RESUMO
AIM: To determine the long term visual and refractive results, and stability and complications of primary polypseudophakia using poly(methylmethacrylate) (PMMA) intraocular lenses (IOLs) for cataract surgery in hypermetropic eyes. METHODS: Prospective study of 15 short or hypermetropic eyes undergoing phacoemulsification with primary polypseudophakia with two PMMA IOLs implanted within the capsular bag. RESULTS: The spherical equivalent was reduced from a mean +4.87 (SD 3.00) dioptres (D) to -0.12 (1.40 D), and the deviation from the intended refraction was +0.005 (1.30) D, 23.6 (12.36) months post-implantation. The deviation from intended refraction was not statistically significant (p = 0.989; paired t test). Postoperative best corrected visual acuity (BCVA) was 6/12 or better in all eyes without macular or optic nerve co-morbidity. Interlenticular opacification (ILO) in the form of peripheral Elschnig pearls was seen in four (26.67%) eyes. A new type of ILO in the form of usually pigmented deposits in the central interface developed in five (33.33%) eyes and resulted in the appearance of Newton's rings in three. None of the eyes with ILO had any loss of BCVA or hyperopic shift. Six (40%) eyes were within 1 D from the intended refraction and 14 (93.33%) within 2 D. There was no statistically significant difference in the accuracy of the two intraocular lens calculation formulas used (SRK II and SRK/T). CONCLUSION: Peripheral Elschnig pearl-type ILO can occur as a late complication of primary in the bag implantation of two PMMA IOLs. A new type of ILO is described. Both types of ILO have not to date resulted in deterioration of visual acuity in our cohort. Use of appropriate biometry techniques and IOL calculation formulas may yield more accurate refractive results.
Assuntos
Extração de Catarata/métodos , Catarata/complicações , Hiperopia/cirurgia , Implante de Lente Intraocular/métodos , Idoso , Idoso de 80 Anos ou mais , Biometria/métodos , Catarata/diagnóstico por imagem , Extração de Catarata/efeitos adversos , Feminino , Humanos , Hiperopia/complicações , Hiperopia/diagnóstico por imagem , Implante de Lente Intraocular/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Refração Ocular , Resultado do Tratamento , Ultrassonografia , Acuidade VisualRESUMO
AIM: To determine the efficacy of apraclonidine hydrochloride 1% in preventing intraocular pressure (IOP) spikes following idiopathic macular hole (IMH) surgery with platelet adjunct and intraocular gas tamponade. METHODS: This is a prospective, double masked, randomised study to compare apraclonidine hydrochloride 1%, an alpha(2) agonist, with a placebo in the prevention of IOP rises following macular hole surgery. Each patient was randomly selected to receive either the study drug or the placebo; one drop was instilled in the conjunctival sac 2 hours preoperatively and on completion of the procedure. IOP was measured at baseline and at 1, 3, 6, 24, 48 hours, and 2 weeks postoperatively. Blood pressure and heart rate were also recorded at baseline and at 3 and 24 hours postoperatively. Macular hole repair surgery was performed as standardised in the unit with a vitrectomy, platelet concentrate, and complete fill of the vitreous cavity with perfluoropropane gas (C(3)F(8)) at a concentration of 16%. RESULTS: 25 patients (26 eyes) were enrolled. 12 eyes received apraclonidine hydrochloride 1% (mean age 70.7; range 62-78 years) and 14 eyes received the placebo (mean age 70.0; range 57-81 years). At baseline evaluation the mean IOP was 15.6 mm Hg for the study group and 14.3 mm Hg for the placebo group. The mean postoperative IOP at 1 hour, 3 hours, 6 hours, and 24 hours was 10.6, 9.6, 8.2, and 14.0 mm Hg in the apraclonidine group. In the control group at the same time intervals the mean IOP was 23.4, 17.5, 19.2, and 24.7 mm Hg. These readings were statistically significant different: 1 hour (p=0.0001); 3 hours (p=0.0015); 6 hours (p<0.0001); and 24 hours (p=0.019), the readings at 48 hours and 2 weeks were not statistically significant different (p=0.15 and p=0.59). Only one of the patients in the study group had an IOP above 25 mm Hg at any time. In the control group an IOP above 25 mm Hg was found in seven patients (50%) at the 1 hour postoperative measurement. At 2 weeks the IOP was recorded below 25 mm Hg in all patients. No statistically significantly difference was noted between the two groups regarding the systolic or diastolic blood pressure values and the heart rate records. No local or systemic adverse reactions were observed. CONCLUSIONS: Apraclonidine hydrochloride 1% appears to be an efficacious and safe drug in the prophylaxis of early postoperative IOP elevations in patients undergoing macular hole surgery.
Assuntos
Agonistas alfa-Adrenérgicos/uso terapêutico , Clonidina/análogos & derivados , Clonidina/uso terapêutico , Hipertensão Ocular/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Perfurações Retinianas/cirurgia , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/efeitos dos fármacos , Método Duplo-Cego , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , VitrectomiaRESUMO
AIM: To evaluate the image quality produced by polypseudophakia used for strongly hypermetropic and nanophthalmic eyes. METHODS: Primary aberration theory and ray tracing analysis were used to calculate the optimum lens shapes and power distribution between the two intraocular lenses for two example eyes: one a strongly hypermetropic eye, the other a nanophthalmic eye. Spherical aberration and oblique astigmatism were considered. Modulation transfer function (MTF) curves were computed using commercial optical design software (Sigma 2100, Kidger Optics Ltd) to assess axial image quality, and the sagittal and tangential image surfaces were computed to study image quality across the field. RESULTS: A significant improvement in the axial MTF was found for the eyes with double implants. However, results indicate that this may be realised as a better contrast sensitivity in the low to mid spatial frequency range rather than as a better Snellen acuity. The optimum lens shapes for minimum spherical aberration (best axial image quality) were approximately convex-plano for both lenses with the convex surface facing the cornea. Conversely, the optimum lens shapes for zero oblique astigmatism were strongly meniscus with the anterior surface concave. Correction of oblique astigmatism was only achieved with a loss in axial performance. CONCLUSIONS: Optimum estimated visual acuity exceeds 6/5 in both the hypermetropic and the nanophthalmic eyes studied (pupil size of 4 mm) with polypseudophakic correction. These results can be attained using convex-plano or biconvex lenses with the most convex surface facing the cornea. If the posterior surface of the posterior intraocular lens is convex, as is commonly used to help prevent migration of lens epithelial cells causing posterior capsular opacification (PCO), then it is still possible to achieve 6/4.5 in the hypermetropic eye and 6/5.3 in the nanophthalmic eye provided the anterior intraocular lens has an approximately convex-plano shape with the convex surface anterior. It was therefore concluded that consideration of optical image quality does not demand that additional intraocular lens shapes need to be manufactured for polypseudophakic correction of extremely short eyes and that implanting the posterior intraocular lens in the conventional orientation to help prevent PCO does not necessarily limit estimated visual acuity.
Assuntos
Hiperopia/terapia , Implante de Lente Intraocular/métodos , Lentes Intraoculares/normas , Acuidade Visual/fisiologia , Astigmatismo/etiologia , Sensibilidades de Contraste/fisiologia , Humanos , Hiperopia/fisiopatologiaRESUMO
To examine the effects of age and training on the active T subpopulation we considered elderly amateur cyclists over 65 in comparison with young amateur cyclists and young and aged sedentary healthy controls. Significant differences were observed between trained and sedentary elderly subjects consisting of an increase in the percentage of active E rosettes after 4 and 24 h of in vitro PHA stimulation, and of a decrease in the in vitro phosphorylation of phosphatydylinositol 4,5-bisphosphate (PtdInsP2) and a corresponding increase in phosphatydylinositol 4-phosphate (PtdInsP) in the early steps of the mitotic response. Our findings support the hypothesis of the involvement of inositol lipids in controlling the expression of lymphocyte surface receptors.