Does the disruption of horizontal anterior ciliary vessels affect the blood-aqueous barrier function?

Evaluation of the effects of strabismus surgery on corneal backward light scattering

BACKGROUND

Investigation of the effects of conventional strabismus surgeries on corneal densitometry (CD).

METHODS

Patients who had strabismus surgery between May 2022 and July 2022 were included in the study. CD software with a Pentacam device was used to determine corneal backward light scattering. CD data were analysed preoperatively and 1 month postoperatively. Patients were classified as those who had single muscle and two-muscle surgery.

RESULTS

The study included 33 eyes of 28 patients. The mean age of the patients was 20.51 ± 8.22 (5-35) years. Of the eyes, 19 underwent single muscle recession surgery. Two-muscle surgeries (recession and resection combination) were performed in 14 eyes. In the 1st month postoperative, the mean CD value decreased statistically significantly only in the total cornea apical 0-2 mm zone among the layers examined (p = 0.039). There was no significant change in the other layers (p > 0.05 for all). Single-muscle and two-muscle surgery groups were similar in the amount of CD reduction, except for one layer.

CONCLUSIONS

CD did not change in most of the corneal layers examined in the first month postoperatively. Single muscle and two-muscle horizontal rectus surgeries did not impair corneal clarity in the postoperative 1st month.

The effect of one- and two-rectus muscle strabismus surgery on anterior chamber flare

PURPOSE

To investigate the effect of the most commonly performed strabismus surgery procedures on the blood-aqueous barrier using laser flare photometry (LFP).

METHODS

Patients who underwent unilateral or bilateral strabismus surgery between January 2020 and May 2021 were included. Eyes were grouped according to the number of rectus muscles operated: one rectus muscle procedure (recession) with or without inferior oblique anterization (IOA), ipsilateral two rectus muscle procedure (recession and resection) with or without IOA, and unoperated fellow eyes of patients undergoing unilateral surgery. Anterior chamber flare values were measured by LFP for each eye the day before the surgery and day 1, week 1, and month 1 postoperatively.

RESULTS

A total of 66 eyes of 33 patients (21 females) were included. There were 29 eyes in the one-muscle group, 22 in the two-muscle group, and 15 in the fellow-eye group. The mean flare values of the two-muscle group were significantly higher than those of the other groups at postoperative day 1 and week 1 (P = 0.001, for both). The mean postoperative day 1, week 1, and month 1 flare values of the two-muscle group were significantly higher than the mean preoperative flare value. There were no significant differences between pre- and postoperative flare values of the one-muscle or fellow-eye groups (P > 0.05, for both).

CONCLUSIONS

In our study cohort, LFP provided evidence of subclinical changes in the blood-aqueous barrier up to the first month postoperatively in otherwise healthy patients undergoing two-muscle surgery compared with those undergoing one-muscle surgery and unoperated fellow eyes.

Interventions for intermittent exotropia

BACKGROUND

The clinical management of intermittent exotropia (X(T)) has been discussed extensively in the literature, yet there remains a lack of clarity regarding indications for intervention, the most effective form of treatment, and whether there is an optimal time in the evolution of the disease at which any given treatment should be carried out.

OBJECTIVES

The objective of this review was to analyze the effects of various surgical and non-surgical treatments in randomized controlled trials (RCTs) of participants with intermittent exotropia, and to report intervention criteria and determine whether the treatment effect varies by age and subtype of X(T).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 1), which contains the Cochrane Eyes and Vision Trials Register; Ovid MEDLINE; Ovid Embase; Latin American and Caribbean Health Science Information database (LILACS); the ISRCTN registry; ClinicalTrials.gov, and the WHO ICTRP. The date of the search was 20 January 2021. We performed manual searches of the British Orthoptic Journal up to 2002, and the proceedings of the European Strabismological Association (ESA), International Strabismological Association (ISA), and American Association for Pediatric Ophthalmology and Strabismus meeting (AAPOS) up to 2001.

SELECTION CRITERIA

We included RCTs of any surgical or non-surgical treatment for intermittent exotropia.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

We included six RCTs, four of which took place in the United States, and the remaining two in Asia (Turkey, India). A total of 890 participants with basic or distance X(T) were included, most of whom were children aged 12 months to 10 years. Three of these six studies were from the 2013 version of this review. Overall, the included studies had a high risk of performance bias as masking of participants and personnel administering treatment was not possible. Two RCTs compared bilateral lateral rectus recession versus unilateral lateral rectus recession with medial rectus resection, but only one RCT (n = 197) reported on the primary outcomes of this review. Bilateral lateral rectus recession likely results in little difference in motor alignment at near (MD 1.00, 95% CI -2.69 to 4.69) and distance (MD 2.00, 95% CI -1.22 to 5.22) fixation as measured in pupillary distance using PACT (moderate-certainty evidence). Bilateral lateral rectus recession may result in little to no difference in stereoacuity at near fixation (risk ratio (RR) 0.77, 95% CI 0.35 to 1.71), adverse events (RR 7.36, 95% CI 0.39 to 140.65), or quality of life measures (low-certainty evidence). We conducted a meta-analysis of two RCTs comparing patching (n = 249) with active observation (n = 252), but were unable to conduct further meta-analyses due to the clinical and methodological heterogeneity in the remaining trials. We found evidence that patching was clinically more effective than active observation in improving motor alignment at near (mean difference (MD) -2.23, 95% confidence interval (CI) -4.02 to -0.44) and distance (MD -2.00, 95% CI -3.40 to -0.61) fixation as measured by prism and alternate cover test (PACT) at six months (high-certainty evidence). The evidence suggests that patching results in little to no difference in stereoacuity at near fixation (MD 0.00, 95% CI -0.07 to 0.07) (low-certainty evidence). Stereoacuity at distance, motor fusion test, and quality of life measures were not reported. Adverse events were also not reported, but study authors explained that they were not anticipated due to the non-surgical nature of patching. One RCT (n = 38) compared prism adaptation test with eye muscle surgery versus eye muscle surgery alone. No review outcomes were reported. One RCT (n = 60) compared lateral rectus recession and medial rectus plication versus lateral rectus recession and medial rectus resection. Lateral rectus recession and medial rectus plication may not improve motor alignment at distance (MD 0.66, 95% CI -1.06 to 2.38) (low-certainty evidence). The evidence for the effect of lateral rectus recession and medial rectus plication on motor fusion test performance is very uncertain (RR 0.92, 95% CI 0.48 to 1.74) (very low-certainty evidence).

AUTHORS' CONCLUSIONS

Patching confers a clinical benefit in children aged 12 months to 10 years of age with basic- or distance-type X(T) compared with active observation. There is insufficient evidence to determine whether interventions such as bilateral lateral rectus recession versus unilateral lateral rectus recession with medial rectus resection; lateral rectus recession and medial rectus plication versus lateral rectus recession and medial rectus resection; and prism adaptation test prior to eye muscle surgery versus eye muscle surgery alone may confer any benefit.

Accommodation changes after strabismus surgery due to anterior ciliary vessel disruption

PURPOSE

To evaluate monocular accommodation changes after strabismus surgery with and without anterior ciliary vessel preservation.

METHODS

Sixty patients with horizontal concomitant strabismus who were scheduled to undergo monocular strabismus surgeries were randomly divided into two groups: A (without anterior ciliary vessel preservation) and B (with anterior ciliary vessel preservation). Group A was further divided into groups A1 (surgical eyes without anterior ciliary vessel preservation) and A2 (corresponding nonsurgical eyes). Group B was further divided into groups B1 (surgical eyes with anterior ciliary vessel preservation) and B2 (corresponding nonsurgical eyes). Monocular accommodative amplitude (AA) and accommodative facility (AF) were evaluated before and 1 day after the surgery to assess accommodation.

RESULTS

In groups A2, B1, and B2, the AA and AF values showed no significant difference preoperatively or postoperatively. However, compared with preoperative values, both the postoperative AA and AF values were significantly reduced in group A1.

CONCLUSION

Strabismus surgery without anterior ciliary vessel preservation reduces monocular accommodation, whereas strabismus surgery with anterior ciliary vessel preservation protects accommodation.