central retinal thickness, and central choroidal thickness (μm), recurrence of SRF, and adverse events) at 3, 6 and 12 months were compared. Confidence in Network Meta-Analysis (CINeMA) informed the certainty of NMA evidence. Eleven RCTs of 458 eyes (450 patients) were included. NMA at 3 months showed that both PDT and SLT were superior to control for resolution of SRF (OR 4.83; 95% CI 1.72 to 13.55 and 2.27; 1.14 to 4.49, respectively) and SLT was superior to control for improving BCVA (MD -0.10; -0.17 to -0.04). PDT was superior to SLT for improving CRT (MD-42.88; -75.27 to -10.50). On probability ranking, PDT and SLT were consistently the best-ranked treatments for each outcome at 3 months, but low confidence of evidence and paucity of studies preclude definitive conclusions.

Ganglion Cell Loss in the Course of Central Serous Chorioretinopathy

INTRODUCTION

Central serous chorioretinopathy (CSCR) as a clinical entity is potentially damaging and may significantly affect retinal morphology and function, especially in the chronic form. Our study aimed to determine the amount of deficit of best corrected visual acuity (BCVA) and individual retinal layers, including ganglion cells, in different types of CSCR and with reference to its duration.

METHODS

The retrospective analysis included 69 eyes of patients with resolved CSCR managed in Dobry Wzrok Ophthalmological Clinic between 1 January 2019 and 30 June 2022. The diagnosis of CSCR was based on the criteria outlined by the Central Serous Chorioretinopathy International Group. The analysis included data obtained from medical history, BCVA testing, and spectral domain optical coherence tomography (SD-OCT) measurements, with specific thickness values for individual retinal layers. The results were compared among affected eyes, unaffected fellow eyes, and healthy controls.

RESULTS

BCVA values were significantly lower in acute (0.08 ± 0.12 logMAR) and chronic (0.26 ± 0.19 logMAR) cases versus controls (0.0 logMAR). The thickness of all retinal layers (central subfoveal thickness, CST; inner retina with ganglion cell complex, GC; outer retina, ORT; and photoreceptor outer segments, POS) and macular volume (MV) were significantly decreased in chronic eyes versus controls (p < 0.01). Acute eyes had significant thinning of the outer retina and POS only compared to control eyes (p < 0.01). The amount of deficit in CST, ORT, GC, and MV was strongly correlated with poorer BCVA (p < 0.001), and the deficit of CST, ORT, and GC was correlated with disease duration (p < 0.05). The subfoveal choroidal thickness was significantly greater in affected and fellow eyes versus controls (p < 0.001).

CONCLUSION

Damage to the outer retina and photoreceptors occurs early in the course of CSCR, with a deficit in ganglion cells noted adjunctively in chronic forms of the disease. Further studies are required to precisely determine correlation between visual loss in CSCR and deficits in individual retinal layers.

Effectiveness, Safety and Choroidal Changes of a Fovea-Sparing Technique for the Treatment of Chronic Central Serous Chorioretinopathy with Yellow Subthreshold Laser

The aim of this study was to evaluate the effectiveness and safety of a yellow subthreshold laser (STL) for the treatment of chronic central serous chorioretinopathy delivered in a fovea-sparing pattern and to analyze the post-laser changes in the choroidal structure by Swept-Source Optical Coherence Tomography. This study was a prospective case series of 43 eyes corresponding to 37 patients. Data were recorded at 6, 12 and 24 weeks after the STL treatment. The best-corrected visual acuity improved in 93% of the patients and remained stable in 7%. The subretinal fluid was completely reabsorbed in 27.9%, 32.6% and 69.8% of the patients at 6, 12 and 24 weeks, respectively. There were reductions in the choroidal thickness of 13.1% and 25.3% at 12 and 24 weeks, which corresponded to reductions of 17.5% and 45.9% in the choriocapillaris and Sattler layer and reductions of 12.2% and 21.2% in the Haller layer at 12 and 24 weeks, respectively (p < 0.05). This might account for the effect of the laser on the inner choroidal vasculature, the dysregulation of which is believed to be at the core of central serous chorioretinopathy. No laser-related complications were detected. Overall, the fovea-sparing STL was safe and effective in this series of patients.

Mineralocorticoid receptor antagonists for chronic central serous chorioretinopathy: systematic review and meta-analyses

BACKGROUND

Mineralocorticoid receptor antagonists (MRAs) are widely used for chronic central serous chorioretinopathy (cCSCR), but their effectiveness remains unclear. This research was conducted to evaluate the efficacy of this drugs for cCSCR.

METHODS

This is a review of randomized clinical trials (RCT) comparing MRAs to placebo in adults with cCSCR, using the effects of MRAs on best-corrected visual acuity (BCVA) and adverse events as primary outcomes and the effects of MRAs on anatomical parameters as secondary outcomes: central subfield thickness (CST), subretinal fluid height (SFH) and central choroidal thickness (CCT). Our all-language online search included Medline (via PubMed), Central, Embase, Lilacs, Ibecs, and RCT registers platforms, as late as May 2021. We used the Cochrane risk-of-bias tool (version 2) to assess the methodological quality of each study and synthesized the results in meta-analyses using a random-effects model.

RESULTS

The search identified 302 records, five of which were eligible, totaling 225 cCSCR patients (aged 45-62 years; M/F ratio 3.1:1) treated for 1 to 12 months with spironolactone (50 mg/day) or eplerenone (50 mg/day) vs. placebo. Moderate-certainty evidence suggests MRAs result in little to no improvement in BCVA compared to placebo (SMD 0.22; 95% CI - 0.04 to 0.48; studies = 5; comparisons = 6; participants = 218; I2 = 0%). Very low-certainty evidence suggests that, when compared to placebo, MRAs have a very uncertain impact on adverse effects (no meta-analysis was performed), and CST (MD 18.1; 95% CI - 113.04 to 76.84; participants = 145; studies = 2; I2 = 68%). MRAs also result in little to no difference in SFH (SMD - 0.35; 95% CI - 0.95 to 0.26; studies = 5; comparisons = 6; participants = 221; I2 = 76%; moderate certainty) and CCT (MD - 21.23; 95% CI - 64.69 to 22.24; participants = 206; studies = 4; comparisons = 5; I2 = 85%; low certainty).

CONCLUSION

MRAs have little to no effect on BCVA. Evidence for adverse events and CST is very uncertain. MRAs also have little to no effect on SFH and CCT. These findings should be considered when prescribing MRAs for cCSCR. This research was previous registration in the PROSPERO platform (CRD42020182601).

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.

Dysregulated Tear Film Proteins in Macular Edema Due to the Neovascular Age-Related Macular Degeneration Are Involved in the Regulation of Protein Clearance, Inflammation, and Neovascularization

Macular edema and its further complications due to the leakage from the choroidal neovascularization in course of the age-related macular degeneration (AMD) is a leading cause of blindness among elderly individuals in developed countries. Changes in tear film proteomic composition have been reported to occur in various ophthalmic and systemic diseases. There is an evidence that the acute form of neovascular AMD may be reflected in the tear film composition. Tear film was collected with Schirmer strips from patients with neovascular AMD and sex- and age-matched control patients. Two-dimensional electrophoresis was performed followed by MALDI-TOF mass spectrometry for identification of differentially expressed proteins. Quantitative analysis of the differential electrophoretic spots was performed with Delta2D software. Altogether, 11 significantly differentially expressed proteins were identified; of those, 8 were downregulated, and 3 were upregulated in the tear film of neovascular AMD patients. The differentially expressed proteins identified in tear film were involved in signaling pathways associated with impaired protein clearance, persistent inflammation, and neovascularization. Tear film protein analysis is a novel way to screen AMD-related biomarkers.

Fluorescence Lifetime Changes Induced by Laser Irradiation: A Preclinical Study towards the Evaluation of Retinal Metabolic States

Fluorescence Lifetime (FLT) of intrinsic fluorophores may alter under the change in metabolic state. In this study, the FLT of rabbit retina was investigated in vivo after laser irradiation using fluorescence lifetime imaging ophthalmoscopy (FLIO). The retina of the Chinchilla bastard rabbits was irradiated with a 514 nm diode laser. FLIO, fundus photography, and optical coherence tomography (OCT) were conducted 30 min and 1 to 3 weeks after treatment. After strong coagulation, the FLT at laser spots was significantly elongated immediately after irradiation, conversely shortened after more than a week. Histological examination showed eosinophilic substance and melanin clumping in subretinal space at the coagulation spots older than one week. The FLT was also elongated right around the coagulation spots, which corresponded to the discontinuous ellipsoid zone (EZ) on OCT. This EZ change was recovered after one week, and the FLT became the same level as the surroundings. In addition, there was a region around the laser spot where the FLT was temporarily shorter than the surrounding area. When weak pulse energy was applied to selectively destroy only the RPE, a shortening of the FLT was observed immediately around the laser spot within one week after irradiation. FLIO could serve as a tool to evaluate the structural and metabolic response of the retina to laser treatments.

Vitreoretinal Society of India practice pattern survey 2020: Medical retina

Purpose:

The aim of this study was to present the outcomes of the Vitreo-retinal Society of India (VRSI) Practice Pattern Survey 2020 in medical retina.

Methods:

An online survey of members of VRSI was conducted in April 2020 regarding their practice-patterns on varied medical and surgical retina topics concerning imaging and management approach. The results were evaluated by two independent experts in this field and compared with the evidence and other practice patterns in the world.

Results:

A total of 107 VRSI members participated in the online survey. Responses were obtained on management of wide-ranging chorioretinal disorders such as Central Serous Chorioretinopathy (CSCR), Polypoidal Choroidal Vasculopathy (PCV), Neovascular age related macular degeneration (n-AMD), Retinal Vein Occlusions (RVO), and Diabetic Retinopathy (DR). Participants were also surveyed regarding their attitudes and perceptions about anti-VEGF practice patterns and role of imaging in their current practice. Each of the survey question responses were then compared to contemporary literature, including evidence-based guidelines, randomized controlled trials (RCTs), real-world evidence and analogous international surveys. Comprehensive analysis related to this has been put forward in the article.

Conclusion:

This survey represents the contemporary practice patterns amongst vitreoretinal specialists in India. The survey results are vital for fellow practitioners to understand the 'standard of care’ practice in medical retina. This will guide them to devise the best possible individualized treatment strategy for most favorable clinical outcomes.

Venous overload choroidopathy: A hypothetical framework for central serous chorioretinopathy and allied disorders

In central serous chorioretinopathy (CSC), the macula is detached because of fluid leakage at the level of the retinal pigment epithelium. The fluid appears to originate from choroidal vascular hyperpermeability, but the etiology for the fluid is controversial. The choroidal vascular findings as elucidated by recent optical coherence tomography (OCT) and wide-field indocyanine green (ICG) angiographic evaluation show eyes with CSC have many of the same venous patterns that are found in eyes following occlusion of the vortex veins or carotid cavernous sinus fistulas (CCSF). The eyes show delayed choroidal filling, dilated veins, intervortex venous anastomoses, and choroidal vascular hyperpermeability. While patients with occlusion of the vortex veins or CCSF have extraocular abnormalities accounting for the venous outflow problems, eyes with CSC appear to have venous outflow abnormalities as an intrinsic phenomenon. Control of venous outflow from the eye involves a Starling resistor effect, which appears to be abnormal in CSC. Similar choroidal vascular abnormalities have been found in peripapillary pachychoroid syndrome. However, peripapillary pachychoroid syndrome has intervortex venous anastomoses located in the peripapillary region while in CSC these are seen to be located in the macular region. Spaceflight associated neuro-ocular syndrome appears to share many of the pathophysiologic problems of abnormal venous outflow from the choroid along with a host of associated abnormalities. These diseases vary according to their underlying etiologies but are linked by the venous decompensation in the choroid that leads to significant vision loss. Choroidal venous overload provides a unifying concept and theory for an improved understanding of the pathophysiology and classification of a group of diseases to a greater extent than previous proposals.

Subthreshold Diode Micropulse Laser Combined with Intravitreal Therapy for Macular Edema-A Systematized Review and Critical Approach

Objective: intravitreal therapy for macular edema (ME) is a common clinical approach to treating most retinal vascular diseases; however, it generates high costs and requires multiple follow-up visits. Combining intravitreal anti–vascular endothelial growth factor (VEGF) or steroid therapy with subthreshold diode micropulse laser (SDM) application could potentially reduce the burden of numerous intravitreal injections. This review sought to explore whether this combination treatment is effective in the course of ME secondary to retinal vascular disease, and in particular, determine whether it is comparable or superior to intravitreal therapy alone. Materials and methods: the following terms and Boolean operators were used to search the PubMed literature database: subthreshold micropulse laser, subthreshold diode micropulse OR micropulse laser treatment AND anti-VEGF, anti-VEGF treatment, intravitreal steroids, OR combined therapy.This analysis included all studies discussing the combination of SDM and intravitreal anti-VEGF or steroid treatment. Results: the search revealed nine studies that met the inclusion criteria, including five comparing combined treatment and anti-VEGF treatment alone, four covering diabetic ME, and one covering ME secondary to branch retinal vein occlusion. All of these five studies suggested that combination therapy results in fewer intravitreal injections than anti-VEGF monotherapy with non-inferior functional and morphological outcomes. The remaining four studies report functional and morphological improvements after combined treatment; however, SDM alone was never superior to intravitreal-alone or combined treatment. There were substantial differences in treatment protocols and inclusion criteria between the studies. Conclusions: the available material was too scarce to provide a reliable assessment of the effects of combined therapy and its relation to intravitreal monotherapy in the treatment of ME secondary to retinal vascular disease. One assumption of note is that it is possible that SDM plus anti-VEGF might require fewer intravitreal injections than anti-VEGF monotherapy with equally good functional and morphological results. However, further randomized research is required to confirm this thesis.

Short Term Presence of Subretinal Fluid in Central Serous Chorioretinopathy Affects Retinal Thickness and Function

Background: Acute central serous chorioretinopathy (CSCR), with subretinal fluid (SRF) resolving spontaneously within a few months from disease onset, has been considered as a benign and self-limiting disease for many years. This study sought to discover if a short presence of SRF can result in morphological and functional damage to the retina. Materials and methods: The study included patients treated by subthreshold diode micropulse laser (SDM) application for acute CSCR at the Dobry Wzrok Ophthalmological Clinic between January 2018 and November 2019. Inclusion criteria were: first episode of CSCR; duration of symptoms of two months or less; complete resolution of subretinal fluid (SRF) after a single session of SDM; and a lack of any retinal pathology, previous CSCR episode, significant anisometropia or amblyopia in the collateral eye. Fifteen patients fulfilled the inclusion criteria, including 13 males and two females aged 42.3 ± 9.5 years. The mean duration of symptoms before treatment was 4.7 ± 1.3 weeks on average. Baseline and follow-up examinations were performed in both the affected and collateral eyes and included best-corrected visual acuity (BCVA); spectral-domain optical coherent tomography measurements such as central retinal thickness (CRT) and minimal foveal thickness (MFT) (at the follow-up visit only); fluorescein angiography (at presentation only) and fundus autofluorescence. The first follow-up visit, when the total resolution of SRF was noted, was conducted between 8 and 12 weeks after SDM. Results: Resolved CSCR eyes had significantly poorer BCVA, CRT, and MFT findings in comparison with healthy collateral eyes (respectively, 0.11 +/− 0.1 vs. 0.01 +/− 0.04 logMAR; 238.80 +/− 23.39 vs. 264.87 +/− 21.22 µm and 178.93 +/− 16.88 vs. 199.47 +/− 17.87 µm) despite the short period of CSCR duration (maximum of 14 ± 2.15 weeks on average). Conclusion: Short presence of SRF typical for acute CSCR can affect retinal function and morphology resulting in poorer visual outcome.

Pachychoroid neovasculopathy: a type-1 choroidal neovascularization belonging to the pachychoroid spectrum-pathogenesis, imaging and available treatment options

PURPOSE

The purpose of this paper is to provide a meaningful literature review about the epidemiology, pathogenesis, imaging and treatment of pachychoroid neovasculopathy (PNV).

METHODS

A computerized search from inception up to December 2019 of the online electronic database PubMed was performed using the following search string: "pachychoroid neovasculopathy". The reference list in each article was scanned for additional relevant publications.

RESULTS

PNV is a type-1 choroidal neovascularization, overlying focal areas of choroidal thickening and dilated choroidal vessels. It can develop in patients affected by pachychoroid pigment epitheliopathy or chronic central serous chorioretinopathy. The absence of drusen, the presence of pachydrusen, younger age of onset and choroidal thickening distinguish it from neovascular age-related macular degeneration (AMD). PNV incidence and prevalence data are lacking. Its pathophysiology is not fully understood, but angiogenic mechanisms involved in neovascular AMD may be different from those in PNV. Due to optical coherence tomography (OCT) improvements, PNV can be diagnosed more easily than before. In particular, PNV shows a shallow pigment epithelium detachment with an undulating retinal pigment epithelium over a subfoveal choroidal thickening, associated with vein enlargement in Haller's layer (named pachyvessels) and choriocapillaris thinning. On OCT angiography, PNV reveals tangled hyper-reflective filamentous neovessels in the choriocapillaris itself. The current first-line PNV treatment is intravitreal anti-VEGF (vascular endothelial growth factor) injections with a treat-and-extend regimen. In particular, aflibercept shows a higher rate of fluid absorption than others. In the case of fluid recurrence or persistence, photodynamic therapy is a valid alternative.

CONCLUSION

Ongoing research into pathophysiology and imaging improvements may be helpful in defining prognostic criteria and stratifying patient risk, allowing responsible monitoring and management of PNV.

Comparison of Subthreshold 577 and 810 nm Micropulse Laser Effects on Heat-Shock Protein Activation Kinetics: Implications for Treatment Efficacy and Safety

Purpose

To compare the safety and efficacy of 810 versus 577 nm laser wavelengths for micropulse subthreshold (sublethal) laser treatment by mathematical analysis.

Methods

Two different representative laser parameter sets for micropulsed subthreshold diode laser treatment, one employing 810 nm and the other 577 nm, are compared with regard to efficacy by analysis of the kinetics of laser-induced heat-shock protein (HSP) activation; and for safety, by scaling law analysis.

Results

Kinetics analysis of laser-induced HSP activation shows that the primary therapeutic effect of laser is thermal incitement of a long-term wavelength-independent increase in the rate of HSP-mediated protein repair specific to sick and dysfunctional cells, rather than from short-term increases in free intracellular HSP concentrations. Scaling law analysis of the same 810 and 577 nm laser parameters, however, finds treatment safety highly wavelength-sensitive, favoring 810 over 577 nm.

Conclusions

Mathematical analyses of the effects retinal laser-induced HSP activation provide important insights into the mechanism of action and the importance of wavelength selection in modern retinal laser therapy. Our analyses find 810 and 577 nm to be equally effective, but 810 nm having a significantly wider therapeutic range/safety margin, and thus less likely to cause inadvertent, and thus unpredictable, laser-induced retinal damage, than 577 nm.

Translational Relevance

Mathematical analysis of enzyme reaction kinetics provides important insights into the mechanism of action and clinical implications of wavelength selection in modern retinal laser therapy.