Postoperative Flare Values Research Articles

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

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

Postoperative aqueous humour flare as a surrogate marker for proliferative vitreoretinopathy development.

As some surgical procedures have been shown to increase postoperative flare values and thus contribute to blood-ocular barrier breakdown, retinal reattachment surgery might influence the risk of developing proliferative vitreoretinopathy (PVR). Therefore, we investigated whether postoperative aqueous flare values are a surrogate marker for the development of postoperative PVR. We prospectively included 195 patients with primary rhegmatogenous retinal detachment (RRD) and measured aqueous laser flare preoperatively, and at 2 and 6weeks postoperatively. Postoperative PVR was defined as reoperation for redetachment due to PVR membranes, within 6months of initial surgery. Logistic regression and receiver operating characteristic (ROC) analysis determined whether higher postoperative flare values were associated with an increased risk of developing PVR later on. Reoperation for postoperative PVR was needed in 12 (6.2%) patients; in 18 (9.2%), reoperation was not related to PVR. The median flare value for patients who would develop PVR was significantly higher than that of patients who would not develop PVR, both at 2weeks (p=0.001) and 6weeks (p<0.001) postoperatively. Logistic regression analyses showed that a higher flare value significantly increased the odds of developing PVR, either at 2weeks [odds ratio (OR) 1.027; 95% CI: 1.010-1.044] or 6weeks (OR 1.076; 95% CI: 1.038-1.115). Flare values both at 2 and 6weeks postoperatively seem a good surrogate marker in terms of sensitivity and specificity for the development of postoperative PVR but have only a modest positive predictive value. The 2-week value would be more useful in terms of early recognition of high-risk patients and hence give the possibility to better study effects of treatment methods.

Clinical research of anterior chamber inflammation after phacoemulsification surgery in patients with complicated cataract secondary to uveitis

To investigate anterior chamber inflammation after phacoemulsification with intraocular lens (IOL) implantation in patients with Vogt-Koyanagi-Harada (VKH) syndrome or Behçet's disease (BD). Cohort study. Seventeen patients (20 eyes) with complicated cataracts and VKH syndrome or BD who underwent phacoemulsification with IOL implantation at Zhongshan Ophthalmic Center, Sun Yat-Sen University (SYSU) between January 2010 and June 2011 were included as the experimental group in this study. Cataract surgery was performed on these patients only when uveitis had been under control for more than three months. Thirty patients (40 eyes) with age-related cataracts who underwent phacoemulsification with IOL implantation in the same period were included as the control group. Quantitative measurements of anterior chamber aqueous flare and inflammatory cells were conducted preoperatively and postoperatively using a Laser Flare Cell Meter (LFCM). Independent t-test was used to compare patients' ages, and the energy and time of phacoemulsification between the two groups. The Student's t-test was used to assess the differences between paired data preoperatively and postoperatively. Independent t-test was also used to assess the quantitative data between groups. The study recruited 20 eyes in the experimental group and 40 eyes in the control group, including 11 eyes from 9 VKH patients and 9 eyes from 8 BD patients. The preoperative and postoperative flare values in the experimental group were (19.86 ± 6.47), (44.28 ± 18.47), (35.60 ± 12.65), (23.85 ± 8.41), and (13.86 ± 4.27) pc/ms, respectively, which were statistically higher than that of the control group preoperatively, and on days 1, 7, 30, and 90 after surgery (tpre = 4.643, Ppre < 0.01; t1 = 6.035, P1 < 0.01; t7 = 3.595, P7 = 0.001; t30 = 4.658, P30 < 0.01; t90 = 3.308, P90 = 0.002). Aqueous flare in Group A and Group B declined to preoperative levels on day 30 (t = 0.320, P = 0.753) and day 7 (t = 0.454, P = 0.653). For the experimental group, the inflammatory cell count on day 1 and 7 was (83.46 ± 27.08) and (27.56 ± 8.32) cells/0.5 mm(3), respectively, which was significantly higher than the preoperative level [(6.47 ± 3.56)cells/ 0.5 mm(3), t1 = 5.261, P1 < 0.01; t7 = 2.766, P7 = 0.012]. On days 30 and 90, the inflammatory cell count was (11.43 ± 4.81) and (4.82 ± 2.29) cells/0.5 mm(3), respectively, and there was no statistically significant difference in the inflammatory cell count compared with the preoperative level (t30 = 2.348, P30 = 0.042; t90 = 1.376, P90 = 0.186). For the control group, inflammatory cell count reduced to pre-operative level on day 7 (t7 = 2.464, P7 = 0.018). Anterior chamber inflammation reaches peak levels one week postoperatively in VKH and BD patients who receive phacoemulsification with IOL implantation. It takes three months for the inflammation to recede, and might take longer for complete restoration of the blood-aqueous barrier.

Randomized clinical trial of cryotherapy versus laser photocoagulation for retinopexy in conventional retinal detachment surgery

PURPOSE: To investigate whether the method of retinopexy influences the visual recovery rate and the breakdown of the blood-ocular barrier after conventional retinal detachment surgery. METHODS: Forty-eight patients (48 eyes) with primary rhegmatogenous retinal detachment entered into the study. All eyes were phakic, had an attached macula, and were scheduled for conventional scleral buckling surgery. Patients were randomly assigned to have either laser or cryotherapy for retinopexy. All visual acuity and flare measurements were performed by a masked observer. The interventional procedure was cryopexy at the time of scleral buckling surgery or postoperative (4 weeks) laser photocoagulation. Visual acuity testing with ETDRS chart and aqueous flare measurement with laser flare photometry were performed by a masked observer at standard intervals: preoperatively and 1 day, 7 days, 4 weeks, and 10 weeks postoperatively. Analysis of covariance by multiple linear regression was used for statistical evaluation. RESULTS: Postoperative flare values from patients receiving cryotherapy were significantly higher at each measurement point in time ( P ≤ .001). The visual recovery was slower in the patients receiving cryotherapy (1 week, P = .003; 4 weeks, P = .03; 10 weeks, P = .081). CONCLUSION: Laser flare photometry proved sufficiently sensitive to quantify an increase in aqueous flare after limited external retinal cryotherapy. Postoperative flare, as a measure of blood-ocular barrier breakdown, was significantly higher and visual recovery slower in the cryotherapy group. Visual acuity after 10 weeks was not significantly different between both groups.

Intraocular lidocaine in phacoemulsification: An endothelium and blood–aqueous barrier permeability study

Objective To evaluate the effects of intraocular lidocaine hydrochloride (HCl) on the corneal endothelium and of blood–aqueous barrier (BAB) permeability in ultrasound phacoemulsification. Design Nonrandomized, comparative trial. Participants Sixty patients who underwent uneventful, single-surgeon, clear cornea phacoemulsification were studied prospectively. Methods Sub-Tenon’s anesthesia was administered to 30 patients (group 1), and intraocular lidocaine hydrochloride was administered to an additional 30 patients (group 2). An endothelial study of at least 120 cells per patient, using a noncontact specular microscope and a digital image analysis system, was performed before surgery and 1 month after surgery. Blood–aqueous barrier permeability was evaluated preoperatively and postoperatively (48 hours, 1 week and 1 month) using a laser flare meter. Main outcome measures Endothelial parameters (cell density, hexagonality, and coefficient of variation in cell area) and BAB permeability. Results No significant differences were found between groups when comparing the postoperative changes produced in endothelial cell density (95% confidence interval [CI], 0.46, 4.7; P = 0.10), hexagonality (95% CI, −2.5, 3.5; P = 0.72), and coefficient of variation in cell area (95% CI, −8.3, 4.6; P = 0.57). A multivariate study detected no significant differences in mean flare values between groups during follow-up ( P = 0.40). No clinically significant differences were found between mean preoperative and 1 month postoperative flare values in either group. Conclusions The recovery of BAB permeability 1 month after surgery seems to suggest that no additional inflammation was induced by intraocular lidocaine HCl. The fact that no differences in postoperative changes in endothelial parameters were found between groups indicates that no further corneal endothelial damage (other than that caused by surgical manipulation) was incurred. According to our results, intracameral lidocaine HCl appears to be safe for the average phacoemulsification patient in the absence of ocular pathologic conditions.

Course of postoperative inflammation after implantation of 4 types of foldable intraocular lenses

Purpose To compare the course of postoperative inflammation after small incision cataract surgery with implantation of 4 types of foldable intraocular lenses (IOLs). Setting Department of Ophthalmology, University Hospital of Vienna, Austria. Methods One hundred twenty eyes were prospectively randomized to receive a foldable silicone (Pharmacia 920), hydrogel (Bausch & Lomb Hydroview™), methyl methacrylate/hydroxyethyl methacrylate (Mentor MemoryLens®), or acrylic (Alcon AcrySof®) IOL. All surgery was performed by the same experienced surgeon using a standardized surgical protocol: clear corneal incision, capsulorhexis, phacoemulsification, and in-the-bag implantation of the IOL. All patients received standardized postoperative medication and follow-up. Postoperative inflammation was evaluated by measuring aqueous flare preoperatively and 1, 3, 7, 14, 28, 90, and 180 days after surgery using the Kowa 1000 laser flare–cell meter. Results Except on the first day after surgery, when the AcrySof group had higher flare values than the other groups ( P = .0265), no significant differences were found up to 6 months. Re-establishment of the blood−aqueous barrier was similar in eyes with the AcrySof, Hydroview, and MemoryLens IOLs; the course of postoperative inflammation was different in eyes with the silicone IOL. Conclusion Comparison of postoperative flare values after implantation of 4 foldable IOLs showed no clinically relevant differences in the course of postoperative inflammation.

Quantification of aqueous flare after phacoemulsification with intraocular lens implantation in eyes with pseudoexfoliation syndrome.

Impairment of the blood-aqueous barrier is a frequent finding in eyes with pseudoexfoliation syndrome (PEX). To perform noninvasive quantification of aqueous flare using the laser flare-cell meter to analyze blood-aqueous barrier breakdown following phacoemulsification with intraocular lens implantation in eyes with and without PEX. After other conditions that might account for impairment of the blood-aqueous barrier were excluded, 11 eyes with PEX and 11 eyes with senile cataract without PEX were included in the study. Aqueous flare was quantitatively determined using a laser flare-cell meter preoperatively as well as 1, 3, and 5 days postoperatively. Phacoemulsification with posterior chamber intraocular lens implantation was performed by one surgeon. On the first postoperative day, flare values (calculated as mean+/-SD photon counts per millisecond) in eyes with PEX were higher (42.2+/-21.3) than in eyes without PEX (30.6+/-15.1) (P>.05). On days 3 and 5, postoperative flare values decreased slowly in eyes with PEX (23.9+/-7.4 and 21.2+/-5.7 photon counts per millisecond, respectively) and were significantly higher than in eyes without PEX (14.8+/-5.4 and 10.5+/-1.4 photon counts per millisecond, respectively) (P<.05). Breakdown of the blood-aqueous barrier is significantly more extensive in eyes with PEX and may be an important risk factor for early postoperative complications. The altered response to surgery should be considered in eyes with PEX.

Quantification of blood-aqueous barrier breakdown after photorefractive keratectomy for myopia.

Photorefractive keratectomy (PRK) using the excimer laser is a well-established surgical technique for correction of mild to moderate myopic refraction errors in case of spectacle or contact lens incompatibility. As it is still uncertain whether this procedure causes intraocular inflammatory changes, it was the purpose of this study to quantify breakdown of the blood-aqueous barrier following PRK and to look for possible correlations with clinical parameters. Aqueous flare was quantified using the laser flare-cell meter after medical pupil dilation preoperatively and on days 1, 3 and 7 as well as 1 month and 3 months following PRK with a 193-nm excimer laser (MEL 60, Aesculap-Meditec) in 37 eyes of 22 patients. The preoperative spherical equivalents were -4.4 +/- 3.1 D (range -1.5 to -8.0 D). Pre-, intra- and postoperative treatment was standardized. Preoperatively, aqueous flare values were 3.9 +/- 0.8 photon counts/ms and showed no significant correlation with the spherical equivalent (p > 0.1). Postoperatively, aqueous flare rise was very small with flare values not significantly higher than preoperative values. All postoperative flare values were below the normal limit (< 8.0 photon counts/ms). Flare was highest on day 3 after PRK surgery. There was no statistically significant correlation between aqueous flare and depth of stromal ablation. The number of aqueous "cells" did not increase following PRK at any postoperative follow-up examination. Our results indicate that PRK in mild to moderate myopia does not cause a significant breakdown of the blood-aqueous barrier.

Subclinical inflammation after laser in situ keratomileusis

Purpose: To determine whether laser in situ keratomileusis (LASIK) for the correction of myopia induces an anterior chamber inflammatory response measurable with laser flare-cell photometry.Setting: Instituto Oftalmolãgico de Alicante, University of Alicante, Alicante, Spain.Methods: Twenty eyes in 20 patients had LASIK to correct myopia ranging from 2.50 to 15.00 diopters (D) (mean -8.94 ± 3.25 [SD]). Anterior chamber inflammation was measured preoperatively and 1, 3, 7, and 15 days and 1 and 3 months postoperatively using the flare mode of a laser flare-cell meter. All eyes received topical fluorometholone 0.1% drops for 2 weeks postoperatively.Results: Anterior chamber flare values at 1 and 3 days and 1 week postoperatively were not significantly different from those found preoperatively. However, a significant decrease was found at 2 weeks and 1 month (P < .01 and P < .05, respectively). Flare values returned to their preoperative levels at 3 months. No significant correlations between postoperative flare values and depth of ablation were found.Conclusion: In this study, LASIK did not induce an inflammatory response in the anterior chamber in the myopic eye.

Effect of heparin in irrigating solution on inflammation following small incision cataract surgery

Purpose: To study the effect of heparin-sodium added to the irrigating solution on postoperative inflammation in patients having cataract surgery.Setting: Department of Ophthalmology, University of Giessen, Giessen, Germany.Methods: Seventy-two patients having phacoemulsification with posterior chamber intraocular lens (IOL) implantation were randomly assigned to receive regular irrigating solution or solution with heparin-sodium (final diluted concentration 10 IU/mL). In half the patients, poly(methyi methacrylate) (PMMA) IOLs were implanted and in half, foldable silicone IOLs. The patients were examined preoperatively, on days 1 and 3, and 1 year postoperatively. Postoperative inflammation was objectively evaluated by measurement of flare and cells using laser flare-cell photometry.Results: The mean postoperative flare values were significantly lower in the groups with additional heparin-sodium at days 1 and 3 (P < .01). Flare values were not significantly different 1 year postoperatively. Cell values for the heparin-treated groups were lower, but the difference did not reach statistical significance. Flare and cells values for the two IOL materials were not significantly different during the entire follow-up.Conclusion: Heparin-sodium added to the infusion solution during small incision cataract surgery reduced inflammation in the early postoperative period.

Chronic subclinical inflammation in phakic eyes with intraocular lenses to correct myopia

Purpose: To evaluate whether either of two anterior chamber intraccular lenses (IOLs) implanted in myopic, phakic eyes induced an inflammatory response that was measurable with a laser flare-cell meter but that could not be measured by other methods.Setting: Jiménez-Díaz Foundation and San Carlos University Hospital, Madrid, Spain.Methods: Thirty eyes with a Worst-Fechner IOL and 30 eyes with a Baikoff ZB5M IOL were evaluated using the flare mode of a laser flare-cell meter. Patients in each group were divided into three subgroups of 10 eyes each according to when the postoperative flare measurements were done: 12 months, 18 months, and 24 months. Thirteen phakic eyes with myopia greater than −6.00 diopters were used as controls.Results: Postoperative flare in the Worst-Fechner group was 27.05 ± 19 photons per millisecond (photons/ms) (mean ± SD) at 12 months, 18.09 ± 17.38 photons/ms at 18 months, and 31.03 ± 28.8 photons/ms at 24 months. Postoperative flare in the Baikoff group was 21.1 ± 5.9 photons/ms at 12 months, 16.13 ± 8.3 photons/ms at 18 months, and 21.05 ± 23.5 photons/ms at 24 months. Flare in the control group was 4.24 ± 2.8 photons/ms. Postoperative flare values were significantly higher in both IOL groups than in the control group at all follow-ups (Mann-Whitney test, P < .05). Postoperative flare values in the Worst-Fechner group were higher than in the Baikoff group at 12, 18, and 24 months, although the difference was not significant (Mann-Whitney test, P > .05).Conclusions: Our study shows chronic subdinical inflammation between 1 and 2 years after implantation of both IOL types.