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1.
BMC Ophthalmol ; 24(1): 174, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38627647

RESUMEN

PURPOSE: To evaluate the long-term clinical outcomes of femtosecond thin-flap LASIK (femto-LASIK) for correction of refractive error after penetrating keratoplasty in keratoconus-affected eyes. SETTING: a private ophthalmology clinic. DESIGN: Prospective interventional case series. METHODS: This prospective interventional case series enrolled 22 eyes of 22 patients who underwent femto-LASIK for the management of post-penetrating keratoplasty ametropia. The refractive error, uncorrected (UDVA), and corrected (CDVA) distance visual acuities and vector analysis were reported in short-term and long-term period after surgery. RESULTS: The mean age was 32.7 ± 7.5 years (range, 23 to 47 years) at the surgery time. The average time between PK and femto-LASIK was 42.5 ± 31.7 months. The average follow-up duration after femto-LASIK was 81.2 ± 18.6 months. The mean preoperative UDVA significantly improved from 0.47 ± 0.15 logMAR to 0.35 ± 0.14 logMAR at 12 months (P = 0.048) and 0.4 ± 0.17 at final follow-up exam (P = 0.007). CDVA was 0.22 ± 0.1 at baseline which improved to 0.18 ± 0.15 and 0.15 ± 0.1 logMAR at 12 and 81 months, respectively. (Ps = 0.027, 0.014). The mean cylinder before surgery was - 5.04 ± 1.4D which significantly decreased to -1.5 ± 0.8 D at 12 months postoperatively. (P < 0.001). There was a significant increase in refractive astigmatism from 12 months to 81 months postoperatively (-3.1 ± 2.0, P = 0.002). At the final visit, the efficacy index was 0.83, and the safety index was 1.16. CONCLUSIONS: Despite the short-term outcome indicated that femo-LASIK was effective for correction of post-keratoplasty ametropia during short-term period, a notable regression in its effect was observed in the long-term follow-up. Therefore, the predictability of this technique might decrease in the long-term.


Asunto(s)
Astigmatismo , Queratomileusis por Láser In Situ , Errores de Refracción , Humanos , Adulto , Queratomileusis por Láser In Situ/efectos adversos , Queratomileusis por Láser In Situ/métodos , Queratoplastia Penetrante/efectos adversos , Estudios Prospectivos , Astigmatismo/etiología , Astigmatismo/cirugía , Refracción Ocular , Rayos Láser , Resultado del Tratamiento , Láseres de Excímeros/uso terapéutico
2.
Int Ophthalmol ; 38(1): 67-74, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28035498

RESUMEN

PURPOSE: To compare the outcomes of the conventional and accelerated corneal collagen cross-linking (CXL) in patients with bilateral progressive keratoconus (KC). METHODS: Fifteen consecutive patients with bilateral progressive KC were enrolled. In each patient, the fellow eyes were randomly assigned to the conventional CXL (3 mW/cm2 for 30 min) or accelerated CXL (ACXL) (9 mW/cm2 for 10 min) groups. Manifest refraction; uncorrected and corrected distant visual acuity; maximum and mean keratometry; corneal hysteresis and corneal resistance factor; endothelial cell density and morphology; central corneal thickness; and wavefront aberrations were measured before and 12 months after the CXL. RESULTS: Manifest refraction spherical equivalent and refractive cylinder improved significantly only in conventional group. Uncorrected and corrected distant visual acuity did not change significantly in either group. Also there was no significant change in the maximum and mean keratometry after 12 months. There was significant decrease in central corneal thickness in both groups which was more prominent in conventional group. Endothelial cell density reduced only in the conventional group which was not statistically significant (P = 0.147). CH, CRF, and wavefront aberrations did not change significantly in either group. We did not observe any significant difference in the changes of the variables between the two groups. CONCLUSIONS: Accelerated CXL with 9 mW/cm2 irradiation for 10 min had similar refractive, visual, keratometric, and aberrometric results and less adverse effects on the corneal thickness and endothelial cells as compared with the conventional method after 12 months follow-up. However, randomized clinical trials with longer follow-ups and larger sample sizes are needed.


Asunto(s)
Colágeno/metabolismo , Reactivos de Enlaces Cruzados/uso terapéutico , Queratocono/tratamiento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/uso terapéutico , Riboflavina/uso terapéutico , Adolescente , Adulto , Córnea/fisiopatología , Topografía de la Córnea , Femenino , Humanos , Queratocono/metabolismo , Queratocono/fisiopatología , Masculino , Estudios Prospectivos , Refracción Ocular/fisiología , Agudeza Visual/fisiología , Adulto Joven
3.
J Res Med Sci ; 19(8): 786-91, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25422666

RESUMEN

BACKGROUND: Ramadan fasting may alter a variety of physiological parameters which by themselves influence ocular system. Here, we review the effects of Ramadan fasting on the health and function of the eye. MATERIALS AND METHODS: Literature records in PubMed/MEDLINE, Web of Science, EMBASE, Google Scholar, and Iran Medex databases as well as proceedings of related meetings from January 1986 to March 2014 were systematically reviewed. The search key words was based on the terms "Ramadan Fasting," "Ramadan," "Islamic Fasting," "Fasting in Ramadan" accompanied with one of the eye, tear drop, myopia, intraocular pressure (IOP), tear break up time, basal tear secretion, refractive error, and visual acuity. RESULTS: Predawn water loading and dehydration in the evening are shown to increase and decrease IOP and tear secretion, respectively. Ocular blood flow is changed in Ramadan fasting, and patients with ocular vein occlusion may experience more frequent attacks. There are no or minimal fluctuations in visual acuity and refractive errors, but most of them are decompensated after Ramadan. CONCLUSION: Although the influence of fasting in different eye parameters is evaluated in several studies, there are no or only limited studies conducted on patients suffering from glaucoma, damage to ophthalmic vasculature, tear dysfunction, and minimal visual acuity. Such studies are required to make a definite decision before fasting is declared harmless to these patients.

4.
J Ophthalmic Vis Res ; 18(4): 369-378, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38250234

RESUMEN

Purpose: To evaluate and compare clinical outcomes after femtosecond laser-assisted implantation of 325-degree versus 340-degree arc length intracorneal ring segments (ICRS) in eyes with keratoconus (KCN). Methods: In this prospective non-randomized interventional case series, 23 eyes of 21 patients diagnosed with KCN, underwent femtosecond laser-assisted implantation of two types of ICRS, which included a 325-degree ICRS (Group 325) and a 340-degree ICRS (Group 340). The primary outcome measures were uncorrected distance visual acuity (UDVA), and the secondary outcome measures included corrected distance visual acuity (CDVA), sphere, cylinder, mean refractive spherical equivalent (MRSE), keratometry, vectorial change in corneal astigmatism, and the location of maximum keratometry relative to the corneal apex. The study groups were compared using the primary and secondary outcome measures obtained at postoperative months six and 12. Results: Groups 325 and 340 consisted of 10 and 13 eyes, respectively. The two groups were comparable in terms of parameters measured preoperatively. On comparison to the baseline values, both study groups exhibited a significant increase in UDVA and CDVA measured at postoperative month six (Ps < 0.05) and a significant decrease in the sphere, cylinder, spherical equivalent refraction, and keratometry readings measured at postoperative months six and 12 (Ps < 0.05). No significant differences were observed between the two groups in terms of visual, refractive, and keratometric outcomes at any time point. No intraoperative or postoperative complications were observed in any of the study groups. Conclusion: Both the 325-degree ICRS and the 340-degree ICRS effectively and equally improved visual, refractive, and keratometric outcomes in keratoconic eyes.

5.
J Ophthalmic Vis Res ; 17(4): 497-504, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36620721

RESUMEN

Purpose: To investigate the effect of static accommodative tasks on intraocular pressure (IOP) of glaucomatous and normal eyes. Methods: Four groups of subjects categorized as primary open-angle glaucoma (POAG), primary angle-closure suspects (PACS), normal age-matched controls, and normal young adults (NYA; age < 40 years) were enrolled. The baseline IOPs were measured after the subjects were looking at a distant target for 15 min. Static accommodation was obtained by execution of near vision tasks (reading at 33 cm in daylight [300 lux] for 60 min). IOPs were measured at 15, 30, 45, and 60 min intervals while accommodating and then measured again after 15 min of relaxing accommodation while looking at a distant target. Results: One-hundred and eighteen eyes of 98 subjects were recruited. The study groups consisted of the following categories: 25 POAG (46 eyes), 24 PACS (47 eyes), 25 matched controls (50 eyes), and 24 NYA (48 eyes). Within all groups, the mean IOP decreased throughout the accommodation period at all time points. Maximum IOP reduction after accommodation was detected at the 30-min time among the POAG subjects, at the 45-min time in the PACS and matched control groups, and at 15 min after the relaxation of accommodation in the NYA group. IOP reduction levels showed no statistically significant difference among POAG, PACS, and the normal matched groups in their response to accommodation. However, NYA had significantly lower IOP and greater IOP reduction after the resting period (relaxation of accommodation). Conclusion: Static accommodative tasks can significantly reduce IOP in normal, POAG, and PACS individuals. Encouraging glaucoma patients to practice periodical near vision tasks could be viewed as an adjunctive measure for glaucoma management.

6.
J Refract Surg ; 27(12): 887-93, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21877678

RESUMEN

PURPOSE: To compare the effects of mechanical versus alcohol-assisted epithelial debridement on corneal cellular elements after photorefractive keratectomy (PRK) using confocal microscopy. METHODS: This randomized, clinical trial included 66 eyes from 33 patients with spherical equivalent refraction <-4.00 diopters (D). Mechanical versus alcohol-assisted epithelial debridement was performed during PRK. The right eye of each patient was randomly assigned to one group (mechanical group or alcohol-assisted group) and the fellow eye to the alternate group. Confocal examination was performed preoperatively and at 3 and 6 months postoperatively. Main outcome measures were keratocyte density and maximum anterior stromal light reflectivity. RESULTS: Mean epithelial healing time was 3.2 ± 0.4 and 3.0 ± 0.3 days in the mechanical and alcohol-assisted groups, respectively (P=.001). Anterior retroablation stromal keratocyte density was 704.3 ± 119.9 cells/mm² and 734.3 ± 103.7 cells/mm² at 3 months (P=.05) and 643.8 ± 134.4 cells/mm² and 696.7 ± 129.6 cells/mm² at 6 months (P=.02) in the mechanical and alcohol-assisted groups, respectively. No significant difference was noted in midstromal and posterior keratocyte density between the two groups. Maximum reflectivity was 61.56 ± 12.64 international units (IU) and 56.93 ± 7.86 IU in the mechanical and alcohol-assisted groups, respectively, 3 months after surgery (P=.018). Corresponding values were 49.46 ± 4.97 IU and 48.98 ± 4.60 IU, respectively, 6 months after surgery (P=.628). CONCLUSIONS: Due to more adverse effects of mechanical epithelial debridement on anterior keratocyte density and anterior stromal reflectivity, alcohol-assisted epithelial debridement is recommended as the procedure of choice for epithelial removal during PRK in patients with mild myopia.


Asunto(s)
Queratocitos de la Córnea/patología , Desbridamiento/métodos , Epitelio Corneal/fisiopatología , Microscopía Confocal , Miopía/cirugía , Queratectomía Fotorrefractiva , Cicatrización de Heridas/fisiología , Adulto , Recuento de Células , Sustancia Propia , Epitelio Corneal/efectos de los fármacos , Epitelio Corneal/cirugía , Etanol/administración & dosificación , Femenino , Humanos , Masculino , Fenómenos Mecánicos , Estudios Prospectivos , Adulto Joven
7.
Rom J Ophthalmol ; 65(2): 150-156, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34179580

RESUMEN

Purpose: To investigate the implantation of Polytetrafluoroethylene (PTFE) as a glaucoma drainage device. Methods: This study has been done in two steps. First, the constructed implants have been used in 4 rabbits and the histopathologic response was evaluated. In the second step, the implants were used in the 6 eyes of 6 patients with end-stage glaucoma with uncontrolled IOP and poor visual acuity. The tube was made of two-layer of PTFE membrane measuring 8 * 6 mm with a thickness of 1.8 mm and a silicone tube. The rabbits and the human eyes underwent surgical implantation of the tube in the anterior chamber. The histopathologic evaluation was done using H&E staining. Visual acuity, intraocular pressure and the number of glaucoma medications were assessed before and after the surgery. Results: In the histopathologic evaluation, subconjunctival polarizing fibers of a synthetic mesh infiltrated by fibrovascular septa was seen. A granulomatous inflammatory reaction composed of histiocytes, lymphocytes, and multinucleated giant cells were seen around and between the synthetic bundles. The average age of patients was 63 ± 5.5 years. The mean IOP reached from 36.6 ± 5.7 mmHg at baseline to 16.2 ± 8.9 mmHg at the final follow-up. Patients were followed for an average of 6.6 ± 4.5 months. One patient found hypotony refractory to medical and surgical treatment, which led to implant removal. One patient had uncontrolled IOP and finally led to phthisis bulbi following slow CPC. The remaining four eyes did well during the follow-up. Conclusion: The use of PTFE as a new polymer in tube shunt construction was reported. Larger studies, modification of the PTFE membranes like changing the porosity amount, and size of PTFE membranes might result in different conclusions.


Asunto(s)
Implantes de Drenaje de Glaucoma , Glaucoma , Animales , Estudios de Seguimiento , Glaucoma/cirugía , Humanos , Presión Intraocular , Proyectos Piloto , Politetrafluoroetileno , Conejos , Estudios Retrospectivos , Resultado del Tratamiento
8.
Cornea ; 26(9): 1074-8, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17893537

RESUMEN

PURPOSE: To report the long-term outcomes of penetrating keratoplasty (PKP) in war victims with chronic and delayed mustard gas keratitis. METHODS: This noncomparative interventional case series includes patients with advanced chronic or delayed mustard gas keratitis who had undergone PKP from 1989 to 2006. Best-corrected visual acuity (BCVA), graft clarity, episodes of graft rejection, duration of steroid use, and complications were evaluated. Histopathologic features of excised corneal buttons were also evaluated. RESULTS: Overall, 22 eyes of 19 patients underwent PKP. Mean age at the time of surgery was 41 +/- 4.6 years (range, 36-54 years), and mean follow-up duration was 40.9 +/- 48 months (range, 4-204 months). The graft remained clear in 17 (77.3%) eyes and failed in 5 (22.7%) eyes. Overall, 13 (59.1%) eyes experienced episodes of endothelial rejection, and 5 (22.7%) eyes had subepithelial immune rejection, 4 of which had simultaneous endothelial rejection. Fifteen (68.2%) eyes received topical steroids for >6 months. Fourteen (63.6%) eyes developed cataracts, leading to cataract extraction in 7 eyes. One eye developed steroid-induced glaucoma after multiple episodes of endothelial graft rejections. Mean preoperative BCVA was 1.92 +/- 0.63 logMAR, which improved to 1.04 +/- 0.65 logMAR (20/200) overall and 0.8 +/- 0.3 logMAR (20/120) in eyes with clear grafts (P < 0.001). Main histopathologic features of excised corneal buttons included corneal thinning and ulceration, loss of keratocytes, acute and chronic inflammation, stromal vascularization, and degenerative sequelae of long-standing inflammation. CONCLUSIONS: PKP in chronic or delayed-onset mustard gas keratitis should be considered as a high-risk graft; however, with appropriate management, graft clarity and visual outcomes may be favorable.


Asunto(s)
Quemaduras Químicas/cirugía , Sustancias para la Guerra Química/efectos adversos , Quemaduras Oculares/inducido químicamente , Queratitis/cirugía , Queratoplastia Penetrante , Gas Mostaza/efectos adversos , Adulto , Quemaduras Químicas/patología , Enfermedad Crónica , Quemaduras Oculares/patología , Quemaduras Oculares/cirugía , Estudios de Seguimiento , Supervivencia de Injerto , Humanos , Irak , Queratitis/inducido químicamente , Queratitis/patología , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Agudeza Visual , Guerra
9.
J Cataract Refract Surg ; 43(10): 1251-1256, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-29120710

RESUMEN

PURPOSE: To evaluate the short-term outcomes of femtosecond laser-assisted implantation of a 340-degree intracorneal ring (ICR) (Keraring) in patients with keratoconus. SETTING: Four centers in Iran. DESIGN: Prospective case series. METHODS: All cases had implantation of the 340-degree ICR after tunnel creation with a femtosecond laser. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, sphere, cylinder, manifest refraction spherical equivalent (MRSE), mean keratometry (K), steep K, and flat K were evaluated preoperatively and 1, 3, and 6 months postoperatively. RESULTS: Eighteen eyes of 17 patients were included. The mean follow-up was 4.33 months (range 1 to 6 months). The mean UDVA improved from 0.95 logarithm of the minimum angle of resolution (logMAR) ± 0.33 (SD) to 0.53 ± 0.35 logMAR (P = .001) and the mean CDVA from 0.39 ± 0.22 logMAR to 0.26 ± 0.21 logMAR (P = .09). The mean sphere decreased from -5.08 ± 3.74 diopters (D) to -1.67 ± 2.59 D, the mean cylinder from -5.83 ± 2.02 D to -2.72 ± 1.81 D, and the mean MRSE from -8.03 ± 3.88 D to -3.01 ± 2.82 D (P < .001). The mean K decreased from 51.43 ± 3.59 D to 47.42 ± 3.59 D (P < .001). All patients with a preoperative mean K greater than 55.0 D had worse CDVA. CONCLUSIONS: Implantation of a 340-degree ICR using femtosecond laser improved the visual, refractive, and topographic parameters in keratoconic patients. The findings indicate that patients with severe keratoconus (mean K >55.0 D) are not good candidates for this type of ICR.


Asunto(s)
Sustancia Propia , Queratocono , Prótesis e Implantes , Refracción Ocular , Sustancia Propia/cirugía , Topografía de la Córnea , Estudios de Seguimiento , Humanos , Queratocono/cirugía , Estudios Prospectivos , Implantación de Prótesis , Resultado del Tratamiento , Agudeza Visual
10.
Scientifica (Cairo) ; 2016: 6789081, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27403376

RESUMEN

Background. Keratoconus is a relatively common corneal disease causing significant visual disability. Individuals with connective tissue disorders that affect the skin such as Marfan's syndrome and Ehlers-Danlos syndrome or patients with atopic dermatitis show an increased prevalence of keratoconus. It seems that there are some concurrent alterations of skin and cornea in patients with keratoconus. Objective. We plan to compare skin biophysical characteristics in patients with keratoconus and healthy controls. Methods. Forty patients with keratoconus (18 females and 22 males) with mean (SD) age of 33.32 (9.55) years (range 19-56) and 40 healthy controls were recruited to this study. Skin biophysical characteristics including cutaneous resonance running time (CRRT), stratum corneum hydration, and melanin values were measured in patients and controls. Results. The median CRRT, stratum corneum hydration, and melanin measurements were significantly lower in patients with keratoconus in comparison with healthy controls. Conclusion. There are some alterations of skin biophysical properties in patients with keratoconus. Therefore, the assessment of these skin parameters could provide us some clues to the possible common biophysical variations of cornea and skin tissue in diseases such as keratoconus.

11.
Cornea ; 35(7): 967-71, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27158805

RESUMEN

PURPOSE: To compare the total energy required for producing patent neodymium:yttrium-aluminum-garnet laser peripheral iridotomy in patients with or without keratoconus (KC). METHODS: In this case-control study, 36 eyes from 36 patients with KC and 24 eyes from 24 patients with myopia with or without astigmatism (as control group) who were scheduled for phakic intraocular lens implantation underwent neodymium:yttrium-aluminum-garnet laser peripheral iridotomy 1 week before surgery. The total laser energy was recorded and compared between the 2 groups. RESULTS: Mean total laser energy was significantly lower in patients with KC compared with the control group (114.7 ± 41.0 mJ and 263.9 ± 79.6 mJ, respectively, P < 0.01). Total laser energy was not correlated with patients' age, sex, race, refraction, maximum keratometry, or corneal thickness. CONCLUSIONS: Lower tissue resistance may be present in other ocular structures, such as iris, in patients with KC. Our findings supported a generalized abnormality in patients with KC rather than a localized corneal disease, at least in some cases.


Asunto(s)
Iris/cirugía , Queratocono/complicaciones , Coagulación con Láser , Láseres de Estado Sólido , Miopía/cirugía , Lentes Intraoculares Fáquicas , Adulto , Astigmatismo/complicaciones , Astigmatismo/cirugía , Estudios de Casos y Controles , Estudios Transversales , Femenino , Humanos , Iridectomía , Implantación de Lentes Intraoculares , Masculino , Miopía/complicaciones , Adulto Joven
12.
Ophthalmology ; 112(4): 617-25, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15808253

RESUMEN

PURPOSE: To report the clinical features of 93 eyes of 48 patients with chronic and delayed-onset mustard gas keratitis. Clinicopathologic correlation in 5 eyes and a review of related literature are presented. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Forty-eight Iranian survivors of Iraqi chemical warfare with chronic or delayed-onset mustard gas keratitis. METHODS: We reviewed the symptoms, clinical findings, course, and treatment of our patients and reviewed the literature. In 5 patients, histopathologic features of corneal and conjunctival specimens were evaluated. MAIN OUTCOME MEASURES: Ocular findings, clinical course, treatment measures, and histopathologic studies. RESULTS: Of 48 patients, 31 (64.6%) had chronic symptomatology, whereas 17 (35.4%) experienced delayed-onset lesions. Visual acuity at referral ranged from hand motions to 20/20. Ocular surface changes included chronic blepharitis and decreased tear meniscus in all patients, limbal ischemia (81.3%), and conjunctival vascular abnormalities (50%). Corneal signs in order of frequency were: scar or opacity (87.5%), neovascularization (70.8%), thinning (58.3%), lipoid deposits (52.1%), amyloid deposits (43.8%), and epithelial defects and irregularity (31.3%). Many patients received conservative treatment; others underwent allograft stem cell transplantation (20 eyes of 17 patients), penetrating keratoplasty (12 eyes of 12 patients), and lamellar keratoplasty (4 eyes of 3 patients). Conjunctival specimens were evaluated by light microscopy. Decreased goblet cell density, attenuated or thickened epithelium, scarring in the substantia propria associated with plasmacytic and lymphocytic infiltration, and dilated lymphatic vessels were noted. Excised corneal buttons disclosed absence of epithelium and Bowman's layer, fibrovascular pannus, stromal scarring, and vascularization. CONCLUSIONS: Mustard gas causes chronic and delayed destructive lesions in the ocular surface and cornea, leading to progressive visual deterioration and ocular irritation. The pathophysiologic features of these changes are not clearly identified. Excised conjunctival and corneal specimens revealed a mixed inflammatory response without any specific features. Based on the clinical appearance of the lesions and the histopathologic findings, an immune-mediated component seems possible. This article contains additional online-only material available at.


Asunto(s)
Quemaduras Químicas/complicaciones , Sustancias para la Guerra Química/efectos adversos , Córnea/efectos de los fármacos , Quemaduras Oculares/inducido químicamente , Queratitis/inducido químicamente , Gas Mostaza/efectos adversos , Adulto , Anciano , Quemaduras Químicas/diagnóstico , Quemaduras Químicas/cirugía , Enfermedad Crónica , Conjuntiva/efectos de los fármacos , Quemaduras Oculares/diagnóstico , Quemaduras Oculares/cirugía , Humanos , Irán , Irak , Queratitis/diagnóstico , Queratitis/cirugía , Queratoplastia Penetrante , Limbo de la Córnea/citología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Trasplante de Células Madre , Guerra
13.
J Ophthalmic Vis Res ; 10(4): 370-4, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-27051480

RESUMEN

PURPOSE: To compare distant and near visual function after cataract surgery with implantation of Crystalens HD or Tek-Clear as accommodating intraocular lenses (IOLs), versus SA60AT as a standard IOL. METHODS: The study included 62 eyes of 58 patients divided into three groups using three different IOLs: Crystalens HD (Bausch and Lomb, NY, USA), Tek-Clear (Tekia, CA, USA) and SA60AT (Alcon, TX, USA) were implanted in 23, 14 and 25 eyes, respectively. Corrected distant visual acuity (CDVA), uncorrected and distance corrected near visual acuities (UCNVA and DCNVA), near point of accommodation (NPA), spectacle freedom and patient satisfaction were assessed six months postoperatively and compared between the three groups. RESULTS: After 6 months, all patients showed significant improvement in CDVA with no significant difference among the study groups. However, UCNVA and DCNVA were significantly better in patients implanted with accommodating IOLs. NPA was closest in the Crystalens HD group, followed by Tek-Clear and monofocal SA60AT (P < 0.001). Patients with accommodating IOLs were more likely to become spectacle free and satisfied with their near vision as compared to subjects receiving a monofocal IOL. CONCLUSIONS: Accommodating IOLs (Crystalens HD and Tek-Clear) effectively reduce the necessity for spectacles after cataract surgery.

14.
J Ophthalmic Vis Res ; 10(4): 358-63, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-27051478

RESUMEN

PURPOSE: To evaluate corneal changes after collagen crosslinking (CXL) therapy for keratoconus (KCN) using the Galilei dual Scheimpflug analyzer. METHODS: This prospective, nonrandomized clinical study included 35 eyes of 32 keratoconus patients who had undergone CXL. The eyes were saturated with riboflavin solution and were subjected for 30 minutes to ultraviolet-A (UV-A) light with irradiance of 3 mW/cm(2). Effectiveness of the treatment was assessed by measuring uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest cylinder/sphere, keratometry, pachymetry, posterior and anterior elevations by the Galilei dual Scheimpflug analyzer. Prior to treatment and 8 months after therapy, Scheimpflug analysis was performed using the Galilei system. The four sets of data including keratometry values, pachymetry, elevation parameters and surface indices were statistically analyzed and compared. RESULTS: Mean patient age was 22.3 ± 3.8 years and mean postoperative follow-up was 8.1 ± 3.2 months. There was a significant increase in UCVA (0.54 ± 0.35 Log MAR preoperatively to 0.49 ± 0.34 LogMAR postoperatively, P = 0.01) and BCVA (0.21 ± 0.19 Log MAR preoperatively to 0.16 ± 0.17 LogMAR postoperatively, P = 0.01). Mean cycloplegic spherical equivalent refractive error was -4.13 ± 2.65 Diopter (D) preoperatively and - 4.67 ± 2.96 D postoperatively (P < 0.001). During the follow-up period, no significant difference was observed in pachymetric and elevation data postoperatively. CONCLUSION: Corneal stabilization could be achieved by collagen crosslinking therapy for keratoconus in terms of corneal thickness, keratometry values, elevation parameters and surface indices.

15.
J Ophthalmic Vis Res ; 10(1): 4-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26005545

RESUMEN

PURPOSE: To compare ultrasound pachymetry and Orbscan II for measurement of central corneal thickness (CCT) in normal eyes. METHODS: The current study was performed at Labbafinejad Medical Center (LMC), Tehran, Iran. Three hundred eyes from 150 healthy individuals referred for keratorefractive surgery were assessed first by Orbscan II and then by ultrasound pachymetry, and CCT values were recorded and compared. RESULTS: Overall, Orbscan II overestimated CCT as compared to ultrasound pachymetry by about 2.4% (mean values 547.6 ± 34.7 versus 534.8 ± 34.7, respectively, P < 0.001). The difference was more significant when CCT was less than 500 microns (mean values 493.2 ± 16.9 versus 479.9 ± 15.6, mean overestimation: 2.6%, P < 0.001). There was good linear correlation between the two methods (Pearson's correlation r = 0.968, P < 0.0001). CONCLUSION: Orbscan II has good correlation with ultrasound pachymetry for measurement of CCT in normal eyes; however Orbscan II should not be used to evaluate corneal thickness before keratorefractive surgeries, as it tends to overestimate corneal thickness and may result in undesirable, low residual stromal thickness.

16.
Cornea ; 22(5): 420-3, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12827046

RESUMEN

PURPOSE: To report the visual results and success rate of penetrating keratoplasty (PKP) in a series of young children with congenital hereditary endothelial dystrophy (CHED). METHODS: This is a retrospective study on twenty-four eyes of 15 patients (seven male and eight female) operated on for CHED. Children less than 12 years of age at the time of surgery who were followed for at least 6 months were recalled. Characteristics of the patients, indications for PKP, final visual outcome, and graft clarity were evaluated. The following tests were employed: McNemmar test for evaluating visual results, Kaplan-Meyer analysis for determination of graft survival, and Mann-Whitney U test for evaluating the relationship between visual outcome and age at PKP. RESULTS: Patients' age at diagnosis and at initial PKP was 6.5 +/- 3.6 and 8.1 +/- 2.5 years, respectively. Follow-up period was 35.5 +/- 36.2 months. Visual acuity could be evaluated by Snellen chart in 19 eyes. Preoperative visual acuity was less than 20/80 in all of these. Postoperatively, visual acuity was less than 20/80 in nine eyes (47.4%) (P < 0.002). Visual acuity improved in 18 (94.7%) of 19 eyes. There was no relationship between age at initial PKP and final visual outcome (P = 0.35). At the last examination (24 grafts), 19 were clear (79.1%), two were hazy (8.3%), and three were opaque (12.5%). Allograft rejection was seen in 10 eyes (43.4%), seven of which were endothelial. Excluding one case of trauma, all graft failures resulted from endothelial rejection. The probability of primary graft survival was 88% at 3 years and 74% at 5 years. CONCLUSION: Regarding the difficulties in pediatric keratoplasty and the absence of a relationship between postoperative visual outcome and age at keratoplasty, a conservative approach and careful risk-benefit ratio evaluation are recommended in patients with CHED.


Asunto(s)
Distrofias Hereditarias de la Córnea/cirugía , Queratoplastia Penetrante , Niño , Preescolar , Femenino , Rechazo de Injerto , Humanos , Masculino , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del Tratamiento , Agudeza Visual
17.
J Ophthalmic Vis Res ; 8(2): 113-8, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23943685

RESUMEN

PURPOSE: To compare corneal higher-order aberrations (HOAs) between normal and keratoconic eyes, and to investigate the association between elevation-based corneal topographic indices and corneal wavefront data in the latter group. METHODS: In this cross-sectional comparative study, 77 normal right eyes of 77 control subjects and 66 eyes of 36 keratoconic patients were included. In each eye, elevation- based corneal topographic indices including mean keratometry readings, best-fit sphere, maximum elevation, and 3-mm and 5-mm zone irregularity indices were measured using Orbscan II. The Galilei Scheimpflug analyzer was used to measure HOAs of the corneal surface. The independent student t-test was used to compare HOAs between the study groups. Spearman correlation was used to investigate possible associations between Orbscan and Galilei data in the keratoconus group. RESULTS: All Zernike coefficients up to the 4th order except for horizontal trefoil, and vertical and horizontal tetrafoil were significantly greater in the keratoconus group than normal eyes (P<0.05). Root mean square (RMS) of HOAs up to the 6th order and total HOAs were significantly higher in the keratoconus group (P<0.05). In the keratoconus group, the strongest association was observed between vertical coma (r=-0.71, P<0.01) and total RMS of HOAs (r=0.94, P<0.01) with irregularity in the 3-mm zone. Spherical and vertical coma aberrations were significantly correlated with mean keratometry (P<0.05 for both comparisons). CONCLUSION: Centrally located corneal HOAs are significantly greater in keratoconic eyes than normal controls. Anterior and inferior displacement of the cornea causes the majority of higher-order aberrations observed in keratoconus.

18.
Cornea ; 31(8): 855-8, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22357385

RESUMEN

PURPOSE: To measure corneal graft biomechanical properties after penetrating keratoplasty (PKP) in a group of keratoconic eyes using the ocular response analyzer (ORA) and to evaluate the relationship between donor size, donor-recipient disparity and central graft thickness (CGT), and ORA parameters. METHODS: This cross-sectional study was conducted on 34 eyes of 34 keratoconus patients who had undergone PKP. Corneal hysteresis (CH), corneal resistance factor (CRF), and cornea-compensated intraocular pressure were measured at least 6 months after complete suture removal. Two groups of donor-recipient disparity (0.25 vs. 0.50 mm) were compared using the independent t test. Multivariate regression analysis was used to investigate the correlation of donor trephine size and CGT with ORA parameters. Factors influencing intraocular pressure measured with the Goldmann applanation tonometer (IOP GAT) after PKP were determined using multiple regression analysis. RESULTS: Mean patient age and follow-up period were 29.6 ± 6.2 years and 82.4 ± 59.6 months, respectively. Mean CGT, CH, and CRF were 564.7 ± 36.9 µm, 10.1 ± 2.1 mm Hg, and 10.0 ± 2.3 mm Hg, respectively. CH and CRF had a significant positive correlation with donor trephine size and CGT. Significantly greater values of CH and CRF were observed in the 0.5-mm disparity group compared with the 0.25-mm disparity group. Among the studied parameters, only CH, CRF, and cornea-compensated intraocular pressure had a significant positive correlation with IOP GAT. CONCLUSION: Graft biomechanics seem to be closer to normal values with larger grafts and greater donor-recipient disparity. These metrics had a significant correlation with IOP GAT after PKP.


Asunto(s)
Fenómenos Biomecánicos/fisiología , Córnea/fisiopatología , Queratocono/fisiopatología , Queratocono/cirugía , Queratoplastia Penetrante , Adolescente , Adulto , Estudios Transversales , Elasticidad/fisiología , Femenino , Humanos , Presión Intraocular/fisiología , Masculino , Donantes de Tejidos , Adulto Joven
19.
Middle East Afr J Ophthalmol ; 19(3): 323-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22837628

RESUMEN

PURPOSE: The aim of this study is to report the indications, techniques, and clinical outcomes of corneal transplantation and investigate any changing trends in surgical techniques over a 6 year period. MATERIALS AND METHODS: Records of patients who had undergone any kind of corneal transplantation at Labbafinejad Medical Center, Tehran, Iran, from January 2004 to December 2009 were reviewed to determine the indications and types of corneal transplantation. Postoperative best-corrected visual acuity, refractive error, graft clarity, and complications were reported. RESULTS: During this period, 1859 eyes of 1624 patients with a mean age of 41.3 ± 21.3 years underwent corneal transplantation. The most common indication was keratoconus (38.4%) followed by aphakic/pseudophakic bullous keratopathy (11.7%), previous failed grafts (10.6%), infectious corneal ulcers (10.1%), non-herpetic corneal scars (7.6%), trachoma keratopathy (4.7%), stromal corneal dystrophies (4.6%), post-herpetic corneal scar (3.7%), Fuchs' endothelial dystrophy (0.8%), and congenital hereditary endothelial dystrophy (0.4%). Techniques of corneal transplantation included penetrating keratoplasty (PKP; 70.9%), deep anterior lamellar keratoplasty (DALK; 20.1%), conventional lamellar keratoplasty (LKP; 4.4%), and Descemet's stripping automated endothelial keratoplasty (DSAEK; 2.3%). Over the study period, there was a significant increase in the relative frequency of infectious corneal ulcers, failed grafts, and trachoma keratopathy. Additionally, a significant reduction was observed in PKP and LKP procedures, and volume of DALK and DSAEK increased significantly. At final follow-up, 69.0% of grafts were clear in the PKP group. This figure was 82.6%, 82.7%, and 97.6% in the DALK, LKP, and DSAEK groups, respectively. CONCLUSION: Keratoconus was the most common indication and PKP was the most prevalent technique used for corneal transplantation. However, significant changes in the indications and surgical techniques were observed from 2004 to 2009.


Asunto(s)
Enfermedades de la Córnea/cirugía , Trasplante de Córnea/métodos , Refracción Ocular , Centros de Atención Terciaria/estadística & datos numéricos , Agudeza Visual , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Estudios de Seguimiento , Supervivencia de Injerto , Humanos , Lactante , Recién Nacido , Irán , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
20.
ISRN Ophthalmol ; 2011: 495047, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-24527227

RESUMEN

Purpose. To report outcomes of graft refractive surgery (GRS) along with clear-cornea phacoemulsification and intraocular lens (IOL) implantation in penetrating keratoplasty (PKP) eyes. Methods. Fourteen eyes of 13 patients who had received PKP underwent simultaneous GRS (relaxing incisions with or without counter-quadrant compression sutures) and clear-cornea phacoemulsification with IOL implantation. To calculate IOL power, preoperative keratometry readings and the SRK-T formula were used. Results. Mean patient age and follow-up period were 50.5 ± 14.4 years and 14.6 ± 7.1 months, respectively. A significant increase was observed in best spectacle-corrected visual acuity (from 0.55 ± 0.18 logMAR to 0.33 ± 0.18 logMAR, P = 0.001). There was a significant decrease in vector keratometric astigmatism by 6.22 D (P = 0.03). Spherical equivalent refraction was reduced from -3.31 ± 3.96 D to -1.69 ± 2.38 D (P = 0.02) which did not significantly differ from the target refraction (-0.76 ± 0.14 D, P = 0.20). No complications developed and all the grafts remained clear at the final examination. Conclusion. Simultaneous phacoemulsification and GRS is a safe and effective method to address post-PKP astigmatism and lens opacity. IOL power can be calculated from preoperative keratometry readings with an acceptable accuracy. However, patients should be informed about the possibility of high refractive errors postoperatively.

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