Selective retina therapy (SRT) of chronic subfoveal fluid after surgery of rhegmatogenous retinal detachment: three case reports

Comparative Treatment Study on Macular Edema Secondary to Branch Retinal Vein Occlusion by Intravitreal Ranibizumab with and without Selective Retina Therapy

The purpose of this study was to compare the safety and efficacy of selective retina therapy (SRT) combined with the intravitreal injection of ranibizumab (IVR) in patients with macular edema (ME) secondary to branch retinal vein occlusion (BRVO). This trial was a 12-month single-center, randomized, single-masked prospective study. Eligible patients were randomized (1:1) to IVR and SRT (IVR + SRT group), or IVR and sham SRT (IVR + sham group). After the initial IVR, all participants received ME resolution criteria-driven pro re nata treatment. SRT or sham SRT was always applied one day after IVR. The primary outcome measure of this study was the mean change in central macular thickness (CMT) from baseline, and the secondary outcome measures were the mean change in visual acuity from baseline and the number of IVR treatments at a 52-week follow-up. Thirteen patients were in the IVR + SRT group, and 11 were in the IVR + sham group. Compared to the baseline, mean CMT and BCVA improved significantly after 52 weeks in both groups, with no significant difference between the two groups. The mean number of IVR was 2.85 ± 1.52 in the IVR + SRT group and 4.73 ± 2.33 in the IVR + sham group at the 52-week follow-up, with a significant difference between the two groups (p < 0.05). IVR combined with SRT may significantly decrease the number of IVR treatments while maintaining the visual and anatomical improvement effect of IVR monotherapy.

Mineralocorticoid receptor antagonists as a potential treatment option in persistent subretinal fluid following the repair of a rhegmatogenous retinal detachment

Purpose

To report the resolution of subretinal fluid persisting more than a year following retinal detachment surgery resolving with a short term course of mineralocorticoid receptor antagonists use.

Observations

A 41 year-old, highly myopic male presented with a temporal rhegmatogenous retinal detachment involving the macula. The tear was treated with a radial sponge without subretinal fluid (SRF) drainage. Post-operatively, SRF persisted for more than 1 year with only slight improvement in visual acuity. On OCT, slow regression of subretinal fluid was noted. In order to stimulate the RPE pump, a systemic mineralocorticoid receptor antagonist (spironolactone 50 mg) was initiated after discussion with the patient. After one month of therapy, there was a complete resolution of SRF and the visual acuity improved. Two years later, there was no reaccumulation of SRF and the visual acuity remained stable.

Conclusions and importance

A short term of course of mineralocorticoid receptor antagonist is a potential treatment for persistent subretinal fluid following a successful detachment surgery.

Persistent Subretinal Fluid Following Successful Rhegmatogenous Retinal Detachment Surgery

PURPOSE

To provide an updated, critical summary of the literature on the topic of persistent subretinal fluid (PSF) following successful rhegmatogenous retinal detachment surgery.

METHODS

Narrative literature review.

RESULTS

PSF remains an insufficiently studied topic. Incidence rates vary significantly between reports, but pars plana vitrectomy seems associated with lower rates than buckle surgery. Multiple etiologies and risk factors have been proposed, none being conclusive. PSF gradually resolves in most cases which may be a lengthy process, often with no effect on potential final visual acuity. There is concern that some cases with PSF may sustain photoreceptor damage, retinal displacement, or retinal fold formation. There is no current evidence to support any treatment modality over observation in uncomplicated cases of PSF.

CONCLUSION

Future large, well-controlled, prospective trials could help elucidate incidence rate, etiological factors, and sequelae of PSF, as well as the value of different interventions in its prevention and management.

PERSISTENT LOCULATED SUBRETINAL FLUID AFTER RHEGMATOGENOUS RETINAL DETACHMENT SURGERY

PURPOSE

To identify factors associated with persistent subretinal fluid (SRF) after small-gauge pars plana vitrectomy for primary rhegmatogenous retinal detachment.

METHODS

This retrospective study included patients from 2 tertiary centers who underwent pars plana vitrectomy for repair of rhegmatogenous retinal detachment between 2013 and 2016. Preoperative and intraoperative parameters were examined for association with development of SRF.

RESULTS

Overall, 153 eyes of 153 patients, mean age of 55.2 ± 17.9 years were included. Persistent SRF occurred in 15.0% (n = 23) and was associated with high myopia (65.22 vs. 26.15%, P < 0.001), macula-involving retinal detachment (91.30 vs. 66.15%, P = 0.02), phakic lens status (86.96 vs. 66.15%, P = 0.04), and younger age (47.8 ± 18.7 vs. 56.5 ± 17.5, P = 0.04) while drainage retinotomy was protective (13.04 vs. 34.11%, P = 0.04). In multivariate analysis, high myopia (P = 0.009) and macula-involving retinal detachment (P = 0.004) were associated with SRF, while drainage retinotomy was protective (P = 0.03). Persistent SRF was associated with outer retinal band irregularity (30.4 vs. 9.3%, P = 0.005). There were no significant differences in terms of change in best-corrected visual acuity from presentation (P = 0.70), or final best-corrected visual acuity (P = 0.54).

CONCLUSION

Eyes with preoperative high myopia and macular involvement, and those in which a drainage retinotomy was not performed, were more likely to develop persistent SRF.

Impact of air injection on subretinal fluid following successful scleral buckling surgery for macular-involving retinal detachment

Air injection is an accessory technique during scleral buckling (SB). Subclinical subretinal fluid (SRF) may presence and persistent after SB. The impact of air injection on SRF is unclear. In the study, we retrospectively enrolled 51 patients with macular-involving RD who had undergone successful SB. They were categorized into Group A (SB without air injection) and Group B (SB with air injection). First, we found that although group B seem to be severer than group A before surgery, Kaplan–Meier graph showed that SRF absorbed more rapidly in group B after surgery, and the incidence of SRF in group B was much lower during the whole follow-up period. Moreover, the cases with superior breaks had the lowest incidence. Second, during the follow-up period, there was no significant difference about postoperative complication between two groups. Lastly, risk factors for persistent SRF were investigated with binary logistic regression, and no risk factor was found. In conclusion, air injection during the SB might accelerate SRF absorption and reduce the incidence of persistent SRF, especially for the longstanding macular-off RD with superior breaks.

Factors affecting resolution of subretinal fluid after selective retina therapy for central serous chorioretinopathy

The purpose of this study was to investigate the factors of clinical outcome of selective retina therapy (SRT) for central serous chorioretinopathy (CSC). This retrospective study included 77 eyes of 77 patients, who were treated with SRT for CSC and observed at least 6 months after the treatment. SRT laser (527 nm, 1.7 µs, 100 Hz) was used for treatment. The mean best-corrected visual acuity (logMAR), central macular thickness (CMT) and central choroidal thickness were changed from baseline to at 6-months follow-up with significant difference. The multivariate analyses found that the rate of change (reduction) in CMT was associated with focal leakage type on fluorescein angiography (FA) (p = 0.03, coefficient 15.26, 95% confidence interval 1.72–28.79) and larger baseline CMT (p < 0.01, coefficient − 0.13, 95% confidence interval − 0.13 to − 0.05). Complete resolution of subretinal fluid was associated with nonsmoking history (p = 0.03, odds ratio 0.276, 95% confidence interval 0.086–0.887) and focal leakage type on FA (p < 0.01, odds ratio 0.136, 95% confidence interval 0.042–0.437). These results may be useful for predicting the therapeutic effectiveness of SRT.

Selective Retina Therapy Reduces Bruch's Membrane Thickness and Retinal Pigment Epithelium Pathology in Age-Related Macular Degeneration Mouse Models

Purpose

To investigate the effect of selective retina therapy (SRT) on age-related macular degeneration (AMD)-like alterations of retinal pigment epithelium (RPE) and Bruch's membrane (BrM) in AMD mouse models as therapeutic approach for the treatment of dry AMD.

Methods

In B6.129P2-Apoe^tm1Unc/J (ApoE^−/−) and B6.129X1-Nfe2I2^tm1Ywk/J (NRF2^−/−), one randomized eye of each mouse in groups of 15 mice was treated by SRT (532 nm, 300 ms, ∼1.4-μs pulse, 100 Hz, 50-μm spot), the fellow eye and healthy C57BL/6J mice served as controls. Clinical examinations were obtained at treatment day and 1 month later, followed by enucleation to analyze BrM thickness and ultrastructural RPE morphology.

Results

Nearly all ApoE^−/− and NRF2^−/− mice showed AMD-like retinal alterations. BrM thickness was increased in both mouse models, RPE had vacuoles within the cell body and shortened apical microvilli. SRT neither affected neuroretinal anatomy nor function. BrM thickness as well as AMD-like ultrastructural alterations of the RPE were significantly reduced in laser-treated eyes compared with fellow control and untreated control eyes.

Conclusions

SRT reduces BrM thickness and AMD-like RPE alterations in AMD mouse models without damage to structural or functional properties of neuroretina. It may be a prophylactic or therapeutic option for dry AMD.

Translational Relevance

SRT shows therapeutic effectivity in murine AMD models and might therefore become an option for the treatment of dry AMD.

Evolution of Concepts and Technologies in Ophthalmic Laser Therapy

Ophthalmology was the first medical specialty to adopt lasers right after their invention more than 50 years ago, and they gradually revolutionized ocular imaging, diagnostics, therapy, and surgery. Challenging precision, safety, and selectivity requirements for ocular therapeutic and surgical procedures keep advancing the laser technologies, which in turn continue enabling novel applications for the preservation and restoration of sight. Modern lasers can provide single-cell-layer selectivity in therapy, submicrometer precision in three-dimensional image-guided surgery, and nondamaging retinal therapy under optoacoustic temperature control. This article reviews the evolution of laser technologies; progress in understanding of the laser-tissue interactions; and concepts, misconceptions, and accidental discoveries that led to modern therapeutic and surgical applications of lasers in ophthalmology. It begins with a brief historical overview, followed by a description of the laser-tissue interactions and corresponding ophthalmic applications.

Comparison of the neuroinflammatory responses to selective retina therapy and continuous-wave laser photocoagulation in mouse eyes

PURPOSE

This study investigated microglia and inflammatory cell responses after selective retina therapy (SRT) with microsecond-pulsed laser in comparison to continuous-wave laser photocoagulation (cwPC).

METHODS

Healthy C57BL/6 J mice were treated with either a train of short pulses (SRT; 527-nm, Q-switched, 1.7-μs pulse) or a conventional thermal continuous-wave (532-nm, 100-ms pulse duration) laser. The mice were sacrificed and their eyes were enucleated 1, 3, 7, and 14 days after both laser treatments. Pattern of cell death on retinal section was evaluated by TUNEL assay, and the distribution of activated inflammatory cells and glial cells were observed under immunohistochemistry. Consecutive changes for the expression of cytokines such as IL-1β, TNF-α, and TGF-β were also examined using immunohistochemistry, and compared among each period after quantification by Western blotting.

RESULTS

The numbers of TUNEL-positive cells in the retinal pigment epithelium (RPE) layer did not differ in SRT and cwPC lesions, but TUNEL-positive cells in neural retinas were significantly less on SRT. Vague glial cell activation was observed in SRT-treated lesions. The population of inflammatory cells was also significantly decreased after SRT, and the cells were located in the RPE layer and subretinal space. Proinflammatory cytokines, including IL-1β and TNF-α, showed significantly lower levels after SRT; conversely, the level of TGF-β was similar to the cwPC-treated lesion.

CONCLUSIONS

SRT resulted in selective RPE damage without collateral thermal injury to the neural retina, and apparently produced negligible glial activation. In addition, SRT showed a markedly less inflammatory response than cwPC, which may have important therapeutic implications for several macular diseases.

Persistent subfoveolar fluid following retinal detachment surgery: an SD-OCT guided study on the incidence, aetiological associations, and natural history

PURPOSE

To investigate the incidence and natural history of persistent subfoveolar fluid (PSF) following surgery for macular off rhegmatogenous retinal detachment and the effect of PSF on photoreceptor structure and final visual acuity.

METHODS

Retrospective study of 61 cases with post-operative optical coherence tomography (OCT) performed within 12 weeks of surgery. Based on aetiology, cases were categorized into tractional retinal tears (TRT) group or atrophic round holes and dialyses (RHD) group to investigate the incidence and duration of PSF. A Kaplan-Meier graph was plotted to compare survival time of subfoveolar fluid for both groups. Following secondary reclassification of cases into those with and without PSF, the effect of PSF on final visual acuity and photoreceptor structure was investigated with Mann-Whitney U-test used for comparison. Spearman's correlation testing was used to probe associations between time to recorded resolution of PSF with final visual acuity and photoreceptor structure.

RESULTS

Incidence of PSF was greater in the RHD group and persisted for longer compared with TRT group. No detectable adverse effect of PSF on final visual acuity was seen however an individual case of severe photoreceptor atrophy was observed. No significant correlation was found between the time to recorded resolution of PSF and the final visual acuity or to photoreceptor grading scores.

CONCLUSIONS

A difference in incidence of PSF was detected between the aetiological groups. PSF was ubiquitous and slow to resolve in the RHD group. Most cases of PSF resolve without adverse sequelae; however, progressive photoreceptor atrophy and sub-optimal visual outcome may result in a minority.

Selective Retina Therapy in Patients With Chronic Central Serous Chorioretinopathy: A Pilot Study

We evaluated visual outcomes, changes of maximum macular thickness (MMT) and subretinal fluid (SRF), and safety in patients with chronic central serous chorioretinopathy (CSC) after treatment with selective retina therapy (SRT). Retrospective cohort study of patients with chronic CSC presenting to a university-based hospital from January 2014 through January 2015 was conducted. A total of 12 eyes of 12 patients with chronic CSC lasting for at least 3 months was recruited. The follow-up period ranged from 3 to 12 months. Following evaluation of test spots at temporal arcades, SRT (Q-switched neodymium-doped yttrium lithium fluoride [Nd:YLF] laser; wavelength, 527 nm, pulse duration, 1.7 microsececond) was applied to the surrounding areas of leakage observed on fluorescein angiogram and/or pigment epithelial detachment (PED). Changes in best-correct visual acuity (BCVA), MMT, and SRF and macular sensitivity (MS) by microperimetry (MP) were evaluated. Eyes received treatment in a mean of 3.83 spots at the pulse energy of 65 to 90 μJ. Mean BCVA (logMAR) improved from 0.23 ± 0.12 at baseline to 0.14 ± 0.13 at 3 months. MMT decreased from 341.4 ± 85.5 μm at baseline to 236.0 ± 57.9 μm at 3 months. SRF completely resolved in 75% (9 eyes) at 3 months. Large PEDs (2 eyes) were flattened at 3 months. Retreatment was performed in 4 eyes. MP showed no evidence of scotoma around SRT-treated lesions. SRT treatment targeting the surrounding area of leakage point showed favorable visual and structural outcomes in chronic CSC patients without the risk of scotoma.

A Comparative Study of Retinal Function in Rabbits after Panretinal Selective Retina Therapy versus Conventional Panretinal Photocoagulation

Purpose. This study evaluates functional changes in electroretinographic findings after selective retina therapy (SRT) compared to panretinal photocoagulation (PRP) in rabbits. Methods. The right eyes of 12 Chinchilla rabbits received 200 laser treatment spots. The right eyes of six rabbits received SRT (SRT group), whereas the other six animals were treated using PRP on the right eye (PRP group). The eyes were investigated using full-field ERG 1 hour and 3 weeks after treatment. Histologic exam to assess the tissue response of lasers was performed on 3 weeks. Results. No significant changes in the mean ROD or CR b-wave amplitudes of the SRT lesions were evident, compared to baseline, 1 h after laser treatment (p = 0.372 and 0.278, resp.). In addition, the OPs and 30 Hz flickers of the SRT lesions were not significantly altered (p = 0.17 and 0.243, resp.). At 3 weeks, similar results were found. Comparing the two groups, the ROD b-wave amplitude was reduced in the PRP and SRT groups to 60.04 ± 4.2% and 92.32 ± 6.43% of baseline (p < 0.001). Histologically, there was no visible photoreceptor alterations on week 3. Conclusions. SRT in rabbit eyes induced less functional loss than PRP in both rod-mediated retinal function and cone-mediated retinal function. In addition, SRT irradiated eyes had no functional loss compared to its control.

Temperature-Controlled Retinal Photocoagulation Reliably Generates Uniform Subvisible, Mild, or Moderate Lesions

PURPOSE

Conventional retinal photocoagulation produces irregular lesions and does not allow reliable control of ophthalmoscopically invisible lesions. We applied automatically controlled retinal photocoagulation, which allows to apply uniform lesions without titration, and aimed at five different predictable lesion intensities in a study on rabbit eyes.

METHODS

A conventional 532-nm photocoagulation laser was used in combination with a pulsed probe laser. They facilitated real-time fundus temperature measurements and automatic exposure time control for different predefined time/temperature dependent characteristics (TTC). We applied 225 control lesions (exposure time 200 ms) and 794 TTC lesions (5 intensities, exposure times 7-800 ms) in six rabbit eyes with variable laser power (20-66.4 mW). Starting after 2 hours, we examined fundus color and optical coherence tomographic (OCT) images over 3 months and classified lesion morphologies according to a seven-stage OCT classifier.

RESULTS

Visibility rates in funduscopy (OCT) after 2 hours were 17% (68%) for TTC intensity group 1, 38% (90%) for TTC group 2 and greater than 94% (>98%) for all consecutive groups. TTC groups 1 through 4 correlated to increasing morphological lesion intensities and increasing median funduscopic and OCT diameters. Group 5 lesions were as large as, but more intense than group 4 lesions.

CONCLUSIONS

Automatic, temperature controlled photocoagulation allows to apply predictable subvisible, mild, or moderate lesions without manual power titration.

TRANSLATIONAL RELEVANCE

The technique will facilitate standardized, automatically controlled low and early treatment of diabetic retinopathy study (ETDRS) intensity photocoagulation independently of the treating physician, the treated eye and lesion location.

Influence of intravitreal triamcinolone acetonide injection in scleral buckling surgery for macula-off retinal detachment

PURPOSE

To investigate the effect of intravitreal triamcinolone acetonide injection on the resolution of subretinal fluid (SRF), and its correlation with visual outcome after scleral buckle (SB) surgery.

METHODS

A prospective consecutive case series was conducted in patients who underwent SB surgery for macula-off rhegmatogenous retinal detachment (RRD) at Farabi Eye Hospital from February 1, 2012 to August 30, 2013. Exclusion criteria included previous ocular surgery (e.g. primary surgical failure) except cataract surgery, recurrent retinal detachment, macular hole, epiretinal membrane, proliferative vitreoretinopathy grade C, history of trauma, other retinal diseases, and diabetes mellitus. Patients were assigned to two groups. In group 1, patients received 2 mg of intravitreal triamcinolone acetonide injection at the end of surgery while patients in group 2 received intravitreal balanced saline solution for balancing the intraocular pressure (IOP). Patients were followed up at 1 day, 1 week, 1 month, 2 months and 3 months after the surgery by best-corrected visual acuity (BCVA), slitlamp examination, indirect ophthalmoscopy and optical coherence tomography (OCT). OCT (Heidelberg Engineering, Heidelberg, Germany) was used at all visits except day 1 after the surgery. Student's t test and χ(2) tests were used for comparisons; p value ≤ 0.05 was considered significant.

RESULTS

Sixty-two eyes of 62 patients were enrolled in the study. There were 33 male patients (53%) and 29 female patients (47%). The average age was 43.8 years (18-72 years). The mean duration of symptoms was 34.7 ± 46.8 days. There were 29 eyes in group 1 and 33 eyes in group 2. Twelve weeks after the operation, 25 patients (40%) had SRF beneath the macula, but there was no significant difference (p = 0.24, χ(2) test) between the two groups. Improvement in BCVA in both groups was statistically significant (p ≤ 0.001) but did not differ between the two groups (p = 0.09) apart from week 12, in which the improvement in group 1 was significantly higher (p = 0.03). The incidence of cystoid macular edema did not differ in a statistically significant way between the groups (p = 0.19). IOP in 4 (15%) patients in group 1 rose above 21 mm Hg but responded quickly to 2 weeks of topical antiglaucoma medication. There was no cataract progression in either group. There was no correlation between the incidence of persistent SRF and the extent of detachment in both groups (p = 0.83). There was no surgical failure or redetachment in either group during the study period.

CONCLUSION

Single-dose intravitreal triamcinolone may increase the final BCVA in macula-off RRD patients despite persistent SRF, suggesting the anti-inflammatory role of this drug.

Laser-based strategies to treat diabetic macular edema: history and new promising therapies

Diabetic macular edema (DME) is the main cause of visual impairment in diabetic patients. The management of DME is complex and often various treatment approaches are needed. At the present time, despite the enthusiasm for evaluating several new treatments for DME, including the intravitreal pharmacologic therapies (e.g., corticosteroids and anti-VEGF drugs), laser photocoagulation still remains the current standard in DME. The purpose of this review is to update our knowledge on laser photocoagulation for DME and describe the developments in laser systems. And we will also discuss the new laser techniques and review the latest results including benefits of combined therapy. In this paper, we briefly summarize the major laser therapeutics for the treatment of diabetic macular edema and allude to some future promising laser therapies.

The evolution of laser therapy in ophthalmology: a perspective on the interactions between photons, patients, physicians, and physicists: the LXX Edward Jackson Memorial Lecture

PURPOSE

To present the evolution of laser therapy in modern ophthalmic practice.

DESIGN

Review of published experimental and clinical studies.

METHODS

A review was undertaken of the work of multiple investigators leading to the invention of the laser, its biophysical effects on ocular tissues from which it derives its name (light-amplified stimulation of emitted radiation), and the development of various laser-based devices and methods to treat common ophthalmologic disorders, with particular emphasis on new and emerging retinal and anterior segment applications.

RESULTS

Because the eye is optimized for the transmission of light and its transduction into neural signals, lasers are particularly well suited for ophthalmic therapy. This fact and the high demands for precision in therapy have inspired the development of highly sophisticated laser systems that have impacted the treatment of common diseases. These include diabetic retinopathy, age-related macular degeneration, retinal venous occlusive disease, retinopathy of prematurity, and optical aberrations including ametropia, cataract, and glaucoma, among others. Recent developments in scanning laser systems, including image-guided systems with eye tracking, real-time feedback, and ultra-short pulse durations, have enabled increased selectivity, precision, and safety in ocular therapy. However, improved outcomes have been associated with increased cost of medical care, and attention to and optimization of their cost effectiveness will continue to be required in the future.

CONCLUSIONS

The invention and evolution of modern ophthalmic lasers have enhanced therapeutic options and can serve as a heuristic model for better understanding the process of innovation, including the societal benefits and also unintended consequences, including increased costs.

Tissue response of selective retina therapy by means of a feedback-controlled energy ramping mode

BACKGROUND

The purpose of the study was to evaluate the safety and selectivity of the retinal pigment epithelium lesions by using automatic energy ramping and dosimetry technique for selective retina therapy and to investigate the healing response.

METHODS

Ten eyes of Chinchilla Bastard rabbits were treated with an automatic dosage controlled selective retina therapy laser (frequency doubled Q-switched Nd:YLF, wavelength: 527 nm, pulse duration: 1.7 μs, repetition rate: 100 Hz, pulse energy: linear increasing from pulse to pulse up to shut down - maximal 110 μJ, max. number of pulses in a burst: 30, retinal spot diameter: 133 μm). After treatment, fundus photography, optical coherence tomography and fluorescein angiography were performed at three time points from 1 h to 3 weeks. Histological analysis was performed.

RESULTS

A total of 381 selective retina therapy laser spots were tested (range 13-104 μJ).Typical fundus photographs obtained at 1 h after irradiation showed that 379 out of 381 lesions produced by selective retina therapy were not visible ophthalmoscopically and the lesions could be detected by angiography only. Optical coherence tomography images revealed that the structure of photoreceptors was preserved, but a disrupted retinal pigment epithelium layer was observed as was expected. By 3 weeks, histology showed selective retinal pigment epithelium damage without any effect on the inner retina and focal proliferation of the retinal pigment epithelium layer.

CONCLUSIONS

Automatically controlled selective retina therapy is a significant improvement in this innovative treatment. It could be demonstrated that the non-contact, reflectometric technique with a controlled pulse energy ramp is safe and selective.

Comprehensive detection, grading, and growth behavior evaluation of subthreshold and low intensity photocoagulation lesions by optical coherence tomographic and infrared image analysis

Purpose. To correlate the long-term clinical effect of photocoagulation lesions after 6 months, as measured by their retinal damage size, to exposure parameters. We used optical coherence tomographic (OCT)-based lesion classes in order to detect and assess clinically invisible and mild lesions. Methods. In this prospective study, 488 photocoagulation lesions were imaged in 20 patients. We varied irradiation diameters (100/300 µm), exposure-times (20–200 ms), and power. Intensities were classified in OCT images after one hour, and we evaluated OCT and infrared (IR) images over six months after exposure. Results. For six consecutive OCT-based lesion classes, the following parameters increased with the class: ophthalmoscopic, OCT and IR visibility rate, fundus and OCT diameter, and IR area, but not irradiation power. OCT diameters correlated with exposure-time, irradiation diameter, and OCT class. OCT classes discriminated the largest bandwidth of OCT diameters. Conclusion. OCT classes represent objective and valid endpoints of photocoagulation intensity even for “subthreshold” intensities. They are suitable to calculate the treated retinal area. As the area is critical for treatment efficacy, OCT classes are useful to define treatment intensity, calculate necessary lesion numbers, and universally categorize lesions in clinical studies.

Persistent subfoveal fluid and increased preoperative foveal thickness impair visual outcome after macula-off retinal detachment repair

PURPOSE

To investigate the influence of subfoveal fluid and foveal thickness on visual outcome in patients who underwent reattachment surgery for rhegmatogenous retinal detachment (RRD).

METHODS

This prospective study included 53 patients who were undergoing successful scleral buckling surgery for primary RRD. A thorough ophthalmologic examination including best-corrected visual acuity, slit-lamp biomicroscopy, binocular indirect ophthalmoscopy, and optical coherence tomography scanning was performed preoperatively and during all subsequent follow-up visits at 1, 3, 6, 9, 12, and 24 months postoperatively.

RESULTS

Preoperative foveal thickness was significantly higher in the macula-off group (n = 38) compared with the macula-on group (n = 15) (P < 0.0001), whereas postoperative measurements were normal in both the groups. Linear mixed-model analysis revealed that persistent subfoveal fluid (P = 0.0004) was an independent predictor of a worse visual outcome after scleral buckling surgery for primary macula-off RRD, although the effect on visual outcome was small (0.1 logarithm of the minimal angle of resolution units). Moreover, increased preoperative foveal thickness was associated with a worse visual prognosis in macula-off RRD (P = 0.010).

CONCLUSION

Persistent subfoveal fluid and increased preoperative foveal thickness were associated with a worse visual prognosis in macula-off RRD patients, albeit the effect of persistent subfoveal fluid was small and temporary.

Persistent subretinal fluid after surgery for rhegmatogenous retinal detachment: hypothesis and review

BACKGROUND

Persistent subretinal fluid after rhegmatogenous retinal detachment (RRD) surgery is responsible for delayed recovery, and may affect the final visual outcome. Cause, consequences, and treatment remain elusive.

DESIGN

Literature review and case series.

METHODS

We reviewed the pathophysiological principles and therapeutic options from the literature, and we report the results from a subretinal fluid cytology study. Nine eyes from nine patients with macula-involving RRD underwent surgical repair. The cellular content of subretinal fluid (SRF) was studied by electron microscopy and anti-rhodopsin immunostaining. All eyes were assessed postoperatively with optical coherence tomography for the detection of persistent submacular fluid (PSF) (Ethics Committee Ghent University Hospital, registration number B6702006169).

RESULTS

Certain patient characteristics as well as surgical methods were implicated. PSF appears to occur more frequently in patients with longstanding detachments treated with buckling surgery. Several therapeutic options have been suggested but safety and efficacy remain unclear. We found PSF in three eyes on postoperative OCT scans, which corresponded to the three cell-rich subretinal samples.

CONCLUSIONS

PSF after successful RRD repair seems to be related to fluid composition. We hypothesize, in the absence of an effective treatment, that a modified surgical drainage, including a washout of the subretinal space, could evacuate the subretinal fluid more completely, and may prevent this complication.