Intravitreal acetazolamide implant for pseudophakic cystoid macular edema.

BACKGROUND: Pseudophakic cystoid macular edema (PCME) is the most common cause of visual acuity deterioration after uncomplicated cataract surgery. There is no consensus regarding how to manage recurrent or refractory cases. REPORT: A 54-year-old woman complained of decreased vision and central metamorphopsia in the right eye (OD) 3 months after uneventful cataract surgery. Visual acuity was 0.3 logMAR (20/40) OD and 0.1 logMAR (20/25) OS. Reduced macular brightness was seen OD on funduscopy associated with increased macular thickness on optical coherence tomography (OCT). Pseudophakic cystoid macular edema (PCME) was diagnosed, and treatment with oral acetazolamide was tried without success. The patient underwent a single intravitreal injection of an acetazolamide implant (260 µg) OD as off-label treatment. Four weeks following the injection, she reported complete resolution of her metamorphopsia and visual loss OD. Four months later, her visual acuity was 0.0 logMAR (20/20) in OD and 0.1 logMAR (20/25) in OS. The patient reported no discomfort after the injection procedure. Laboratory and ophthalmologic tests did not identify any adverse effects of the medication. CONCLUSION: We show that PCME refractory to conventional treatment improved after intravitreal acetazolamide implant injection. Further investigation is warranted to confirm these preliminary findings.

Comprehensive variant spectrum of the CNGA3 gene in patients affected by achromatopsia.

Achromatopsia (ACHM) is a congenital cone photoreceptor disorder characterized by impaired color discrimination, low visual acuity, photosensitivity, and nystagmus. To date, six genes have been associated with ACHM (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6), the majority of these being implicated in the cone phototransduction cascade. CNGA3 encodes the CNGA3 subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors and is one of the major disease-associated genes for ACHM. Herein, we provide a comprehensive overview of the CNGA3 variant spectrum in a cohort of 1060 genetically confirmed ACHM patients, 385 (36.3%) of these carrying "likely disease-causing" variants in CNGA3. Compiling our own genetic data with those reported in the literature and in public databases, we further extend the CNGA3 variant spectrum to a total of 316 variants, 244 of which we interpreted as "likely disease-causing" according to ACMG/AMP criteria. We report 48 novel "likely disease-causing" variants, 24 of which are missense substitutions underlining the predominant role of this mutation class in the CNGA3 variant spectrum. In addition, we provide extensive in silico analyses and summarize reported functional data of previously analyzed missense, nonsense and splicing variants to further advance the pathogenicity assessment of the identified variants.

Safety of intravitreal metoprolol in eyes with central serous chorioretinopathy.

PURPOSE: To investigate ocular safety of intravitreal metoprolol in eyes with central serous chorioretinopathy. METHODS: Five eyes of five patients diagnosed with chronic central serous chorioretinopathy (cCSC) previously treated unsuccessfully with oral spironolactone, micropulse laser and intravitreal anti-vascular endothelial growth factor agents were enrolled and received off-label intravitreal metoprolol (50 µg/0.05 ml). Baseline and follow-up examinations included measurement of best-corrected visual acuity (BCVA), intraocular pressure, anterior chamber cellular/flare scores, vitritis classification, fluorescein and indocyanine green angiography, spectral domain optical coherence tomography and electroretinography (ERG), recorded by means of DTL electrodes and following the standard suggested by the International Society for Clinical Electrophysiology of Vision (ISCEV). The total follow-up period was 4 weeks. RESULTS: There were no significant differences between baseline and follow-up ERG parameters: scotopic or photopic, a- and b-wave amplitude and implicit time, nor oscillatory potentials amplitude, or whatsoever. No intraocular inflammation sign was observed. In addition, BCVA showed small improvement in 4 or kept baseline values in 1 patient. The subretinal and/or intraretinal fluid volume reduced in all patients at 1 month after treatment. CONCLUSION: Patients with refractory cCSC treated with intravitreal 50 µg/0.05 ml metoprolol showed no signs of acute ocular toxicity, along with intraretinal fluid reduction and slight BCVA improvement 1 month after injection. This data suggest that intravitreal metoprolol may be a safe alternative for cCSC.

Proliferative diabetic retinopathy treated with intravitreal ranibizumab and photocoagulation directed at ischemic retinal areas-A randomized study.

PURPOSE: To compare ETDRS panretinal laser photocoagulation (PRP) combined with intravitreal injection of ranibizumab (IVR) and photocoagulation targeted to ischemic retina (PIR) combined with IVR in patients with proliferative diabetic retinopathy (PDR). METHODS: PDR patients were randomly assigned to treatment with either PRP + IVR or PIR + IVR. ETRDS Best-corrected visual acuity (BCVA) and central subfield thickness (CSFT) measured on optic-coherence tomography images (OCT-Heidelberg Spectralis) were recorded at baseline and every 4 weeks for one year. Fluorescein leakage area (FLA) from active new vessels was measured every 12 weeks. Full-field ERG was recorded by means of DTL electrodes, following ISCEV standard recommendations, at baseline and after 3 months. RESULTS: Twenty-eight eyes completed the study period. At baseline, mean ± SE BCVA (logMAR) was 0.44 ± 0.07 and 0.37 ± 0.08 (P = 0.5030); CSFT (µm) was 324.0 ± 20.4 and 330.1 ± 22.1 (P = 0.8417); and FLA (mm2) was 16.10 ± 4.42 and 9.97 ± 1.83 (P = 0.2114) for PRP + IVR and PIR + IVR groups, respectively. There were no relevant changes on BCVA or CSFT, but a significant reduction for FLA was observed at all visits compared to baseline for both groups, with no differences between groups. ERG showed at baseline reduced dark-adapted amplitudes, and these changes were also significantly amplified after laser treatment. ROD b-wave amplitude was further reduced in 62 ± 6% for PRP + IVR and 59 ± 4% for group PIR + IVR, but with no between-groups significant difference (P = 0.9082). CONCLUSIONS: PIR + IVR or PRP + IVR are comparable strategies regarding FLA control in PDR and led to similar retinal function impairment, based on ERG changes up to one-year follow-up. TRIAL REGISTRATION NUMBER: NCT03904056, date of registration 02/11/2019, retrospectively registered.

Retinal function after intravitreal injection of autologous bone marrow-derived mesenchymal stromal cells in advanced glaucoma.

PURPOSE: To report electroretinographic (ERG) findings in advanced glaucoma treated with a single intravitreal injection of bone marrow-derived mesenchymal stem cells (MSCs). METHODS: Intravitreal injection of autologous MSCs (1 × 106 cells) was performed in 2 eyes from 2 patients with open-angle glaucoma in advanced stage of optic neuropathy (ClinicalTrials.gov, NCT02330978, 01.05.2015): cup/disk ratio worse than 0.9, visual field mean deviation index lower than - 15 dB, visual acuity of light perception, but controlled intraocular pressure. ERG tests were recorded at baseline and week 1, 4 and 48 after injection, using DTL electrodes following the ISCEV standard: After dark adaptation, ERG was elicited using white flashes of 0.01 cd.s/m2 and 3.0 cd.s/m2, followed by 10-min light adaptation (30 cd/m2) and stimuli of 3.0 cd.s/m2 and 30 Hz flicker. RESULTS: Patients did not show improvement on visual acuity or visual field after treatment. At baseline, ERG responses showed typical findings for advanced glaucoma, with a- and b-wave amplitude and latency within normative range, but reduced photopic negative responses. No noteworthy changes were observed on ERG responses for both cases up to 1 week after treatment, but at day 15, one patient showed retinal detachment with proliferative vitreoretinopathy and was removed from the trial. The other patient kept ERG responses stable throughout study period. CONCLUSION: Although no ERG response changes were observed after MSCs injection in one case, the complication observed on the second one, along with the lack of visual function improvement, warrants further studies involving modified MSCs to treat ocular disorders, including glaucoma. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02330978- missed in pdf.

Intravitreal metoprolol for circumscribed choroidal hemangiomas: a phase I clinical trial.

BACKGROUND: Choroidal hemangioma is a visual threatening condition for which treatments is neither uniform nor widely available. New management options are necessary. The purpose of this study is to assess the safety and early outcome of intravitreal metoprolol tartrate in five patients with CCH. METHODS: Five eyes of five patients diagnosed with subfoveal or peripapillary CCH and unsuccessfully treated with intravitreal anti-VEGF agents were enrolled and received off-label intravitreal injections of metoprolol (50µg/0.05 ml). Baseline and follow-up evaluations included best-corrected visual acuity, intraocular pressure measurement, assessment of anterior chamber cellular score/flare and vitritis, retinography, fundus autofluorescence, and ERG. Patients were followed for a period of 30 days. Statistical analysis involved comparison of pre- and post-treatment findings using a paired t-test. RESULTS: There was no significant difference in all ERG parameters regarding a- and b-wave amplitude and implicit time, and oscillatory potentials' maximal amplitude. There were no significant changes in visual acuity. None of the patients developed clinical signs of intraocular inflammation. The subretinal and/or intraretinal fluid improved in 3 out of 5 patients 4 weeks after the metoprolol injection. CONCLUSIONS: Patients with CCH treated with a single injection of 50µg/0.05ml intravitreal metoprolol injections showed no signs of acute ocular toxicity. This pilot study did not assess long-term retinal toxicity, different concentrations, drug resistance, and complications from repeated-intravitreal injections.

Combined pars plana vitrectomy (PPV) and phacoemulsification (phaco) versus PPV and deferred phaco for phakic patients with full-thickness macular hole (FTMH) and no significant cataract at baseline: 1-year outcomes of a randomized trial combined PPV/phaco vs PPV/deferred phaco for MH.

PURPOSE: To compare functional and anatomic outcomes of combined pars plana vitrectomy (PPV) and phacoemulsification (phaco) versus PPV and deferred phaco in patients with full-thickness macular hole (FTMH) and no significant cataract. METHODS: Thirty-four patients were randomized to group 1 (combined PPV/phaco) and 34 to group 2 (PPV/deferred phaco). Group 2 patients could undergo phaco any time after FTMH surgery if significant cataract developed. RESULTS: Sixty-five patients (33 group 1 and 32 group 2) completed the 12-month visit. Mean ± SEM logMAR best-corrected visual acuity (BCVA) was 0.92 ± 0.04 and 0.90 ± 0.04 at baseline and improved significantly to 0.60 ± 0.05 and 0.58 ± 0.05 at month 12 (p < 0.0001) in groups 1 and 2, respectively. There was no significant difference between the groups in mean BCVA at baseline or at month 12. Mean macular sensitivity (dB) was 18.22 ± 0.93 and 16.72 ± 0.93 at baseline and increased to 21.13 ± 0.86 and 21.07 ± 0.85 in groups 1 and 2, respectively (p < 0.05) with no significant difference between the groups (p = 0.449) at month 12. FTMH closure rate was 73% and 75% in groups 1 and 2, respectively (p = 0.834). CONCLUSION: Among patients with FTMH and no significant cataract at baseline, combined PPV/phaco was associated with similar BCVA, microperimetry, and FTMH closure outcomes at 1-year compared with PPV/deferred phaco. TRIAL REGISTRATION: ( clinicaltrials.gov.br ): Ensaios clínicos brasileiros: RBR-3wmd9s; UTN number: U1111-1190-5013; Plataforma Brasil CAAE number: 50455415.3.0000.5440; IRB number: 1.433.000.

Central mfERG amplitude ratio as a predictor for visual outcome of macular hole surgery.

PURPOSE: To investigate whether visual acuity improvement achieved after surgical treatment for macular hole (MH) can be predicted by preoperative multifocal ERG (mfERG) central/peripheral amplitude ratio. METHODS: Thirty patients with unilateral MH were included. Evaluations with comprehensive ophthalmological examination including best-corrected visual acuity (BCVA) were performed at baseline and 1, 3, 8, 24 and 48 weeks after surgery, while mfERG (Diagnosys LLC; 61 hexagons-30°) and spectral-domain optic coherence tomography (sOCT-Heidelberg Engineering) were performed at baseline and 2 months after surgery. mfERG results are shown by means of the ratio between the amplitudes' average from rings 1 and 2 (central) and rings 4 and 5 (peripheral): the P1 ratio. mfERG data from 20 normally sighted age-matched subjects was used for comparison. A macular hole index (MH index) was defined as the quotient between hole height and base measured on OCT. RESULTS: Twenty-six patients finished the 48-week follow-up. Mean ± SE (logMAR) preoperative BCVA was 0.93 ± 0.22 and improved in 0.25 ± 0.07 at 48 weeks. mfERG P1 ratio was reduced at baseline and increased significantly after surgery. A significant correlation was observed between preoperative P1 ratio and BCVA gain at week 8 (r = -0.42; P = 0.033). There was no significant correlation between preoperative MH index and postoperative BCVA (P > 0.05). CONCLUSION: Retinal function assessed using the ratio between central and peripheral mfERG responses might be used as predictor of visual acuity outcome after macular surgery for MH.

Bevacizumab versus triamcinolone for persistent diabetic macular edema: a randomized clinical trial.

PURPOSE: To evaluate 24-week visual acuity and anatomic outcomes of two "pro re nata" (prn) treatment strategies (intravitreal bevacizumab [IVB] prn versus intravitreal triamcinolone acetonide [IVT] prn) in patients with persistent diabetic macular edema (pDME) after 24 weeks of prn-IVB. METHODS: One hundred eyes with center-involving DME were enrolled and treated with prn-IVB for 24 weeks; at week 24, eyes with pDME (central subfield thickness [CST] on spectral domain optical coherence tomography > 300 µm) were randomized to IVB monthly prn (group I; prn-IVB) or IVT every 3 months prn (group II; prn-IVT) and eyes in which the CST was ≤ 300 µm were assigned to continue prn-IVB (group III). RESULTS: Seventy-four eyes completed a 48-week study period. At week 24, 65 (79.3%) eyes still had DME with CST > 300 µm and, therefore, were randomized to prn-IVB (group I, n = 33) or prn-IVT (group II, n = 32); the remaining 17 (20.7%) eyes had CST ≤ 300 µm and were assigned to continued treatment with prn-IVB (group III). At baseline, mean CST (µm) ± standard error of the mean (SEM) was 447.2 ± 24.4, 478.0 ± 19.7, and 386.0 ± 21.0 in groups I, II, and III, respectively (p > 0.05). At week 48, there was no significant difference in mean CST between groups I and II (369.9 ± 23.3 and 426.0 ± 26.1, respectively; p = 0.9995). A significant reduction in mean CST, compared with baseline, was noted at weeks 28 (p = 0.0002) and 44 (p = 0.0002) in group II. Group I did not show a significant reduction in mean CST compared with baseline at any study visit. There were no significant differences in mean CST between groups I and II at any study visit. At baseline, mean ± SEM best-corrected visual acuity (BCVA) (logMAR) was 0.50 ± 0.00, 0.60 ± 0.10, and 0.50 ± 0.10 in groups I, II, and III, respectively (p > 0.05). At week 48, there was no statistically significant difference in mean BCVA between groups I and II (0.50 ± 0.10 and 0.80 ± 0.10, respectively; p = 0.4473). There was no significant improvement in mean BCVA, as compared with baseline, at any study follow-up visit in any of the groups. Group II demonstrated significantly lower BCVA after 24 weeks of IVT (at week 48) compared with baseline (p = 0.0435). There was no significant difference in mean BCVA between groups I and II at any time-point. CONCLUSION: In eyes with pDME after 24 weeks of treatment with prn-IVB, there was no difference between continued treatment with prn-IVB versus a treatment switch to prn-IVT with respect to mean BCVA or mean CST at week 48. However, BCVA was stable in the prn-IVB group, while prn-IVT was associated with BCVA reduction from baseline and a higher risk of IOP elevation.

ISCEV extended protocol for the stimulus-response series for the dark-adapted full-field ERG b-wave.

The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum protocol for clinical testing but encourages more extensive testing where appropriate. This ISCEV extended protocol describes an extension of the ISCEV full-field ERG standard, in which methods to record and evaluate the growth of the dark-adapted (DA) ERG b-wave with increasing stimulus energy are described. The flashes span a range that includes the weakest flash required to generate a reliable DA ERG b-wave and that required to generate a maximal b-wave amplitude. The DA ERG b-wave stimulus-response series (also known historically as the "intensity-response" or "luminance-response" series) can more comprehensively characterize generalized rod system function than the ISCEV standard ERG protocol and may be of diagnostic or prognostic value in disorders that cause generalized rod system dysfunction.

ISCEV extended protocol for the stimulus-response series for light-adapted full-field ERG.

The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum protocol for clinical testing but encourages additional ERG testing when appropriate. This ISCEV extended protocol describes methods to record and evaluate a light-adapted (LA) ERG stimulus-response series with increasing flash strengths. The LA ERG stimulus-response series (also referred to as the luminance-response or intensity-response series in the published literature) can characterise generalised cone system function more comprehensively than the ISCEV standard LA ERGs alone. The amplitude of LA ERG a-waves, arising from cones and cone off-bipolar cells, typically shows a saturating function. The LA ERG b-wave amplitudes, which arise primarily from activity of retinal bipolar cells, show an amplitude peak followed by a nonzero plateau (the "photopic hill" phenomenon). This ISCEV extended protocol specifies a stimulus-response series suitable to evaluate generalised dysfunction affecting the LA retina, to aid in distinguishing between the on- and off-responses of the cone system and to monitor ERG changes in these characteristics. The LA ERG stimulus-response series for a- and b-waves is recorded to a sequence of nine flash stimuli ranging from 0.03 to 300 cd s m-2, superimposed on a standard background of 30 cd m-2. A shorter protocol is also presented to measure the mid-range of the function (the "photopic hill") using 5 flash stimuli.

Spatial correlation between localized decreases in exploratory visual search performance and areas of glaucomatous visual field loss.

BACKGROUND: Visual search is a critical skill for several daily tasks and may be compromised in patients with impaired vision. The objective of this study was to study the relationships between exploratory visual search performance (EVSP) visual field (VF) sensitivity in patients with glaucoma. METHODS: Primary open-angle glaucoma patients (POAG; n = 29) and healthy (Control; n = 28) individuals with best corrected visual acuity better than 0.2 logMAR underwent a comprehensive ophthalmological examination, including Humphrey VF tests (24-2 SITA-Standard), and a monocular exploratory visual search digit-based task performed using a software that quantifies the time spent to find a targert on a random array of digits distributed on nine sequential screens. The screens were divided into five areas to topographically match with five VF sectors. RESULTS: As expected, POAG eyes had worse VF mean deviation (MD) sensitivity and EVSP than Controls (MD - 8.02 ± 7.88 dB vs - 1.43 ± 1.50 dB, p < 0.0001; and total EVSP time 106.42 ± 59.64 s vs 52.75 ± 19.07 s, p < 0.0001). MD sensitivity of both groups significantly correlated with total EVSP time (POAG r = - 0.45, p = 0.01; and Control r = 0.37, p = 0.049). A significant relationship was observed between EVSP (individual time) and both visual acuity (p = 0.006) and glaucoma diagnosis (p = 0.005). The mean sensitivity of the peripheral VF areas of the POAG group showed significant correlation with the individual search time in the corresponding spatial areas, except in the peripheral superior temporal area (r = - 0.35, p = 0.06). CONCLUSION: These data indicate that POAG patients' EVSP is impaired in topographically-correspondent VF areas with sensitivity loss. Visual search may be considered as a measure of impairment of daily activities in glaucoma patients, if further similar tests using binocular conditions corroborate our findings.

Retinal function in eyes with proliferative diabetic retinopathy treated with intravitreal ranibizumab and multispot laser panretinal photocoagulation.

PURPOSE: To compare retinal function changes in eyes with proliferative diabetic retinopathy (PDR) after intravitreal ranibizumab (IVR), combined or not with conventional (ETDRS) or multispot laser panretinal (PASCAL) photocoagulation (PRP). METHODS: This study included laser-naive PDR patients that required PRP. Eyes were randomly and prospectively assigned to receive IVR or IVR combined with PASCAL or EDTRS. PRP was performed at baseline in 1 (PASCAL) or 2 (ETDRS) sessions. In eyes with macular edema, macular short pulse grid laser was associated with IVR at baseline and IVR was repeated monthly or quarterly if neovascularization was detected on angiography. Comprehensive ophthalmological evaluations, including SD-OCT, were performed at baseline and every 4 weeks after treatment. Full-field electroretinography (ERG: extended ISCEV standard) was performed at baseline and at 12, 24 and 48 weeks. RESULTS: IVR = 13, PASCAL = 15 and ETDRS = 15 eyes finished 48-week follow-up. There was a statistically significant BCVA improvement of 0.1-0.3 logMAR in all groups, and fluorescein angiography leakage area (FLA) reduced in 56%, 73%, and 73% from baseline for ETDRS, IVR and PASCAL, respectively, up to 48 weeks without significant differences between groups (p > 0.05). A significant a- and b-wave amplitudes reduction was observed for dark- and light-adapted ERG for ETDRS and PASCAL, but only minor dark-adapted b-wave reduction was found for IVR, up to 48 weeks. As an example, at week 48, combined response b-wave amplitude reduced in 181.5 ± 31.4 µV, 128.0 ± 27.9 µV and 82.4 ± 15.2 µV for ETDRS, PASCAL and IVR (p < 0.05 each group), respectively. No significant difference was observed between ETDRS and PASCAL for any ERG parameter. CONCLUSIONS: IVR combined with single or multiple spot PRP causes similar retinal function impairment during 48 weeks of observation, while IVR alone seems to be similarly effective controlling FLA without changing retinal function.

Haigis and SRKT formulae accuracy for intentional myopic overcorrection.

PURPOSE: To investigate the influence of preoperative biometric parameters on the accuracy of Haigis and SRKT formulae in predicting postoperative target refraction. METHODS: Retrospective analysis of 108 eyes (70 patients) underwent uneventful phacoemulsification surgery with implant of Alcon-SN60WF intraocular lens (IOL). Forty-five eyes were intentionally targeted to myopia (-0.75 to -1.25 dpt), while the others targeted between 0 and -0.75 dpt. Preoperative axial length and keratometry (K) were measured with optical biometry (LENSTAR-Haag-Streit). Postoperative spherical equivalent was assessed 3 ± 2 months after surgery. RESULTS: There is a significant correlation between the mean keratometry (K) and the Haigis-SRKT prediction differences (P < 0.001; r = 0.749). Linear regression indicates that a decrease of 1 diopter (D) on K implies an increase of 0.23 D on the difference between formulae prediction. K alone does not influence the prediction error for both formulas. The difference between the two formulae is dependent on K (r = -0.75; P < 0.01). Moreover, eyes with K <43.75 targeted at myopia (n = 23) showed a significant myopic shift of -0.26 ± 0.09 dpt (P < 0.05) with Haigis, but a hyperopic shift of 0.24 ± 0.09 dpt (P < 0.05) with SRKT. CONCLUSION: Divergences between Haigis and SRKT formulae cause uncertainty in choosing the IOL. Our results indicate that, in eyes with lower preoperative K, an IOL targeted at myopia might result in a small, but significant myopic shift with the Haigis formula, while a hyperopic shift with the SRKT formula.

Ophthalmological assessment of cannabis-induced persisting perception disorder: is there a direct retinal effect?

PURPOSE: Cannabis is a psychotomimetic agent that induces impairment of sensory perception. We present detailed clinical and electrophysiological data of patients with hallucinogen persisting perception disorder (HPPD) after marijuana consumption. METHODS: A HPPD patient and four heavy cannabis smokers with no visual disturbances (controls) underwent complete ophthalmological examination including psychophysical tests (visual acuity, color vision, visual field, and dark adaptation) and detailed electrophysiological examinations, including extended Ganzfeld ERG, multifocal ERG, and electrooculography (EOG). Furthermore, electrically evoked phosphene thresholds (EPTs) were measured to further evaluate retinal function. RESULTS: Ophthalmological and most electrophysiological examinations were within normal limits for the HPPD patient and for all control subjects. Interestingly, EOG results of the HPPD patient showed a slightly reduced fast oscillation ratio, diminished standing potentials of the slow oscillations, and a light peak within normal range resulting in higher Arden ratios. The EPTs of the patient were reduced, in particular for pulses with long durations (50 ms) causing visual sensations even at lowest possible currents of the neurostimulator. The control subjects did not reveal such alterations. CONCLUSIONS: Our findings suggest a direct effect of cannabinoids on the retina and retinal pigment epithelium function, which may be involved in disturbances of the visual function experienced after drug consumption. The observations presented here may contribute to the elucidation of the detailed mechanism. Furthermore, EOG and EPT measurements may be useful tools to demonstrate long-term retinal alterations in cannabis-induced HPPD in patients.

In vivo release and retinal toxicity of cyclosporine-loaded intravitreal device.

PURPOSE: To determine the in vivo release profile and retinal safety of cyclosporine A (CsA) delivered from a biodegradable poly-lactide-co-glycolide (PLGA) device in the vitreous cavity of rabbits' eyes. METHODS: A total of 60 animals (60 eyes) divided into two groups were used. For the in vivo release study, 32 eyes received PLGA implants containing 350 µg of CsA, and 16 eyes received the implants without drug (control). Four animals of CsA group and two of the control group were killed weekly until 8 weeks; the vitreous was removed, and CsA concentration was evaluated. Ophthalmological examination was performed in the animals prior to implant placement and weekly during the study period. Electroretinography (ERG) was performed in other six animals for each group, treated and control, at the beginning and at the end of the study (8 weeks) when they were killed and had their eyes processed for histology. RESULTS: No sign of inflammation was noticed on slit lamp examinations and the IOP maintained stable during the study period in CsA and control groups. CsA concentration in the vitreous (ng/ml) was 257.07 ± 117.23, 271.15 ± 98.96, 296.66 ± 86.25, 256.27 ± 99.22, 304.50 ± 88.18, 326.35 ± 105.24, 491.25 ± 119.90 and 589.93 ± 132.55 after 1, 2, 3, 4, 5, 6, 7 and 8 weeks of implantation, respectively. At the end of the study, 21.67 % of mass loss was found. The retina did not show any histological alteration in either group, but a significant reduction in dark-adapted b-wave amplitude was observed in the CsA group, with no changes in a-wave amplitude. CONCLUSIONS: These data show that the PLGA system is safe, but the selective reduction in ERG b-wave amplitude indicates that the PLGA with 350 µg CsA causes retinal function impairment, specifically on the rod postreceptor pathway, 8 weeks after implantation. These ERG changes were not associated with any histological damage as seen at the light microscopy level.

Neuroprotective effects of intravitreal triamcinolone acetonide and dexamethasone implant in rabbit retinas after pars plana vitrectomy and silicone oil injection.

PURPOSE: To investigate potential retinal neuroprotective effects of intravitreal triamcinolone acetonide and dexamethasone implant in rabbits after pars plana vitrectomy and intravitreal silicone oil injection. METHODS: The right eyes of 84 rabbits, divided into 3 groups of 28 rabbits each, underwent standard 3-port pars plana vitrectomy with silicone oil (SO group), silicone oil and intravitreal dexamethasone implant (SO/DEX group), or silicone oil and triamcinolone acetonide (SO/TA group). The retina from the left eye of each rabbit served as a control. The animals were killed at 4 weeks after surgery. Qualitative and quantitative histopathologic analyses were performed 4 weeks after surgery, and investigation for apoptosis was performed using the Tunel assay. RESULTS: Intravitreal triamcinolone acetonide and dexamethasone implant were associated with increased retinal neuronal survival, primarily in the outer nuclear layer, inner nuclear layer, and ganglion cell layer. In the SO group, the cell density in eyes that underwent PPV/SO was 31% lower in the outer nuclear layer, 33% lower in the inner nuclear layer, and 45% lower in the ganglion cell layer compared to control eyes (p < 0.05 for all PPV/SO versus control comparisons). Compared to eyes that underwent PPV/SO, the cell density in eyes treated with triamcinolone was 27% higher in the outer nuclear layer, 66% higher in the inner nuclear layer, and 100% higher in the ganglion cell layer (p < 0.05 for all triamcinolone versus PPV/SO comparisons). Compared to eyes that underwent PPV/SO, the cell density in eyes treated with dexamethasone was 46% higher in the outer nuclear layer, 62% higher in the inner nuclear layer, and 77% higher in the ganglion cell layer (p < 0.05 for all dexamethasone versus PPV/SO comparisons). Analyses using the Tunnel assay demonstrated apoptotic bodies in all eyes in the SO group, compared with none of the eyes in the SO/TA and SO/DEX groups. The presence of cell nuclei stained with 49,6-diamidino-2-phenylindole (DAPI) was demonstrated in all groups. CONCLUSION: In this experimental model of neuroprotection, increased retinal neuronal survival was seen in the steroid-treated groups compared with the controls.

Electroretinographic assessment of retinal function during acute exposure to normobaric hypoxia.

BACKGROUND: The current study aimed to investigate retinal function during exposure to normobaric hypoxia. METHODS: Standard Ganzfeld ERG equipment (Diagnosys LLC, Cambridge, UK) using an extended ISCEV protocol was applied to explore intensity-response relationship in dark- and light- adapted conditions in 13 healthy volunteers (mean age 25 ± 3 years). Baseline examinations were performed under atmospheric air conditions at 341 meters above sea level (FIO2 of 21 %), and were compared to hypoxia (FIO2 of 13.2 %) by breathing a nitrogen-enriched gas mixture for 45 min. All subjects were monitored using infrared oximetry and blood gas analysis. RESULTS: The levels of PaCO2 changed from 38.4 ± 2.7 mmHg to 36.4 ± 3.0 mmHg, PaO2 from 95.5 ± 1.9 mmHg to 83.7 ± 4.6 mmHg, and SpO2 from 100 ± 0 % to 87 ± 4 %, from baseline to hypoxia respectively. A significant decrease (p < 0.05) was found for saturation amplitude of the dark-adapted b-wave intensity-response function (Vmax), dark-adapted a- and b-wave amplitudes of combined rod and cone responses (3 and 10 cd.s/m(2)), light-adapted b-wave amplitudes of single flash (3 and 10 cd.s/m(2)), and flicker responses (5-45 Hz) during hypoxia compared to baseline, without changes in implicit times. The a-wave slope of combined rod and cone responses (3 and 10 cd.s/m(2)) and the oscillatory potentials were significantly lower during hypoxia (p < 0.05). A isolated light-adapted ON response (250 ms flash) showed a reduction of amplitudes at hypoxia (p < 0.05), but no changes were observed for the OFF response. CONCLUSIONS: The results show significant impairment of retinal function during simulated normobaric short-term hypoxia affecting specific retinal cells of rod and cone pathways.

Two-dimensional video analysis of the upper eyelid motion during spontaneous blinking.

PURPOSE: To validate and to report the results of a new inexpensive video-based method to measure upper eyelid motion during spontaneous blinks. METHODS: Spontaneous blinks were simultaneously recorded in 21 healthy adult subjects for 5 minutes with magnetic search coil (MSC) and a portable video system (VDS) composed by a commercial high-speed camera coupled to a laptop computer and a blue light-emitting diode. Agreement between the 2 methods was assessed using qualitative comparison of the eyelid motion traces and Bland-Altman plots. RESULTS: The blink traces registered with both methods were virtually identical. With the either method, the relationship between amplitude and maximum velocity was well fitted by linear regression with mean r values = 0.81 (MSC) and 0.85 (VDS). Bland-Altman plots showed good agreement between methods. The mean ± SE differences of amplitude (0.06 ± 0.17 mm) and maximum velocity (5.0 ± 3.4 mm/s) were not significant. With the VDS, it was also possible to quantify the horizontal component of the blink movements. The amplitude of the horizontal shift of the eyelid during blinks was 40% of the vertical downward phase of the movement. CONCLUSIONS: Blinking kinematics can be precisely measured using a simple and inexpensive video system suitable for clinical settings.

Visual performance and photic disturbances with diffractive and nondiffractive EDOF intraocular lenses using mini-monovision: randomized trial.

PURPOSE: To compare visual performance and photic visual disturbances of patients implanted with 2 different extended depth-of-focus (EDOF) intraocular lenses (IOLs) using mini-monovision. SETTING: Ambulatory surgical center at the University of São Paulo in Ribeirão Preto, Brazil. DESIGN: Prospective, examiner-masked, randomized clinical trial. METHODS: Patients were assigned to either a bilateral Symfony (SYM) or Vivity (VIV) IOL group, with 1 eye targeted for myopia (-0.75 diopter [D]). Defocus curve, contrast sensitivity (Pelli-Robson), Patient-Reported Spectacle Independence Questionnaire, and Quality of Vision questionnaire were recorded at 3 months postoperatively. RESULTS: A total of 126 patients finished the follow-up: group SYM: n = 60 and group VIV: n = 66. Regarding near visual acuity, 80% of patients in the SYM group and 84% of patients in the VIV group achieved J2 or better on the near-planned eye ( P = .3840). No significant differences were found between groups for distance visual acuity, defocus profiles, PRISC, contrast sensitivity, or reading speed ( P > .05). Notably, significant between-group differences were observed for bothersome visual disturbances ( P = .0235), with 45% of patients in the SYM group with a score of 0 for bothersome disturbances compared with 66% in the VIV group. CONCLUSIONS: Mini-monovision using these EDOF IOLs was well-tolerated in the patient cohort. No significant differences were found for visual performance tests between the VIV and SYM groups. However, the data suggest that Vivity IOL is associated with a lower probability of bothersome visual disturbances compared with Symfony IOL.