Visualization and Grading of Vitreous Floaters Using Dynamic Ultra-Widefield Infrared Confocal Scanning Laser Ophthalmoscopy: A Pilot Study.

PURPOSE: To describe the appearance of vitreous opacities using dynamic ultra-widefield infrared confocal scanning laser ophthalmoscopy (IRcSLO). DESIGN: Retrospective case series. METHODS: Eyes of patients complaining of myodesopsia were analyzed using dynamic ultra-widefield IRcSLO imaging (Nidek Mirante, Nidek Co., Ltd., Gamagori, Japan), and classified according to a vitreous opacity severity scale. RESULTS: Thirty eyes of 21 patients were included in this study. The average age was 56 years. Symptom duration ranged from 1 to more than 365 days. The most common cause of vitreous floaters was posterior vitreous detachment (63.3%), followed by vitreous syneresis (23.3%), asteroid hyalosis (10%) and vitreous hemorrhage (3.3%). Opacities were classified as Grade 1 in three eyes (10%), Grade 2 in 10 eyes (33.3%), Grade 3 in 11 eyes (36.6%), Grade 4 in two eyes (6.6%) and Grade 5 in four eyes (13.3%). Patients with Grade 1 opacities were younger than patients with opacities Grade 2 or greater. A visible Weiss ring could be identified in 0% of eyes with Grade 1 opacities, 40% of eyes with Grade 2 opacities, 100% of eyes with Grade 3 opacities, and 100% of eyes with Grade 4 opacities. In patients with Grade 5 opacities, a Weiss ring could not be identified. CONCLUSION: Dynamic ultra-widefield IRcSLO imaging is a useful tool to evaluate patients with vitreous floaters. It allows for accurate visualization of the number, density, and behavior of the shadows that vitreous opacities project over a very wide area of the retina, which has a positive correlation with patient perception of floaters.

Kocuria Endophthalmitis: Clinical Spectrum and Long-term Outcomes.

PURPOSE: To expand the knowledge regarding the clinical presentation of Kocuria endophthalmitis. METHODS: We included six cases of Kocuria endophthalmitis between January 2018 and December 2020. From all cases, we collected general demographic data, relevant medical, ophthalmological history, microbiological and antibiotic sensitivity results. All cases had a minimum follow-up of 9 months. All cases were treated with intravitreal moxifloxacin and dexamethasone and pars plana vitrectomy. Undiluted vitreous, corneal, conjunctival, and aqueous samples were cultured and analyzed with the Vitek 2 system. RESULTS: The prevalence of Kocuria endophthalmitis was 6%. (95%CI: 2.26%-12.73%). The mean age at diagnosis was 60.5 ± 15.5 years. All patients had poor visual acuity, severe pain, and severe conjunctival hyperemia at diagnosis. Only one case had a significant improvement in visual acuity at the end of the follow-up. CONCLUSION: Kocuria spp are an emerging cause of endophthalmitis and should be considered as part of the differential diagnosis.

Fundus autofluorescence in premature infants.

To describe fundus autofluorescence (FAF) patterns in premature infants and to determine whether FAF increases gradually with increasing post-gestational age. This was a cross-sectional, observational and descriptive case series. FAF images were obtained from patients screened for Retinopathy of Prematurity. The presence of the following hypo-autofluorescence areas/structures was graded and ranked: macular pigment (foveal centre), optic nerve head, peripapillary vessels/vascular arcade (PP/VA), and equatorial vessels (EqV). Ranks were attributed to the number of structures visualized from the posterior pole towards the periphery. The rank of FAF could then be analysed by Spearman's correlation against age. Additionally, patients were divided by age into group 1 (< 40 weeks of corrected gestational age (WCGA)) and group 2 (> 40 WCGA). Differences between groups were tested with the Mann-Whitney U test. Thirteen patients were analysed. The mean WCGA at examination was 47.85 weeks. Spearman's correlation showed a strong positive correlation (r = 0.714) (P = 0.006) of FAF and WCGA. The Mann-Whitney U test revealed that the PP/VA and EqV were significantly more visible at > 40 WCGA than at < 40 WCGA (8.0 [P = 0.016] and 7.5 [P = 0.03], respectively). Patterns of FAF are described for the first time in premature infants. FAF increases gradually with age and centrifugally from the posterior pole towards the equator in premature infants.

Primary Cancer Sites and Clinical Features of Choroidal Metastasis in Mexican Patients.

PURPOSE: To describe the primary cancer sites and clinical features of choroidal metastasis in Mexican patients. METHODS: This was a retrospective, observational, and multi-center study. Data were recollected from 6 ophthalmological hospitals in Mexico from patients with choroidal metastasis diagnosed from 2000 to 2018. RESULTS: Seventy-eight patients were studied: 43 were female and 35 were male. Mean age at presentation was 57.6 years. Overall, primary cancer sites were: 1) breast: 27 cases (34.6%); 2) lung: 19 cases (24.3%); 3) unknown: 8 cases (10.2%); 4) gastrointestinal: 7 cases (8.9%); 5) renal: 5 cases (6.4%); 6) testicular: 3 cases (3.8%); 7) ovary: 3 Cases (3.8%); 8) prostate: 2 cases (2.5%); 9) thyroid: 2 cases (2.5%); 10) carcinoid: 1 case (1.2%); and 11) multiple myeloma: 1 case (1.2%). Divided by gender, for women, the main three sites were: breast, unknown, and ovary. For men, the main three sites were: lung, gastrointestinal, and testicular. Oldest cases were breast cancer (87 and 85 years); youngest cases were testicular (23 and 25 years). Solitary lesions were observed in 56 cases (71.7%); multiple lesions were observed in 22 cases (28.2%). Forty-two cases had a white or yellowish color, while 6 cases presented an orange color. CONCLUSION: Primary cancer sites and clinical features of choroidal metastasis in Mexican patients show important differences from other populations previously studied, mainly the presence of a higher proportion of gastrointestinal and renal cancer, as well as higher incidence of ovarian and testicular cancer. These types of cancer, although not as common as breast or lung, need to be taken into account when studying Mexican patients living abroad.

Unilateral Orbital Emphysema Secondary to Vitreoretinal Surgery.

PURPOSE: To describe preoperative, intraoperative, and postoperative characteristics, imaging findings, and clinical evolution of patients who developed orbital emphysema after vitreoretinal surgery. DESIGN: Retrospective, descriptive, observational case series. PARTICIPANTS: Patients with orbital emphysema after vitreoretinal surgery who were diagnosed and treated between January 2006 and October 2018 at a single ophthalmology referral center. METHODS: Medical records and orbital computed tomography images were reviewed and analyzed. A minimum follow-up of 3 months was required. MAIN OUTCOME MEASURES: Final best-corrected visual acuity (BCVA). RESULTS: This study included 16 patients with a mean age of 47.9 ± 14.7 years, 50% were women, and 25% had a history of previous ocular trauma. A diagnosis of rhegmatogenous retinal detachment was established in 75% of patients. Twenty-five percent of patients underwent pars plana vitrectomy (PPV), 50% underwent encircling scleral buckling plus PPV, 18.8% underwent repeat PPV, and 6.2% underwent scleral buckling plus repeat PPV. Additionally, 62.5% received silicone oil endotamponade. The median time between vitreoretinal surgery and orbital emphysema was 8 days (interquartile range [IQR] 5-15 days). Mean proptosis was 6.7 ± 4.6 mm. Orbital cellulitis was considered as a differential diagnosis in 31.2% of patients, and tomographic evidence of fracture was observed in 25% of patients. Treatment with compressive patching was prescribed for 87.5% of patients, transpalpebral drainage was prescribed for 75% of patients, hyperbaric oxygen therapy was prescribed for 43.8% of patients, and surgical management was prescribed for 31.2% of patients. The comparison between BCVA before vitreoretinal surgery (median, 1.8 logarithm of the minimum angle of resolution [logMAR]; IQR, 1.33-2.3 logMAR) and at the last follow-up (median, 2.3 logMAR; IQR, 1.42-2.8 logMAR) was not statistically significant (P = 0.125, Wilcoxon matched-pairs signed-rank test). No association was found between surgeon experience and lower final BCVA (P = 0.604, Fisher exact test); however, development of ocular hypertension was associated with worse final BCVA (P = 0.0101; relative risk, 7; 95% confidence interval, 1.01-44.63). CONCLUSIONS: Although orbital emphysema constitutes a very unusual complication of vitreoretinal surgery, it is important to identify this condition promptly and treat patients efficiently to avoid potential vision loss.

A Proposed Method to Quantify Vitreous Hemorrhage by Ultrasound.

PURPOSE: To propose a method for quantification of vitreous hemorrhages (VH) termed minimum image gain (MIG). Therefore, to obtain MIG measurements in patients with VH and to compare them to normal controls; to compare results between graders; and to obtain and compare MIG from two different ultrasound systems. METHODS: Retrospective and cross-sectional, observational, and comparative study performed in two parts: Part 1) Retrospective comparison of MIG in VH vs controls by two experienced graders, with intra/inter-observer variability: MIG technique is described. MIG is performed retrospectively in two groups, VH patients and normal controls. Groups are compared with independent samples t-test. Intra- and interobserver variability between graders was obtained. Part 2) Cross-sectional analysis of variability from nonexperienced graders and with different ultrasound systems: MIG is performed in cross-sectional measurements of VH patients, by two unexperienced graders, and with two ultrasound systems. Interobserver variability and Bland-Altman plot with levels of agreement (LoA) were obtained. RESULTS: Part 1: 50 patients with VH resulted in mean MIG: 52.8 dB; 34 controls resulted in mean MIG: 77.97 dB. Independent samples t-test resulted in a statistical significant difference. Intra- and inter-observer variability resulted in an almost perfect agreement between experienced graders. Part 2: 63 patients with VH, mean MIG: 56.19 dB. Inter-observer variability resulted in a very high agreement between unexperienced observers. LoA resulted in a statistical difference between the two ultrasound systems. CONCLUSION: MIG may provide an objective and reproducible way to quantify vitreous hemorrhage density and potentially any vitreous humor opacity. Agreement is high even with unexperienced graders. However, the two ultrasound systems analyzed may not be interchangeable.

Anti-VEGF treatment switch in neovascular age-related macular degeneration: a comparison of aflibercept versus ranibizumab after a single-dose switch.

PURPOSE: To determine the effect achieved from a single dose of anti-VEGF treatment switch, in patients with nAMD previously treated with bevacizumab, switched to either aflibercept or ranibizumab, and to compare the response between aflibercept and ranibizumab. METHODS: In retrospective, observational, and comparative study, patients were divided into two groups: Group 1, patients switched to aflibercept; Group 2, patients switched to ranibizumab. Paired samples t test was performed to measure differences in central macular thickness (CMT). To compare whether there were differences between groups mixed-design ANOVA was used. RESULTS: In Group 1, CMT changed from 360.51 to 260.16 µm, presenting a significant mean difference from PreSwitch to PostSwitch of 100.34 µm (p = 0.002, paired samples t test). In Group 2, CMT changed from 366.33 to 260.72 µm, showing a significant difference from PreSwitch to PostSwitch of 105.61 µm (p ≤ 0.000, paired samples t test). The mixed-design ANOVA compared both groups and resulted in a nonsignificant value of 0.90. CONCLUSION: The effect achieved from a single dose in patients switched to aflibercept or ranibizumab reduced significantly CMT measurements. Comparing aflibercept and ranibizumab, the effect appears to be similar in both drugs, in terms of reduction of CMT.

Changes in Retinal and Choroidal Vascular Blood Flow after Oral Sildenafil: An Optical Coherence Tomography Angiography Study.

PURPOSE: To describe changes in the retina and choroidal flow by optical coherence tomography angiography (OCT-A) after a single dose of oral sildenafil. METHOD: A case-control study. Patients in the study group received 50 mg of oral sildenafil. Patients in the control group received a sham pill. Retinal and choroidal images were obtained at baseline (before pill ingestion) and 1 hour after ingestion. Central macular and choroidal thickness, choroidal and outer retina flow, and the retinal and choroidal vascular density were compared using a Mann-Whitney U test. RESULTS: Twenty eyes were enrolled into the study group and 10 eyes in the control group. There was a significant difference in central choroidal thickness and outer retina blood flow between groups after 1 hour of sildenafil ingestion (p < 0.01). There were no differences in central macular thickness, choroidal flow, and retinal vascular density among groups. CONCLUSIONS: A single dose of oral sildenafil increases choroidal thickness, probably due to sildenafil-induced vasodilation.

Sensitivity, specificity and predictive values of anterior chamber tap in cases of bacterial endophthalmitis.

BACKGROUND: To assess the sensitivity, specificity, positive predictive value and negative predictive value of anterior chamber tap for the diagnosis of bacterial endophthalmitis on a population with high prevalence. METHODS: Retrospective, single centre, case series study. We reviewed all medical records with clinical diagnosis of bacterial endophthalmitis in our hospital from January 1st, 2000 to December 31st 2014. From each record, we documented general demographic data, best corrected visual acuity and vitreous and aqueous tap microbiological results. All cases were further divided according to the endophthalmitis aetiology to perform individual calculations of sensitivity, specificity, positive predictive value, negative predictive value, accuracy and prevalence. We used the results of the vitreous tap as the gold standard for diagnosis of bacterial endophthalmitis. We excluded those records in which the aqueous and vitreous samples were not taken simultaneously or had an incomplete microbiological report. Significance were assessed with chi squared statistics, with an alpha value of 0.05 for statistical significance. RESULTS: A total of 190 cases fulfilled the inclusion/exclusion criteria. Positive culture rate from vitreous samples was 64.74%. Positive culture rate from aqueous sample was 32.11%. Bacteria isolated from aqueous samples matched those isolated from vitreous samples 78.68% of the time. The overall sensitivity was 38.21%, specificity: 75.51%, positive predictive value: 79.66%, negative predictive value: 32.74% (p = 0.08). Subgroup analysis showed that anterior chamber taps in cases of post-surgical endophthalmitis had a moderate to low sensitivity (37.73%), high specificity (93%) and high positive predictive value (95%) (p < 0.04). CONCLUSION: The sensitivity and specificity of anterior chamber tap are low and should not be used for critical therapeutic decisions in patients with suspected bacterial endophthalmitis. In cases of post-surgical endophthalmitis, the result of an anterior chamber tap could be used for therapeutic guidance, but only in conjunction with clinical presentation and in the absence of a better method for diagnosis.

Long-term follow-up of patients with choroidal neovascularization due to angioid streaks.

BACKGROUND: The following case series describes the long-term anatomical and functional outcome of a group of seven patients with choroidal neovascularization (CNV), secondary to angioid streaks (AS), who were treated with antiangiogenic drugs in a pro re nata (PRN) regimen. After the 4-year mark, visual acuity tends to return to pretreatment level. Treatment delays and lack of awareness and self-referral by the patients are believed to be the cause of the PRN regimen failure. PURPOSE: To assess the long-term outcomes (>4 years) of patients with CNV due to AS treated with a PRN regimen of antiangiogenic. METHODS: This was a retrospective, case series, single-center study. We reviewed the electronic medical records from patients with CNV due to AS. From each record, we noted general demographic data and relevant medical history; clinical presentation, changes in best-corrected visual acuity (BCVA) over time, optical coherent tomography parameters, treatment and retreatment details, and systemic associations. Changes in BCVA and central macular thickness were assessed with a Wilcoxon two-sample test, with an alpha value of ≤0.05 for statistical significance. RESULTS: The mean follow-up time was 53.8±26.8 months. BCVA at baseline was: 1.001±0.62 logMAR; at the end of follow-up: 0.996±0.56 logMAR (P=0.9). Central macular thickness at baseline was: 360.85±173.82 µm; at the end of follow-up: 323.85±100.34 µm (P=0.6). Mean number of intravitreal angiogenic drugs: 6±4.16 injections (range 4-15). Mean time between injections was 3.8±2.7 months (range 1.9-5.8 months). CONCLUSION: Despite initial anatomical and functional improvement, patients at the end of the follow-up had no visual improvement after a pro re nata regimen of antiangiogenic drugs. The amount of retreatments, number of recurrences, and time between intravitreal injections were similar to previous reports with shorter follow-up.

ANATOMICAL AND FUNCTIONAL OUTCOMES OF SYMPTOMATIC IDIOPATHIC VITREOMACULAR TRACTION: A Natural History Study From the Pan American Collaborative Retina Study Group.

PURPOSE: To describe the natural history of eyes with symptomatic idiopathic vitreomacular traction (VMT). METHODS: Retrospective multicenter study of 168 eyes with spectral-domain optical coherence tomography (SD-OCT) findings consistent with idiopathic VMT. All eyes were graded according to SD-OCT findings. Grade 1 was defined as incomplete cortical vitreous separation with foveal attachment. Grade 2 was defined as Grade 1 plus intraretinal cysts or clefts. Grade 3 was defined as Grade 2 plus a foveal detachment. All patients were followed for at least 6 months. RESULTS: There were 168 patients (51 men) with a mean age of 68.8 ± 10.7 years. Patients were followed for a mean of 22.7 ± 20.1 months. The mean duration of symptoms before the initial presentation was 3.65 ± 5.42 months. At baseline, 72 eyes had Grade 1, 74 eyes had Grade 2, and 22 eyes had Grade 3 SD-OCT findings. Over the follow-up period, 36 eyes (21.4%) had spontaneous resolution of the VMT with normalization of the foveal anatomy. The mean time to resolution was 12.3 ± 12.6 months. An unfavorable anatomical outcome occurred in 7.7% (13 of 168) of the eyes, with 6 eyes developing a lamellar macular hole and 7 eyes developing a full-thickness macular hole. This occurred at a mean of 10.3 ± 10.7 months after the presentation. Subgroup analysis based on baseline SD-OCT grade showed that 4.1% (3 of 73) of Grade 1 eyes compared with 6.8% (5 of 74) of Grade 2 eyes, and 23.8% (5 of 21) of Grade 3 eyes developed a full-thickness macular hole or lamellar macular hole (P = 0.0109, chi-square test). In the remaining 119 eyes, at the last follow-up, 65 eyes had Grade 1, 42 eyes had Grade 2, and 12 eyes had Grade 3 VMT. On average, the best-corrected visual acuity improved from 0.40 ± 0.35 logarithm of the minimum angle of resolution (Snellen, 20/50) at baseline to 0.35 ± 0.36 logarithm of the minimum angle of resolution (Snellen, 20/45; P = 0.0372), and the mean central macular thickness improved from 350 ± 132 µm to 323 ± 121 µm. CONCLUSION: Spontaneous resolution of VMT occurred in 21.4% (36 of 168) of eyes after a mean follow-up of 11.4 ± 12.6 months. An unfavorable anatomical outcome occurred in 7.7% (13 of 168) of eyes. The baseline SD-OCT grade may predict the progression to full-thickness macular hole.

Intravitreal bevacizumab for diabetic macular oedema: 5-year results of the Pan-American Collaborative Retina Study group.

BACKGROUND/AIMS: To report the long-term anatomical and functional outcomes of patients with centre-involved diabetic macular oedema (DME) treated with intravitreal bevacizumab (IVB). METHODS: Retrospective case series. Patients diagnosed with centre-involved DME that were treated with at least one injection of 1.25 mg IVB and had a minimum follow-up of 60 months. Patients underwent measurement of best-corrected visual acuity (BCVA), ophthalmoscopy, optical coherence tomography and fluorescein angiography at baseline, 6-month, 12-month, 24-month, 36-month, 48-month and 60-month visits. The paired samples t test was used to compare the central macular thickness (CMT) and BCVA with baseline values. Statistical significance was indicated by p<0.05. RESULTS: Two hundred and one consecutive patients (296 eyes) were included. The mean number of IVB injections per eye was 8.4±7.1 (range: 1-47 injections). At 5 years, the BCVA remained stable at 20/100 (logarithm of the minimum angle of resolution=0.7±0.4). Eighty-six (29%) eyes improved ≥2 lines of BCVA, 129 (43.6%) eyes remained stable and 81 (27.4%) eyes lost ≥2 lines of BCVA at 60 months. Mean CMT decreased from 403.5±142.2 µm at baseline to 313.7±117.7 µm over 5 years follow-up (p≤0.0001). CONCLUSIONS: The early visual gains due to IVB were not maintained 5 years after treatment.

Primary Repair of Moderate Severity Rhegmatogenous Retinal Detachment: A Critical Decision-Making Algorithm.

We reviewed all the available data regarding the current management of non-complex rhegmatogenous retinal detachment and aimed to propose a new decision-making algorithm aimed to improve the single surgery success rate for mid-severity rhegmatogenous retinal detachment. An online review of the Pubmed database was performed. We searched for all available manuscripts about the anatomical and functional outcomes after the surgical management, by either scleral buckle or primary pars plana vitrectomy, of retinal detachment. The search was limited to articles published from January 1995 to December 2015. All articles obtained from the search were carefully screened and their references were manually reviewed for additional relevant data. Our search specifically focused on preoperative clinical data that were associated with the surgical outcomes. After categorizing the available data according to their level of evidence, with randomized-controlled clinical trials as the highest possible level of evidence, followed by retrospective studies, and retrospective case series as the lowest level of evidence, we proceeded to design a logical decision-making algorithm, enhanced by our experiences as retinal surgeons. A total of 7 randomized-controlled clinical trials, 19 retrospective studies, and 9 case series were considered. Additional articles were also included in order to support the observations further. Rhegmatogenous retinal detachment is a potentially blinding disorder. Its surgical management seems to depend more on a surgeon´s preference than solid scientific data or is based on a good clinical history and examination. The algorithms proposed herein strive to offer a more rational approach to improve both anatomical and functional outcomes after the first surgery.

Progression of gyrate atrophy measured with ultra-wide-field imaging.

The study aims to determine the progression of gyrate atrophy by measuring the area growth of chorioretinal atrophic lesions using ultra-wide-field images (UWFI). A retrospective, observational, and comparative study was conducted and UWFI (200°) were obtained from two patients with gyrate atrophy at baseline and follow-up. Measurements of atrophy were obtained for three types of lesions: Solitary atrophic lesions (SAL), De novo solitary lesions (DNSL), and peripapillary atrophy (PPA). Comparison of baseline and follow-up was done using t tests. Two patients with gyrate atrophy were included. Patient 1 presented 16 SAL, 5 DNSL, and PPA measured for both eyes (BE). Overall area growth (OAG) for SAL (expressed in decimals) presented a mean of 3.41, σ 3.07. DNSL area for BE presented a mean of 1586.08 P (2), σ 1069.55. OAG for PPA presented a mean of 1.21, σ 0.17. Patient 2 presented 5 SAL, no DNSL, and PPA was measured for BE. OAG for SAL presented a mean of 1.58, σ 1.05 (range 1.02-3.47). OAG for PPA presented a mean of 1.05, σ 0.001. Gyrate atrophy progression can be determined by measuring the changes in area using UWFI.

Enhanced High-Density Line Spectral-Domain Optical Coherence Tomography Imaging of the Vitreoretinal Interface: Description of Selected Cases.

PURPOSE: We introduce a new method to observe the morphologic features of the vitreous with spectral-domain optical coherence tomography (SD-OCT) by evaluating and describing the posterior vitreous structure of various selected cases using enhanced high-density (HD) line mode. METHODS: This is a descriptive case series of SD-OCT images with enhanced HD line at Denver Health Medical Center, University of Colorado School of Medicine, in 2014. The medical records with ocular images for these patients were analyzed. RESULTS: Enhanced HD line in vitreoretinal mode with SD-OCT offered wide images with well-visible vitreoretinal interface. The posterior precortical vitreous pocket (PPVP), often mistaken as a posterior vitreous detachment on standard retina-based cross line mode, was easily identified. Vitreomacular adhesion and traction, absence or presence of connecting channels between PPVP and Cloquet's canal, liquefied vitreous lacuna, and emulsified silicone oil droplet-layer could be observed. CONCLUSIONS: SD-OCT using enhanced HD line in vitreoretinal mode enables clear visualization of the posterior vitreous structure and often reclassifies patients previously thought to have a posterior vitreous detachment.

Spectral domain optical coherence tomographic analysis of healthy retina in branch retinal vein occlusion and its response to antiangiogenic therapy.

PURPOSE: To propose a model that measures the effect of intravitreal bevacizumab (IVB) on relatively healthy retina. The purpose is to analyze the remote effect of a branch retinal vein occlusion in the healthy retina, to determine the response it may have to IVB, and to determine if IVB has an atrophic effect on the healthy retina. METHODS: Retrospective, longitudinal comparative analysis of patients with branch retinal vein occlusion treated with IVB. Eyes were divided into experimental (branch retinal vein occlusion eye) and control (contralateral eye) groups. Each eye was analyzed for thickness and area. Thickness measurements were performed for total retinal thickness, inner retina thickness, and outer retina thickness. Area was measured for photoreceptors, choroid, and total retina. RESULTS: Eighteen eyes of 9 patients. For thickness analysis, 1,050 scans were studied, and 126 measurements were performed on 42 scans for area analysis. No difference was observed for thickness, except for inner retina thickness. No difference was observed for area. No difference was observed when analyzing a cumulative exposure to IVB. CONCLUSION: There is no evidence to suggest an atrophic effect caused by IVB when analyzing thickness or area in this experiment. This model could be used to analyze the long-term safety of IVB in larger studies.

Vitreous humor thermodynamics during phacoemulsification.

The purpose of this study is to determine baseline vitreous humor temperature during a combined phacoemulsification and pars plana vitrectomy (PPV) procedure; to determine what is the temperature variation during phacoemulsification; and to compare vitreous temperature to sublingual temperature. The methods used are prospective, interventional and comparative study. Patients with a diagnosis of cataract and vitreous hemorrhage, programed for a combined procedure of phacoemulsification and PPV, were included. Patients were excluded if posterior capsular rupture existed during the anterior segment procedure. A thermoprobe was inserted through a PPV trocar. Measurement of the vitreous temperature was obtained at baseline and throughout phacoemulsification, at the end of every surgical step, and every 5 min. Sublingual temperature was measured with the same probe at the end of the surgery. Room temperature was registered. Seventeen eyes of 17 patients were included. Mean sublingual temperature was 36.5 °C (standard deviation [σ] 0.26 °C). Mean total vitreous temperature was 31.47 °C (σ 2.1 °C). Mean baseline vitreous temperature was 33.04 °C (σ 0.99 °C). Comparison of sublingual temperature with baseline vitreous temperature resulted in a significant difference (t test P < 0.000. 95 % confidence interval 2.93-3.98). Temperature measured by surgical step and surgical time presented a significant decrease in temperature from baseline (Kruskal-Wallis P < 0.000, P = 0.003, respectively). Vitreous humor is significantly hypothermic when compared to sublingual temperature. Vitreous temperature decreases significantly during phacoemulsification.