Biocompatibility of intraocular lens power adjustment using a femtosecond laser in a rabbit model

Posted Posted in Cataracts and Cataract Surgery

Biocompatibility, intraocular lens, power adjustment, femtosecond laser

2017 Aug;43(8):1100-1106. doi: 10.1016/j.jcrs.2017.05.040.

Biocompatibility of intraocular lens power adjustment using a femtosecond laser in a rabbit model.

Abstract

PURPOSE:

To evaluate the biocompatibility (uveal and capsular) of intraocular lens (IOL) power adjustment by a femtosecond laser obtained through increased hydrophilicity of targeted areas within the optic, creating the ability to build a refractive-index shaping lens within an existing IOL.

SETTING:

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

DESIGN:

Experimental study.

METHODS:

Six rabbits had phacoemulsification with bilateral implantation of a commercially available hydrophobic acrylic IOL. The postoperative power adjustment was performed 2 weeks after implantation in 1 eye of each rabbit. The animals were followed clinically for an additional 2 weeks and then killed humanely. Their globes were enucleated and bisected coronally just anterior to the equator for gross examination from the Miyake-Apple view to assess capsular bag opacification. After IOL explantation for power measurements, the globes were sectioned and processed for standard histopathology.

RESULTS:

Slitlamp examinations performed after the laser treatments showed the formation of small gas bubbles behind the lenses that disappeared within a few hours. No postoperative inflammation or toxicity was observed in the treated eyes, and postoperative outcomes and histopathological examination results were similar to those in untreated eyes. The power measurements showed that the change in power obtained was consistent and within ±0.1 diopter of the target.

CONCLUSIONS:

Consistent and precise power changes can be induced in the optic of commercially available IOLs in vivo by using a femtosecond laser to create a refractive-index shaping lens. The laser treatment of the IOLs was biocompatible.

 

Biocompatibility, intraocular lens, power adjustment, femtosecond laser

 

PMID:
28917413
DOI:
10.1016/j.jcrs.2017.05.040

Cataract Study II: reducing complications by preoperative risk stratification and case allocation

Posted Posted in Cataracts and Cataract Surgery
Cataract , complications, teaching hospital
2017 Jun 27. pii: S0002-9394(17)30259-3. doi: 10.1016/j.ajo.2017.06.014. [Epub ahead of print]

The Auckland Cataract Study II: reducing complications by preoperative risk stratification and case allocation in a teaching hospital.

Abstract

PURPOSE:

To assess the effect of preoperative risk stratification for phacoemulsification surgery on intraoperative complications in a teaching hospital. Design; Prospective cohort study.

METHODS:

Prospective assessment of consecutive phacoemulsification cases (N=500) enabled calculation of a risk score (M-score of 0-8) using a risk stratification system (Muhtaseb et al). M-scores of >3 were allocated to senior surgeons. All surgeries were performed in a public teaching hospital setting, Auckland, New Zealand, in early 2016. Post-operatively data were reviewed for complications and corrected distance visual acuity (CDVA). Results were compared to a prospective study (N=500, Phase 1) performed prior to formal introduction of risk stratification.

RESULTS:

Intraoperative complications increased with increasing M-scores (P=0.044). Median M-score for complicated cases was higher (P=0.022). Odds ratio for a complication increased 1.269 per unit increase in M-score (95% CI 1.007-1.599, P=0.043). Overall rate of any intraoperative complication was 5.0%. Intraoperative complication rates decreased from 8.4% to 5.0% (OR=0.576, P=0.043) comparing Phase 1 and Phase 2 (formal introduction of risk stratification). The severity of complications also reduced. A significant decrease in complications for M=0 (i.e. minimal risk cases) was also identified comparing the current study (3.1%) to Phase 1 (7.2%) P=0.034. There was no change in postoperative complication risks (OR 0.812, P=0.434) or in mean postoperative CDVA (20/30, P=0.484) comparing current with Phase 1 outcomes.

CONCLUSION:

A simple preoperative risk stratification system, based on standard patient information gathered at preoperative consultation, appears to reduce intraoperative complications and support safer surgical training by appropriate allocation of higher risk cases.

PMID:
28666731
DOI:
10.1016/j.ajo.2017.06.014

Evaluating structural progression of retinitis pigmentosa after cataract surgery

Posted Posted in Cataracts and Cataract Surgery, Retina

cataract surgery, ellipsoid zone, optical coherence tomography, phacoemulsification, posterior subcapsular cataract, retinitis pigmentosa, visual acuity

2017 Jun 7. pii: S0002-9394(17)30238-6. doi: 10.1016/j.ajo.2017.05.026. [Epub ahead of print]

Evaluating structural progression of retinitis pigmentosa after cataract surgery.

Abstract

PURPOSE:

To determine whether cataract surgery accelerates disease progression in retinitis pigmentosa (RP).

DESIGN:

Retrospective cohort study.

METHODS:

Seventy eyes of 40 patients with RP were categorized as having had phacoemulsification with intraocular lens implantation versus no cataract surgery at a single tertiary-level institution. Spectral domain optical coherence tomography (SD-OCT) was used to measure the ellipsoid zone (EZ) width, which has been demonstrated to be a reliable marker of RP severity, at baseline and throughout follow-up (median 768 days). RP progression was calculated as the loss of EZ width over time for all patients. Additional post-operative data was collected for the cataract surgery group, including pre- and post-operative best-corrected visual acuity, incidence of macular edema, posterior capsular opacification, epiretinal membrane, and intraocular lens subluxation.

RESULTS:

Multivariable analysis including age, baseline EZ width, mode of inheritance, and cataract surgery status showed that there was no significant difference in RP progression between the cataract surgery and control groups (P=0.23). Mode of inheritance was associated with RP progression, with autosomal recessive RP progressing at 148 microns/year and autosomal dominant RP progressing at 91 microns/year (P=0.003). Visual acuity improved in almost all eyes that underwent surgery (17/19, 89%), and remained stable in remaining eyes (2/19, 11%). There was a high incidence of post-surgical posterior capsular opacification (18/19, 95%). There were no serious complications such as lens subluxation or endophthalmitis.

CONCLUSIONS:

Our findings suggest that cataract surgery is a safe and effective means of improving visual acuity in RP patients and that it does not seem to be associated with faster disease progression as measured using SD-OCT.

KEYWORDS:

IS/OS; cataract surgery; ellipsoid zone; optical coherence tomography; phacoemulsification; posterior subcapsular cataract; retinitis pigmentosa; visual acuity

PMID:
28601586
DOI:
10.1016/j.ajo.2017.05.026
cataract surgery, ellipsoid zone, optical coherence tomography, phacoemulsification, posterior subcapsular cataract, retinitis pigmentosa, visual acuity
Retinitis pigmentosa example not from article

Four-year Follow-up of the Changes in Anterior Segment After Phakic Collamer Lens Implantation

Posted Posted in Cataracts and Cataract Surgery, cornea
Anterior segment, phakic, collamer, lens implantation
Am J Ophthalmol. 2017 Jun;178:140-149. doi: 10.1016/j.ajo.2017.03.020. Epub 2017 Mar 23.

Four-year Follow-up of the Changes in Anterior Segment After Phakic Collamer Lens Implantation.

Author information

 Anterior segment, phakic, collamer, lens implantation

Abstract

PURPOSE:

To assess the changes and relationship in central vaulting, flare intensity, and crystalline lens thickness during a follow-up period of 4 years after implantable collamer lens (ICL) implantation in eyes with high myopia.

DESIGN:

Retrospective observational study.

METHODS:

Ninety-eight eyes of 50 patients were followed up with routine measurements of central vaulting, crystalline lens thickness, endothelial cell density, and aqueous flare postoperatively. Data were analyzed by repeated-measures analysis of variance. The relationship between the annual change in crystal lens thickness after surgery and age was evaluated by Pearson correlation coefficient and linear regression.

RESULTS:

There was a continuous reduction in central vaulting and endothelial cell density as well as an increase in crystalline lens thickness in ICL eyes from 1 month onward to 5 years postoperatively (P < .001). Although the trend of variation during the individual visit period was accentuated, the variation turned out to be smaller between 12 and 36 months or 60 months postoperatively (P = .42, P = .65). Aqueous flare intensity increased significantly after surgery and returned to normal 1 year later. Additionally, a positive correlation between patient age and crystalline lens thickness (r = 0.617, P < .0001) was observed in eyes with ICL implantation.

CONCLUSIONS:

The changes in central vaulting, endothelial cell density, and crystalline lens thickness are more prominent during the first year after ICL implantation, tending to be relatively stable afterwards. The anterior inflammation during the early postoperative period synchronizes with the sharp progression of crystalline lens changes within the first year.

Anterior segment, phakic, collamer, lens implantation
Not from article but Anterior segment, phakic, collamer, lens implantation

Impact of First Eye versus Second Eye Cataract Surgery on Visual Function and Quality of Life

Posted Posted in Cataracts and Cataract Surgery
Cataract surgery, visual function, quality life
Ophthalmology. 2017 May 16. pii: S0161-6420(16)30787-4. doi: 10.1016/j.ophtha.2017.04.014. [Epub ahead of print]

Impact of First Eye versus Second Eye Cataract Surgery on Visual Function and Quality of Life.

Abstract

PURPOSE:

To compare the impact of first eye versus second eye cataract surgery on visual function and quality of life.

DESIGN:

Cohort study.

PARTICIPANTS:

A total of 328 patients undergoing separate first eye and second eye phacoemulsification cataract surgeries at 5 veterans affairs centers in the United States. Patients with previous ocular surgery, postoperative endophthalmitis, postoperative retinal detachment, reoperation within 30 days, dementia, anxiety disorder, hearing difficulty, or history of drug abuse were excluded.

METHODS:

Patients received complete preoperative and postoperative ophthalmic examinations for first eye and second eye cataract surgeries. Best-corrected visual acuity (BCVA) was measured 30 to 90 days preoperatively and postoperatively. Patients completed the National Eye Institute Visual Functioning Questionnaire (NEI-VFQ) 30 to 90 days preoperatively and postoperatively. The NEI-VFQ scores were calculated using a traditional subscale scoring algorithm and a Rasch-refined approach producing visual function and socioemotional subscale scores.

MAIN OUTCOME MEASURES:

Postoperative NEI-VFQ scores and improvement in NEI-VFQ scores comparing first eye versus second eye cataract surgery.

RESULTS:

Mean age was 70.4 years (±9.6 standard deviation [SD]). Compared with second eyes, first eyes had worse mean preoperative BCVA (0.55 vs. 0.36 logarithm of the minimum angle of resolution (logMAR), P < 0.001), greater mean BCVA improvement after surgery (-0.50 vs. -0.32 logMAR, P < 0.001), and slightly worse postoperative BCVA (0.06 vs. 0.03 logMAR, P = 0.039). Compared with first eye surgery, second eye surgery resulted in higher postoperative NEI-VFQ scores for nearly all traditional subscales (P < 0.001), visual function subscale (-3.85 vs. -2.91 logits, P < 0.001), and socioemotional subscale (-2.63 vs. -2.10 logits, P < 0.001). First eye surgery improved visual function scores more than second eye surgery (-2.99 vs. -2.67 logits, P = 0.021), but both first and second eye surgeries resulted in similar improvements in socioemotional scores (-1.62 vs. -1.51 logits, P = 0.255).

CONCLUSIONS:

Second eye cataract surgery improves visual function and quality of life well beyond levels achieved after first eye cataract surgery alone. For certain socioemotional aspects of quality of life, second eye cataract surgery results in comparable improvement to first eye cataract surgery.

Comparison of 2 pupil expansion devices for small-pupil cataract surgery.

Posted Posted in Cataracts and Cataract Surgery
Comparison,pupil expansion devices,small pupil, cataract surgery
J Cataract Refract Surg. 2016 Aug;42(8):1235-7. doi: 10.1016/j.jcrs.2016.07.002.

Comparison of 2 pupil expansion devices for small-pupil cataract surgery.

Abstract

We compared the degree of postoperative iris distortion with the diamond-shaped Malyugin ring and the circular Visitec I-Ring iris dilators using postoperative iris photographs in a patient with bilateral small nondilating pupils. Routine phacoemulsification was performed in the right eye with the assistance of a Malyugin ring for iris dilation. One month later, the same procedure was performed in the left eye using the circular ring for iris dilation. Anterior chamber slitlamp photographs were taken of both eyes. The amount of distortion in the postoperative pupils was calculated using the ratio of the postoperative pupil area to the area of the circle of best fit. The circular ring, constructed from a softer material, resulted in 11% distortion and the Malyugin ring, 49%, suggesting that the circular ring caused less trauma to the iris.

Comparison of 2 pupil expansion devices for small-pupil cataract surgery.

Abstract

We compared the degree of postoperative iris distortion with the diamond-shaped Malyugin ring and the circular Visitec I-Ring iris dilators using postoperative iris photographs in a patient with bilateral small nondilating pupils. Routine phacoemulsification was performed in the right eye with the assistance of a Malyugin ring for iris dilation. One month later, the same procedure was performed in the left eye using the circular ring for iris dilation. Anterior chamber slitlamp photographs were taken of both eyes. The amount of distortion in the postoperative pupils was calculated using the ratio of the postoperative pupil area to the area of the circle of best fit. The circular ring, constructed from a softer material, resulted in 11% distortion and the Malyugin ring, 49%, suggesting that the circular ring caused less trauma to the iris.

Cataract Surgery on the Previous Corneal Refractive Surgery Patient

Posted Posted in Cataracts and Cataract Surgery
Cataract Surgery, Refractive surgery, Lasik, RK, Complications
Surv Ophthalmol. 2016 Jul 13. pii: S0039-6257(15)30064-3. doi: 10.1016/j.survophthal.2016.07.001. [Epub ahead of print]

Cataract Surgery on the Previous Corneal Refractive Surgery Patient.

Abstract

Cataract surgery in cases with previous corneal refractive surgery may be a major challenge for the ophthalmologist. The refractive outcome of the case deserves special attention in the preoperative planning process, which should be tailored for the type of prior refractive procedure: incisional, ablative under a flap, or on the corneal surface. Avoiding refractive surprise after cataract surgery in these cases is principally dependent upon the accuracy of the IOL calculation, together with the selection of the appropriate biometric formula for each case. Modern techniques for cataract surgery help surgeons to move towards the goal of cataract surgery as a refractive procedure free from refractive error. We give practical guidelines for the cataract surgeon in the management of these challenging cases.

Abstract

Cataract surgery in cases with previous corneal refractive surgery may be a major challenge for the ophthalmologist. The refractive outcome of the case deserves special attention in the preoperative planning process, which should be tailored for the type of prior refractive procedure: incisional, ablative under a flap, or on the corneal surface. Avoiding refractive surprise after cataract surgery in these cases is principally dependent upon the accuracy of the IOL calculation, together with the selection of the appropriate biometric formula for each case. Modern techniques for cataract surgery help surgeons to move towards the goal of cataract surgery as a refractive procedure free from refractive error. We give practical guidelines for the cataract surgeon in the management of these challenging cases.

Avoiding refractive surprise after cataract surgery in these cases is principally dependent upon the accuracy of the IOL calculation, together with the selection of the appropriate biometric formula for each case. Modern techniques for cataract surgery help surgeons to move towards the goal of cataract surgery as a refractive procedure free from refractive error. We give practical guidelines for the cataract surgeon in the management of these challenging cases

Annular Salzmann degeneration: Avoiding perturbations and pitfalls in phacoemulsification surgery.

Posted Posted in Cataracts and Cataract Surgery, cornea
Salzmann degeneration,phacoemulsification surgery.
J Cataract Refract Surg. 2015 Nov;41(11):2580-3. doi: 10.1016/j.jcrs.2015.10.037.

Annular Salzmann degeneration: Avoiding perturbations and pitfalls in phacoemulsification surgery.

Abstract

We highlight potential problems and pitfalls in cases of Salzmann nodular degeneration by reporting the case of an 84-year-old man with reduced visual acuity due to particularly extensive bilateral Salzmann nodules and moderate cataracts. Large annular Salzmann lesions were removed by superficial keratectomy in each eye. The reproducibility and accuracy of keratometry and biometry improved significantly, and uneventful phacoemulsification cataract surgery was performed 4 weeks after the keratectomy. The phacoemulsification procedures were routine other than the development of pronounced epithelial bullae in the area of Salzmann nodule excision. At final review, the uncorrected distance visual acuity was 20/20 in the right eye and 20/25 in the left eye.

J Cataract Refract Surg. 2015 Nov;41(11):2580-3. doi: 10.1016/j.jcrs.2015.10.037.

Annular Salzmann degeneration: Avoiding perturbations and pitfalls in phacoemulsification surgery.

Abstract

We highlight potential problems and pitfalls in cases of Salzmann nodular degeneration by reporting the case of an 84-year-old man with reduced visual acuity due to particularly extensive bilateral Salzmann nodules and moderate cataracts. Large annular Salzmann lesions were removed by superficial keratectomy in each eye. The reproducibility and accuracy of keratometry and biometry improved significantly, and uneventful phacoemulsification cataract surgery was performed 4 weeks after the keratectomy. The phacoemulsification procedures were routine other than the development of pronounced epithelial bullae in the area of Salzmann nodule excision. At final review, the uncorrected distance visual acuity was 20/20 in the right eye and 20/25 in the left eye.

Abstract

We highlight potential problems and pitfalls in cases of Salzmann nodular degeneration by reporting the case of an 84-year-old man with reduced visual acuity due to particularly extensive bilateral Salzmann nodules and moderate cataracts. Large annular Salzmann lesions were removed by superficial keratectomy in each eye. The reproducibility and accuracy of keratometry and biometry improved significantly, and uneventful phacoemulsification cataract surgery was performed 4 weeks after the keratectomy. The phacoemulsification procedures were routine other than the development of pronounced epithelial bullae in the area of Salzmann nodule excision. At final review, the uncorrected distance visual acuity was 20/20 in the right eye and 20/25 in the left eye.

Removal of intracameral metallic foreign body by encapsulation with an intraocular lens injector

Posted Posted in Cataracts and Cataract Surgery
metallic foreign body,intraocular lens injector
J Cataract Refract Surg. 2015 Dec;41(12):2605-8. doi: 10.1016/j.jcrs.2015.10.046.

Removal of intracameral metallic foreign body by encapsulation with an intraocular lens injector.

Abstract

We describe a technique in which a metallic foreign body in the anterior chamber is safely removed by encapsulation with an intraocular lens (IOL) injector instead of with a forceps or a magnet. A forceps sometimes provides inadequate grip over an intraocular foreign body and requires a large incision, which may damage the surrounding tissue. A magnet is an alternative to a forceps; however, magnets are ineffective in removing nonmagnetic foreign bodies and are seldom available in every operating room. We propose that the IOL injector can be used as an effective tool for extracting both magnetic and nonmagnetic intracameral foreign bodies

J Cataract Refract Surg. 2015 Dec;41(12):2605-8. doi: 10.1016/j.jcrs.2015.10.046.

Removal of intracameral metallic foreign body by encapsulation with an intraocular lens injector.

Abstract

We describe a technique in which a metallic foreign body in the anterior chamber is safely removed by encapsulation with an intraocular lens (IOL) injector instead of with a forceps or a magnet. A forceps sometimes provides inadequate grip over an intraocular foreign body and requires a large incision, which may damage the surrounding tissue. A magnet is an alternative to a forceps; however, magnets are ineffective in removing nonmagnetic foreign bodies and are seldom available in every operating room. We propose that the IOL injector can be used as an effective tool for extracting both magnetic and nonmagnetic intracameral foreign bodies

J Cataract Refract Surg. 2015 Dec;41(12):2605-8. doi: 10.1016/j.jcrs.2015.10.046.

Abstract

We describe a technique in which a metallic foreign body in the anterior chamber is safely removed by encapsulation with an intraocular lens (IOL) injector instead of with a forceps or a magnet. A forceps sometimes provides inadequate grip over an intraocular foreign body and requires a large incision, which may damage the surrounding tissue. A magnet is an alternative to a forceps; however, magnets are ineffective in removing nonmagnetic foreign bodies and are seldom available in every operating room. We propose that the IOL injector can be used as an effective tool for extracting both magnetic and nonmagnetic intracameral foreign bodies

Injectable suture device for intraocular lens fixation

Posted Posted in Cataracts and Cataract Surgery
Injectable suture,intraocular lens fixation
J Cataract Refract Surg. 2015 Dec;41(12):2609-13. doi: 10.1016/j.jcrs.2015.11.013.

Injectable suture device for intraocular lens fixation.

Abstract

We describe a surgical technique for scleral fixation of a posterior chamber intraocular lens (PC IOL) using a 24-gauge injectable polypropylene suture delivery system. A 3-piece PC IOL is inserted into the anterior chamber of the eye. Two sclerotomies are made 1.5 mm posterior to the limbus using a microvitreoretinal blade. The 24-gauge injector delivers a preformed suture loop into the eye with the double-armed needles still external to the eye. Each polypropylene IOL haptic is directed through the loop using microforceps. The suture loop is tightened around the haptic, and the attached needles are used to fixate the IOL to the sclera and close the sclerotomies simultaneously. This technique has been used in an ex vivo porcine eye and in an aphakic patient. In the latter, the IOL was quickly fixated to the sclera and maintained a stable position postoperatively.

J Cataract Refract Surg. 2015 Dec;41(12):2609-13. doi: 10.1016/j.jcrs.2015.11.013.

Injectable suture device for intraocular lens fixation.

Abstract

We describe a surgical technique for scleral fixation of a posterior chamber intraocular lens (PC IOL) using a 24-gauge injectable polypropylene suture delivery system. A 3-piece PC IOL is inserted into the anterior chamber of the eye. Two sclerotomies are made 1.5 mm posterior to the limbus using a microvitreoretinal blade. The 24-gauge injector delivers a preformed suture loop into the eye with the double-armed needles still external to the eye. Each polypropylene IOL haptic is directed through the loop using microforceps. The suture loop is tightened around the haptic, and the attached needles are used to fixate the IOL to the sclera and close the sclerotomies simultaneously. This technique has been used in an ex vivo porcine eye and in an aphakic patient. In the latter, the IOL was quickly fixated to the sclera and maintained a stable position postoperatively.