The effects of phaco-emulsification-aspiration and intra-ocular lens implantation on the pupil: pupillographic and pharmacologic study

Pupil size differences between female and male patients after cataract surgery

PURPOSE

To evaluate the changes in pupil diameter in women and men after cataract surgery. The correlation of pupillary changes with the variables age and anterior chamber depth will be analyzed.

METHODS

The values of 109 randomized eyes who underwent cataract surgery were obtained and divided into two groups, 71 women and 38 men. Pupil diameter was measured preoperatively and 3-months postoperatively using the pupillometer software of the Topolyzer Vario (Wavelight Laser Technologie AG). Anterior chamber depth was obtained with Pentacam® (Oculus). Differences in pupillary diameters were investigated and correlations with age and anterior chamber depth were analyzed.

RESULTS

For mesopic pupils, the male group had greater reduction in their postoperative pupillary diameter, -0.56 mm (-12.4%), than the female group, -0.38 mm (-8.2%), P = 0.025. Photopic postoperative pupils reduced to a lesser extent, yet more in men than in women (-0.11mm [-4.5%] vs. -0.04 [-1.6%], P = 0.048). Weak significant negative correlation was found between photopic pupillary changes in women with age (r = -0.24, P = 0.041), and positive correlation for mesopic pupillary changes in men with age (r = +0.34, P = 0.039).

CONCLUSIONS

Patients experience pupil reduction after cataract surgery in general, but more in men than in women and for both photopic and mesopic lighting conditions. The differences are statistically significant and have moderate clinical relevance. Concerning pupillary changes, weak but opposite sign correlations were found between male/female gender and age. Trial registration number at ClinicalTrials.gov Identifier: NCT04286646.

Pupillary light response after cataract surgery in healthy patients

PURPOSE

To examine the changes in the pupillary light response after phacoemulsification and to compare the difference in the response among patients in different age categories.

STUDY DESIGN

Prospective observational study.

METHODS

Four-hundred twenty-two eyes of 422 patients in 3 age categories (60-69 years, 70-79 years, and 80-89 years) scheduled for phacoemulsification were consecutively enrolled. The eyes underwent examinations with an infrared pupillometer to obtain the parameters of the pupillary light response preoperatively and at 1 day and 1 and 3 months postoperatively. Differences in the parameters of the pupillary response were compared among 4 time intervals and the 3 age categories.

RESULTS

The mean maximum and minimum pupillary diameters significantly decreased at 1 day postoperatively and returned to the preoperative level by 1 month postoperatively (P<.0001). The mean percentage of pupillary constriction was significantly reduced at 1 and 3 months postoperatively compared with preoperatively and at 1 day postoperatively (P<.0001). The average pupillary constriction and dilation velocities were significantly lower at 1 and 3 months postoperatively than they were preoperatively and at 1 day postoperatively (P<.0001). The latency to constriction did not differ significantly among the time intervals. The percentage of pupillary constriction was significantly smaller, and the average constriction and dilation velocities were lower in association with higher age categories at all time intervals (P≤.0185).

CONCLUSION

The pupillary light response was impaired several months after cataract surgery and worsened with increasing patient age, indicating that cataract surgery may compromise the pupillary constriction and dilation functions in association with age.

Changes in pupillometry associated with dissipated energy during phacoemulsification

PURPOSE

To investigate the effect of ultrasound level during phacoemulsification on pupil dynamics.

METHODS

Comparative retrospective study on patients who underwent routine cataract surgery at the Royal Liverpool University Hospital. Clinical parameters, anterior chamber measurements, axial length, surgeon grade, time of surgery, level of ultrasound used (cumulative dissipated energy, CDE), intra- and post-operative complications were collected. Pupil diameters were collected before and 4 ± 1 weeks after surgery in static scotopic, mesopic, photopic pupil conditions. Also, pupil dynamic measurements after luminous stimulus were recorded. Changes in static pupil diameters, relative dilation at 3.5 s after luminous stimulus, and time to reach 75% and 95% of maximum dilation were measured.

RESULTS

Forty-eight eyes of 24 patients (13 males) were included with a mean age of 73.1 ± 14.6 years. Mean CDE value was 18.11 ± 10.56. Mean scotopic pupil diameters decreased by 0.24 ± 0.48 mm (p = 0.021) in the operated eye. Significant correlation was found between reduction in scotopic pupil diameter and CDE (p = 0.05). A generalized linear model confirmed that the level of CDE was significantly associated with reduction in scotopic pupil diameter (p = 0.026). Patients who underwent surgeries with lower CDE (0 < CDE ⩽ 10 and 10 < CDE ⩽ 20) did not experience significant changes in scotopic pupil diameter after surgery (p = 0.28 and p = 0.79, respectively) as opposed to those with higher CDE (CDE > 20; p = 0.03).

CONCLUSION

Phacoemulsification cataract surgery and the cumulative dissipated energy may be associated with changes in pupil behaviour.

Post-phacoemulsification iris changes in eyes with glaucoma or glaucoma suspect status

Purpose

This prospective study used anterior segment optical coherence tomography (AS-OCT) to determine how phacoemulsification (phaco) changes iris parameters in eyes with glaucoma or glaucoma suspect status.

Methods

Using Visante AS-OCT (Carl Zeiss Meditec AG), the following pre- and post-phaco parameters were measured: IT750 = iris thickness at 750 μm from the scleral spur; IT2000 = iris thickness 2000 μm from the scleral spur; ITCM = the maximum iris thickness at the middle one third of the iris; ICURV = iris curvature; IAREA = iris area; and pupil size = pupil diameter (mm). Only high-quality images with an identifiable scleral spur were included, and only the nasal quadrant was analyzed. A single glaucoma specialist analyzed the parameters according to the Zhongshan Angle Assessment Program (ZAAP, Guangzhou, China). Multivariate analysis was performed using mixed effects regression correcting for age, gender, and ethnicity.

Results

89 subjects and 110 eyes were included in this study. The mean age of subjects was 74.83 {+/-} 8.69 years old. Most common diagnoses were POAG and glaucoma suspect (23% and 52%, respectively), and 16% of subjects had an LPI. In multivariate analysis of AS-OCT parameters, decreases in IT750, IT2000, ITCM, ICURV, and pupil size were statistically significant (p<0.05).

Conclusions

After phacoemulsification, eyes with glaucoma as well as glaucoma suspect eyes have thinner irises and smaller pupils. This may lead to less iris-mediated aqueous outflow obstruction, providing support for early phacoemulsification glaucoma treatment.

Translational relevance

Our AS-OCT imaging findings may guide clinical practice as iris parameters become increasingly relevant in preoperative phaco planning.

Pupil Dynamics Induced by Light Reflex After Posterior Chamber Phakic Intraocular Lens Implantation

PURPOSE

To assess the light reflex of the pupil after Implantable Collamer Lens (ICL) (KS-aquaPORT; STAAR Surgical, Nidau, Switzerland) implantation to determine whether the ICL implantation might affect the pupil dynamics.

METHODS

This study examined 28 eyes of 28 consecutive patients who underwent implantation of the posterior phakic ICL for the correction of myopia and astigmatism. Patient age at the time of surgery was 31.1 ± 6.8 years (range: 25 to 42 years). Preoperative refraction was -7.38 ± 2.26 diopters (D) (range: -3.25 to -11.80 D). Light reflex was evaluated using the infrared pupillometer Iriscorder C7364 (Hamamatsu Photonics, Hamamatsu, Japan). Measured parameters included pupil diameter (D1), constriction ratio, maximum constriction velocity, maximum dilation velocity, and the time required to recover 63% of the pupil diameter (T5). At 6 months postoperatively, the authors also investigated the relationship with the amount of vault using the Pentacam (Oculus Optikgeräte, Wetzlar, Germany). Evaluations with the instrument were performed before and at 1, 3, and 6 months after surgery.

RESULTS

There was no significant association found between any of the parameters (analysis of variance, D1: P = .99, constriction ratio: P = .59, maximum constriction velocity: P = .87, maximum dilation velocity: P = .13, T5: P =.57). The vault of the ICL at 6 months postoperatively was 382.1 ± 176.5 μm. There were no significant associations between the maximum constriction velocity, maximum dilation velocity, and amount of vaulting (Spearman correlation coefficient maximum constriction velocity: r = 0.07, P = .71, maximum dilation velocity: r = 0.26, P = .28).

CONCLUSIONS

The light reflex of the pupillary dynamics continued to be maintained at 6 months after ICL implantation. Current findings also verified that ICL implantation had little influence on the postoperative function of the iris. [J Refract Surg. 2017;33(10):704-707.].