Effect of brimonidine on vascular density and imagej-derived flow index of optic nerve head and macula in primary open angle glaucoma.

PURPOSE: To study the effect of brimonidine on vascular density and flow index of optic nerve head (ONH) and macula in primary open angle glaucoma (POAG) using optical coherence tomography angiography (OCTA). METHODS: Twenty-three brimonidine-naïve POAG patients were started on brimonidine. They underwent OCTA ONH and macula before commencing brimonidine and one month thereafter. Systemic arterial blood pressure (SABP) and intraocular pressure (IOP) were measured at each visit to calculate mean ocular perfusion pressure (MOPP). The OCT angiograms were analyzed using ImageJ software to calculate ONH and macular flow indices. RESULTS: Thirty-seven eyes (23 patients) with a mean age of 56.7 ± 12.49 years were included of whom 60.8% were males. Brimonidine was associated with an increase in the superficial flow index (SFI) (P-value = 0.02) and optic nerve head flow index (ONHFI) (P-value = 0.01). Also, superficial vascular density (SVD) for whole image, superior-hemi and fovea increased (P-value = 0.03, 0.02, 0.03 respectively). ONH inferior-hemi vascular density decreased (P-value = 0.01) despite an increase in inferior quadrant retinal nerve fiber layer thickness (RNFLT) (P-value = 0.03). There was no statistically significant correlation between flow indices and MOPP at baseline and follow-up. A moderate negative correlation was found between SVD and DVD at the fovea and MOPP at baseline and follow-up (P-value = 0.03, 0.05) (P-value = 0.02, 0.01) respectively. CONCLUSIONS: Brimonidine was associated with an increase in SFI, ONHFI and SVD indicating improved GCC and RNFL perfusion in POAG. Despite the increase in inferior quadrant RNFLT, the concomitant decrease in inferior-hemi ONHVD precluded a conclusion of hemodynamically-mediated improvement of RNFLT.

Validity of a novel optical coherence tomography angiography flow index in a cohort of primary open angle glaucoma.

BACKGROUND: Vascular mechanisms are implicated in many ocular diseases. Therefore, different vascular imaging modalities are used in management of such conditions. Optical coherence tomography angiography (OCTA) has high spatial resolution and segmentable 3D volumetric sampling enabling isolation of retinal and peripapillary vascular beds. However, OCTA only indirectly derives quantitative flow data i.e. velocimetry through methods and algorithms liable to limitations like signal saturation. This study introduces and validates novel mathematical OCTA flow indices that may compensate for some OCTA velocimetric limitations. METHODS: Thirty-seven eyes of 23 POAG patients were included. Each underwent baseline and follow-up assessment one month thereafter. Assessment comprised full ophthalmological examination, intraocular pressure (IOP), systemic arterial blood pressure (SABP) and OCTA macula and ONH. Angiograms were processed using ImageJ to calculate OCTA intensity-based flow indices (FIOs), for superficial vascular plexus (SVP), deep vascular plexus (DVP) and optic nerve head vascular plexus (ONH-RPC), i.e. SFIO, DFIO and ONHFIO respectively. Mean ocular perfusion pressure (MOPP) was calculated using IOP and SABP. OCTA vascular densities (VD) and MOPP were used to calculate three respective mathematical flow indices (FIMs) for SVP, DVP and ONH-RPC, based on Hagen-Poiseuille law, i.e. SFIM, DFIM, ONHFIM respectively. Pearson test was used for correlation between the two sets of indices. Intraclass correlation coefficient (ICC) was tested for baseline and follow-up values for each index. RESULTS: There was positive correlation between the three FIMs and their respective FIOs at baseline and follow-up ranging between high and moderate. Correlation coefficients (CCs) were 0.773 and 0.609 for SFIM and SFIO P-value < 0.001, 0.829 and 0.624 for DFIM and DFIO P-value < 0.001 and 0.516 and 0.737 for ONHFIM P-value = 0.001 for baseline and follow-up respectively. ICCs were 0.772 P-value < 0.001, 0.328 P-value = 0.022 and 0.888 P-value < 0.001 for SFIM, DFIM and ONHFIM respectively. For SFIO, DFIO and ONHFIO, ICCs were 0.420 P-value = 0.004, 0.079 P-value = 0.320 and 0.833 P-value < 0.001 respectively. CONCLUSION: The novel FIMs are reliable alternatives to FIOs and may compensate for OCTA signal saturation in extremes of MOPP. SFIM and ONHFIM showed high ICCs with excellent reliability. While DFIM demonstrated low ICC indicating poor reliability, it still performed better than its corresponding DFIO.

Purtscher-like retinopathy following coronary artery bypass grafting in an antiphospholipid syndrome patient: a case report.

BACKGROUND: Purtscher retinopathy is a rare occlusive microangiopathy comprising a constellation of retinal signs including cotton wool spots, retinal hemorrhages and Purtscher flecken. While classical Purtscher must be antedated by a traumatic incident, Purtscher-like retinopathy is used to refer to the same clinical syndrome in the absence of trauma. Various non-traumatic conditions have been associated with Purtscher-like retinopathy e.g. acute pancreatitis, preeclampsia, parturition, renal failure and multiple connective tissue disorders. In this case study, we report the occurrence of Purtscher-like retinopathy following coronary artery bypass grafting in a female patient with primary antiphospholipid syndrome (APS). CASE PRESENTATION: A 48-year-old Caucasian female patient presented with a complaint of acute painless diminution of vision in the left eye (OS) that occurred approximately two months earlier. Clinical history revealed that the patient underwent coronary artery bypass grafting (CABG) two months earlier and that visual symptoms started 4 days thereafter. Furthermore, the patient reported undergoing percutaneous coronary intervention (PCI) one year before for another myocardial ischemic event. Ophthalmological examination revealed multiple yellowish-white superficial retinal lesions i.e. cotton-wool spots, exclusively in the posterior pole and predominantly macular within the temporal vascular arcades only OS. Fundus examination of the right eye (OD) was normal and the anterior segment examination of both eyes (OU) was unremarkable. A diagnosis of Purtscher-like retinopathy was made based on clinical signs, suggestive history and consolidated by fundus fluorescein angiography (FFA), spectral domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA) of macula, optic nerve head (ONH) according to the diagnostic guidelines of Miguel. The patient was referred to a rheumatologist to identify the underlying systemic cause and was diagnosed with primary antiphospholipid syndrome (APS). CONCLUSIONS: We report a case of Purtscher-like retinopathy complicating primary antiphospholipid syndrome (APS) following coronary artery bypass grafting. This conveys a message to clinicians that patients presenting with Purtscher-like retinopathy should undergo meticulous systemic work-up in order to identify potentially life-threatening underlying systemic diseases.

Early onset monocular hydroxychloroquine maculopathy in a systemic lupus erythematosus patient with history of central retinal artery occlusion: a case report.

BACKGROUND: Hydroxychloroquine is a widely used medication for various clinical conditions mainly rheumatological and dermatological autoimmune diseases e.g. systemic lupus erythematosus, rheumatoid arthritis and psoriasis. While it is considered a safe medication, it is well-established that it can cause retinal toxicity i.e. HCQ maculopathy. Guidelines for HCQ retinal toxicity screening include factors like body weight, daily dose, duration, systemic diseases and retinal diseases. In this case study, we report a specific association between CRAO as a retinal disease and early onset HCQ maculopathy in a SLE patient. CASE PRESENTATION: A 42-year-old Caucasian female SLE patient presented with a complaint of gradual progressive painless diminution of vision in the left eye that started 16 months earlier. Clinical evaluation of the patient revealed a history of sudden profound painless diminution of vision in the same eye 18 months earlier after which the patient experienced only partial improvement of vision. That episode of sudden diminution of vision was attributed to left CRAO, complicating SLE-related thrombophilia, confirmed by fundus fluorescein angiography. Based on that diagnosis, the patient had been prescribed HCQ. At the time of presentation, fundus examination revealed left bull's eye maculopathy and right normal fundus. Therefore, a diagnosis of HCQ maculopathy in the left eye was made after exclusion of other causes of unilateral bull's eye maculopathy. CONCLUSION: Our case study is the first to report an association between CRAO as a specific retinal disease and early onset of HCQ maculopathy in a SLE patient. The unilateral bull's eye presentation which occurred in the eye with CRAO after only 16 months of HCQ treatment highly suggests that CRAO is probably the cause of such unusually early maculopathy. This case report highlights the importance of retinal diseases as risk factors for HCQ maculopathy. It also points out the lack of specific evidence concerning the association between specific retinal diseases and HCQ maculopathy.

Association of Postural Blood Pressure Response With Disease Severity in Primary Open Angle Glaucoma.

PRCIS: Patients with primary open angle glaucoma (POAG) demonstrated exaggerated postural blood pressure dip in recumbency that was positively correlated with the severity of glaucomatous optic neuropathy (GON). Postural dip testing can be used clinically as a marker of systemic vascular dysregulation in GON risk assessment. OBJECTIVE: To investigate whether patients with POAG demonstrated abnormal postural blood pressure response to recumbency and whether such abnormal postural response correlated with GON severity. PATIENTS AND METHODS: This is a prospective observational study where 47 patients with POAG underwent intraocular pressure and systemic arterial blood pressure, systolic blood pressure (SBP) and diastolic blood pressure (DBP), measurement in seated and after 20-minute recumbency positions. Mean arterial blood pressure (MABP) was calculated for seated and recumbent positions. The percentage difference between seated and recumbent SBP, DBP, and MABP was calculated according to which participants were divided into 3 groups, that is, nondippers, normal dippers, and exaggerated dippers with percentage dips of <10%, ≥10%≤20%, >20%, respectively. Participants underwent optical coherence tomography of optic nerve head to measure retinal nerve fiber layer thickness (RNFLT) which was used as a structural biomarker of GON. RESULTS: RNFLT was lower in exaggerated dippers than in nondippers and normal dippers. There was a negative correlation between postural dip and average RNFLT. Linear regression showed that postural dip was associated with lower RNFLT independent of age and intraocular pressure. The χ 2 independence test demonstrated a strong relation among corresponding dip groups for SBP, DBP, and MABP. However, it showed no significant relation between hypertension and postural dip. Fisher exact test showed no relation between antihypertensive medication and postural dip. CONCLUSIONS: Patients with POAG demonstrated abnormal postural blood pressure response comprising exaggerated recumbent dip which was positively correlated with disease severity. Postural dip assessment may serve as a simple clinic-based test of systemic vascular dysregulation as part of GON risk evaluation.

Validation of WINROP algorithm as screening tool of retinopathy of prematurity among Egyptian preterm neonates.

BACKGROUND: Retinopathy of prematurity (ROP) is a leading cause of preventable childhood blindness worldwide. Proper screening for ROP can prevent loss of vision. WINROP (weight, insulin-like growth factor 1, neonatal, retinopathy of prematurity) is an online surveillance system based on gestational age, birth weight and weekly weight gain that can predict infants at risk of sight-threatening retinopathy of prematurity. AIMS: To evaluate the diagnostic accuracy of WINROP algorithm in detecting sight-threatening ROP in Egyptian preterm neonates. METHODS: Birth weight (BW), gestational age (GA) and weekly weight measurement of 365 preterm infants were prospectively entered into WINROP algorithm. Based on these inputs, the algorithm would output and a screening was performed as is standard. Sensitivity, specificity, and predictive values were calculated by comparing WINROP outcomes with ROP screening outcomes. RESULTS: Of the infants included in the study the mean GA was ±31.24 and mean BW was ±1508.78. A high risk WINROP alarm was triggered in 62 infants of whom 16 infants develop type 1 or type 2 ROP. These infants had associated comorbidities including sepsis, Intraventricular hemorrhage (IVH), Necrotizing enterocolitis (NEC), history of transfusion of packed red blood cells (RBCS) and history of platelet transfusion. A low risk WINROP alarm was triggered in 303 infants of whom 15 infants developed type 1 or type 2ROP. WINROP showed a sensitivity of 51.6%, a specificity of 86.2%, a positive predictive value (PPV) of 52.8% and a negative predictive value (NPV) of 95% for detection of type 1 or type 2 ROP. CONCLUSION: WINROP has low sensitivity and high specificity for detection of ROP. It may help in ROP prediction but can't be used alone. Modification of WINROP algorithm taking into account other risk factors may improve sensitivity and reduce number for ROP examination.

Macular and peripapillary vascular parameters in the fellow eyes of unilateral primary congenital glaucoma: a comparative study.

PURPOSE: To study the fellow eyes of patients with unilateral primary congenital glaucoma (PCG) using optical coherence tomography angiography (OCTA) and compare them to normal age- and refractive error-matched healthy controls. METHODS: Using OCTA, the foveal avascular zone (FAZ) area, cup:disk ratio, vessel density (VD) of the optic nerve head (ONH) and peripapillary area and the macular VD in superficial (SCP) and deep vascular complexes in both 3 mm and 6 mm scans of both groups were compared. Clinical data included best-corrected visual acuity (BCVA), cycloplegic refraction, intraocular pressure (IOP), anterior and posterior segments examination findings, including ONH cup:disk ratio. RESULTS: A total of 48 eyes of 48 children (24 eyes in each group) were included. There was no difference in the mean retinal nerve fiber layer thickness, cup:disk ratio, baseline visual acuity, or spherical equivalent between groups (P > 0.05). In the 3 mm macular scan, the VD of the SCP at the fovea was significantly higher in the PCG group compared to controls (P = 0.04). In the ONH scans, there was a significantly reduced inside the disk VD in the PCG group compared to controls (P = 0.03). There was no significant difference in other macular and ONH vascular parameters between groups (P > 0.05). CONCLUSIONS: In our study cohort, there was no difference in most of the macular and ONH vascular parameters between groups. However, the fellow eyes of PCG patients exhibited higher VD of the SCP at the fovea and reduced inside the disk VD compared with control eyes.

Relative Flow Index as a Novel Optical Coherence Tomography Angiography Biomarker in Primary Open Angle Glaucoma.

PRCIS: Relative flow indices as novel optical coherence tomography angiography (OCTA) biomarkers demonstrated reduced optic nerve head and peripapillary large vessel and capillary perfusion in primary open angle glaucoma (POAG). Large vessel perfusion correlated with disease severity and progression. PURPOSE: To introduce relative flow indices as novel OCTA biomarkers and their pathologic insights in POAG. MATERIALS AND METHODS: This is a retrospective case-control study where 57 POAG and 57 control eyes were included. OCTA 4.5×4.5 mm optic nerve head (ONH) were analyzed using ImageJ 1.53t to calculate global flow indices (GFIs) and relative flow indices (RFIs) for whole image optic nerve head, isolated radial peripapillary capillary plexus, and isolated large vessel angiograms. RESULTS: Retinal nerve fiber layer thickness (RNFLT), ONH vascular density (VD), except inside disc and large vessel VD, GFIs, and RFIs were lower in POAG than control. There was a positive correlation between RNFLT and both VD and GFIs. Among RFIs, only large vessel RFI (ONHLVRFI) demonstrated a positive correlation with average RNFLT. Linear regression demonstrated a significant positive coefficient for ONHLVRFI with RNFLT as the dependent variable. The area under receiver operating characteristic curve showed diagnostic accuracy ranging fair, good, and excellent for all biomarkers. Inferior RNFLT had the highest area under the curve (0.922) while optic nerve head large vessel density had the lowest (0.523). CONCLUSIONS: POAG showed structural loss of RNFL neurovascular unit manifesting as positively correlated reduction of VD and RNFLT. Also, POAG had lower global perfusion of the optic nerve head and peripapillary area, resulting in the positively correlated reduction of GFIs and RNFLT. Although RFIs were lower in POAG, only ONHLVRFI demonstrated a positive correlation and regression with RNFLT, implying that large vessel hypoperfusion was associated with POAG severity and progression.

Macular and Optic Nerve Microvascular Alteration in Relation to Axial Length, by Optical Coherence Tomography Angiography (OCTA).

Aim: To study the effect of axial length (AL) on quantitative characterization of macular and optic nerve microvasculature using optical coherence tomography angiography (OCTA) in healthy individuals. Methods: A cross-sectional study where participants were divided into 3 groups according to AL; A: ≤22.5 mm, B: 22.6-24.5 mm, C: >24.5 mm. Superficial vascular density (SVD), deep vascular density (DVD), foveal avascular zone (FAZ), and radial peripapillary capillary density (RPCD) were calculated using OCTA. Pearson correlation was run to identify the relation between AL and study parameters. Results: One hundred and twelve eyes of 56 participants (20 males, 36 females) were included. Mean FAZ was 0.33 ± 0.15 mm2, 0.27 ± 0.1 mm2 and 0.28 ± 0.2 mm2 in Groups A, B, and C, respectively (p value 0.073). No significant difference was found between 3 groups, as regards superficial foveal density and vessel density inside the disc. Deep foveal density was significantly lower in Group A in comparison to Groups B and C (p value 0.021 and 0.005, respectively). As for other parameters of SVD, DVD and RPCD, no significant difference was observed between Groups A and B; however, the same parameters were significantly lower in Group C when compared to Group A and B. AL was found to be negatively correlated to FAZ (r -0.191, p value 0.043) and most of parameters of SVD, DVD, and RPCD (p value < 0.0001). Conclusion: Most of optic nerve and macular microvascular parameters were significantly lower in eyes with longer axial lengths when compared to those with shorter axial lengths. Moreover, most of these parameters were negatively correlated with AL.

Multiplex ligation-dependent probe amplification versus fluorescent in situ hybridization for screening RB1 copy number variations in Egyptian patients with retinoblastoma.

BACKGROUND: Retinoblastoma (RB) is the most common primary intraocular malignant tumor in children. RB is mostly caused by biallelic mutations in RB1 and occurs in hereditary and non-hereditary forms according to the "two-hit" theory. RB1 mutations comprise point mutations, indels, large deletions, and duplications. Genetic testing is essential for the comprehensive treatment and management of patients with RB. AIM: The aim was to evaluate RB1 copy number variations (CNVs) using MLPA versus FISH assays in group of Egyptian patients with RB. RESULTS: 16.67% showed an RB1 deletion, abnormal methylation status, or both. CONCLUSION: Our results suggested MLPA is a fast, reliable, and powerful method and should be used as a first-line screening tool for detecting RB1 CNVs in patients with RB. Moreover, MLPA is advantageous as it evaluates the methylation status/inactivation of RB1, not possible by FISH.

Anterior chamber granuloma: conservative treatment versus surgical intervention.

PURPOSE: A distinct pattern of granulomatous anterior uveitis, with white anterior chamber (AC) granuloma, has been reported in certain endemic areas. The aim of this work was to compare the outcome of conservative treatment to surgical intervention for the treatment of large AC granulomas presenting with moderate-severe anterior uveitis. The secondary outcome is ultrasound biomicroscopy (UBM) characterization of AC granulomas. METHODS: This is a prospective randomized interventional study including 41 eyes of 39 patients with active AC granuloma ≥3 mm (flare & cells ≥ +2). Patients were randomly assigned to either conservative treatment in the form of topical prednisolone and cycloplegic drops with orbital floor (transseptal) injection of Triamcinolone acetonide (20 eyes) or surgery in the form of granuloma excision and AC wash (21 eyes). As a perioperative care, topical steroids and cycloplegic drops were given few days before surgery and tapered gradually over 6 weeks. Patients were followed up at first day, 2 weeks, 1 and 3 months. RESULTS: Thirty-seven patients were males, and 2 were females (13.0 ± 3.5 years). After 2 weeks, disappearance/healing of granuloma was achieved in 20 eyes in the surgical group versus 2 eyes in the conservative group (p < 0.0001). This effect was maintained throughout the follow-up period, for the surgical group and reached up to 70%, for the medical group. At every follow-up, BCVA was better in the surgical group, but this was only statistically significant at 1 and 3 months. The granuloma appeared as a homogenous hyperreflective lesion in examined eyes (16 eyes of 15 patients). CONCLUSION: Surgical treatment of large granulomas leads to a more complete and rapid resolution of inflammation.

Horizontal Extraocular Muscle Insertion Site in Relation to Axial Length Using Swept-Source Anterior Segment OCT.

PURPOSE: The purpose of this study was to correlate between the axial length of the globe and the insertion site of horizontal extraocular muscles using swept-source anterior segment optical coherence tomography (SS-ASOCT), with posing an equation to calculate the muscle insertion site from the axial length. METHODS: The study design was observational and cross-sectional. It was performed on 157 eyes of 157 healthy subjects. The distance of the medial rectus (MR) and the lateral rectus (LR) insertion sites from the limbus were measured using SS-ASOCT. The insertion sites' distances were correlated to the axial length (hypermetropes < 22.5 mm, myopes > 24.5). Correlation between numerical variables was done by Pearson's correlation coefficient and confirmed by linear regression analysis and scatter diagrams. RESULTS: The mean MR insertion site was 5.47 ± 0.19 mm in hypermetropes versus 5.68 ± 0.23 mm in myopes, whereas the mean LR insertion site was 6.81± 0.23 mm in hyperopes versus 7.08 ± 0.16 mm in myopes. The axial length showed a moderate positive, but significant, correlation to the insertional position for the medial and lateral rectus muscles (MR: r=0.417, p<0.001; LR: r=0.410, p<0.001). CONCLUSION: Comparing the horizontal extraocular muscle insertion site to axial length using SS-ASOCT showed a significant positive correlation. The model equation for MR insertion: MR (mm) = 4.522 + 0.045 (AXL in mm) with an R = 0.437, R2= 0.191, F=12.071, P<0.001. The model equation for LR insertion: LR (mm) = 5.72 + 0.048 (AXL in mm) with an R = 0.438, R2= 0.192, F=12.116, P<0.001.

Anterior Chamber Angle Evaluation following Phakic Posterior Chamber Collamer Lens with CentraFLOW and Its Correlation with ICL Vault and Intraocular Pressure.

Purpose. To assess intraocular pressure (IOP), lens vaulting, and anterior chamber (AC) angle width, following V4C implantable Collamer lens (ICL) procedure for myopic refractive error. Methods. A prospective case series that enrolled 54 eyes of 27 patients that were evaluated before and after V4C phakic posterior chamber Collamer lens implantation for correction of myopic refractive error. Preoperative measurement of IOP was done using Goldmann applanation tonometer and anterior chamber angle width using both Van Herick slit lamp grading system and Scheimpflug tomography imaging (Oculus Pentacam). Follow-up of the aforementioned variables was at 1, 6, and 18 months postoperatively, together with ICL vault measurements. Results. The mean baseline IOP of 11.69 ± 2.15 showed a statistically significant (P = 0.002) increase after 1 month that remained unchanged at 6 and 18 months postoperatively, with mean value of 16.07 ± 4.12, 16.07 ± 4.10, and 16.07 ± 4.13, respectively. Pentacam AC angle width showed a statistically significant decrease at 1 (P = 0.025), 6 (P = 0.016), and 18 (P = 0.010) months postoperatively, with mean preoperative value of 40.14 ± 5.49 that decreased to 25.28 ± 5.33, 25.46 ± 5.44, and 25.49 ± 5.38, at 1, 6, and 18 months, respectively. Mean ICL vault showed moderate correlation with Pentacam AC angle width at 1 (r = -0.435) and 6 (r = -0.424) months. Conclusion. V4C ICL implantation resulted in decrease in AC angle width and increase in IOP, within acceptable physiological values at all time points.

Subthreshold diode-laser micropulse photocoagulation as a primary and secondary line of treatment in management of diabetic macular edema.

BACKGROUND: The purpose of this study was to evaluate subthreshold diode-laser micropulse (SDM) photocoagulation as a primary and secondary line of treatment for clinically significant diabetic macular edema (CSDME). METHODS: In this prospective nonrandomized case series, 220 cases of nonischemic CSDME were managed primarily and secondarily by SDM photocoagulation on a 15% duty cycle with a mean power of 828 mW and a spot size of 75-125 µm. SDM treatment was repeated at 3-4-month intervals if residual leakage was observed. Additional intravitreal pharmacologic therapy was used according to the response. Follow-up varied from 12 to 19 (mean 14±2.8) months. Novel software designed by the authors was used to record the subvisible threshold laser applications and their parameters on the fundus image of the eye. Evaluation of the results of treatment was done using fluorescein angiography and optical coherence tomography (OCT). Primary outcome measures included changes in visual acuity and foveal thickness at OCT. Secondary outcome measures included visual loss of one or more Snellen lines and laser scars detectable on fundus biomicroscopy or fluorescein angiography. RESULTS: In the primary treatment group, there was significant improvement or stabilization of visual acuity after the first 3-4 months, which was stable thereafter. Visual acuity was stable in the secondary treatment group. A corresponding reduction of macular thickness on OCT was noted during the follow-up period in both groups. Additional therapy included repeat SDM photocoagulation, intravitreal injection of triamcinolone, and pars plana vitrectomy. Laser marks seen as changes in retinal pigment epithelium on fundus biomicroscopy and fluorescein angiography were noted in 3.3% and 5.7% of cases. Our novel software could accurately record the location of all SDM-invisible applications. CONCLUSION: Micropulse laser is an effective minimal intensity therapy that offers the clear advantage of minimizing or avoiding laser-induced visible retinal burn/scarring while reducing the foveal thickness in the management of selected cases of CSDME. Future prospective studies should include the use of SDM photocoagulation as a combined minimally invasive therapy to consolidate the prompt but temporary effects of anti-vascular endothelial growth factor or anti-inflammatory agents. Virtual localization of SDM-invisible applications using our proprietary software could be used to guide further retreatments.