Transient increase of higher-order aberrations after lateral rectus recession in children

Refractive Changes After Horizontal Strabismus Surgery

PURPOSE

To investigate the changes in refractive status after surgery in patients with horizontal strabismus and high refractive error.

METHODS

This was a prospective study of patients with horizontal strabismus and high refractive error. The patients were divided into a horizontal rectus recession group (group 1) and a horizontal rectus recession combined with horizontal rectus resection group (group 2). The postoperative follow-up duration was 3 months. The refractive status of the patients was evaluated at each postoperative examination, and the refractive changes in the two groups were compared.

RESULTS

The spherical equivalent in group 1 changed by -0.26 D at 3 months postoperatively relative to the preoperative value (p = 0.078), indicating gradual progression toward myopia over time, but the difference was not significant; however, the postoperative cylinder in group 1 significantly increased by 0.34 D at 3 months postoperatively relative to the preoperative value (p = 0.03). The spherical equivalent in group 2 also indicated progression toward myopia; compared with the preoperative value, the spherical equivalent significantly decreased by -0.28 D (p = 0.019) at 1 month postoperatively and decreased by -0.21 D at 3 months postoperatively. The regression line drawn among the points also indicated a progression in the spherical equivalent toward myopia. In group 2, the cylinder increased by 0.30 D (p = 0.004) from the preoperative level at 1 month postoperatively, peaked, then decreased by 3 months postoperatively.

CONCLUSIONS

Patients with high refractive error who undergo horizontal strabismus correction will experience myopic shift. Patients who undergo rectus recession surgery should be fully informed of the possibility of changes in astigmatism preoperatively. For patients who undergo horizontal rectus recession combined with horizontal rectus resection, it is not recommended that glasses be changed within 1 month after surgery.

Evaluation of aberrometry changes following strabismus surgery in patients with horizontal strabismus

BACKGROUND

The aim is to investigate the change in aberrations following strabismus surgery in patients with horizontal strabismus.

MATERIALS AND METHODS

This prospective study included patients who underwent surgery for horizontal strabismus. The patients were assessed preoperatively and 1 month and 3 months after the surgery, in terms of logMAR best-corrected visual acuity, eye deviation, spherical equivalent refractive error, tomographic and aberrometric corneal changes. Corneal tomography was performed using Orbscan II device. Wavefront analyses were performed using Bausch and Lomb Zywave II.

RESULTS

A total of 25 patients (48 eyes) with exotropia or esotropia were entered in this study. Mean values of exotropia in the distance and near deviations were reported as 31.42 ± 7.13 and 28.82 ± 6.96 prism diopters (PD), respectively. Mean scores of esotropia in the distance and near deviations were 25.22 ± 5.41 and 30.45 ± 9.4 PD, respectively. Evaluation of irregularity in 5 mm zone, horizontal coma, spherical aberration changes, and root mean square of higher-order aberrations (HOAs) in 6 mm, and HOA w/o Z 400 changes showed that there was a significant difference before the intervention and 1 month after the surgery (P < 0.05). However, no difference was observed in the aforementioned variables before and 3 months after the intervention (P > 0.05).

CONCLUSIONS

Results of the present study indicated a transient increase in HOAs and corneal irregularity following strabismus surgery on horizontal eye muscles that returned to the baseline after 3 months.

Analysis of the Changes and Possible Reasons in Aberrations before and after Surgery in Patients with Concomitant Exotropia

Objective. The objective is to observe the changes in aberrations before and after surgery in patients with common horizontal strabismus and to analyze the possible reasons for the changes. Methods. Forty eyes of 40 cases with concomitant exotropia who underwent strabismus correction at the Ophthalmology Department of Nantong University Hospital from October 2020 to July 2021 were included in this study, all of whom underwent unilateral lateral rectus recession combined with a medial rectus resection in the same eye. Aberration parameters were measured 1 day before surgery and 1 week, 1 month, 3 months, and 6 months after surgery. Differences in the indicators at each time period were compared by analysis of variance (ANOVA) of repeated measures data for a single factor, and data were analyzed using SPSS 25.0 statistical application software. Results. 5 mm pupil diameter: the preoperative and postoperative RMS of total aberration showed statistically significant difference ( $P<0.01$ ). Postoperation test (Bonferroni method) and preoperative comparison at each period after surgery showed statistically significant differences between 6 months after surgery ( $P=0.002$ ) and preoperative comparison. The preoperative and postoperative comparison of RMS in LOAs was statistically significant ( $P<0.01$ ); postoperative test (Bonferroni method) and preoperative comparison showed that there were statistically significant differences between 1 week ( $P=0.033$ ) and 6 months ( $P=0.002$ ) after operation. The difference of RMS of defocus before and after operation was statistically significant ( $P<0.01$ ); postoperation test (Bonferroni method) and preoperative comparison showed that there was statistically significant difference between 6 months after operation ( $P=0.007$ ) and preoperative comparison. There was statistically significant difference in preoperative and postoperative RMS of HOAs ( $P=0.013$ ). Postoperative test (Bonferroni method) and preoperative comparison showed that there was statistically significant difference 6 months after surgery ( $P=0.03$ ). The RMS of secondary astigmatism showed a statistically significant difference before and after operation ( $P=0.001$ ), and the postoperation test (Bonferroni method) showed a statistically significant difference 6 months after operation ( $P=0.002$ ). In 5 mm pupil diameter, the preoperative and postoperative RMS of total aberration showed statistically significant difference ( $P<0.01$ ), postoperative test (Bonferroni method) was used to compare each period after surgery with that before surgery, and there were statistically significant differences between 1 week after surgery ( $P=0.034$ ), 3 months after surgery ( $P=0.033$ ), and 6 months after surgery ( $P=0.003$ ). The preoperative and postoperative comparison of RMS in LOAs was statistically significant ( $P<0.01$ ), postoperative test (Bonferroni method) was used to compare each period after surgery with that before surgery, and there were statistically significant differences between 1 week after surgery ( $P=0.04$ ), 3 months after surgery ( $P=0.034$ ), and 6 months after surgery ( $P=0.004$ ). The difference of RMS of defocus before and after surgery was statistically significant ( $P=0.002$ ), and the comparison between postoperation test (Bonferroni method) and preoperation showed that the difference was statistically significant 6 months after surgery ( $P=0.027$ ). The RMS of astigmatism showed statistically significant difference before and after operation ( $P=0.002$ ), and the postoperation test (Bonferroni method) showed statistically significant difference between 6 months after operation ( $P=0.009$ ) and before operation. Conclusion. We found that horizontal rectus surgery had a transient effect on LOAs and almost no effect on HOAs. Long-term follow-up is recommended after strabismus surgery to observe eye position and binocular visual function. Because of the high prevalence of strabismus in adolescents, long-term observation of the eye axis and aberration is recommended.

Higher Order Aberrations following Scleral Buckling Surgery in Patients with Rhegmatogenous Retinal Detachment

We aim to evaluate magnitudes of higher order aberrations (HOAs) from 3rd–6th order after scleral buckling (SB) for rhegmatogenous retinal detachment (RRD). A retrospective cross-sectional study of 19 patients with RRD who received SB (six receiving encircling SB, thirteen receiving segmental SB) was conducted. A wavefront analysis for surveying HOAs and other ophthalmic parameters were collected. Data between operated and fellow eyes, and a subgroup analysis of operated eyes, were analyzed by the Mann–Whitney U test, while a generalized linear model was applied to evaluate the correlation of HOAs to best-corrected visual acuity (BCVA) and optical symptoms. BCVA in the operated eyes was significantly worse (LogMAR: 0.18 ± 0.23 versus 0.05 ± 0.07, p = 0.001). Tilt (0.32 ± 0.14 versus 0.13 ± 0.08, p = 0.004), defocus (1.78 ± 0.47 versus 1.05 ± 0.17, p = 0.019) and coma (0.43 ± 0.11 versus 0.27 ± 0.09, p = 0.016) were significantly increased after SB. All root mean square (RMS), including RMS-3, RMS-4 and total RMS, were higher in operated eyes (all p < 0.05). Regarding Zernike terms, a significant elevation of vertical coma in the operated eyes was found (p = 0.038). In addition, tilt (0.41 ± 0.10 versus 0.17 ± 0.12, p = 0.007), defocus (2.27 ± 0.58 versus 0.82 ± 0.39, p = 0.001) and coma (0.59 ± 0.17 versus 0.11 ± 0.10, p = 0.015) were higher in the segmental subgroup, whereas spherical aberration (SA) was higher in the encircling subgroup (0.22 ± 0.04 versus 0.40 ± 0.15, p = 0.024) and RMS-4 and total RMS were increased in the segmental subgroup (both p < 0.05). Besides, tilt was correlated to worse BCVA (p = 0.036), whereas all four HOAs were correlated to the presence of optical symptoms (all p < 0.05). In conclusion, SB may increase HOAs, which could be associated with unfavorable postoperative visual outcomes and subject symptoms.

Transient Increase of Wavefront Aberrations after Horizontal Rectus Muscle Surgery in Exotropia

Aims: Wavefront aberration (WA) has become one of the important indicators for measuring the visual quality. Whether strabismus surgery affects the WA remain controversial. This study aims to investigate the postoperative alterations of WA in patients who underwent horizontal rectus muscle surgery.Methods: A total of 34 patients were enrolled and divided into two groups: bilateral lateral rectus recession (BLR) group and unilateral lateral rectus recession and medial rectus resection (R&R) group. The WA was examined 1 day before surgery, 3 days, and 6 weeks after surgery using the iTrace Visual Function Analyzer (Tracey Technologies).Results: Significant increases in total WA, lower-order aberration (LOA) and higher-order aberration (HOA) of both groups were detected in 3 days after surgery (P < 0.05), while no significant differences in 6 weeks after surgery. Significant increases in astigmatism, secondary astigmatism, and trefoil of both groups were detected in 3 days after surgery (P < 0.05), while no significant differences in individual order of LOA and HOA in 6 weeks postoperatively. Z₂², Z₃³, and Z₄² of both groups increased significantly 3 days after surgery (P < 0.05) and returned to baseline level 6 weeks after surgery, while the rest Zernike coefficients remained the same postoperatively. When comparing the differences between the two groups, there were no statistically significant differences in these parameters between baseline and each follow-up visit postoperatively.Conclusions: The increase of WA restored to pre-operative level in 6 weeks after surgery, indicating the influences of horizontal rectus muscle surgery to WA were transient and reversible.

Changes of corneal topographic measurements and higher-order aberrations after surgery for exotropia

Purpose

To analyze changes in corneal topographic measurements and higher-order aberrations (HOAs) after horizontal muscle surgery for exotropia.

Design

Retrospective, observational study.

Methods

A total of 131 eyes of 121 patients who had undergone surgery for exotropia were included. The eyes with unilateral lateral rectus (ULR) or bilateral lateral rectus (BLR) recession(s) were assigned to group A, and those with unilateral lateral rectus recession & medial rectus resection (R&R) to group B. Corneal topographic measurements and HOAs were compared between the preoperative and postoperative periods using a Placido-dual Scheimpflug analyzer (Galilei 2^TM, Ziemer, Port., Switzerland) for each group.

Results

In group A, simulated keratometery (sim K) was significantly changed until 3 months postoperatively relative to the preoperative value (postoperative 1 week, p = 0.017; 1 month, p = 0.037; and 3 months, p = 0.023, respectively). All steep K (steep sim K, steep-Kpost, and TCP-steep K) parameters also were significantly changed at postoperative 1 month (p<0.001, p = 0.015, p<0.001, respectively), but not at 3 months. Among the higher-order aberrations, spherical aberration (Z₄⁰) and secondary horizontal astigmatism (Z₄²) at postoperative 1 week had significantly changed from the preoperative values, as had horizontal quadrafoil (Z₄⁴) at 1 month. However, in group B, only vertical quadrafoil (Z₄^-4) showed statistically significant changes, at postoperative 1 and 3 months. None of the other postoperative parameters was significantly different from the corresponding preoperative value.

Conclusion

Lateral rectus recession induced changes in both corneal topographic measurements and HOAs, whereas R&R did so only in HOAs. These changes might explain some patients' complaints about poor quality of vision.