Facoemulsificação versus extração extracapsular no sistema público de saúde: análise de custos para o hospital, para o governo e para a sociedade

OBJETIVO: Comparar custos da cirurgia de catarata em larga escala para um hospital público, para o governo e para a sociedade, pelas técnicas de facoemulsificação (FACO) e extração extracapsular (EECP). MÉTODOS: Foi realizada revisão baseada principalmente em diversos estudos clínicos realizados entre 2002 e 2010, no Centro Cirúrgico Ambulatorial do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. RESULTADOS: Os gastos estimados com os insumos utilizados para as cirurgias foram de R$ 468,92 no grupo FACO e R$ 259,96 no grupo EECP. As despesas hospitalares com o acompanhamento pós-operatório foram em média de R$ 16,40 (42%) menores no grupo FACO. Com relação ao gasto estimado para a Previdência Social, o grupo EECP custou em média, US$ 44,58 por paciente a mais que o grupo FACO. CONCLUSÃO: O incentivo e o investimento governamental para a realização da FACO no SUS são socialmente justificados, deve-se considerar também a economia dos pacientes e do sistema empresarial, bem como as vantagens clínicas para os pacientes e vantagens econômicas para os hospitais.

Cirurgia de catarata e glaucoma

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Carotenoids and ocular disease: a review

Background: Carotenoids are not considered to be essential nutrients, but their antioxidant and photoprotective properties have prompted interest in their potential role in disease prevention. Our aim is to review the evidence In relation to ocular disease. Method: Web of Science and Medline via PubMed database search. Results Lutein and zeaxanthin intake has been associated with a 22% reduced risk of cataract extraction in women (RR 0.78, p = 0.04), and a 19% lower risk of cataract in men (RR 0.8, p = 0, 03). A randomised controlled trial (RCT) found a significant improvement in visual acuity in cataract patients supplemented with lutein. Two RCTs investigating the effect of P-carotene, in combination with other nutrients, on cataract report conflicting results. Several studies show no inverse association between cataract and P-carotene. Lutein and zeaxanthin are the only carotenoids found in the human macula. RCTs have found beneficial effects of both lutein and beta-carotene supplementation, in combination with other antioxidants, on visual function age-related macular disease affected subjects. Evidence for a role of lutein in preventing deterioration of visual function in retinitis pigmentosa patients is conflicting. CONCLUSIONS: Further research into the role of lutein and zeaxanthin in prevention of onset and progression of ocular disease is warranted.

Examination variability in short-wavelength automated perimetry

The study evaluated sources of within- and between-subject variability in standard white-on-white (W-W) perimetry and short-wavelength automated perimetry (SWAP). The Influence of staircase strategy on the fatigue effect in W-W perimetry was investigated for a 4 dB single step, single reversal strategy; a variable step size, single reversal dynamic strategy; and the standard 4-2 dB double reversal strategy. The fatigue effect increased as the duration of the examination Increased and was greatest in the second eye for all strategies. The fatigue effect was lowest for the 4dB strategy, which exhibited the shortest examination time and was greatest for the 4-2 dB strategy, which exhibited the longest examination time. Staircase efficiency was lowest for the 4 dB strategy and highest for the dynamic strategy which thus offers a reduced examination time and low inter-subject variability. The normal between-subject variability of SWAP was determined for the standard 4-2 dB double reversal strategy and the 3 dB single reversal FASTPAC strategy and compared to that of W-W perimetry, The decrease in sensitivity with Increase in age was greatest for SWAP. The between-subject variability of SWAP was greater than W-W perimetry. Correction for the Influence of ocular media absorption reduced the between-subject variability of SWAP, The FASTPAC strategy yielded the lowest between-subject variability In SWAP, but the greatest between-subject variability In WoW perimetry. The greater between-subject variability of SWAP has profound Implications for the delineation of visual field abnormality, The fatigue effect for the Full Threshold strategy in SWAP was evaluated with conventional opaque, and translucent occlusion of the fellow eye. SWAP exhibited a greater fatigue effect than W-W perimetry. Translucent occlusion reduced the between-subject variability of W-W perimetry but Increased the between-subject variability of SWAP. The elevation of sensitivity was greater with translucent occlusion which has implications for the statistical analysis of W-W perimetry and SWAP. The influence of age-related cataract extraction and IOL implantation upon the visual field derived by WoW perimetry and SWAP was determined. Cataract yielded a general reduction In sensitivity which was preferentially greater in SWAP, even after the correction of SWAP for the attenuation of the stimulus by the ocular media. There was no correlation between either backward or forward light scatter and the magnitude of the attenuation of W-W or SWAP sensitivity. The post-operative mean deviation in SWAP was positive and has ramifications for the statistical Interpretation of SWAP. Short-wavelength-sensitive pathway isolation was assessed as a function of stimulus eccentricity using the two-colour Increment threshold method. At least 15 dB of SWS pathway Isolation was achieved for 440 nm, 450 nm and 460 nm stimuli at a background luminance of 100 cdm-2, There was a slight decrease In SWS pathway Isolation for all stimulus wavelengths with increasing eccentricity which was not of clinical significance. Adopting a 450 nm stimulus may reduce between-subject variability In SWAP due to a reduction In ocular media absorption and macular pigment absorption.

Dimensional changes in the ageing cornea

The study investigated the central and peripheral corneal characteristics of groups of subjects from 20 to 90 years of age to assist the understanding of ageing changes in the cornea, and to see whether relationships between ocular parameters were revealed. After age 45 the corneal horizontal radius of curvature gradually decreased with age. This trend was shown by the Aston University subjects (group B). The effect was very significant for the hospital patients undergoing biometry before cataract extraction operation (group D). Vertical radius of curvature showed a slight decrease with age after age 45, but similar to corneal eccentricity, this showed no significant age effect. Corneal astigmatism progressed from with the rule towards against the rule, particularly after age 60. The shift seemed mainly due to the decreasing horizontal corneal curvature. In biometry no significant age relation was found for axial length, but a significant relation was found between curvature and axial length in the larger group D. Lens thickness showed a very significant relation to age and to axial length, but no significant relation to corneal curvature. Anterior chamber depth showed a very significant relation to age, lens thickness and axial length, but no significant relation to corneal curvature. A significant age effect was found for corneal thickness decreasing with age for the central, nasal and temporal regions of the right eye. Analysis of the biometry results indicated the influence of two major factors. Firstly, the natural growth of the eye in youth, leading to greater values of axial length, radius of corneal curvature, lens thickness and anterior chamber depth. Secondly, the typical ageing changes where the increasing lens thickness caused a reduction in anterior chamber depth. The decrease in corneal thickness with age shown in some corneal regions may be a sign of ageing changes in the tissue proteins and hydration balance.

Requirement for and optimisation of premium intraocular lenses

Premium intraocular lenses (IOLs) aim to surgically correct astigmatism and presbyopia following cataract extraction, optimising vision and eliminating the need for cataract surgery in later years. It is usual to fully correct astigmatism and to provide visual correction for distance and near when prescribing spectacles and contact lenses, however for correction with the lens implanted during cataract surgery, patients are required to purchase the premium IOLs and pay surgery fees outside the National Health Service in the UK. The benefit of using toric IOLs was thus demonstrated, both in standard visual tests and real-world situations. Orientation of toric IOLs during implantation is critical and the benefit of using conjunctival blood vessels for alignment was shown. The issue of centration of IOLs relative to the pupil was also investigated, showing changes with the amount of dilation and repeat dilation evaluation, which must be considered during surgery to optimize the visual performance of premium IOLs. Presbyopia is a global issue, of growing importance as life expectancy increases, with no real long-term cure. Despite enhanced lifestyles, changes in diet and improved medical care, presbyopia still presents in modern life as a significant visual impairment. The onset of presbyopia was found to vary with risk factors including alcohol consumption, smoking, UV exposure and even weight as well as age. A new technique to make measurement of accommodation more objective and robust was explored, although needs for further design modifications were identified. Due to dysphotopsia and lack of intermediate vision through most multifocal IOL designs, the development of a trifocal IOL was shown to minimize these aspects. The current thesis, therefore, emphasises the challenges of premium IOL surgery and need for refinement for optimum visual outcome in addition to outlining how premium IOLs may provide long-term and successful correction of astigmatism and presbyopia.

Refracting the pseudophakic patient

Pseudophakic patients are frequently encountered in optometric practice, often the result of cataract extraction but also presbyopia correction. Given advances in technology and surgery, the demand for intraocular lenses for correcting a variety of refractive requirements has increased owing to an ageing population. Based on the patient’s needs, either fixed focus, toric, accommodating or multifocal intraocular lenses (IOLs) may be implanted. During optometric examination, attention should be drawn to a history of IOLs and the potential complications they may cause in order to manage them effectively, particularly where sight is threatened. Although objective and subjective refraction does not differ greatly between phakic and pseudophakic patients, care should be taken to set the patient up correctly and the reflex during retinoscopy observed for posterior sub-capsular opacification. Additional tests such as reading speed, and glare and contrast sensitivity are necessary to determine the outcome of IOL surgery and detect potential problems associated with multifocal and accommodating IOLs. Based upon the results of these tests, refraction, and type of IOL, contact lens or spectacle correction may be required to meet the visual demands of the patient.

Cataract surgery induces retinal pro-inflammatory gene expression and protein secretion

To investigate the effect(s) of cataract surgery on the expression of pro-inflammatory genes and proteins in the retina using an experimental rodent model. An extracapsular lens extraction was performed in one eye of C57BL/6 mice (n=24); the contralateral unoperated eyes (n =24) as well as eyes from unoperated animals (n = 9) served as controls. The neurosensory retina and retinal pigment epithelium (RPE)/choroid were collected postoperatively. Expression of genes involved in the acute inflammatory/ injury response, including IL-1ß, fibroblast growth factor, transforming growth factor ß, chemokine CCL2, SDF-1, and complements C3, C4, and factor B (CFB), were examined by real-time PCR and, selectively, by immunohistochemistry. The expression of IL-1 ß and CCL2 genes was markedly upregulated (>0-fold, P >0.01) in the neurosensory retina 30 minutes postoperatively and maintained for the 2-week postoperative period of observation; IL-1 ß expression was also upregulated in RPE/choroid. The expression of complement C3 (>-fold) and CFB (>0-fold) genes in the neurosensory retina was also significantly upregulated (P

Modified extracapsular extraction versus endocapsular phacoemulsification: intraoperative and immediate postoperative events

Compararam-se os eventos clínicos e as variações da pressão intra-ocular (PIO) das técnicas facoemulsificação endocapsular e extração extracapsular com modificações, no intra e no pós-operatório imediato. A facoemulsificação resultou em menor edema corneano, menor desconforto ocular e menos intercorrências no pós-operatório em relação à extração extracapsular modificada. É imperativo que se faça o monitoramento da PIO no pós-operatório, uma vez que ela ocorreu na facoemulsificação, e o uso de hipotensores oculares, quando os valores da PIO ultrapassarem os limites aceitáveis.