Paulo Henrique Morales

Choriocapillaris photodynamic therapy using indocyanine green

PURPOSE To evaluate the potential of photodynamic therapy using indocyanine green for occlusion of choroidal neovascularization, the authors studied efficiency and collateral damage of photodynamic therapy-induced photothrombosis in the rabbit choriocapillary layer. METHODS Fundus photography, fluorescein angiography, and light and transmission electron microscopy were used to study the efficiency of photodynamic therapy-induced photothrombosis using indocyanine green as the photosensitizer, and to assess the resultant collateral damage. The delivery system consisted of a modified infrared diode laser tuned to 810 nm, near the maximum absorption peak of indocyanine green. RESULTS Choriocapillary occlusion was achieved at indocyanine green doses of 10 and 20 mg/kg and a radiant as low as 6.3 J/cm(2). When photodynamic therapy was performed with indocyanine green doses of 10 mg/kg, damage to the neural retina was minimal. Only inner photoreceptor segments showed degeneration, probably secondary to choroidal ischemia. Bruch membrane remained intact. Retinal pigment epithelium was invariably damaged, as seen with other photosensitizers. Temporary occlusion of large choroidal vessels occurred at both dye doses. CONCLUSIONS In this experimental study, photodynamic therapy using indocyanine green and 810-nm light irradiation produced endothelium-bound intraluminal photothrombosis, with preservation of the retinal architecture and minimal loss of visual cells. Membrane targetability, hydrophilic and fluorescent properties, and activation at 805 nm suggest indocyanine green as a potential photosensitizer for choroidal neovascularization. These combined considerations point toward further study of photodynamic therapy using indocyanine green for the treatment of choroidal vascular disease.

Optical Coherence Tomography Evaluation of Idiopathic Macular Hole Treatment by Gas-assisted Posterior Vitreous Detachment

PURPOSE To report a case of idiopathic macular hole, with vitreoretinal traction confirmed by optical coherence tomography that was successfully treated by a single intravitreous perfluoropropane (C(3)F(8)) gas bubble injection. METHODS Case report. A 65-year-old patient with idiopathic macular hole (stage 2, one eye) received an intravitreous gas injection and was prospectively followed with optical coherence tomography. RESULTS A complete posterior vitreous detachment was achieved within 6 weeks after gas injection. Visual acuity improved from 20/80 to 20/25 by 10 months of follow-up. Optical coherence tomography disclosed vitreoretinal traction release and macular hole closure. No complications were related to the procedure. CONCLUSION This simple procedure can assist a complete posterior vitreous detachment with relief of the hyaloid-foveolar traction, facilitating macular hole closure.

Prevalence and Causes of Vision Impairment and Blindness in Older Adults in Brazil: The São Paulo Eye Study

Purpose: Investigate prevalence and causes of vision impairment/blindness in older adults in a low-middle income area of São Paulo, Brazil. Methods: Cluster sampling, based on geographically defined census sectors, was used in randomly selecting cross-sectionally persons 50 years of age or older. Subjects were enumerated through a door-to-door survey and invited for measurement of presenting and best-corrected visual acuity and an ocular examination. The principal cause was identified for eyes with presenting visual acuity less than 20/32. Results: A total of 4,224 eligible persons in 2,870 households were enumerated, and 3,678 (87.1%) examined. The prevalence of presenting visual acuity ≥ 20/32 in both eyes was 61.6% (95% confidence interval [CI]: 59.4%–63.9%), and 80.4% (95% CI: 78.8%–82.1%) with best correction. The prevalence of visual impairment (< 20/63 to ≥20/200) in the better eye was 4.74% (95% CI: 3.97%–5.53%), and 2.00% (95% CI: 1.52%–2.49%) with best correction. The prevalence of presenting bilateral blindness (< 20/200) was 1.51% (95% CI: 1.20%–1.82%), and 1.07% (95% CI: 0.79%–1.35%) with best correction. Presenting blindness was associated with older age and lack of schooling. Retinal disorders (35.3%) and cataract (28.3%) were the most common causes of blind eyes. Cataract (33.2%), refractive error (32.3%), and retinal disorders (20.3%) were the main causes of vision impairment < 20/63 to ≥ 20/200, with refractive error (76.8%) and cataract (12.2%) as main causes for eyes with acuity < 20/32 to ≥ 20/63. Conclusions: Vision impairment is a significant problem in older Brazilians reinforcing the need to implement prevention of blindness programs for elderly people with emphasis on those without schooling.

Prevalence of visual impairment, blindness, ocular disorders and cataract surgery outcomes in low-income elderly from a metropolitan region of São Paulo - Brazil

PURPOSE To determine prevalence and causes of visual impairment, blindness, ocular disorders and cataract surgery outcomes in a low-income elderly population from a metropolitan area in the city of São Paulo, Brazil. METHODS Observational study where 801 individuals of 60 years and older underwent presented and best corrected visual acuity measurements as well as ophthalmologic examination. Definition of blindness and visual impairment followed studies conducted in Nepal, China and India. RESULTS The prevalence of presented and best-corrected visual acuity worse than 20/400 in both eyes was 1.38% (95% CI: 0.69% - 2.45%) and 1.25% (95% CI: 0.60% - 2.29%). Prevalence of visual impairment considering presented and best-corrected visual acuity was, respectively, 24.16% (95% CI: 21.22% - 27.28%) and 12.77% (95% CI: 10.53% - 15.28%). Cataract was the main cause of blindness (30.00%) and visual impairment (54.90%). A total of 54 participants (6.74%) had previous cataract surgery and, with best-corrected visual acuity, 35.12% showed visual acuity better than 20/60 in both eyes. Rates of visual impairment and blindness in this low-income elderly population were high. There was a considerable decrease in prevalence after optical correction emphasizing the importance of uncorrected refractive errors. CONCLUSION Cataract was the main cause of blindness; poor visual outcomes in eyes previously operated for cataract reinforce the need to seek good quality cataract services and to provide careful postoperative follow-up.

Usefulness of corneal esthesiometry for screening diabetic retinopathy

OBJECTIVE To assess the usefulness of corneal esthesiometry for screening diabetic retinopathy. METHODS A cross-sectional study was carried out comprising 575 patients attending a diabetic retinopathy-screening program in the city of São Paulo. Corneal esthesiometry was assessed with the Cochet-Bonnet esthesiometer. The presence of diabetic retinopathy was detected with indirect fundoscopy. The validity of corneal esthesiometry in identifying diabetic retinopathy was evaluated by the Receiver Operating Characteristic (ROC) curve. RESULTS Sensitivity and specificity analyses of the corneal esthesiometry for detecting the stages of diabetic retinopathy using different cut-offs showed values less than 80%. The best indices (72.2% sensitivity and 57.4% specificity) were obtained for the identification of patients with proliferative diabetic retinopathy. CONCLUSIONS In the study series, corneal esthesiometry was not a good indicator of diabetic retinopathy.

Intravitreal gas injection for the treatment of experimental vitreous hemorrhage in rabbits.

Purpose. To determine the effectiveness of intravitreous gas injection in the management and clearing of experimental vitreous hemorrhage. Methods. A total of ten New Zealand white rabbits received an injection of 0.4 ml of autologous blood into the vitreous of the right eye. After 24 hours of the vitreous hemorrhage simulation, six eyes were randomly assigned for treatment with na intravitreous injection of 0.2 ml of 100% perfluoropropane gas (C3F8) (group A), while four eyes received a control injection of an equivalent volume of balanced salt solution (group B). The persistence of vitreous opacification, which was graded at pre-established time points during 32 days of follow-up, was evaluated on the basis of visibility of retinal details in each of the four quadrants. Results. In the gas-treated group (A), a partial view of the retina in the four quadrants was possible at 15 days, while at 32 days, the vitreous cavity was completely free of blood in all eyes, allowing unobstructed observation of the fundus. No retinal details could be observed in the control group after 32 days of follow-up. Conclusions. Gas injection proved effective in the treatment of experimental vitreous hemorrhage. It was significantly better than the injection of balanced salt solution, according to criteria of extension, intensity, and clearing time. Its technical facility, lack of complications, and low cost encourage additional research into gas injection to add knowledge to this initial study and to clarify its potential usefulness to treat persistent vitreous hemorrhage as well as to elucidate some unique pathophysiology features of blood catabolism in the vitreous.

Vision Status in Older Adults: The Brazilian Amazon Region Eye Survey

Older adults living in remote areas with limited access to health services are at higher risk to develop visual impairment and blindness. We conducted a population-based survey to determine the vision status in subjects 45 years of age and older from urban and rural areas of Parintins city, Brazilian Amazon Region. Participants underwent ophthalmic examination, including uncorrected (UCVA), presenting (PVA) and best-corrected visual acuity (BCVA). Vision status was described as lines of visual acuity (VA) impairment and lines of VA improvement from UCVA to BCVA and from PVA to BCVA in the better-seeing eye. A total of 2384 subjects were enumerated, 2041 (85.6%) were examined, with reliable VA measurements obtained from 2025 participants. Vision status in lines of VA impairment was (mean ± standard deviation): 3.44 ± 3.53 for UCVA, 2.85 ± 3.52 for PVA and 1.50 ± 3.51 for BCVA. Female gender, older age and lower education were associated with ≥6 lines of UCVA impairment. Lines of improvement ≥3 was found in 626 (30.9%) participants and associated with female gender and rural residency. In conclusion, a third of participants could have at least three lines of VA improvement with proper refraction. Strategies to improve access to eye care and affordable glasses are needed.

Existe concordância no acometimento renal e retiniano da microangiopatia diabética

Associations of microangiopathy with risk factors, correlation of diabetic nephropathy (DN) and retinopathy (DR) as well as the concordance between different degrees of these complications were evaluated. 157 patients submitted to indirect ophtalmoscopy were referred to the Diabetes Center for the screening of DN. A standardized questionnaire including socio-demographic and clinical aspects was applied. Glycemic control was assessed by glycated hemoglobin and DN by the presence of microalbuminuria. Scores were given to DR and DN to test correlation and concordance. 103 patients (57.9±12.9 yrs) completed all the steps of the study; 72% of the referred patients had any DR, who did not differ from those without DR concerning their main characteristics. Patients were stratified into 4 groups according to the presence or absence of each complication. No difference was observed concerning gender and skin color distributions and years in school among the groups. Duration of DM was longer in patients with DN+DR as compared to those without DR, with or without DN (14.8±6.4 vs. 7.2±5.3 and 9.2±5.6 yrs, p< 0.05, respectively). Frequencies of smokers and self-reported dyslipidemia, BMI, glycemia and glycated hemoglobin did not differ among the groups. Patients with both complications showed higher mean blood pressure than those without DR, with or without DN (147±23 vs. 128±20 and 118±18mmHg, p< 0.05, respectively). Patients with DN, independent of the presence of DR, had higher A/C than those without DN (p< 0.05); A/C of the normal group and that with only DR were not different. High A/C levels in patients with both complications did not differ from the DN patients without DR. 80% of DN patients showed DR, while 74% of DR patients also had DN (c2= 6.39, p< 0.05). Significant correlation was detected between the 2 complications (r= 0.47, p< 0.05), as well as the concordance between their degrees, whose kappa was 0.154 (95%CI, 0.031-0.276, p< 0.01). Hypertension was associated with severe cases with both complications. The occurrence of microvascular complication in the absence of the other may suggest organ-specific pathogenetic factors. Our data indicated concordance between degrees of renal or retinal lesions in the microangiopathy of DM2. Patients with DN had higher risk of retinal disease. Even in microalbuminuric phase, the finding of abnormal A/C in a diabetic patient requires screening for DR.

Presbyopia and Ocular Conditions Causing Near Vision Impairment in Older Adults From the Brazilian Amazon Region

PURPOSE To investigate the prevalence and causes of near vision impairment (NVI) in a population of older adults from the Brazilian Amazon Region. DESIGN Population-based cross-sectional study. METHODS Cluster sampling was used in randomly selecting subjects 45 years of age and older from urban and rural areas of Parintins city, Brazil. Participants underwent ophthalmic examination, including uncorrected (UCNVA), presenting (PNVA), and best-corrected near visual acuity (BCNVA) from each eye; biomicroscopy; funduscopy; and subjective refraction, including testing with additional lenses for near vision optical correction. A principal cause for NVI was assigned by the ophthalmologist and presbyopia was defined as UCNVA ≤ 20/40 changing to > 20/40 with BCNVA. Free-of-charge glasses were provided for those in need. RESULTS A total of 2384 subjects were enumerated and 2025 had reliable NVA measurements from both eyes. The prevalence of NVI in the better-seeing eye was 96.5% with UCNVA, decreasing to 81.1% with PNVA and to 20.5% with BCNVA. Presbyopia was the principal cause of NVI in 71.8%, followed by cataract (16.5%) and pterygium (2.5%), and was associated with younger age and high schooling. Glasses for near vision were prescribed and provided to 1414 (69.8%) participants. CONCLUSIONS A high prevalence of NVI was detected even in those wearing glasses for near. Prescription and provision of low-cost reading glasses should be considered by Brazilian health authorities to address this easily and promptly correctable form of vision impairment.

Microalbuminuria is associated with increased choroidal thickness in type 1 diabetes mellitus patients without diabetic retinopathy

pattern was observed for CPFT. SCT decreased from 245 57 lm at treatment start and remained decreased throughout the follow-ups. On average, 7.6 3.4 injections were given per eye. Only seven eyes (24%) needed additional PDT. No major adverse events, retinal detachment or endophthalmitis were observed. A Kaplan–Meier analysis showed that eyes in need of retreatment were 88% after 12 months and 59% after 24 months (Fig. 1). This is one of few studies to report treatment results of PCV in Caucasians and the first study to report results of aflibercept treatment beyond the first year. We ran the analyses separately for the treatment-na€ıve, which did not change the direction of the results or the conclusions. Overall, we found a short-term improvement in the BCVA, which on long term was more of a stabilization. Unlike in our Caucasian patients, lesions are more often located macular in Asians, which may explain why Asians present with a worse baseline BCVA but also experience a better treatment response (Kikushima et al. 2017; Lee et al. 2017). Hence, the relative worse response in terms of BCVA improvement in our Caucasian patients is likely a question of more peripherally located lesions that remains relatively unaffected by anatomical improvements from the treatment.