How does sevoflurane induction, followed by a ketamine maintenance infusion, affect intraocular pressure? Establishment of an anaesthetic protocol for paediatric glaucoma examinations under anaesthesia

Investigation into the usefulness of cynomolgus monkeys with spontaneously elevated intraocular pressure as a model for glaucoma treatment research

Many glaucoma treatments focus on lowering intraocular pressure (IOP), with novel drugs continuing to be developed. One widely used model involves raising IOP by applying a laser to the trabecular iris angle (TIA) of cynomolgus monkeys to damage the trabecular meshwork. This model, however, presents challenges such as varying IOP values, potential trabecular meshwork damage, and risk of animal distress. This study investigated whether animals with naturally high IOP (>25 mmHg) could be used to effectively evaluate IOP-lowering drugs, thereby possibly replacing laser-induced models. Relationships between TIA size, IOP, and pupil diameter were also examined. Three representative IOP-lowering drugs (latanoprost, timolol, ripasudil) were administered, followed by multiple IOP measurements and assessment of corneal thickness, TIA, and pupil diameter via anterior segment optical coherence tomography (AS-OCT). There was a positive correlation was noted between IOP and corneal thickness before instillation, and a negative correlation between IOP and TIA before instillation. Our findings suggest animals with naturally high IOP could be beneficial for glaucoma research and development as a viable replacement for the laser-induced model and that measuring TIA using AS-OCT along with IOP yields a more detailed evaluation.

Changes in intraocular pressure and ocular pulse amplitude of rhesus macaques after blue light scleral cross-linking

BACKGROUND

Scleral cross-linking can enhance the biomechanical strength of the sclera and is expected to be a new operative method for the prevention of myopia. However, studies investigating the changes in intraocular pressure (IOP) and ocular pulse amplitude (OPA) after blue light-riboflavin induced scleral collagen cross-linking (SXL) in rhesus monkeys are limited. This study aimed to investigate the changes in IOP and OPA in three-year-old rhesus macaques 1 week, 1 month, and 3 months after blue light-riboflavin SXL.

METHODS

Seven three-year-old rhesus macaques (14 eyes) were randomly divided into two groups, with 4 monkeys in group A (8 eyes) and 3 monkeys in group B (6 eyes). The right eye of each rhesus macaque was used as the experimental eye, whereas the left eye was used as the control. In group A, one quadrant of each right eye was irradiated. In group B, two quadrants of each right eye and one quadrant of each left eye were irradiated. The IOP and OPA of both eyes were measured in all seven rhesus macaques before SXL and 1 week, 1 month, and 3 months postoperatively, and differences in the IOP and OPA between the experimental and control eyes were evaluated via the paired t test.

RESULTS

In groups A and B, there were no significant differences between the experimental and control eyes in the IOP or OPA before SXL or 1 week, 1 month, or 3 months postoperatively (P > 0.05).

CONCLUSIONS

The IOP and OPA are not significantly affected in 1 vs 0 or in 1 vs 2 quadrants of blue light SXL.

Effects of Humanized Nursing on Perioperative Glaucoma Patients under Local Anesthesia and Sleep Quality

OBJECTIVE

We assessed the effects of humanized nursing on perioperative glaucoma patients under local anesthesia and their sleep quality.

METHODS

Fifty glaucoma patients who underwent surgery under local anesthesia from January 2018 to January 2020 were enrolled and randomly divided into 2 groups (N=25). The control group received routine nursing care whereas the observation group underwent humanized nursing care. We compared negative emotion scores, treatment compliance, incidence of postoperative complications, comfort score, sleep quality score, and nursing satisfaction.

RESULTS

After nursing, the observation group had lower SAS and SDS scores than the control group (p < .05). The total treatment compliance rate was higher in the observation group than that in the control group (96.0% vs 72.0%, p < .05). The observation group had a lower incidence rate of postoperative complications than the control group (4.0% vs 24.0%, p < .05). After nursing, the observation group exhibited an increased GCQ score and a decreased PSQI score compared to the control group (p < .05). The total satisfaction rate of nursing was higher in the observation group than that in the control group (96.0% vs 76.0%, p < .05).

CONCLUSION

Humanized nursing for glaucoma patients during the perioperative period under local anesthesia is able to relieve the negative emotion of patients and enhance their treatment compliance, which is conducive to reducing postoperative complications, increasing physical comfort level, and ameliorating sleep quality, thereby improving nursing satisfaction by patients.

Effect of general inhalational anesthesia on intraocular pressure measurements in normal and glaucomatous children

PURPOSE

To investigate the agreement between the intraocular pressure (IOP) measurements in the awake condition and under different stages of general inhalational anesthesia using sevoflurane in both glaucomatous and normal children.

METHODS

A prospective study was performed on 43 glaucomatous children and 30 age-matched controls. Baseline IOP of one eye was measured immediately before general anesthesia using Perkins tonometer and then re-measured under light, intermediate, and deep anesthesia, and then after intubation. Depth of anesthesia was determined using bispectral index pediatric sensor. The agreement between the IOP measurements before and during different stages of anesthesia was analyzed using Bland-Altman plots. Systematic and proportionate deviations between the IOP measurements were analyzed.

RESULTS

The mean age was 58.6 ± 41.99 months. The mean IOP was significantly lower at all stages of anesthesia in both groups. The coefficient of variation was over 20% in all measurements under anesthesia. For all IOP measurements during anesthesia, the limits of agreement were > 7 mmHg difference in the control group and > 20 mmHg in the glaucomatous group. The best agreement was with the IOP measurement after intubation (mean limit of agreement of -1.4 mmHg, 1.96 s range, -8.8-6 mm Hg) in the control group and with the IOP measurement under intermediate anesthesia (mean limit of agreement of -4.2 mmHg, 1.96 s range, -15.1-6.8 mm Hg) in the glaucomatous group.

CONCLUSIONS

Inhalational anesthesia has variable effects on IOP measurement at all stages of anesthesia. Caution should be taken when extrapolating the true IOP from these measurements.

Non-Penetrating Deep Sclerectomy versus Trabeculectomy in Primary Congenital Glaucoma

PURPOSE

To evaluate the safety and efficacy of non-penetrating deep sclerectomy with a collagen implant versus trabeculectomy in primary congenital glaucoma.

SUBJECTS AND METHODS

This was a retrospective interventional comparative non-randomized clinical study that included 80 eyes of 80 children presenting with primary congenital glaucoma under the age of 3 years. Forty eyes have undergone non-penetrating deep sclerectomy (NPDS) and the other 40 eyes have undergone penetrating trabeculectomy. The main outcome measure was the reduction in intraocular pressure (IOP). Secondary outcomes included percentage of patients with complete and qualified success, need for topical antiglaucoma medications, rate of complications, and need for further interventions. Complete success of the surgical outcome was considered an IOP ≤16 mmHg with no antiglaucoma medications. Qualified success was considered an IOP ≤16 mmHg using antiglaucoma medications.

RESULTS

The mean preoperative IOP was 27.4 ± 6.9 and 28.5 ± 6.6 mmHg in NPDS and trabeculectomy groups, respectively (p = 0.175). At the end of the follow-up period, the mean IOP was 11.2 ± 4.5 and 11.1 ± 3.4 mmHg with a mean reduction of 16.2 and 17.4 mmHg in NPDS and trabeculectomy groups, respectively. At the end of the follow-up period, ie at 36 months postoperative, the complete success rate was 60% (24 eyes) versus 57.5% (23 eyes), the qualified success rate was 25% (10 eyes) versus 25% (10 eyes), the overall success rate was 85% (34 eyes) versus 82.5% (33 eyes), and the rate of failure was 15% (6 eyes) versus 17.5% (7 eyes) in NPDS and trabeculectomy groups, respectively (p = 0.952). Eight cases (20%) of the trabeculectomy group had shallow anterior chamber. None of the NPDS group cases suffered from shallow anterior chamber.

CONCLUSION

Non-penetrating deep sclerectomy appears to be an efficient and safe surgical alternative to penetrating trabeculectomy in treatment of primary congenital glaucoma. Non-penetrating deep sclerectomy has fewer postoperative complications in comparison to penetrating trabeculectomy with a comparative postoperative reduction in the intraocular pressure and overall success rates.

TRIAL REGISTRATION

The trial was registered on 11/01/2020 with number PACTR202002874953456 (https://pactr.samrc.ac.za).

[360° trabeculotomy for pediatric glaucoma]

Congenital glaucoma disease leads to blindness if left untreated. It is estimated that 1 child in 10,000 in Germany is born with congenital glaucoma. In adults the disease develops slowly and insidiously, whereas congenital glaucoma leads to a rapid growth of the eye (buphthalmos) mostly directly after birth due to a very high intraocular pressure. The cause is dysgenesis of the iridocorneal angle. Successful operative treatment of congenital glaucoma is possible in the majority of cases (approximately 80-90%). The treatment of childhood glaucoma is primarily surgical. Since 1960 classical probe trabeculotomy has been the most commonly used procedure, which has the advantage that unlike goniotomy, it can also be performed in cases with clouding of the cornea. In this surgery the canal of Schlemm is probed and the inner wall as well as the trabecular meshwork is opened inwardly over approximately 120°. In recent years the 360° trabeculotomy procedure has become established, in which an illuminated catheter filled with viscoelastic material is used (as with conventional canaloplasty) to dilate the canal of Schlemm. The trabecular meshwork is then inwardly opened by pulling on the ends of the catheter. The results of this method are explained in this article.