Bleb failure and intraocular pressure rise following Nd: Yag laser capsulotomy

The Immediate Early Response of Lens Epithelial Cells to Lens Injury

Cataracts are treated by lens fiber cell removal followed by intraocular lens (IOL) implantation into the lens capsule. While effective, this procedure leaves behind numerous lens epithelial cells (LECs) which undergo a wound healing response that frequently leads to posterior capsular opacification (PCO). In order to elucidate the acute response of LECs to lens fiber cell removal which models cataract surgery (post cataract surgery, PCS), RNA-seq was conducted on LECs derived from wild type mice at 0 and 6 h PCS. This analysis found that LECs upregulate the expression of numerous proinflammatory cytokines and profibrotic regulators by 6 h PCS suggesting rapid priming of pathways leading to inflammation and fibrosis PCS. LECs also highly upregulate the expression of numerous immediate early transcription factors (IETFs) by 6 h PCS and immunolocalization found elevated levels of these proteins by 3 h PCS, and this was preceded by the phosphorylation of ERK1/2 in injured LECs. Egr1 and FosB were among the highest expressed of these factors and qRT-PCR revealed that they also upregulate in explanted mouse lens epithelia suggesting potential roles in the LEC injury response. Analysis of lenses lacking either Egr1 or FosB revealed that both genes may regulate a portion of the acute LEC injury response, although neither gene was essential for expression of either proinflammatory or fibrotic markers at later times PCS suggesting that IETFs may work in concert to mediate the LEC injury response following cataract surgery.

Clinical implications of energy used in Neodymium: Yttrium Aluminum Garnet posterior capsulotomy on intraocular pressure

Purpose

To study the trend of the rise of intraocular pressure (IOP), with the energy used during Neodymium: Yttrium Aluminum Garnet (Nd: YAG) posterior capsulotomy.

Methods

This is a prospective interventional study undertaken at a tertiary care center. The study was conducted on 221 non-glaucomatous eyes that underwent Nd: YAG posterior capsulotomy, of which 181 patients completed the study. IOP was recorded before laser and at 1, 2, 3, 4 hours, one day, one week, and one month during the post-laser period. Patients were grouped, depending on the amount of energy used, into Group 1 (≤ 40 mJ), Group 2 (40-80 mJ), and Group 3 (>80 mJ).

Results

Raised IOPs were noted in all the groups at various time points; however, such cases were more in Group 3 (P = <0.001). IOP was noted to peak at the fourth hour and declined to reach baseline by one week in Group 2 and by one month in Group 3.

Conclusion

There exists a relationship between the quantum of energy used and the amount of rising of IOP following Nd: YAG laser capsulotomy. In uncomplicated cases without preexisting glaucoma, if the amount of energy for posterior capsulotomy is limited to 40 mJ, routine use of ocular hypotensive medication can be avoided.

Cataract surgeon viewpoints on the need for novel preventative anti-inflammatory and anti-posterior capsular opacification therapies

Purpose: To determine cataract surgeon viewpoints on the efficacy of available therapies/preventatives for two common sequelae of cataract surgery: inflammation and posterior capsular opacification (PCO). Methods: Cataract surgeons practicing worldwide specializing in adult, pediatric and veterinary patients were interviewed between March and August 2018. Results: Ocular inflammation following cataract surgery is treated by either corticosteroids and/or nonsteroidal anti-inflammatories (NSAIDs). Adult and pediatric cataract surgeons are satisfied with current treatments whereas this inflammation is still considered a problem by some in veterinary practice due to its slow resolution. Yttrium-aluminum-garnet (YAG) laser therapy is the PCO treatment of choice for adult cataract surgeons and they are generally pleased with its outcome. However, pediatric cataract surgeons find YAG problematic, especially in patients under 6 years of age, and invasive surgery is often needed to correct PCO/visual axis opacification (VAO). Veterinary ophthalmologists report that YAG is not effective for PCO in animals, especially dogs, due to the density of the fibrotic plaques; 86% of adult and 100% of veterinary and pediatric cataract surgeons surveyed agree that effective anti-PCO therapeutics would improve clinical care. Conclusions: Surgeons treating human patients are pleased with the available treatments for ocular inflammation following cataract surgery, although some veterinary ophthalmologists disagree. The surgeons surveyed agree that PCO/VAO remains an unsolved problem in pediatric and veterinary cataract surgery while the long-term outcome of adult cataract surgery could be improved by additional attention to this issue.

Advanced glaucoma following Nd:YAG capsulotomy: a case report

Background

We present a case of aphakic pupil block caused by vitreous prolapse into the anterior chamber following Nd:YAG capsulotomy.

Case presentation

This resulted in advanced glaucoma in a young patient, which presented a significant clinical management challenge.

Conclusions

Ultimately, at the time of writing, her intraocular pressure and uveitis were well controlled, however the long-term outcome remains uncertain, given the uncompromising natural history of her complicated ocular condition.