José Ramón Villada - Academia.edu (original) (raw)

Chapters by José Ramón Villada

Anillo de tensión capsular abierto para uso oftalmológico de una aleación de níquel-titanio con m... more Anillo de tensión capsular abierto para uso oftalmológico de una aleación de níquel-titanio con memoria de forma y enrollado en espiral, recubierto por una cápsula de un material seleccionado del grupo compuesto por poliácido láctico (PLA), gelatina y celulosa.

Villada JR, Villada-Warrington T, Mompeán-Morales B, Ortega-Usobiaga J. BiometríaIn: Llovet-Osuna F, Ortega-Usobiaga J. Cirugía Refractiva: Protocolos. Madrid: Sociedad Española de Oftalmología; 104-106., Sep 1, 2014

Papers by José Ramón Villada

Journal of Cataract and Refractive Surgery, May 1, 1997

To ascertain how many patients in a rural area of Spain would qualify for and choose to have day-... more To ascertain how many patients in a rural area of Spain would qualify for and choose to have day-case cataract surgery. Departmento de Oftalmología, Hospital Comarcal, Hellín, Albacete, Spain. All patients intending to have cataract surgery in 1993 responded to a five-question survey. Only patients answering yes to all five questions were considered candidates for day-case surgery. Thirty-three of 374 patients (9.0%) answered yes to all five questions. Only 7 of the 33 (1.9%) subsequently had day-case surgery. Establishing a day-case cataract surgery, unit in rural areas requires consideration of factors not present in urban areas and may require more time for patient acceptance.

Case Reports in Ophthalmology, Jul 12, 2021

We report a case of ocular injury caused by a bombardier beetle in a young boy. Ocular injuries d... more We report a case of ocular injury caused by a bombardier beetle in a young boy. Ocular injuries due to this coleoptera have not previously been reported. An 11-year-old boy experienced an eye injury while trying to place a bombardier beetle inside an anthill. The boy was diagnosed with a second-degree burn on the skin of the upper right eyelid and conjunctival and corneal erosion in the right eye. The condition resolved completely after 2 weeks of appropriate treatment. Education about the dangers of playing with insects is crucial to prevent this type of lesions.

Journal of Cataract and Refractive Surgery, Feb 1, 2000

also implanted IOLs in eyes in which the position of the retina was thought to be unstable. We ta... more also implanted IOLs in eyes in which the position of the retina was thought to be unstable. We take exception to this approach. Accurate axial length measurement is the most important factor for effective biometry. In an era in which the success of cataract surgery is judged by the refractive outcome, it is no longer acceptable to use approximations such as measurements of the fellow eye. Also, when scleral buckling is done as part of the retinal procedure, the length of the eye may change. The authors used scleral buckling in 4 eyes (10.5%) but do not mention how they estimated postoperative axial length in these cases. Six of the 38 eyes had postoperative refractive errors greater than 2.0 diopters from the target. It would be interesting to know whether the eyes having scleral buckling were in this group. We do not think it advisable to implant an IOL when the retina is thought to be unstable. If further retinal procedures become necessary, the IOL may impede clear visualization of the peripheral retina and make the surgery difficult to the extent that the IOL may have to be explanted. In both these situations, it is better to perform phacoemulsification and a vitreoretinal procedure at 1 sitting and implant the IOL at a secondary procedure, once the retina is stable and accurate biometry can be performed. This is more likely to lead to a stable retina and a better refractive result than that achieved by an all-in-1 procedure. The authors implanted the IOL before intraocular tamponade was performed. We routinely carry out implantation after intraocular gas tamponade and closure of sclerotomies. This allows us to complete the vitreoretinal procedure under optimal visualization before IOL implantation. Implantation is facilitated by slightly underfilling the eye with gas at the completion of the vitrectomy. The IOL can then be placed easily. Finally, the gas is “topped up” using a 30 gauge needle through the pars plana.

Journal of Refractive Surgery, 2004

To assess the effectiveness of optical and ultrasonic pachymetry when examining corneas of patien... more To assess the effectiveness of optical and ultrasonic pachymetry when examining corneas of patients before and after laser in situ keratomileusis (LASIK). We conducted a prospective study of 25 patients (50 eyes) who had LASIK for myopia or myopic astigmatism (mean spherical equivalent refraction -4.80 +/- 3.60 D; range -1.75 to -12.00 D). Corneal thickness was measured using 1) conventional ultrasonic pachymetry (20 MHz probe) in the central cornea, 2) ASL confocal microscopy (CMTF analysis), 3) Orbscan II Analyzer, and 4) ultrasound biomicroscopy (UBM) (50 MHz probe) preoperatively and 3 months postoperatively. Preoperative pachymetry values measured with the Orbscan II Analyzer (551.3 +/- 27.3 microm) were almost identical to those measured with the 20 MHz ultrasonic probe (553.7 +/- 25.7 microm; t-test P = .652). The mean preoperative pachymetry for UBM was 566.7 +/- 38.8 microm and for CMTF was 553.2 +/- 15.5 microm. The optic and ultrasonic system measurements differed in operated eyes; 20 MHz ultrasonic pachymetry yielded an average 478.7 +/- 23.5 microm and the UBM, 482.4 +/- 40.3 microm. These measurements differed from the Orbscan II (Tukey test; P = .023) measurement of 461.1 +/- 37.5 microm but not from the confocal microscopy measurement of 475.2 +/- 41.8 microm. UBM registered greater values that were more variable than those obtained with ultrasonic pachymetry. In non-operated eyes, corneal thickness was similar using conventional ultrasound, Orbscan II, or confocal techniques, with ultrasound biomicroscopy giving thicker readings.

Eye, Jul 1, 1994

A prospective, randomised, double-masked, placebo controlled study was carried out on 169 patient... more A prospective, randomised, double-masked, placebo controlled study was carried out on 169 patients under going cataract extraction to compare the topical anaes thetic cream amethocaine with EMLA (eutetic mixture of local anaesthetic, lignocaine and prilocaine) and placebo in reducing pain during retrobulbar injection. Fifty-eight patients received EMLA, 55 amethocaine and 56 the pla cebo. The pain was assessed objectively by the anaesthe tist and subjectively by the patient. Significantly lower pain scores were observed in those patients who had ame thocaine (p<O.OOl) or EMLA (p<O.005) in comparison with those who had placebo, but there was no statistical difference between amethocaine and EMLA (p>O.I; t-test). No systemic or local side-effects were encountered in any group. Since the introduction of the topical anaesthetic cream EMLA (eutetic mixture of local anaesthetic, lignocaine and prilocaine) into clinical practice, other local anaes thetic agents have been evaluated for topical use. A study comparing a local anaesthetic cream containing ametho caine (Anethaine, Evans) with EMLA found that ame thocaine had a rapid onset of action, longer duration of action and provided equally effective analgesia as EMLA.l With the increasing trend for local anaesthesia in the United Kingdom (retrobulbar, peribulbar or posterior bul bar injections) the need to relieve patient anxiety and pain is important.2 Recently it has been shown that EMLA is effective in relieving the pain of needle puncture of the skin at the time of retrobulbar injection.} We wished, therefore, to compare EMLA cream with amethocaine cream in relieving this pain.

Journal of Cataract and Refractive Surgery, Jul 1, 2001

1. J Cataract Refract Surg. 2001 Jul;27(7):968. Cataract surgery in the nanophthalmic eye. Villad... more 1. J Cataract Refract Surg. 2001 Jul;27(7):968. Cataract surgery in the nanophthalmic eye. Villada JR, Osman AA, Alío JL. Comment on: J Cataract Refract Surg. 2000 Dec;26(12):1702-13. PMID: 11496909 [PubMed - indexed for MEDLINE]. ...

Eye, May 1, 1992

Previously unreported adverse drug reactions can be dif ficult to detect and it may be even more ... more Previously unreported adverse drug reactions can be dif ficult to detect and it may be even more difficult to estab lish a cause and effect relationship, particularly if the adverse reacions mimic naturally occurring disease. In a previous paper we reported 29 patients with granuloma tous anterior uveitis, blepharoconjunctivitis, periorbital dermatitis, marginal keratitis and elevation in intra ocular pressure (lOP), suspected to be caused by meti pranolol (Glauline). With the approval of the District Ethics Committee 7 of those patients were rechallenged with metipranolol 0.3% compared to timolol maleate 0.5% in a double blind trial. The 7 metipranolol treated eyes developed an adverse reaction within 14 days. Meti pranolol (Glauline) has been conclusively proven to cause granulomatous anterior uveitis, blepharoconjunctivitis and elevation in lOP, adverse effects never previously reported with any of the ophthalmic topical beta-block ers. The multi dose preparations of metipranolol (Glau line) in all three strengths 0.1 %,0.3% and 0.6% and the single dose minim preparation of metipranolol 0.6 % have now been withdrawn from clinical use in the United Kingdom.

British Journal of Ophthalmology, May 1, 1992

Ninety seven eyes with anterior chamber implants and a best corrected visual acuity of at least 6... more Ninety seven eyes with anterior chamber implants and a best corrected visual acuity of at least 6/12 were studied, firstly, to compare the predictive accuracies of the commonly used formulas for intraocular lens (IOL) power calculation and, secondly, to determine the effect of optimising the 'A' constant on the predictive accuracies ofthe empirical Sanders-Retzlaff-Kraff (SRK) formulas. The accuracies of the empirical formulas (SRK and SRK II) were generally similar to those of the theoretical formulas (Binkhorst II and Colenbrander-Hoffer). However the original SRK formula was more accurate than the two theoretical formulas in long eyes and in all eyes overall. Optimisation of the 'A' constants did not improve the predictive accuracy of the empirical SRK formulas.

Eye, May 1, 1992

Fifty patients (50 eyes) with posterior chamber intra• ocular lenses and a best corrected visual ... more Fifty patients (50 eyes) with posterior chamber intra• ocular lenses and a best corrected visual acuity of at least 6/12 were studied. The Allergan•Humphrey 570 (AH•570) and Canon RK•l autorefractors were com• pared in terms of ease of operation, time taken and their accuracy relative to clinical refraction. Both the auto• refractors were equally easy to operate but the AH•570 was quicker. The AH•570 had a higher percentage of eyes within 110 of clinically determined cylinder axis while the Canon RK•l had a higher percentage of patients within

British Journal of Ophthalmology, 1991

Automated refraction with the Canon RK-1 Autoref keratometer was evaluated in 85 eyes of 85 patie... more Automated refraction with the Canon RK-1 Autoref keratometer was evaluated in 85 eyes of 85 patients with an anterior chamber intraocular lens implant and a best corrected visual acuity of at least 6/12. Autorefraction readings were obtained in 80 (94%) of these eyes. The agreement between autorefraction and clinical refraction data was 89% for spherical equivalence <0-51 dioptres (D), 91% for sphere power <051 D, 82% for cylinder power <0-51 D, and 91% for cylinder axis <11°. Autorefraction provides acceptably accurate postoperative refraction values in anterior chamber pseudophakia.

Eye, May 1, 1992

Fifty normal subjects were studied comparing objective autorefraction using the Allergan Uumphrey... more Fifty normal subjects were studied comparing objective autorefraction using the Allergan Uumphrey 570 (AU 570) and Canon RK-l autorefractors in terms of ease of operation, the time taken and their accuracy compared with clinical refraction. Both the auto refractors were equally easy to operate but the AU 570 was quicker. Objective autorefraction with the AU 570 was more accu rate than using the Canon RK-l especially with respect to spherical equivalence, sphere power and cyclinder axis: approximately 80% of the values were within 0.51 dioptres or 110 of clinical refraction compared to approximately 60% for the Canon RK-l. The possible reasons for the superior performance of the AU 570 are discussed.

British Journal of Ophthalmology, Sep 1, 1991

This paper presents for the first time documented evidence, clinical details, and photographic il... more This paper presents for the first time documented evidence, clinical details, and photographic illustrations, of metipranololassociated granulomatous anterior uveitis in 26 eyes of 15 patients being treated for glaucoma. There were 56 episodes of granulomatous anterior uveitis, all associated with large (mutton-fat) keratic precipitates, flare, cells, and 'white eyes' (except in seven episodes). In 30 (53.6%) of these episodes there was loss of control of intraocular pressure. Metipranolol 0-6% was implicated in 54 ofthe 56 episodes and metipranolol 0 3% in the remaining two. Fifty-one other cases of metipranolol-associated granulomatous anterior uveitis have so far been reported from other parts of the country to the Committee on Safety of Medicines. As a result multidose metipranolol in 0-1%, 0.3%, and 0-6% strengths has been withdrawn from clinical use in the United Kingdom. The pathogenesis of this adverse drug reaction is uncertain.

Eye, Sep 1, 1992

One hundred and fifty-one eyes with anterior chamber implants and a best corrected visual acuity ... more One hundred and fifty-one eyes with anterior chamber implants and a best corrected visual acuity of at least 6 / 12 were studied to compare the predictive accuracies of the newer generation intraocular lens power calculation for mulae. There was no statistically significant difference between the predictive accuracies of the SRK (Sanders Retzlaff-Kraff), SRK II, SRK / Theoretical (SRK / T) and Holladay formulae. All these four formulae were more accurate than the Binkhorst II formula.

Eye, May 1, 1992

This paper reviews the behaviour of intraocular pressure (lOP) in glaucomatous eyes treated with ... more This paper reviews the behaviour of intraocular pressure (lOP) in glaucomatous eyes treated with metipranolol with and without drug-induced adverse reactions (ADRs). Two hundred and forty seven patients with open angle glaucoma who were receiving the three different strengths of metipranolol (0.1 %, 0.3 %, and 0.6 %) in our Department and the 7 patients who participated in the metipranolol rechallenge trial were included in this study. Out of the 247 patients, there were 52 eyes of 29 patients who showed 78 episodes of ADRs associated with meti pranolol. Forty five of these 78 episodes (57.6%) were associated with loss of lOP control. Two of the 7 eyes treated with metipranolol in the rechallenge trial showed loss of lOP control, 1 of them without any signs of ocular inflammation. We further studied all the glaucomatous eyes controlled with metipranolol 0.6% only and 22 eyes were identified with loss of lOP control but without rec ognisable signs or symptoms of ADR. Five other eyes in this group later developed metipranolol-induced ADRs. The possible pathophysiological mechanisms for the loss of lOP control are discussed and it is suggested that the active drug, metipranolol, could be directly implicated.

Journal of Cataract and Refractive Surgery, Jun 1, 2002

Modeling and Artificial Intelligence in Ophthalmology

Purpose: To analyze and understand the zonular tension and distribution of forces in the presence... more Purpose: To analyze and understand the zonular tension and distribution of forces in the presence of zonular disinsertion in a model simulation with and without a capsular tension ring (CTR). Methods: This study was conducted at Complejo Hospitalario Universitario Albacete, University of Castilla La Mancha, Spain. Twelve load cells were arranged in a circular fashion to simulate the 360 degrees of zonulae in the eye. An elastic band was prestretched in a uniform and radial manner in 12 directions. Force measurements were taken using 12 load cells, uniformly arranged at 30° spacing around the elastic band. Tension was measured at each cell, before and after the simulated zonulardisinsertion. Every clock hour of zonular disinsertion was cycled through all 12 load cells. The tension was evaluated for zonular disinsertion ranging from 0 to 5 clock hours (0° to 150°) with and without a CTR. Results: An increase in zonular tension was recorded in the load cells adjacent to the segments of...

Http Www Libreriasaulamedica Com, 2007

Anillo de tensión capsular abierto para uso oftalmológico de una aleación de níquel-titanio con m... more Anillo de tensión capsular abierto para uso oftalmológico de una aleación de níquel-titanio con memoria de forma y enrollado en espiral, recubierto por una cápsula de un material seleccionado del grupo compuesto por poliácido láctico (PLA), gelatina y celulosa.

Villada JR, Villada-Warrington T, Mompeán-Morales B, Ortega-Usobiaga J. BiometríaIn: Llovet-Osuna F, Ortega-Usobiaga J. Cirugía Refractiva: Protocolos. Madrid: Sociedad Española de Oftalmología; 104-106., Sep 1, 2014

Journal of Cataract and Refractive Surgery, May 1, 1997

To ascertain how many patients in a rural area of Spain would qualify for and choose to have day-... more To ascertain how many patients in a rural area of Spain would qualify for and choose to have day-case cataract surgery. Departmento de Oftalmología, Hospital Comarcal, Hellín, Albacete, Spain. All patients intending to have cataract surgery in 1993 responded to a five-question survey. Only patients answering yes to all five questions were considered candidates for day-case surgery. Thirty-three of 374 patients (9.0%) answered yes to all five questions. Only 7 of the 33 (1.9%) subsequently had day-case surgery. Establishing a day-case cataract surgery, unit in rural areas requires consideration of factors not present in urban areas and may require more time for patient acceptance.

Case Reports in Ophthalmology, Jul 12, 2021

We report a case of ocular injury caused by a bombardier beetle in a young boy. Ocular injuries d... more We report a case of ocular injury caused by a bombardier beetle in a young boy. Ocular injuries due to this coleoptera have not previously been reported. An 11-year-old boy experienced an eye injury while trying to place a bombardier beetle inside an anthill. The boy was diagnosed with a second-degree burn on the skin of the upper right eyelid and conjunctival and corneal erosion in the right eye. The condition resolved completely after 2 weeks of appropriate treatment. Education about the dangers of playing with insects is crucial to prevent this type of lesions.

Journal of Cataract and Refractive Surgery, Feb 1, 2000

also implanted IOLs in eyes in which the position of the retina was thought to be unstable. We ta... more also implanted IOLs in eyes in which the position of the retina was thought to be unstable. We take exception to this approach. Accurate axial length measurement is the most important factor for effective biometry. In an era in which the success of cataract surgery is judged by the refractive outcome, it is no longer acceptable to use approximations such as measurements of the fellow eye. Also, when scleral buckling is done as part of the retinal procedure, the length of the eye may change. The authors used scleral buckling in 4 eyes (10.5%) but do not mention how they estimated postoperative axial length in these cases. Six of the 38 eyes had postoperative refractive errors greater than 2.0 diopters from the target. It would be interesting to know whether the eyes having scleral buckling were in this group. We do not think it advisable to implant an IOL when the retina is thought to be unstable. If further retinal procedures become necessary, the IOL may impede clear visualization of the peripheral retina and make the surgery difficult to the extent that the IOL may have to be explanted. In both these situations, it is better to perform phacoemulsification and a vitreoretinal procedure at 1 sitting and implant the IOL at a secondary procedure, once the retina is stable and accurate biometry can be performed. This is more likely to lead to a stable retina and a better refractive result than that achieved by an all-in-1 procedure. The authors implanted the IOL before intraocular tamponade was performed. We routinely carry out implantation after intraocular gas tamponade and closure of sclerotomies. This allows us to complete the vitreoretinal procedure under optimal visualization before IOL implantation. Implantation is facilitated by slightly underfilling the eye with gas at the completion of the vitrectomy. The IOL can then be placed easily. Finally, the gas is “topped up” using a 30 gauge needle through the pars plana.

Journal of Refractive Surgery, 2004

To assess the effectiveness of optical and ultrasonic pachymetry when examining corneas of patien... more To assess the effectiveness of optical and ultrasonic pachymetry when examining corneas of patients before and after laser in situ keratomileusis (LASIK). We conducted a prospective study of 25 patients (50 eyes) who had LASIK for myopia or myopic astigmatism (mean spherical equivalent refraction -4.80 +/- 3.60 D; range -1.75 to -12.00 D). Corneal thickness was measured using 1) conventional ultrasonic pachymetry (20 MHz probe) in the central cornea, 2) ASL confocal microscopy (CMTF analysis), 3) Orbscan II Analyzer, and 4) ultrasound biomicroscopy (UBM) (50 MHz probe) preoperatively and 3 months postoperatively. Preoperative pachymetry values measured with the Orbscan II Analyzer (551.3 +/- 27.3 microm) were almost identical to those measured with the 20 MHz ultrasonic probe (553.7 +/- 25.7 microm; t-test P = .652). The mean preoperative pachymetry for UBM was 566.7 +/- 38.8 microm and for CMTF was 553.2 +/- 15.5 microm. The optic and ultrasonic system measurements differed in operated eyes; 20 MHz ultrasonic pachymetry yielded an average 478.7 +/- 23.5 microm and the UBM, 482.4 +/- 40.3 microm. These measurements differed from the Orbscan II (Tukey test; P = .023) measurement of 461.1 +/- 37.5 microm but not from the confocal microscopy measurement of 475.2 +/- 41.8 microm. UBM registered greater values that were more variable than those obtained with ultrasonic pachymetry. In non-operated eyes, corneal thickness was similar using conventional ultrasound, Orbscan II, or confocal techniques, with ultrasound biomicroscopy giving thicker readings.

Eye, Jul 1, 1994

A prospective, randomised, double-masked, placebo controlled study was carried out on 169 patient... more A prospective, randomised, double-masked, placebo controlled study was carried out on 169 patients under going cataract extraction to compare the topical anaes thetic cream amethocaine with EMLA (eutetic mixture of local anaesthetic, lignocaine and prilocaine) and placebo in reducing pain during retrobulbar injection. Fifty-eight patients received EMLA, 55 amethocaine and 56 the pla cebo. The pain was assessed objectively by the anaesthe tist and subjectively by the patient. Significantly lower pain scores were observed in those patients who had ame thocaine (p<O.OOl) or EMLA (p<O.005) in comparison with those who had placebo, but there was no statistical difference between amethocaine and EMLA (p>O.I; t-test). No systemic or local side-effects were encountered in any group. Since the introduction of the topical anaesthetic cream EMLA (eutetic mixture of local anaesthetic, lignocaine and prilocaine) into clinical practice, other local anaes thetic agents have been evaluated for topical use. A study comparing a local anaesthetic cream containing ametho caine (Anethaine, Evans) with EMLA found that ame thocaine had a rapid onset of action, longer duration of action and provided equally effective analgesia as EMLA.l With the increasing trend for local anaesthesia in the United Kingdom (retrobulbar, peribulbar or posterior bul bar injections) the need to relieve patient anxiety and pain is important.2 Recently it has been shown that EMLA is effective in relieving the pain of needle puncture of the skin at the time of retrobulbar injection.} We wished, therefore, to compare EMLA cream with amethocaine cream in relieving this pain.

Journal of Cataract and Refractive Surgery, Jul 1, 2001

1. J Cataract Refract Surg. 2001 Jul;27(7):968. Cataract surgery in the nanophthalmic eye. Villad... more 1. J Cataract Refract Surg. 2001 Jul;27(7):968. Cataract surgery in the nanophthalmic eye. Villada JR, Osman AA, Alío JL. Comment on: J Cataract Refract Surg. 2000 Dec;26(12):1702-13. PMID: 11496909 [PubMed - indexed for MEDLINE]. ...

Eye, May 1, 1992

Previously unreported adverse drug reactions can be dif ficult to detect and it may be even more ... more Previously unreported adverse drug reactions can be dif ficult to detect and it may be even more difficult to estab lish a cause and effect relationship, particularly if the adverse reacions mimic naturally occurring disease. In a previous paper we reported 29 patients with granuloma tous anterior uveitis, blepharoconjunctivitis, periorbital dermatitis, marginal keratitis and elevation in intra ocular pressure (lOP), suspected to be caused by meti pranolol (Glauline). With the approval of the District Ethics Committee 7 of those patients were rechallenged with metipranolol 0.3% compared to timolol maleate 0.5% in a double blind trial. The 7 metipranolol treated eyes developed an adverse reaction within 14 days. Meti pranolol (Glauline) has been conclusively proven to cause granulomatous anterior uveitis, blepharoconjunctivitis and elevation in lOP, adverse effects never previously reported with any of the ophthalmic topical beta-block ers. The multi dose preparations of metipranolol (Glau line) in all three strengths 0.1 %,0.3% and 0.6% and the single dose minim preparation of metipranolol 0.6 % have now been withdrawn from clinical use in the United Kingdom.

British Journal of Ophthalmology, May 1, 1992

Ninety seven eyes with anterior chamber implants and a best corrected visual acuity of at least 6... more Ninety seven eyes with anterior chamber implants and a best corrected visual acuity of at least 6/12 were studied, firstly, to compare the predictive accuracies of the commonly used formulas for intraocular lens (IOL) power calculation and, secondly, to determine the effect of optimising the 'A' constant on the predictive accuracies ofthe empirical Sanders-Retzlaff-Kraff (SRK) formulas. The accuracies of the empirical formulas (SRK and SRK II) were generally similar to those of the theoretical formulas (Binkhorst II and Colenbrander-Hoffer). However the original SRK formula was more accurate than the two theoretical formulas in long eyes and in all eyes overall. Optimisation of the 'A' constants did not improve the predictive accuracy of the empirical SRK formulas.

Eye, May 1, 1992

Fifty patients (50 eyes) with posterior chamber intra• ocular lenses and a best corrected visual ... more Fifty patients (50 eyes) with posterior chamber intra• ocular lenses and a best corrected visual acuity of at least 6/12 were studied. The Allergan•Humphrey 570 (AH•570) and Canon RK•l autorefractors were com• pared in terms of ease of operation, time taken and their accuracy relative to clinical refraction. Both the auto• refractors were equally easy to operate but the AH•570 was quicker. The AH•570 had a higher percentage of eyes within 110 of clinically determined cylinder axis while the Canon RK•l had a higher percentage of patients within

British Journal of Ophthalmology, 1991

Automated refraction with the Canon RK-1 Autoref keratometer was evaluated in 85 eyes of 85 patie... more Automated refraction with the Canon RK-1 Autoref keratometer was evaluated in 85 eyes of 85 patients with an anterior chamber intraocular lens implant and a best corrected visual acuity of at least 6/12. Autorefraction readings were obtained in 80 (94%) of these eyes. The agreement between autorefraction and clinical refraction data was 89% for spherical equivalence <0-51 dioptres (D), 91% for sphere power <051 D, 82% for cylinder power <0-51 D, and 91% for cylinder axis <11°. Autorefraction provides acceptably accurate postoperative refraction values in anterior chamber pseudophakia.

Eye, May 1, 1992

Fifty normal subjects were studied comparing objective autorefraction using the Allergan Uumphrey... more Fifty normal subjects were studied comparing objective autorefraction using the Allergan Uumphrey 570 (AU 570) and Canon RK-l autorefractors in terms of ease of operation, the time taken and their accuracy compared with clinical refraction. Both the auto refractors were equally easy to operate but the AU 570 was quicker. Objective autorefraction with the AU 570 was more accu rate than using the Canon RK-l especially with respect to spherical equivalence, sphere power and cyclinder axis: approximately 80% of the values were within 0.51 dioptres or 110 of clinical refraction compared to approximately 60% for the Canon RK-l. The possible reasons for the superior performance of the AU 570 are discussed.

British Journal of Ophthalmology, Sep 1, 1991

This paper presents for the first time documented evidence, clinical details, and photographic il... more This paper presents for the first time documented evidence, clinical details, and photographic illustrations, of metipranololassociated granulomatous anterior uveitis in 26 eyes of 15 patients being treated for glaucoma. There were 56 episodes of granulomatous anterior uveitis, all associated with large (mutton-fat) keratic precipitates, flare, cells, and 'white eyes' (except in seven episodes). In 30 (53.6%) of these episodes there was loss of control of intraocular pressure. Metipranolol 0-6% was implicated in 54 ofthe 56 episodes and metipranolol 0 3% in the remaining two. Fifty-one other cases of metipranolol-associated granulomatous anterior uveitis have so far been reported from other parts of the country to the Committee on Safety of Medicines. As a result multidose metipranolol in 0-1%, 0.3%, and 0-6% strengths has been withdrawn from clinical use in the United Kingdom. The pathogenesis of this adverse drug reaction is uncertain.

Eye, Sep 1, 1992

One hundred and fifty-one eyes with anterior chamber implants and a best corrected visual acuity ... more One hundred and fifty-one eyes with anterior chamber implants and a best corrected visual acuity of at least 6 / 12 were studied to compare the predictive accuracies of the newer generation intraocular lens power calculation for mulae. There was no statistically significant difference between the predictive accuracies of the SRK (Sanders Retzlaff-Kraff), SRK II, SRK / Theoretical (SRK / T) and Holladay formulae. All these four formulae were more accurate than the Binkhorst II formula.

Eye, May 1, 1992

This paper reviews the behaviour of intraocular pressure (lOP) in glaucomatous eyes treated with ... more This paper reviews the behaviour of intraocular pressure (lOP) in glaucomatous eyes treated with metipranolol with and without drug-induced adverse reactions (ADRs). Two hundred and forty seven patients with open angle glaucoma who were receiving the three different strengths of metipranolol (0.1 %, 0.3 %, and 0.6 %) in our Department and the 7 patients who participated in the metipranolol rechallenge trial were included in this study. Out of the 247 patients, there were 52 eyes of 29 patients who showed 78 episodes of ADRs associated with meti pranolol. Forty five of these 78 episodes (57.6%) were associated with loss of lOP control. Two of the 7 eyes treated with metipranolol in the rechallenge trial showed loss of lOP control, 1 of them without any signs of ocular inflammation. We further studied all the glaucomatous eyes controlled with metipranolol 0.6% only and 22 eyes were identified with loss of lOP control but without rec ognisable signs or symptoms of ADR. Five other eyes in this group later developed metipranolol-induced ADRs. The possible pathophysiological mechanisms for the loss of lOP control are discussed and it is suggested that the active drug, metipranolol, could be directly implicated.

Journal of Cataract and Refractive Surgery, Jun 1, 2002

Modeling and Artificial Intelligence in Ophthalmology

Purpose: To analyze and understand the zonular tension and distribution of forces in the presence... more Purpose: To analyze and understand the zonular tension and distribution of forces in the presence of zonular disinsertion in a model simulation with and without a capsular tension ring (CTR). Methods: This study was conducted at Complejo Hospitalario Universitario Albacete, University of Castilla La Mancha, Spain. Twelve load cells were arranged in a circular fashion to simulate the 360 degrees of zonulae in the eye. An elastic band was prestretched in a uniform and radial manner in 12 directions. Force measurements were taken using 12 load cells, uniformly arranged at 30° spacing around the elastic band. Tension was measured at each cell, before and after the simulated zonulardisinsertion. Every clock hour of zonular disinsertion was cycled through all 12 load cells. The tension was evaluated for zonular disinsertion ranging from 0 to 5 clock hours (0° to 150°) with and without a CTR. Results: An increase in zonular tension was recorded in the load cells adjacent to the segments of...

Http Www Libreriasaulamedica Com, 2007

The EuroBiotech Journal

Introduction: The biocompatibility of nitinol in the human body has extensively been demonstrated... more Introduction: The biocompatibility of nitinol in the human body has extensively been demonstrated. Although nitinol is already being used for intraocular surgeries such as lens fragmentation and foreign body extraction, little is known about its intracapsular, long-term behavior. The purpose of this study is to evaluate the long-term uveal and capsular biocompatibility of a nitinol CTR placed in the capsular bag after cataract surgery in an animal model. Method: After approval of the study by the Institutional Animal Care and the Ethics Committee, bilateral phacoemulsification was performed in 6 rabbits; 1 eye received a nitinol CTR and the other a control polymethylmethacrylate (PMMA) open-ended ring. Ophthalmic evaluation for the presence of infections in all 12 eyes was performed after 7 days, 4 weeks, 3 months, and 6 months follow-up period. After a follow-up period of 6 months, the eyes were enucleated, and a histopathologic evaluation was performed. Results: Neither of the gro...