Subthreshold micropulse laser combined with anti-vascular endothelial growth factor therapy for diabetic macular edema: a systematic review and meta-analysis

PURPOSE

To evaluate the effects of subthreshold micropulse laser (SML) in addition to anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME).

METHODS

MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were systematically searched for studies that compared anti-VEGF with SML and anti-VEGF monotherapy for DME. Outcome measures were best-corrected visual acuity (BCVA), central macular thickness (CMT), and the number of anti-VEGF injections.

RESULTS

Eight studies including 493 eyes were selected. Four studies were randomized controlled, and the other four were retrospective. Meta-analysis showed that there was no significant difference in BCVA (mean difference [MD] -0.04; 95%CI -0.09 to 0.01 logMAR; P = 0.13;). CMT was thinner in the group of anti-VEGF with SML (MD -11.08; 95%CI -21.04 to -1.12 µm; P = 0.03); however, it was due to a single study that weighed higher, and the sensitivity and subcategory analyses did not support the finding. The number of anti-VEGF injections was significantly decreased in the group of anti-VEGF with SML (MD -2.22; 95%CI -3.02 to -1.42; P < 0.0001).

CONCLUSION

Current evidence indicates that adding SML to anti-VEGF therapy could significantly reduce the number of anti-VEGF injections compared to anti-VEGF monotherapy, while achieve similar BCVA and CMT.

Postoperative vision loss due to bilateral vitreous hemorrhage after robot-assisted laparoscopic hysterectomy: A case report

Purpose

To report a case of bilateral vitreous hemorrhage (VH) resulting in postoperative vision loss (POVL) after robot-assisted laparoscopic hysterectomy in a 71-year-old female patient.

Observations

At initial presentation, best-corrected visual acuity was hand motion at 20 cm in the right eye and 20/666 in the left eye. VH in both eyes and preretinal hemorrhage in the left eye was observed. As the hemorrhage gradually resolved, a full-thickness macular hole was discovered in the right eye, for which the patient did not agree with a surgical treatment.

Conclusions and importance

This report describes a rare incidence of bilateral VH as a cause of POVL after non-ophthalmic surgery, which may be related to Trendelenburg positioning, CO2 pneumoperitoneum, and a long surgical duration. Given that POVL can cause severe visual impairment, consultation with ophthalmologists is crucial.

Encircling continuous suture technique for the management of extensive traumatic cyclodialysis: A case report

PURPOSE

To report a surgical technique of cyclopexy, wherein two laps of encircling continuous sutures are placed around the limbus to treat refractory extensive cyclodialysis.

METHODS

Color fundus photography, swept-source optical coherence tomography (OCT) for the anterior segment, and spectral-domain OCT for the macula.

RESULTS

Previous attempts, including indirect cyclopexy and direct external cyclopexy with gas injection, failed to successfully resolve the severe cyclodialysis and associated hypotonic maculopathy. In the third surgery, two laps of encircling continuous sutures were placed around the limbus at the distances of 2-3 mm and 3-4 mm, along with phacoemulsification, intraocular lens implantation, and capsular tension ring placement. Following the surgery, hypotony and hypotonic maculopathy were effectively resolved, resulting in a significant improvement in visual acuity, that has been maintained over a year.

CONCLUSION

The described surgical technique of encircling continuous sutures may be a viable option for the treatment of severe cyclodialysis.

Navigated direct photocoagulation with a 30-ms short-pulse laser for treating microaneurysms in diabetic macular edema exhibits a high closure rate

This study carried out direct photocoagulation for treating microaneurysms (MAs) in diabetic macular edema (DME) using a navigation laser system with a 30-ms pulse duration. The MA closure rate after 3 months was investigated using pre and postoperative fluorescein angiography images. MAs primarily inside the edematous area based on optical coherence tomography (OCT) maps were selected for treatment, and leaking MAs (n = 1151) were analyzed in 11 eyes (eight patients). The total MA closure rate was 90.1% (1034/1151), and the mean MA closure rate in each eye was 86.5 ± 8.4%. Mean central retinal thickness (CRT) decreased from 471.9 ± 73.0 μm to 420.0 ± 87.5 μm (P = 0.049), and there was a correlation between the MA closure rate and the CRT reduction rate (r = 0.63, P = 0.037). There was no difference in the MA closure rate depending on the degree of edema thickness based on a false-color topographic OCT map image. Direct photocoagulation for DME with a short pulse using the navigated photocoagulator resulted in a high MA closure rate in just 3 months and a corresponding improvement in retinal thickness. These findings encourage the use of a new therapeutic approach for DME.

Microperimetric analysis of diabetic macular edema after navigated direct photocoagulation with short-pulse laser for microaneurysms

BACKGROUND

Focal laser photocoagulation is an important treatment option for diabetic macular edema (DME). This study aimed to examine the retinal sensitivity (RS) and morphological changes at the coagulated site after direct photocoagulation of microaneurysms (MAs) in patients with DME using a navigated laser photocoagulator with a short-pulse duration of 30 ms.

METHODS

Images of early-phase fluorescein angiography were merged with images from the optical coherence tomography (OCT) map with 9 Early Treatment Diabetic Retinopathy Study grid circles, and MAs inside the edema area were selected for direct photocoagulation. The best-corrected visual acuity (BCVA), parameters of the OCT map including central retinal thickness and retinal thickness in edema range, central RS, and RS in the edema area were assessed at 1 and 3 months after the laser treatment. The RS points that overlapped with the laser spots were identified by merging the Navilas' digital treatment reports and the microperimetry images.

RESULTS

Seventeen eyes from 14 patients were studied. The mean retinal thickness in the edema range decreased at 3 months compared with pretreatment (P = 0.042), but the BCVA, central retinal thickness, central RS, and RS in the edema area remained unchanged. Overall, 32 of 400 sensitivity points overlapped with the laser-coagulated spots. The mean RS at these spots were 22.4 ± 5.3 dB at 1 month and 22.5 ± 4.8 dB at 3 months, with no significant change from the baseline of 22.7 ± 3.5 dB.

CONCLUSIONS

Retinal thickness improved in the coagulated edema area without a decrease in RS after direct photocoagulation of MAs with a short 30-ms pulse using Navilas. This promising therapeutic strategy for DME is effective and minimally invasive.

Macular and peripapillary retinal nerve fiber layer thinning in eyes with prediabetes in the elderly population: OTASSHA study

PURPOSE

To investigate retinal thickness parameters in the elderly with prediabetes mellitus (preDM) and type 2 DM without retinopathy (non-diabetic retinopathy [NDR]).

METHODS

This cross-sectional study included a total of 1273 eyes without retinal pathologies of 699 volunteers aged ≥ 65 years were included. The eyes were categorized into non-DM (606 eyes), preDM (480 eyes), and NDR (187 eyes) groups according to their HbA1c levels. Fundus photography, swept-source optical coherence tomography, and comprehensive systemic examination were conducted. The thicknesses of the retinal nerve fiber layer in the macula (mRNFL) and peripapillary (pRNFL), ganglion cell complex (GCC), and ganglion cell inner plexiform layer (GCIPL), as well as central subfield thickness (CST) and central foveal thickness (CFT) were investigated for their association with DM stage using linear mixed model.

RESULTS

A statistically significant thinning of mRNFL was observed in preDM vs. non-DM and in NDR vs. preDM in 3/6 sectors. A significant thinning of pRNFL was observed in preDM vs. non-DM and in NDR vs. preDM in 2/12 sectors. Such DM stage-dependent thinning of RNFL was observed mainly in the temporal and superior sectors. GCIPL and GCC were less sensitive to reflect DM-dependent inner retinal thinning. CST and CFT were not significantly associated with different DM stages.

CONCLUSION

The thinning of mRNFL in the temporal and superior sectors might be a sensitive parameter associated with early neurodegeneration in preDM and NDR.

Optical coherence tomography findings after surgery for sub-inner limiting membrane hemorrhage due to ruptured retinal arterial macroaneurysm

Ruptured retinal arterial macroaneurysm (RAM) can cause sub-inner limiting membrane (ILM) hemorrhage, leading to acute vision loss in the elderly. Vitrectomy has been established as an effective treatment to remove hemorrhage and facilitate visual recovery. Although optical coherence tomography (OCT) is useful for the diagnosis of sub-ILM hemorrhage before surgery, little is known about the postoperative OCT findings. Here, we retrospectively investigated the records of nine eyes of nine patients who underwent surgery for sub-ILM hemorrhage due to RAM rupture. On postoperative OCT, hyperreflectivity throughout the full thickness of the central fovea was observed in eight eyes (88.9%), and disruption of the ellipsoid/interdigitation zone (EZ/IZ) was observed in seven out of eight eyes (87.5%). The widths of the hyperreflectivity and EZ disruption gradually decreased. Visual recovery was least favorable in two eyes, in which the EZ line continuation did not recover until the final follow-up. The OCT findings corresponded to the hemorrhagic staining identified on fundus photographs in at least four eyes; as per the fundus photographs the findings persisted even after the hemorrhage was absorbed. In contrast, the OCT findings resembled the appearance before the development of a full-thickness macular hole, suggesting fragility caused by the RAM rupture.

Bionic eye system mimicking microfluidic structure and intraocular pressure for glaucoma surgery training

Among increasing eye diseases, glaucoma may hurt the optic nerves and lead to vision loss, the treatment of which is to reduce intraocular pressure (IOP). In this research, we introduce a new concept of the surgery simulator for Minimally Invasive Glaucoma Surgery (MIGS). The concept is comprised of an anterior eye model and a fluidic circulatory system. The model made of flexible material includes a channel like the Schlemm’s canal (SC) and a membrane like the trabecular meshwork (TM) covering the SC. The system can monitor IOP in the model by a pressure sensor. In one of the MIGS procedures, the TM is cleaved to reduce the IOP. Using the simulator, ophthalmologists can practice the procedure and measure the IOP. First, considering the characteristics of human eyes, we defined requirements and target performances for the simulator. Next, we designed and manufactured the prototype. Using the prototype, we measured the IOP change before and after cleaving the TM. Finally, we demonstrated the availability by comparing experimental results and target performances. This simulator is also expected to be used for evaluations and developments of new MIGS instruments and ophthalmic surgery robots in addition to the surgical training of ophthalmologists.

A force measurement platform for a vitreoretinal surgical simulator using an artificial eye module integrated with a quartz crystal resonator

To provide quantitative feedback on surgical progress to ophthalmologists practicing inner limiting membrane (ILM) peeling, we developed an artificial eye module comprising a quartz crystal resonator (QCR) force sensor and a strain body that serves as a uniform force transmitter beneath a retinal model. Although a sufficiently large initial force must be loaded onto the QCR force sensor assembly to achieve stable contact with the strain body, the highly sensitive and wide dynamic-range property of this sensor enables the eye module to detect the slight forceps contact force. A parallel-plate strain body is used to achieve a uniform force sensitivity over the 4-mm-diameter ILM peeling region. Combining these two components allowed for a measurable force range of 0.22 mN to 29.6 N with a sensitivity error within -11.3 to 4.2% over the ILM peeling area. Using this eye module, we measured the applied force during a simulation involving artificial ILM peeling by an untrained individual and compensated for the long-term drift of the obtained force data using a newly developed algorithm. The compensated force data clearly captured the characteristics of several types of motion sequences observed from video recordings of the eye bottom using an ophthalmological microscope. As a result, we succeeded in extracting feature values that can be potentially related to trainee skill level, such as the mean and standard deviation of the pushing and peeling forces, corresponding, in the case of an untrained operator, to 122.6 ± 95.2 and 20.4 ± 13.2 mN, respectively.

Changes in entropy on polarized-sensitive optical coherence tomography images after therapeutic subthreshold micropulse laser for diabetic macular edema: A pilot study

Purpose

To investigate the dynamics of the healing process after therapeutic subthreshold micropulse laser (SMPL) for diabetic macular edema (DME) using polarization-sensitive optical coherence tomography (PS-OCT).

Methods

Patients with treatment-native or previously-treated DME were prospectively imaged using PS-OCT at baseline, 1, 2, 3, and 6 months. The following outcomes were evaluated: changes in the entropy value per unit area (pixel²) in the retinal pigment epithelium (RPE) on the B-scan image; changes in the entropy value in each stratified layer (retina, RPE, choroid) based on the ETDRS grid circle overlaid with en face entropy mapping, not only the whole ETDRS grid area but also a sector irradiated by the SMPL; and the relationship between edema reduction and entropy changes.

Results

A total of 11 eyes of 11 consecutive DME patients were enrolled. No visible signs of SMPL treatment were detected on PS-OCT images. The entropy value per unit area (pixel²) in the RPE tended to decrease at 3 and 6 months from baseline (35.8 ± 17.0 vs 26.1 ± 9.8, P = 0.14; vs 28.2 ± 18.3, P = 0.14). Based on the en face entropy mapping, the overall entropy value did not change in each layer in the whole ETDRS grid; however, decrease of entropy in the RPE was observed at 2, 3, and 6 months post-treatment within the SMPL-irradiated sectors (P < 0.01, each). There was a positive correlation between the change rate of retinal thickness and that of entropy in the RPE within the SMPL-irradiated sector at 6 months (r² = 0.19, P = 0.039).

Conclusion

Entropy measured using PS-OCT may be a new parameter that facilitates objective monitoring of SMPL-induced functional changes in the RPE that could not previously be assessed directly. This may contribute to a more promising therapeutic evaluation of DME.

Clinical trial

This clinical study was registered in UMIN-CTR (ID: UMIN000042420).

Surgical Treatment for a Full-Thickness Macular Hole That Developed on a Large Drusenoid Pigment Epithelial Detachment

Full-thickness macular hole (FTMH) and age-related macular degeneration (AMD) can affect the same eyes in the older population. Previously reported phenotypes of AMD concurrent with FTMH include early/intermediate AMD and serous pigment epithelial detachment (PED). A 68-year-old woman presented to our clinic with decreased vision due to a cataract and a large drusenoid PED in both eyes. After ruling out choroidal neovascularization, she underwent cataract surgery. Three days after the cataract surgery, an FTMH was found in the left eye. Although the FTMH was not closed after the initial pars plana vitrectomy (PPV) with the inner limiting membrane (ILM) peeling and air tamponade, it was closed after reoperation with additional ILM peeling, retinal massage, and SF6 gas tamponade. Best-corrected visual acuity (BCVA) was improved from 20/60 before the first PPV to 20/40 at six months after the reoperation. Some large soft drusen in the macula were fused after surgeries in the operated eye, but not in the fellow eye. An FTMH concurrent with a large drusenoid PED is rare. It can be closed surgically, and postoperative visual function can improve.

Fovea-Sparing as Opposed to Total Peeling of Internal Limiting Membrane for Myopic Foveoschisis: A Systematic Review and Meta-analysis

TOPIC

The effectiveness of fovea-sparing (FS) peeling of internal limiting membrane (ILM) to treat myopic foveoschisis (MF) has not been understood fully. The present meta-analysis aimed to compare postoperative visual and anatomic outcomes between FS peeling and total peeling (TP) of ILM in pars plana vitrectomy for the treatment of MF.

CLINICAL RELEVANCE

Postoperative macular hole (MH) development is not uncommon and is a serious complication after surgery for MF, with poor visual prognosis. Fovea-sparing peeling of ILM is expected to reduce the risk of postoperative MH; however, no statistically significant evidence exists to prove this hypothesis. In addition, its effect on postoperative visual acuity has not been clear.

METHODS

MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE were reviewed systematically, and studies that compared FS with total ILM peeling in MF surgery were retrieved. The protocol was registered in International Prospective Register of Systematic Reviews (identifier, CRD42020201675). Primary outcome measures were the postoperative best-corrected visual acuity (BCVA) and frequency of postoperative MH development. Certainty of evidence was evaluated by the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

Eight studies with 300 eyes from 289 patients were included. All studies were nonrandomized and observational. The postoperative BCVA was significantly better in eyes treated with FS (mean difference [MD], -0.15 logarithm of the minimum angle of resolution [logMAR]; 95% confidence interval [CI], -0.24 to -0.05 logMAR; P = 0.002). The risk of postoperative MH was significantly lower in the FS group (odds ratio, 0.19; 95% CI, 0.06-0.56; P = 0.003). No significant difference was found in postoperative central foveal thickness (MD, 12.59 μm; 95% CI, -2.8 to 28.0 μm; P = 0.11). The certainty of evidence regarding lower frequency of postoperative MH after FS peeling was considered moderate, whereas the certainty regarding better postoperative BCVA after FS peeling was judged to be low.

DISCUSSION

Fovea-sparing peeling may contribute to better visual acuity outcome and lower risk of postoperative MH development in eyes with MF.

Continued smoking and posterior vitreous adhesion in the elderly evaluated on swept-source optical coherence tomography

In this cross-sectional study including 1150 eyes of 681 volunteers ≧ 65 years old without retinal pathology, factors affecting the progression of posterior vitreous detachment (PVD) were investigated. PVD stages were diagnosed based on swept-source optical coherence tomography (SS-OCT). Linear mixed effect model was used to determine whether age, gender, diabetes mellitus (DM), hypertension (HT), dyslipidemia (DL), and smoking status were associated with various stages of PVD. As a result, the multivariable analysis disclosed that the associations between older age and higher PVD stages (estimate [95% CI], 0.031 [0.020 to 0.042]; P < 0.0001), and current smokers and lower PVD stages (estimate [95% CI], − 0.24 [− 0.43 to − 0.056]; P = 0.011) were statistically significant. In contrast, female gender was not an independent factor affecting PVD stages in the elderly. Our analysis indicated that higher PVD stages observed in female eyes may be due to confounding effect, in which current smokers were predominantly males (i.e., 12.6% among males vs. 3.9% among females, P < 0.0001). In conclusion, our findings suggest that continuous smoking is associated with an adherent vitreoretinal interface in the elderly.

Posterior vitreous detachment and macular microvasculature in the elderly

PURPOSE

To investigate the association between different stages of posterior vitreous detachment (PVD) and macular microvasculature in the elderly.

METHODS

Swept-source optical coherence tomography (OCT), OCT angiography, and color fundus images of 490 eyes without retinal pathologies of 322 participants aged ≥65 years were evaluated. PVD was classified using enhanced vitreous visualization mode as no apparent PVD (stage 0/1), vitreous adhesions at the fovea and optic disc (stage 2), adhesion at the optic disc (stage 3), or complete PVD (stage 4). Microvascular parameters, including foveal avascular zone (FAZ) and vessel density (VD), were analyzed for their associations with complete PVD. Additionally, the association between PVD and central retinal thickness (CRT) was also addressed.

RESULTS

Overall, 80, 31, 31, and 349 eyes were categorized into stages 0/1, 2, 3, and 4, respectively. Using multivariate mixed-effects model, the mean superficial FAZ area was smaller in stage 4 compared with stages 0-3 (0.29 vs. 0.32 mm2; P = 0.014), and the mean superficial VD was lower in stage 4 compared with stages 0-3 (34.96% vs. 35.24%; P = 0.0089). However, PVD was not significantly associated with deep macular microvascular parameters or CRT.

CONCLUSIONS

Complete PVD was associated with smaller FAZ area and lower VD in superficial macular microvasculature, while it was not associated with central retinal thickness.

Correlation between anterior chamber flare changes and diabetic macular edema after intravitreal injection of ranibizumab and aflibercept

PURPOSE

To evaluate aqueous flare change patterns following anti-vascular endothelial growth factor therapy for diabetic macular edema (DME) and investigate the relationship between changes in flare values and central macular thickness (CMT).

STUDY DESIGN

Retrospective, interventional case series METHODS: A total of 84 eyes of 62 patients with DME received either intravitreal ranibizumab (IVR; n = 62) or aflibercept (IVA; n = 22). A laser flare photometer (Kowa FM500, Kowa Company, Ltd) was used to measure flare values, and CMT was assessed using optical coherence tomography. Flare values and CMT were measured prior to injection (baseline) and at, 1, 7 and 14 days after injection.

RESULTS

Flare values in the IVR group decreased significantly at day 14 (P = 0.001), whereas the IVA group showed a significant increase in flare values at day 1 (P < 0.001). In the IVA group, the baseline flare values were significantly higher in the CMT reduction group than in the non-CMT reduction group (P = 0.035). There was no correlation between changes in flare values and CMT either in the IVA or IVR group.

CONCLUSIONS

Flare value changes in patients treated with IVR decreased at day 14 post-injection. This may indicate when the most anti-inflammatory effect was obtained. There was no correlation between changes in flare values and CMT either in the IVA or IVR group; nevertheless, our research suggests that the baseline flare value is a predictive factor for the efficacy of IVA in DME.

Ursodeoxycholic Acid Attenuates the Retinal Vascular Abnormalities in Anti-PDGFR-β Antibody-Induced Pericyte Depletion Mouse Models

As a clinical manifestations of diabetic retinopathy (DR), pericytes (PCs) loss from the capillary walls is thought to be an initial pathological change responsible for the breakdown of the blood-retinal barrier (BRB). This study was performed to investigate the effects of ursodeoxycholic acid (UDCA) in PC depletion mice by injection of an antibody against platelet-derived growth factor reception-β (PDGFR-β clone APB5). To assess the integrity of the retinal vessels, their density, diameters, vessel branching points, and number of acellular capillaries were evaluated. While all types of retinal vessels became enlarged in APB5-induced mice, treatment with UDCA rescued the vasculature; the vessel density, diameter of the veins and capillaries, and vessel branching points were significantly lower in mice treated with UDCA. Although APB5-induced mice displayed progressive exacerbation of retinal edema, whole retinal thickness upon treatment with UDCA was significantly decreased. Additionally, UDCA reduced the expression of F4/80⁺ macrophages in the APB5-induced retina according to immunofluorescent labeling. UDCA also reduced the increased expression of angiogenic factors and inflammatory mediators (vascular endothelial growth factor, intercellular adhesion molecule-1, and monocyte chemotactic protein-1). These findings suggest that UDCA can be used to prevent the progression of and treat DR.

A Case of Diabetic Retinopathy with both Retinal Neovascularization and Complete Posterior Vitreous Detachment

PURPOSE

Report of a case with retinal neovascularization developing in the setting of diabetic retinopathy despite complete posterior vitreous detachment (PVD).

CASE REPORT

A 76-year-old man had had type II diabetes mellitus for more than 30 years. Weiss' ring was detected by direct and indirect ophthalmoscopy. PVD was thus considered to be complete. On the other hand, fluorescein angiography showed two areas of hyperfluorescence at the margin of the retinal nonperfusion area.

CONCLUSIONS

The present case underscores the importance of periodic follow-up using fluorescein angiography, given the probability of retinal neovascularization development and proliferative changes for many years even in diabetic retinopathy associated with complete PVD.

Experimental verification of subthreshold laser therapy using conventional pattern scan laser

Purpose

Leading-edge therapeutic laser technologies are not available at every medical facility; therefore, alternative approaches incorporating novel advances in digital and laser technology into more readily available conventional methods have generated significant research interest. Using a rabbit model, this study investigated whether the algorithm used in the Endpoint Management (EM) software system of the latest devices could enable subthreshold laser treatment in conventional retinal tissue laser therapy systems.

Materials and methods

Two types of devices were used, the PASCAL Streamline 577 and the MC 500-Vixi™, and the laser method was classified into three categories: EM; single-shot using PASCAL with arbitrary energy settings (PSS-SDM); and MC500-Vixi^TM (VX-SDM), which were performed in eight eyes from four Dutch-Belted rabbits. In EM, 100 mW (100%) was set as a landmark, and the laser energy parameters were gradually decreased to 80%, 60%, 50%, 40%, 30%, 20%, and 10%, using a 2 × 3 square pattern. In PSS-SDM and VX-SDM, as control, the laser energy was gradually decreased to 100, 80, 60, 50, 40, 30, 20, and 10 mW. The laser settings were fixed at 200 μm, 20 ms, and a wavelength of 577 μm. To identify and compare the extent of tissue damage at each spot size, optical coherence tomography (OCT) and histological findings were used to construct a three-dimensional histopathology image using a confocal laser scanning fluorescence microscope.

Results

The spot size at 50% setting on EM was 7183 μm²; PSS-SDM required 50 mW (5503 μm²) to 60 mW (10279 μm²) and VX-SDM required 50 mW (7423 μm²) to create the approximate spot size. Furthermore, at 50 mW of PSS-SDM and VX-SDM, the extent of tissue damage in all three methods was generally in accord with the outer nuclear layer by OCT and inner nuclear layer by histopathological imaging.

Conclusion

These findings suggest that it may be possible to perform subthreshold laser therapy using approximations from the EM algorithm.

Aqueous cytokine levels are associated with reduced macular thickness after intravitreal ranibizumab for diabetic macular edema

Purpose

It is controversial whether the administration of anti-vascular endothelial growth factor drugs for diabetic macular edema (DME) affects intraocular inflammatory cytokines. In this study, we measured cytokine concentration in aqueous humor before and after intravitreal injection of ranibizumab (IVR). The aim was to determine changes in cytokine concentration and their effects on DME reduction.

Methods

Twelve patients (13 eyes) with DME received two IVR (0.5 mg) with a 1 month interval, and a total of 26 aqueous humor samples were obtained. Macular thickness was measured with an optical coherence tomography (OCT) using thickness-map mode with an Early Treatment Diabetic Retinopathy Study (ETDRS) 9-zone grid that was divided into two zones: a central circle with a diameter of 1 mm (zone1); and an outer circle with a diameter of 6 mm (zone2).

Results

The concentration of eotaxin-1 in aqueous humor samples decreased significantly after IVR. Baseline cytokine concentration was associated with IVR-induced DME reduction. In zone1, higher baseline concentration of interferon-induced protein (IP)-10, and in zone 2, higher baseline concentration of granulocyte-macrophage colony-stimulating factor, IP-10, and tumor necrosis factor (TNF) α; and lower baseline concentration of eotaxin-1, interleukin (IL)-5, and IL-8 were associated with improved DME. Cytokine changes were associated with IVR-induced DME reduction. In zone1, lower concentration of IP-10 compared to baseline or higher concentration of macrophage inflammatory protein (MIP) -α, and in zone 2, lower concentration of IL-5 compared to baseline, IL-8, and IP-10 or higher concentration of eotaxin-1 and MIP-1β were associated with improved DME.

Conclusions

These findings suggest that ranibizumab affects the concentration of cytokines in aqueous humor. Various cytokines contribute to a decrease in retinal thickness, both in the center of the macula and in a larger area of the retina.

Influence of surface light scattering in hydrophobic acrylic intraocular lenses on laser beam transmittance

The aim of this study was to experimentally examine the changes in the transmittances of photocoagulation lasers when surface light scattering increases in AcrySof intraocular lenses (IOLs). SA60AT IOLs (Alcon) were acceleratingly aging for 0, 3, 5, and 10 years to simulate surface light scattering, and the surface light-scattering intensities of both IOL surfaces were measured using a Scheimpflug photographer. The powers of laser beams that passed from a laser photocoagulator through the aged IOLs were measured at 532, 577, and 647 nm. Changes in the laser power and transmittance with the years of aging and the intensities of surface light scattering were examined. Although the intensity of surface light scattering increased with the years of aging, the laser power did not change with the years of aging (P > 0.30, Kruskal-Wallis test). There were no significant changes in the laser transmittance with the years of aging or the laser wavelength (P > 0.30 and 0.57, respectively). The intensity of surface light scattering revealed no significant association with the laser transmittance at any wavelength (P > 0.37, liner regression). The increases in the surface light scattering of the AcrySof IOLs would not influence retinal photocoagulation treatments for up to 10 years after implantation.

Influence of a yellow-tinted intraocular lens on laser beam transmittance

PURPOSE

To compare the transmittance of laser beams that are used for photocoagulation through a yellow-tinted intraocular lens (IOL) and a clear IOL.

METHODS

The transmittance of laser beams of different wavelengths (488 + 514, 514, 521, 568 and 647 nm) through yellow-tinted and clear IOLs of varying dioptric powers [+10, +20 and +30 dioptres (D)] was measured using a laser power meter. The transmittance ratio was defined as the ratio of the transmittance thorough a tinted IOL to that through a clear IOL, assuming that the transmittance value of the latter is 1; this ratio was calculated for each IOL and each wavelength of the laser beam.

RESULTS

There were no apparent differences in the transmittance values between the tinted and clear IOLs when the 521, 568 and 647 nm wavelengths were used. In contrast, the transmittance ratio decreased for the tinted IOL when the short wavelengths - 488 + 514 and 514 nm - were used, especially when an IOL of a higher dioptric power was used. This ratio was found to be 91.9% for a +10 D, 86.7% for a +20 D and 82.2% for a +30 D lens when a 488 + 514 nm wavelength beam was used.

CONCLUSION

When treating patients using photocoagulation, we must bear in mind the decreased transmittance ratio of short-wavelength laser beams when passed through tinted IOLs and increase the setting power of the beam accordingly.

Vitreous hemorrhage and fibrovascular proliferation after laser-induced chorioretinal venous anastomosis

AIM

To describe a case in which vitrectomy was required for vitreous hemorrhage and fibrovascular proliferation after laser-induced chorioretinal venous anastomosis (LCVA) for non-ischemic central retinal vein occlusion (CRVO).

METHODS

Observational case report.

RESULTS

A 72-year-old man complained of central scotoma in the left eye, and was diagnosed as suffering from non-ischemic CRVO. LCVA was performed in another hospital. Although favorable visual function was briefly maintained postoperatively,severe vitreous hemorrhage developed in his left eye, necessitating vitrectomy.

CONCLUSION

Considering that LCVA carries a risk of serious complications, we must apply this treatment with caution, especially in ethnic groups, such as the Japanese, in whom pigmentation reacts to photocoagulation excessively.