More than 10 Years of Experience with Immediate Sequential Bilateral Cataract Extraction (ISBCE)--A Retrospective Study

Background: To evaluate the safety of immediate sequential bilateral cataract extraction (ISBCE) with respect to indications, visual outcomes, complications, benefits and disadvantages. Methods: This is a retrospective review of all ISBCEs performed at Kantonsspital Winterthur, Switzerland, between April 2000 and September 2013. The case notes of 500 eyes of 250 patients were reviewed. Of these 500 eyes, 472 (94.4%) had a straight forward phacoemulsification with posterior chamber intraocular lens implantation;21 (4.2%) had a planned extracapsular cataract extraction;4 (0.8%) had an intracapsular cataract extraction and 3 (0.6%) had a combined phacoemulsification with trabeculectomy. Results: Over 66% of eyes achieved improved visual acuity (at least 3 Snellen lines) following ISBCE. Median preoperative best corrected visual acuity (BCVA) was 0.5 LogMAR;the interquartile range was [0.4, 1] LogMAR. At one week control the median BCVA was 0.3 LogMAR, IQR [0.1, 0.5] LogMAR. At one month the median BCVA was 0.15 LogMAR, IQR [0.05, 0.3] (p < 0.01). There were no sight-threatening intraoperative or postoperative complications observed. Conclusions: ISBCE is an effective and safe option with high degree of patient satisfaction. The relative benefits of ISBCE should be balanced against the theoretically enhanced risks.

Identifying more reliable parameters for the detection of change during the follow-up of mild to moderate keratoconus patients

Background:Reaching a consensus on which parameters are most reliable at detecting progressive keratoconus patients with serial topography imaging is not evident.The aim of the study was to isolate the parameters best positioned to detect keratoconus progression using the Pentacam HR^(®)measures based on the respective limits of repeatability and range of measurement.Method:Using the Pentacam HR^(®),a tolerance index was calculated on anterior segment parameters in healthy and keratoconic eyes.The tolerance index provides a scale from least to most affected parameters in terms of measurement noise relative to that observed in healthy eyes.Then,based on the“number of increments”from no disease to advanced disease,a relative utility(RU)score was also calculated.RU values close to 1 indicate parameters best positioned to detect a change in keratoconic eyes.Results:The tolerance index values indicated that 36%of ocular parameters for keratoconic eyes had repeatability limits which were wider than normative limits(worse),but 28%of the ocular parameters were narrower than normative limits(better).Considering only those parameters with a RU greater than 0.95,a small number of parameters were within this range,such as corneal curvature and asphericity indices.Conclusions:This study demonstrates that measurement error in keratoconic eyes is significantly greater than healthy eyes.Indices implemented here provide guidance on the levels of expected precision in keratoconic eyes relative to healthy eyes to aid clinicians in distinguishing real change from noise.Importantly maximal keratometry(Kmax),central corneal thickness(CCT)and thinnest corneal thickness(TCT)were highlighted as problematic indices for the follow-up of keratoconus in terms of repeatability.

Predictability of refraction following immediate sequential bilateral cataract surgery(ISBCS)performed under general anaesthesia

Background:To evaluate the predictability of refraction following immediate sequential bilateral cataract surgery(ISBCS)performed under general anaesthesia.Methods:This is a retrospective review of all ISBCS performed at Kantonsspital Winterthur,Switzerland,between April 2000 and September 2013.The case notes of 250 patients were reviewed.Patients having full refraction reported(110 patients/220 eyes)were included.210(95%)eyes had a straight forward phacoemulsification with posterior chamber intraocular lens implantation,seven eyes had a planned extracapsular cataract extraction(ECCE);three eyes had an intracapsular cataract extraction.Results:Both eyes of 110 patients(64 women,46 men)with a mean age of 79.0 years,standard deviation(SD)±11.4(range 26 to 97 years)were included.Median preoperative best corrected visual acuity(BCVA)was 0.5 LogMAR in the first eye,the interquartile range(IQR)was[0.4,1.2];0.7 LogMAR in the second eye with IQR[0.4,1.8].At one month,the median BCVA was 0.2 LogMAR,IQR[0.1,0.3]in the first eye,median BCVA was 0.1 LogMAR and IQR[0.0,0.5]in the second eye.There were 3 eyes(3%)that lost 3 lines or more in BCVA at one month(control vs.pre-operatively).In all three cases,poor visual acuity had been recorded pre-operatively(>1 LogMAR).Achieved refraction was within±1.0 D of the target in 83%of eyes.There were only 5%(n=6)of cases where if delayed sequential bilateral extraction had been performed could potentially intraocular lens(IOL)choice have been adjusted,in four of these cases,target refraction was within±1.0 D in the second eye.Conclusions:ISBCS performed under general anaesthesia achieves target refraction in 83%of eyes after consideration of complications,ocular co-morbidities and systemic restrictions.In the majority of cases where IOL power calculation could be considered,the achieved refraction of the second surgical eye was within±1.0 D of intended refraction.This undermines the utility of IOL power adjustments in the second surgical eye.