Astigmatic equivalence of 2.2-mm and 1.8-mm superior clear corneal cataract incision.

PURPOSE: To evaluate the astigmatic effects of 2.2-mm and 1.8-mm cataract incisions. METHODS: A randomized prospective study of 190 eyes of 151 patients undergoing superior clear corneal incision (SCCI) was divided into three groups: 61 eyes with a control 3.2-mm SCCI; 66 eyes with a 2.2-mm SCCI; and 63 eyes with a 1.8-mm SCCI. The corneal astigmatism was measured with an autokeratometer preoperatively and 1 month after surgery. The with-the-wound (WTW), against the-wound (ATW), and WTW-ATW changes were calculated using the Holladay-Cravy-Koch formula. RESULTS: The WTW, ATW, and WTW-ATW changes were significantly higher for the control 3.2-mm SCCI than for the 2.2- and 1.8-mm SCCI (all p < 0.001), and no difference was found between the 2.2- and 1.8-mm SCCI incision groups. CONCLUSION: In our study, the astigmatic effects were the same for the 2.2 mm and 1.8 mm incisions and as expected, were significantly lower than the control 3.2 mm incision group.

Effect of preterm birth on blood pressure in later life: A systematic review and meta-analysis.

Introduction: Preterm birth is linked to various complications in both infancy and adulthood. We assessed the association between preterm birth and hypertension in adulthood. Materials and Methods: PubMed, EMBASE, and Cochrane CENTRAL Register were searched for randomized controlled trials (RCT) comparing systolic and diastolic blood pressures in individuals born preterm and those born full-term, from inception till April 11th, 2022. Data were extracted, pooled, and analyzed. Forest plots were created for a visual demonstration. Results: Twenty-eight studies were included in our meta-analysis. SBP and DBP across all categories (Mean, Ambulatory, Daytime, and Nighttime) were higher in the preterm group compared to the term group. Mean SBP, mean ambulatory SBP, mean daytime SBP and mean nighttime SBP were 4.26 mmHg [95% CI: 3.09-5.43; P < 0.00001], 4.53 mmHg [95% CI: 1.82-7.24; P = 0.001], 4.51 mmHg [95% CI: 2.56-6.74; P < 0.00001], and 3.06 mmHg [95% CI: 1.32-4.80; P = 0.0006] higher in the preterm group, respectively. Mean DBP, mean ambulatory DBP, mean daytime DBP, and mean nighttime DBP were 2.32 mmHg [95% CI: 1.35-3.29; P < 0.00001], 1.54 mmHg [95% CI 0.68-2.39; P = 0.0004], 1.74 mmHg [95% CI: 0.92-2.56; P < 0.0001], and 1.58 mmHg [95% CI: 0.34-2.81; P = 0.01] higher in the preterm group, respectively. Conclusion: Our observations suggest that individuals who were born preterm may have higher blood pressures as compared to those who were born full-term.

Correction of high astigmatism: case studies using the mixed-cylinder approach.

PURPOSE: To explain the use of the mixed-cylinder approach in treating moderate to high astigmatism with the NIDEK EC-5000 excimer laser system. METHODS: Retrospective case series report. RESULTS: Three patients with bilateral moderate to high astigmatism were treated successfully using the mixed cylinder approach. CONCLUSIONS: The use of the mixed-cylinder approach with the NIDEK EC-5000 excimer laser may be a safe and predictable option for treating moderate to high astigmatism.

Reversibility and exchangeability of intrastromal corneal ring segments.

PURPOSE: To evaluate the effect of removal and/or exchange of intrastromal corneal ring segments (ICRS, Intacs); specifically the risk factors, degree of reversibility, and visual outcomes. SETTING: Gimbel Eye Centres, Calgary, Edmonton, and Vancouver, Canada. METHODS: Prospective cohort data were collected on 71 eyes that had ICRS placement by 3 surgeons at the Gimbel Eye Centres between August 1998 and July 1999. Data included patient symptoms, best spectacle-corrected visual acuity, uncorrected visual acuity (UCVA), manifest refraction, reason for removal or replacement, keratometry, corneal topography, and complications. RESULTS: Twenty-four eyes (33.8%) had exchange or removal procedures because of underresponse, 20 eyes; overresponse, 2 eyes; and induced astigmatism and shallow placement, 1 eye each. Secondary procedures were removal and replacement, removal with subsequent laser in situ keratomileusis, and segment repositioning. Two risk factors for secondary surgery were identified: high preoperative refractive astigmatism and postoperative spherical equivalent greater than +/-0.5 diopter (D). The 6 eyes that had ICRS removal stabilized to within +/-0.25 D of the original refractive error with no surgically induced astigmatism within 1 to 7 weeks (mean 4 weeks) and had a final UCVA of 20/20 or better. In the 15 eyes that had ICRS exchange procedures, the UCVA improved by at least 1 line and median UCVA improved from 20/40 to 20/20. CONCLUSION: Preliminary data from this study indicate that removal of segments resulted in reversal of the refractive effect.

Detection of static cyclotorsion and compensation for dynamic cyclotorsion in laser in situ keratomileusis.

PURPOSE: To evaluate the degree of static and dynamic cyclotorsion using a rotational eye tracker in laser in situ keratomileusis (LASIK) to correct myopic astigmatism. SETTING: Rothschild Foundation, Paris, France. DESIGN: Cohort study. METHODS: Laser in situ keratomileusis with active iris registration using a Zyoptix 100 Hz excimer laser with Advanced Control Eyetracking was performed in eyes with myopic astigmatism. In all cases, iris registration was used to evaluate the degree of static cyclotorsion preoperatively and the degree of dynamic cyclotorsion and intraoperatively. The direction, mean values, and ranges of static and dynamic cyclotorsion were recorded. The amplitude of intraoperative cyclotorsion was reported. RESULTS: The study included 74 consecutive eyes (38 patients). The direction of cyclotorsion was not statistically significant. The mean static cyclotorsion was 3.08 degrees ± 2.68 (SD) (range -7.0 to 14.0 degrees) and the mean dynamic cyclotorsion, 3.39 ± 2.94 degrees (range -10.3 to 13.5 degrees). During photoablation, the mean amplitude of cyclotorsion was 2.69 ± 1.63 degrees (range 0.0 to 9.2 degrees). The magnitude of dynamic cyclotorsion was less than 5 degrees in 66% of eyes, 5 degrees or more in 34% of eyes, and 10 degrees or more in 4% of eyes. CONCLUSIONS: Static and dynamic cyclotorsion was detected with a dynamic eye tracker in eyes having LASIK. Rotational movements were mainly static but had significant amplitude during photoablation.