Management and outcomes of the small pupil in cataract surgery: iris hooks, Malyugin ring or phenylephrine?

Comparison of pupil expansion devices in small pupil phacoemulsification

PURPOSE

To study the outcomes of phacoemulsification in small pupils (≤4 mm) using pupil expansion devices at a tertiary eye care center in South India.

METHODS

The study design is prospective, randomized, comparative, and interventional. Mechanical pupil dilatation with iris retractors (group I), B-HEX ring (group II), and Gupta ring (group III) was compared with respect to pupil size achieved (intraoperative), total surgical time, device addition time, complications, endothelial cell loss, and postoperative best corrected visual acuity.

RESULTS

Among 36 participants (12 in each group), the mean pupil size, total surgical time, and device addition time were maximum with iris retractors. Intraoperatively, sphincter tear was seen in two eyes in the iris retractors group and one eye in the Gupta ring group. In the B-HEX ring group, only two flanges of the ring could be engaged in two participants, one patient had iris bleeding (during stretching of the iris), and one patient had anterior lens capsular tear. Among all three groups, there was no statistically significant difference in best corrected visual acuity (BCVA), endothelial cell count, and coefficient of variation obtained in the preoperative period, postoperative Day 7 and Day 30, respectively.

CONCLUSION

In our study, in more than 50% of cases, the cause of small pupil was idiopathic/senile. Among nonidiopathic causes, PXF was the most common association. Although iris retractors are cost-effective and give maximum intraoperative dilatation, there is a need of four additional side ports to be made, thus increasing the total surgical time and device addition time. On the other hand, B-HEX and Gupta ring provide comparable intraoperative dilation and device addition time and also have comparable postoperative outcomes in terms of postoperative pupil size and complications.

Improved visibility of illuminated chopper-assisted cataract surgery involving iris challenges

Purpose

The aim of this study was to evaluate the efficacy of the illuminated chopper-assisted cataract surgery in terms of shortening the surgical time and reducing the use of pupil expansion devices in eyes with iris challenges.

Methods

This was a retrospective case series of a university hospital. Four hundred forty-three eyes of 433 consecutive patients who underwent illuminated chopper-assisted cataract surgery were included in this study. Cases with preoperative or intraoperative miosis, iris prolapse, and intraoperative floppy iris syndrome were included in the iris challenge group. Use of tamsulosin, iris hooks, pupil size, surgical time, and improved visibility (100/surgical time × pupil size) were compared between eyes with and without iris challenges. Mann-Whitney U test, Pearson's Chi-square test, and Fisher's exact test were used for statistical analysis.

Results

Of 443 eyes, 66 were included in the iris challenge group (14.9%). Tamsulosin use was more common in patients with iris challenges and iris hooks were used more frequently (9.1% vs. 0%, P < 0.001) in patients with iris challenges than in those without iris challenges. Pupil size was smaller in patients with iris challenges (6.01 vs. 7.64 mm, P < 0.001). However, surgical time was not different (16.9 vs. 16.5 min, P = 0.064) between the two groups. As a result, improved visibility was calculated to be higher in patients with iris challenges (1.05 vs. 0.81, P < 0.001).

Conclusion

In terms of surgical time and improved visibility, using the illuminated chopper simplified cataract surgery involving iris challenges. The use of an illuminated chopper is expected to be a good solution for challenging cataract surgeries.

α1-Adrenergic Receptors: Insights into Potential Therapeutic Opportunities for COVID-19, Heart Failure, and Alzheimer's Disease

α1-Adrenergic receptors (ARs) are members of the G-Protein Coupled Receptor superfamily and with other related receptors (β and α2), they are involved in regulating the sympathetic nervous system through binding and activation by norepinephrine and epinephrine. Traditionally, α1-AR antagonists were first used as anti-hypertensives, as α1-AR activation increases vasoconstriction, but they are not a first-line use at present. The current usage of α1-AR antagonists increases urinary flow in benign prostatic hyperplasia. α1-AR agonists are used in septic shock, but the increased blood pressure response limits use for other conditions. However, with the advent of genetic-based animal models of the subtypes, drug design of highly selective ligands, scientists have discovered potentially newer uses for both agonists and antagonists of the α1-AR. In this review, we highlight newer treatment potential for α1A-AR agonists (heart failure, ischemia, and Alzheimer's disease) and non-selective α1-AR antagonists (COVID-19/SARS, Parkinson's disease, and posttraumatic stress disorder). While the studies reviewed here are still preclinical in cell lines and rodent disease models or have undergone initial clinical trials, potential therapeutics discussed here should not be used for non-approved conditions.

Dilation devices in cataract surgery

PURPOSE OF REVIEW

Cataract surgery in the setting of small pupil represent a major challenge and it is associated with a higher risk of complications. When pharmacologic pupil dilation fails, mechanical pupil expansion devices are needed to obtain and maintain sufficient intraoperative mydriasis. The purpose of this review is to assess the pupil expansion devices currently available.

RECENT FINDINGS

A variety of pupil expansion devices are offered on the market. They differ for design, material, shape, size, cost, and easiness of insertion/removal, nonetheless they all seem to be effective in improving the pupil size and easing the cataract surgery.

SUMMARY

Mechanical pupil expansion can be effectively achieved with a variety of devices, which are well tolerated and can facilitate cataract surgery in the setting of poor mydriasis.

Surgical outcomes of complicated cataract with pediatric trematode granulomatous uveitis

AIM

To describe the clinical characteristics and surgical outcomes of complicated cataract with pediatric trematodal granulomatous uveitis (TGU).

METHODS

Patients of cataract with TGU in the membranous (inactive) stage underwent cataract surgery with intraocular lens (IOL) implantation. Preoperative history and ophthalmic examination were conducted for all cases, whereas Schimphlug imaging and corneal topography were done for some patients. Postoperative follow up was done on the 1^st, 2^nd, and 5^th postoperative days after surgery. Then, it was done at least at one, three, and six months postoperatively. Intraoperative and postoperative complications and the methods of their management were reported.

RESULTS

Twelve eyes of 12 male children were included in this study ranging from 8 to 16y. The mean best corrected Snellen visual acuity (BCVA) was significantly improved from 0.09±0.06 preoperatively to 0.37±0.11 at the final visit 6mo postoperatively (P<0.001). Schimphlug imaging and corneal topography showed flattening of the anterior surface of the inferior cornea. Intraoperative difficulties and complications included the poor dilatability of the drown down pupil, strong posterior synechia between the anterior lens capsule and the iris at the site of the inferior retrocorneal vascularized membrane and hyphema. All cases underwent primary hydrophobic IOL implantation.

CONCLUSION

Surgery for this type of cataract is relatively safe and effective. It is associated with some specific difficulties and complications that should be considered during surgery and follow up.

The safety of intracameral phenylephrine - A systematic review

Intracameral phenylephrine is commonly used in ophthalmic surgery as an alternative or supplement to mydriatic eye drops; hence, the importance of an evidence-based understanding of its risk-benefit profile is vital. We performed a comprehensive search in the PubMed, Google Scholar and Cochrane databases for published studies and case reports relating to the use of intracameral phenylephrine. Articles from 1958 to 2021 with the following keywords were used: "intracameral phenylephrine", "intracameral mydriatics", "phenylephrine", "pupil dilation", "complications". Intracameral phenylephrine was first used in 2003 as an alternative to topical mydriatics. Since then, it is being increasingly used with a variety of benefits, including rapid onset of mydriasis, and cost-effectiveness. There are various case reports, however, of ocular and systemic complications associated with intracameral phenylephrine such as generation of free radicals, toxic anterior segment syndrome, inconsistent pupillary dilation during surgery, and ventricular fibrillation. Alternatives to intracameral phenylephrine such as iris hooks, a Malyugin ring, intracameral epinephrine, and intracameral tropicamide were compared with intracameral phenylephrine. Intracameral phenylephrine appears to have a good safety profile.

Relationship Between Tamsulosin Use and Surgical Complications of Cataract Surgery in Elderly Patients: Population-Based Cohort Study

Purpose

Although several previous studies have investigated the relationship between tamsulosin use and surgical complications of cataract surgery, no population-based cohort study has been conducted for the Asian population. We aimed to investigate the relationship between tamsulosin use and surgical complications of cataract surgery in the Korean elderly population.

Methods

This nationwide population-based retrospective cohort study included elderly patients (≥60 years) who had undergone cataract surgery in the period from 2003 to 2015. Baseline characteristics were age, sex, income, residence, and systemic, and ocular comorbidities (glaucoma, myopia, eye trauma, diabetes mellitus with ophthalmic manifestations, severe cataract, age-related macular degeneration). The exposure of interest was tamsulosin use within 1 year before cataract surgery. Logistic regression model was used to evaluate the relationship of tamsulosin use with surgical complications of cataract surgery.

Results

The rate of surgical complications of cataract surgery was 0.88% (375/42,539) in the non-tamsulosin group and 0.83% (71/8,510) in the tamsulosin group. The groups showed no significant difference in the risk of surgical complications of cataract surgery in the unadjusted model [odds ratio (OR) = 0.946; 95% confidence interval (CI):0.733–1.220; P = 0.669]. Additionally, tamsulosin use was not significantly associated with surgical complications of cataract surgery in the fully adjusted model accounting for age, income, residence, and systemic and ocular comorbidities (OR = 0.997; 95% CI: 0.749–1.325; P = 0.981).

Conclusions

The rate or risk of surgical complications of cataract surgery does not change with tamsulosin use. We suggest that better surgical techniques and surgeons' cognizance of the patient's tamsulosin use could improve surgical outcomes, without increasing surgical complications.

Evaluation of the Optical Aspects of the Ophthalmic Viscosurgical Device During Femtosecond Laser-Assisted Cataract Surgery

Purpose

In femtosecond laser-assisted cataract surgery (FLACS), capsulorhexis can be performed with an ophthalmic viscosurgical device (OVD) filled in the anterior chamber. We aimed to investigate changes in the laser properties in various optical aspects, such as focal shifting, reflection, and absorption associated with OVD.

Methods

Simulation was achieved by calculating the laser power attenuation due to reflection and spot size change using the Gullstrand eye model. Additionally, we calculated the absorption coefficient by measuring the laser power passing through the OVD with a laser meter and evaluated the effect of absorption by the OVD.

Results

In our simulation, power attenuation due to reflection was a maximum of 0.07%, and power attenuation was 0.08% even when considering the change according to the incident angle. Power attenuation due to the change of the spot size at the focus was 0.005%. Owing to the absorption of the OVD, a power increase of up to 13.5% was required for an anterior chamber depth of 3.0 mm to obtain the same effect as the aqueous humor.

Conclusions

The main reason for laser power attenuation associated with OVD was laser absorption through the OVD, and could also be caused by laser cavitation bubbles. To complete a safe capsulotomy during FLACS, the laser power should be increased appropriately, considering the absorption by the OVD in the anterior chamber.

Translational Relevance

The study results can be applied to calculate the optimal femtosecond laser energy to achieve complete capsulotomy during FLACS in the presence of anterior chamber OVD.

Evaluation of a uniplanar pupil expansion ring in small-pupil cataract surgery: a feasibility study

PURPOSE

The aim of this study was to evaluate the effectiveness of a disposable uniplanar pupil expansion device in small-pupil cataract surgery.

METHODS

This is a feasibility study carried out at the Rothschild Foundation, Paris, France. Patients undergoing routine cataract surgery with a dilated pupil size < 6 mm, and who agreed to participate in the study were included. The trial enrolled 25 patients, of whom 21 proceeded to cataract surgery using the pupil expansion device to be evaluated. The pupil diameter was measured at defined stages during the cataract surgery, which was performed by a single surgeon, in a single center setting. The 1st generation Bhattacharjee pupil expansion ring was used if the preoperative pupil size was < 6 mm. Intraoperative and postoperative adverse events were recorded.

RESULTS

Pupil size immediately after the Bhattacharjee ring implantation was ≥ 6 mm for 15 eyes (71.4%). The mean dilated pupil size before ring insertion was 4.5 ± 0.8 mm (range 2.5-5.8 mm), and the mean pupil size after ring insertion was 6.1 ± 0.3 mm (range 5.9-6.8 mm). Mean pupil size following removal of the ring was 4.2 ± 0.8 mm (range 2.5-5.4 mm). Two adverse events occurred during the surgeries: 1 Bhattacharjee ring broke prior to implantation, and 1 implanted Bhattacharjee ring was unstable and removed before the end of the surgery. No postoperative adverse event was recorded.

CONCLUSIONS

The Bhattacharjee ring is an effective pupil expansion device, which facilitates stable pupil expansion during cataract surgery. This study was registered as a clinical trial at clinicaltrials.gov under the number NCT02434588.