Joel Edmur Boteon

Spherical Aberration and Contrast Sensitivity in Eyes Implanted with Aspheric and Spherical Intraocular Lenses: A Comparative Study

PURPOSE To determine whether implantation of an intraocular lens (IOL) with a modified anterior aspheric surface results in reduced spherical aberration and improved contrast sensitivity after cataract surgery. DESIGN Prospective, comparative, interventional case series. METHODS In an intraindividual randomized prospective study of 25 patients with bilateral cataract, an IOL with a modified anterior surface (Tecnis Z9001; Advanced Medical Optics, Santa Ana, California, USA; group 1) was compared with biconvex lens with spherical surfaces (ClariFlex; Advanced Medical Optics; group 2). Ocular aberrations for a 5.0-mm pupil and 6.0-mm pupil were measured with Hartmann-Shack aberrometer. Quality of vision was measured by visual acuity and contrast sensitivity under mesopic and photopic conditions. All patients were followed up for three months. RESULTS No statistically significant difference in postoperative uncorrected and best-corrected distance vision acuity after a follow-up of three months existed between the groups. Postoperative contrast sensitivity testing revealed significant differences between the groups under photopic and mesopic conditions. These differences reached statistical significance under photopic conditions at three spatial frequencies and under mesopic conditions at all spatial frequencies. When analyzing higher-order aberrations, the difference between the groups was statistically significant at the 5.00-mm and 6.00-mm pupil diameters, with the group 1 inducing less higher-order aberration and also less spherical aberration compared with group 2. CONCLUSIONS Results show the Tecnis Z9001 IOL with a modified anterior aspheric surface induced significantly less higher-order aberration and spherical aberration compared with the ClariFlex IOL. Contrast sensitivity revealed better values under photopic and mesopic conditions with the Tecnis Z9001 IOL.

Ocular aberrations and contrast sensitivity after cataract surgery with AcrySof IQ intraocular lens implantation Clinical comparative study

PURPOSE: To determine whether implantation of an intraocular lens (IOL) with a modified posterior aspherical surface (AcrySof IQ, Alcon Surgical Laboratories) results in reduced ocular aberrations (spherical aberration) and improved contrast sensitivity after cataract surgery. SETTING: Brasilia Ophthalmologic Hospital, Brasilia, and Sao Geraldo Eye Hospital, Federal University of Minas Gerais, Belo Horizonte, Brazil. METHODS: In an intraindividual randomized prospective study of 25 patients with bilateral cataract, an IOL with a modified posterior surface (AcrySof IQ) was compared with a biconvex IOL with spherical surfaces (AcrySof Natural, Alcon). Ocular aberrations with a 5.0 mm and 6.0 mm pupil were measured with a Hartmann‐Shack aberrometer. Quality of vision was measured by visual acuity and contrast sensitivity under mesopic and photopic conditions. All patients were followed for 3 months. RESULTS: There were no statistically significant differences between eyes in postoperative uncorrected and best corrected distance visual acuities after a follow‐up of 1 month and 3 months. Postoperatively, there was a statistically significant between‐group difference in contrast sensitivity under photopic conditions without glare at 18 cycles per degree (cpd) (P = .04) and under mesopic conditions without glare at all spatial frequencies (3 cpd, 6 cpd, 12 cpd, and 18 cpd; P = .03, P = .009, P = .003, and P = .003, respectively) and with glare at 3 cpd and 6 cpd (P = .001 and P = .02, respectively). The difference in higher‐order aberration (HOA) values between groups was statistically significant with a 5.0 mm and 6.0 mm pupil, with the AcrySof IQ IOL inducing less HOA than the AcrySof Natural IOL. Eyes with an AcrySof IQ IOL also had statistically significant less spherical aberration than eyes with an AcrySof Natural IOL with both pupil diameters (P<.001). CONCLUSIONS: The AcrySof IQ IOL with a modified posterior surface induced significantly less HOA and spherical aberration than the AcrySof Natural IOL. Contrast sensitivity was better under mesopic conditions with the AcrySof IQ IOL.

Treatment of astigmatism during phacoemulsification.

PURPOSE To compare the effectiveness of limbal relaxing incisions (LRI) with that of toric intraocular lens (IOL) implantation for the treatment of astigmatism during phacoemulsification using nonvectorial (predictability, safety, and efficacy) and vectorial analyses. METHODS This longitudinal observational case series assessed 62 eyes of 31 consecutive cataract patients with preoperative corneal astigmatism of 0.75-2.50 diopters (D) in both eyes. Patients were randomly assigned to 2 groups: a toric IOL group, which received toric IOLs in both eyes, and an LRI group, which received spherical IOLs associated with LRI placement in both eyes. All patients were evaluated at 1, 3, and 6 months after surgery, when refractive astigmatism analysis was performed using both nonvectorial and Alpins vectorial methods. Outcomes were assessed within each group and compared between groups. RESULTS The proportion of eyes within ±0.50 D of the intended correction at 3 and 6 months after surgery was 75% and 71.88%, respectively, in the LRI group and 40% and 66.67%, respectively, in the toric IOL group. In the remaining period, the proportion was greater in the toric IOL group. The safety index showed no difference at any time point. The efficacy index at 1 and 3 months after surgery was significantly higher in the toric IOL group (0.43 and 0.44, respectively) than in the LRI group (0.31 and 0.36, respectively). At 6 months after surgery, the status of eyes in the LRI group was as follows: 53.13% were undercorrected, 43.74% achieved the intended correction, and 3.13% were overcorrected. In the toric IOL group, 16.76% eyes were undercorrected, 76.67% achieved the intended correction, and 6.67% were overcorrected. The success rates for astigmatic surgery, astigmatism reduction at the intended axis, and astigmatism corrected were 43%, 62%, and 64%, respectively, in the LRI group and 57%, 81%, and 94%, respectively, in the toric IOL group. CONCLUSIONS Our results suggest that the use of toric IOLs may be advantageous over the use of LRIs for the treatment of astigmatism during phacoemulsification. Although such advantages seem subtle in nonvectorial analyses, they are highlighted in vectorial analyses.

Indicações de transplante de córnea no Hospital São Geraldo da Universidade Federal de Minas Gerais

Realizou-se estudo retrospectivo de 887 ceratopatias penetrantes, com dados obtidos dosarquivos da Central Estadual de Notificacao de Minas Gerais, MG Transplantes, e dosprontuarios dos pacientes do Departamento de Cornea do Hospital Sao Geraldo. Osdados analisados foram: idade, sexo e diagnostico pre-operatorio das alteracoes corneanas.As indicacoes de transplante do periodo de janeiro de 1999 a junho de 2002 foramcomparadas as de julho de 2002 a dezembro de 2005.

Comparison of clinical outcomes between limbal relaxing incisions and toric intraocular lenses in eyes with astigmatic corneas

Objective: To compare refractive and vectorial outcomes of limbal relaxing incisions (LRI) versus toric intraocular lenses (IOL) in the treatment of preexisting corneal astigmatism at the time of phacoemulsification. Methods: This longitudinal observational case series assessed 62 eyes of 31 consecutive cataract patients with preoperative corneal astigmatism between 0.75 and 2.50 diopters in both eyes. Patients were randomly assorted in two groups: one assigned to receive AcrySof Toric™ IOL in both eyes, and another one assigned to have AcrySof Natural™ IOL associated with LRI, also in both eyes. All patients were re-evaluated, postoperatively, at 1, 3 and 6 months, when refractive astigmatism analysis was performed using vectorial methods proposed by Thibos. Variability of outcomes within each group and between groups were assessed and compared. Results: Manifest refractive cylinder, in diopters (D), as means ± standard deviation, in the LRI group for 1-month, 3-month and 6-month re-evalutions were respectively -0.66 ± 0.30; -0.70 ± 0.21 and -0.74 ± 0.26 when compared to -0.58 ± 0.24; -0.63 ± 0.20, and -0.62 ± 0.17 in the toric IOL group. (p value ≥ 0.06). Vectorial analysis evidenced greater astigmatism reduction in the toric IOL group in the 6th postoperative month, when postoperative mean astigmatic power vector was 0.31 D, when compared to 0.37 D in the LRI group (p value = 0.00). Conclusions: A trend of slightly better refractive outcomes favoring toric IOL group was seen, although such a trend was not statistically significant. Vectorial analysis, however, suggests that the use of toric IOL may constitute a more advantageous approach in the treatment of pre-existing corneal astigmatism, simultaneously with phacoemulsification.

Astigmatism treatment during phacoemulsification: a review of current surgical strategies and their rationale

Preexisting corneal astigmatism, present at the time of cataract surgery, is reviewed in detail throughout this article on its most important aspects such as occurrence rates, clinical relevance and current treatment options. Special emphasis is given to the latter aspect. Each methods rationale, advantage and limitation ishigh lightened. Comparisons between treatment options, whenever possible, are also provided.

Refractive lens exchange using SN60T5 AcrySof Toric intraocular lens in stage 2 keratoconus

Relatamos o caso de uma senhora de 45 anos de idade, portadora de ceratocone grau 2 e consequente anisometropia, submetida a extracao do cristalino transparente, e uso da lente intraocular modelo SN60T5 AcrySof Toric para o olho esquerdo. Facoemulsificacao seguida pelo implante da lente intraocular torica no olho esquerdo. No pos-operatorio, resultados refracionais e visuais satisfatorios foram alcancados. O uso de lentes intraoculares toricas pode se constituir em opcao terapeutica para casos selecionados de ceratocone grau 2.

Alpins and thibos vectorial astigmatism analyses: proposal of a linear regression model between methods

PURPOSE: To determine linear regression models between Alpins descriptive indices and Thibos astigmatic power vectors (APV), assessing the validity and strength of such correlations. METHODS: This case series prospectively assessed 62 eyes of 31 consecutive cataract patients with preoperative corneal astigmatism between 0.75 and 2.50 diopters in both eyes. Patients were randomly assorted among two phacoemulsification groups: one assigned to receive AcrySof®Toric intraocular lens (IOL) in both eyes and another assigned to have AcrySof Natural IOL associated with limbal relaxing incisions, also in both eyes. All patients were reevaluated postoperatively at 6 months, when refractive astigmatism analysis was performed using both Alpins and Thibos methods. The ratio between Thibos postoperative APV and preoperative APV (APVratio) and its linear regression to Alpins percentage of success of astigmatic surgery, percentage of astigmatism corrected and percentage of astigmatism reduction at the intended axis were assessed. RESULTS: Significant negative correlation between the ratio of post- and preoperative Thibos APVratio and Alpins percentage of success (%Success) was found (Spearmans ρ=-0.93); linear regression is given by the following equation: %Success = (-APVratio + 1.00)x100. CONCLUSION: The linear regression we found between APVratio and %Success permits a validated mathematical inference concerning the overall success of astigmatic surgery.

Tratamento homeopático de crianças com úlcera de córnea em escudo por ceratoconjuntivite primaveril: relato de casos e aspectos bioéticos

OBJECTIVES: present a homeopathic treatment of corneal ulcers for vernal keratoconjunctivitis and its bioethical implications. METHODS: nine cases were studied, after having been referred following the failure of conventional treatments. Medications were chosen according to the specific characteristics of the patients, including psychiatric disorders. The medication costs were gathered by consulting three homeopathic and three non-homeopathic pharmacies in Belo Horizonte. The estimate for conventional treatment cost was based on the medication prescribed for the patient prior to the commencement of homeopathic care. RESULTS: scarring occurred between fifteen and one-hundred eighty days, with an average medication cost of eight dollars, roughly one-thirteenth of the estimated direct cost of one month of conventional treatment. The similarity of therapeutic approaches should minimize bioethical concerns regarding the medical care of children with vernal keratoconjunctivitis. CONCLUSIONS: homeopathy can contribute to both the medical and bioethical aspects of treatment of this disease..

Pseudoaccommodating bifocal intraocular lens implantation in eyes with previous corneal refractive surgery - refractive outcomes: case series of 8 eyes

OBJECTIVE: Accurate intraocular lens power calculation may be a challenging issue in eyes with previous corneal refractive surgery. METHODS: The authors present a series of 8 eyes (4 previously submitted to hyperopic laser in situ keratomileusis and 4 to radial keratectomy) submitted to phacoemulsification and implantation of pseudoaccommodating bifocal intraocular lens. Double-K SRK/T formula has been used. RESULTS: Acceptable refractive visual outcomes have been achieved. CONCLUSION: Pseudoaccommodating bifocal intraocular lenses can be safely implanted in patients with previous corneal refractive surgery.