A cross-sectional study of ophthalmologic examination findings in 5385 Koreans presenting with intermittent exotropia

The Korean Intermittent Exotropia Multicenter Study (KIEMS) was a retrospective, cross-sectional and multicenter study for the investigation of intermittent exotropia involved 65 strabismus specialists from 53 institutions in Korea. Purpose of this study was to present ophthalmologic findings of intermittent exotropia from the KIEMS. Consecutive patients with intermittent exotropia of ≥ 8 prism diopters (PD) at distance or near fixation were included. Best-corrected visual acuity, cycloplegic refraction data, angles of deviation at several cardinal positions, ocular dominance, fusion control, oblique muscle function, and binocular sensory outcomes were collected. A total of 5385 participants (2793 females; age 8.2 years) were included. Non-dominant eye was more myopic than the dominant eye (- 0.60 vs. - 0.47 diopters, P < 0.001). Mean exodeviation angles were 23.5 PD at distance and 25.0 PD at near fixation. Basic type (86.2%) was the most, followed by convergence insufficiency (9.4%) and divergence excess (4.4%) types. Alternating ocular dominance and good fusion control were more common at near than at distance fixation. Good stereopsis at 40 cm was observed in 49.3% in Titmus stereo test (≤ 60 arcsec) and in 71.0% in Randot stereo test (≤ 63 arcsec). Intermittent exotropia was mostly diagnosed in childhood and patients with the condition showed relatively good binocular functions. This study may provide objective findings of intermittent exotropia in a most reliable way, given that the study included a large study population and investigated comprehensive ophthalmology examinations.

Retinopathy of Prematurity Treatment Trends from 2003 to 2020 in the United States

We used population-based data obtained from Optum’s Clinformatics® Data Mart Database to characterize recent trends in retinopathy of prematurity (ROP) treatments and outcomes in the United States. Laser photocoagulation was utilized more frequently every year compared to anti-VEGF.

Incidence of infectious complications following strabismus surgery

A total of 167 cases (0.111%) of infectious complications (endophthalmitis, orbital cellulitis, preseptal cellulitis, and postoperative infection) were identified in patients after strabismus surgery. The incidence of postoperative endophthalmitis was approximately 1 per 13,700 strabismus surgeries (0.007%) among 151,011 strabismus surgeries in US claims databases.

Trends in congenital nasolacrimal duct obstruction surgical procedures in the United States from 2003 to 2016

In this population-based retrospective cohort study, the Optum claims dataset was used to identify children <4 years of age with the diagnosis of nasolacrimal duct obstruction during the period 2003-2016. A total of 156,044 children were identified, of whom 16,538 (9.43%) underwent a surgical procedure. There was a downward trend for the frequency of all types of treatments but particularly for facility-based probings.

Endophthalmitis after pediatric cataract surgery in the United States: report using an insurance claims database

PURPOSE

To describe the characteristics and incidence of children developing endophthalmitis within the first 90 days following pediatric cataract surgery.

SETTING

Deidentified commercial and Medicare Advantage health claims across the United States.

DESIGN

Population-based retrospective cohort study.

METHODS

In a retrospective review of approximately 58 million charts in Optum's deidentified Clinformatics Data Mart Database, patients aged <13 years who underwent cataract surgery in one or both eyes with or without primary intraocular lens (IOL) implantation between 2003 and 2017 were identified. Excluded were patients with traumatic cataract, <90 days of continuous insurance coverage, a prior diagnosis of endophthalmitis, and a diagnosis of endophthalmitis occurring after 90 days of cataract surgery. The main outcome measure was the incidence of endophthalmitis occurring within the first 90 days of cataract surgery and the odds ratio for developing endophthalmitis according to demographic and intraoperative factors.

RESULTS

Cataract surgery was performed on 789 eyes (52.6% male), with a median age of 4 (interquartile range 1-8) years. The rate of IOL implantation at the time of cataract surgery was 66.8%. Endophthalmitis was diagnosed in 4 of 789 eyes (0.51%). The median time to diagnosis of endophthalmitis was 6.5 days (range: 5-44 days). There was no significant association between endophthalmitis and age, sex, or primary IOL implantation.

CONCLUSIONS

In this large insurance claims database, the incidence of endophthalmitis following pediatric cataract surgery reported was more than the rate previously reported by any study with patients of a similar age.

An Overview of the Korean Intermittent Exotropia Multicenter Study by the Korean Association for Pediatric Ophthalmology and Strabismus

The Korean Intermittent Exotropia Multicenter Study (KIEMS), which was initiated by the Korean Association of Pediatric Ophthalmology and Strabismus, is a collaborative multicenter study on intermittent exotropia in Korea. The KIEMS was designed to provide comprehensive information, including subjective and objective findings of intermittent exotropia in a large study population. A total of 65 strabismus specialists in 53 institutions contributed to this study, which, to date, is one of the largest clinical studies on intermittent exotropia. In this article, we provide a detailed methodology of the KIEMS to help future investigations that may use the KIEMS data.

The Effect of Absorbable and Non-absorbable Scleral Suture on Strabismus Surgery in the Rabbits

Purpose: To evaluate and compare the histopathological changes in a rabbit model, following strabismus surgery using either absorbable or non-absorbable suture materials. Methods: Superior rectus muscle recession was performed in rabbits using either an absorbable (Vicryl®) or non-absorbable (Prolene®) suture material. Hematoxylin-eosin staining was performed and histologic changes in the sclera were evaluated at the first, second, fourth, and eighth weeks, postoperatively. Moreover, the postoperative scleral thickness was measured and the postoperative pattern of arrangement of scleral fibers was analyzed. Results: Suture material-induced limited inflammatory reaction and formation of new vessels were observed in the study subjects, in the early postoperative phase, in both the Vicryl® and Prolene® groups. In the Vicryl® group, multinucleated giant cells were dominant during the inflammatory phase, and replacement by fibrotic scar tissues was observed. In the Prolene® group, the suture material was observed to be intact, and the inflammatory reactions around the sutures were observed to be less severe compared to the Vicryl® group. Meanwhile, neither group exhibited reduction in scleral thickness or irregular rearrangement of scleral fibers. Conclusions: The current histological study demonstrated that there was no significant postoperative scleral tissue changes after a strabismus surgery. Furthermore, the absorbable suture material was observed to induce inflammatory reactions of greater severity, compared to the non-absorbable suture material, in scleral tissues.

Incidence of Strabismus and Amblyopia Among Children Initially Diagnosed With Pseudostrabismus Using the Optum Data Set

PURPOSE

To determine the frequency of strabismus among children initially diagnosed with pseudostrabismus using big data.

DESIGN

Population-based retrospective cohort study.

METHODS

Setting: Population-based retrospective cohort study using claims data. StudyPopulation: 17,885 children diagnosed with pseudostrabismus at age ≤3 years who were later diagnosed with strabismus using the Optum deidentified Clinformatics Data Mart Database (2003-2016). We excluded patients diagnosed with strabismus before the diagnosis of pseudostrabismus or diagnosed simultaneously with strabismus and pseudostrabismus.

OBSERVATIONS

We assessed age, refractive error, and presence of amblyopia. Patients with pseudostrabismus were compared to a group of patients from the Optum data set diagnosed with esotropia, exotropia, and unspecified heterotropia who had not been previously diagnosed with pseudostrabismus. MainOutcomeMeasures: Incidence of strabismus, among patients initially diagnosed with pseudostrabismus vs those without an initial diagnosis of pseudostrabismus.

RESULTS

Strabismus was diagnosed in 9.6% (n = 1,725) of children initially diagnosed with pseudostrabismus at a median age of 1.65 years (IQR: 1.17-2.46) compared to 1.7% (136,047 of 7,787,743) of children in the control group (P < .001). Strabismus was diagnosed more than a year later in the pseudostrabismus group (3.32 years; IQR: 2.28-4.74) compared with the control group (2.28 years, IQR: 1.43-3.16) (P < .001). Esotropia was the most common type of strabismus in both groups (pseudostrabismus, 69.7%; control, 62.1%). A total of 377 children (21.9%) in the pseudostrabismus group underwent strabismus surgery compared with 12.1% of children in the control group (P < .001).

CONCLUSIONS

Young children diagnosed with pseudostrabismus are at increased risk of developing strabismus and undergoing strabismus surgery.

Clinical Manifestations of Strabismus in Patients with Primary Congenital Glaucoma

Purpose: To determine the clinical manifestations and risk factors of developing strabismus in primary congenital glaucoma (PCG) patients who underwent glaucoma surgery. Methods: A retrospective case-series study of 54 PCG patients who were followed for at least 3 years after glaucoma surgery. The subjects were divided into 2 groups based on the occurrence of strabismus. Age at glaucoma diagnosis and surgery, visual acuity, intraocular pressure, amblyopia, cup-disc ratio, and orthoptic status were compared between the 2 groups. Results: Twenty of 54 patients (37.0%) developed strabismus after glaucoma surgery. The mean ages at the time of glaucoma diagnosis and surgery were 3.2 ± 2.7 months and 3.4 ± 2.8 months in the strabismus group and 24.3 ± 19.1 months and 26.4 ± 18.9 months in the non-strabismus group, respectively (p < .05). In addition, the mean logMAR visual acuities were 0.87 ± 0.38 in the strabismus group and 0.24 ± 0.21 in the non-strabismus group (p < .05). The proportion of patients experiencing amblyopia was 90.0% in the strabismus group. Low visual acuity and young age at glaucoma surgery were significant predictors of developing strabismus. Kaplan-Meier survival analysis demonstrated that the probability of developing strabismus after glaucoma surgery was 50.6% at 10 years post-surgery. Conclusions: PCG patients who developed strabismus after glaucoma surgery were diagnosed with glaucoma and underwent surgery at a younger age, exhibited a worse mean best corrected visual acuity, and exhibited a higher amblyopia incidence than did patients in the non-strabismus group.

Pattern of Extraocular Muscle Involvements in Miller Fisher Syndrome

Background and Purpose

The most-common initial manifestation of Miller Fisher syndrome (MFS) is diplopia due to acute ophthalmoplegia. However, few studies have focused on ocular motility findings in MFS. This study aimed to determine the pattern of extraocular muscle (EOM) paresis in MFS patients.

Methods

We consecutively recruited MFS patients who presented with ophthalmoplegia between 2010 and 2015. The involved EOMs and the strabismus pattern in the primary position were analyzed. Antecedent infections, other involved cranial nerves, and laboratory findings were also reviewed. We compared the characteristics of the patients according to the severity of ophthalmoplegia between complete ophthalmoplegia (CO) and incomplete ophthalmoplegia (IO).

Results

Twenty-five patients (15 males and 10 females) with bilateral ophthalmoplegia were included in the study. The most-involved and last-to-recover EOM was the lateral rectus muscle. CO and IO were observed in 11 and 14 patients, respectively. The patients were aged 59.0±18.4 years (mean±SD) in the CO group and 24.9±7.4 years in the IO group (p<0.01), and comprised 63.6% and 21.4% females, respectively (p=0.049). Elevated cerebrospinal fluid protein was identified in 60.0% of patients with CO and 7.7% of patients with IO (p=0.019) for a mean follow-up time from the initial symptom onset of 3.7 days.

Conclusions

The lateral rectus muscle is the most-involved and last-to-recover EOM in ophthalmoplegia. The CO patients were much older and were more likely to be female and have an elevation of cerebrospinal fluid protein than the IO patients.

Postoperative Muscle Migration Through Stretched Scar Formation After Superior Rectus Muscle Nonscleral Sutured Resection in Rabbit Eyes

PURPOSE

To determine whether suturing to the residual muscle stump induces postoperative muscle migration after superior rectus muscle (SRM) resection in rabbit eyes.

METHODS

Twenty-four eyes in 12 rabbits were randomly divided into two groups. Each group underwent a 3-mm SRM resection. The muscle stump was not removed in one randomly assigned eye in each rabbit and the resected muscle was sutured to the residual muscle stump (residual muscle stump group). In the other eye, the muscle stump was completely removed and the resected muscle was sutured to the original insertion site (control group). At postoperative weeks 1, 2, and 4, the distances between the most anterior aspect of the reattached muscle and the corneal limbus were measured. Histopathologic differences at the new attachment sites were assessed between the two groups at postoperative week 4.

RESULTS

The mean distance between the corneal limbus and SRM was 2.97 ± 1.00 mm in the residual muscle stump group and 1.99 ± 0.40 mm in the control group at postoperative week 2 (P = .026) and 3.14 ± 0.78 mm in the residual muscle stump group and 1.81 ± 0.44 mm in the control group at postoperative week 4 (P = .002). Connective tissue, fibrosis, and myofibroblast proliferation in the front of the SRM were identified based on histopathologic findings.

CONCLUSIONS

Postoperative loosening associated with a stretched scar frequently occurred in cases with suturing to the residual muscle during rectus muscle resection and could result from fibrosis and connective tissue proliferation in front of the rectus muscle. [J Pediatr Ophthalmol Strabismus. 2019;56(4):254-260.].

Is Severe and Long-lasting Linezolid-induced Optic Neuropathy Reversible?

Linezolid is a useful drug for treating drug-resistant tuberculosis. However, the associated toxicities, especially optic neuritis, are a major obstacle for its long-term use. We recently experienced a case of severe optic and peripheral neuropathy during the treatment of multidrug-resistant tuberculosis. The treatment continued for 12 months despite severe optic and peripheral neuropathy. At eight months after the discontinuation of the drug, the optic neuropathy recovered, but the peripheral neuropathy did not. Considering the grave prognosis of drug-resistant tuberculosis, the continuation of linezolid despite neurotoxicity under close observation may be a suitable option.

Classification of Lacrimal Punctal Stenosis and Its Related Histopathological Feature in Patients with Epiphora

Purpose

To evaluate the classification of punctal stenosis based on the shape of the external punctum, clinical characteristics and histopathologic features.

Methods

Patients who experienced tearing and were diagnosed with punctal stenosis were evaluated in this study. Punctal stenosis was classified according to the shape of the lower external punctum, which included membranous type, slit type, horseshoe type, and pinpoint type. Tear meniscus height, 2% fluorescein dye disappearance test and lacrimal pathway irrigation were measured or performed. For treatment, a punctal snip operation and silicone tube placement were performed, and the peripunctal histopathological findings were evaluated.

Results

Punctal stenosis was classified into four types: membranous type (17 eyes, 21.5%), slit type (11 eyes, 13.9%), horseshoe type (25 eyes, 31.6%), and pinpoint type (26 eyes, 32.9%). The tear meniscus was significantly higher, and the 2% fluorescein dye disappeared significantly more slowly in the punctal stenosis group. However, correlation of the tear meniscus height and 2% fluorescein dye disappearance test with the punctum shape was not statistically significant. A history of previous chemotherapy was significantly associated with the occurrence of punctal stenosis, especially the membranous type (p < 0.05). Histopathologic evaluation of the punctum showed differences between the punctum types. Pinpoint puncta exhibited a high density of muscle fibers, while they were faintly visible in the membranous type.

Conclusions

Acquired punctal stenosis has various shapes, and the major types of stenotic puncta exhibited unique histopathologic features. Punctal stenosis and its pathophysiology may be related to multiple factors, such as age and systemic 5-fluorouracil chemotherapy history.

Effects of upper lid blepharoplasty on visual quality in patients with lash ptosis and dermatochalasis

AIM

To assess the effects of upper lid blepharoplasty on visual quality.

METHODS

Seventy-three eyelids of 39 patients were subjected to upper lid blepharoplasty. Pre- and post-operative contrast sensitivity, visual acuity, vertical palpebral aperture and the degree of lash ptosis were measured.

RESULTS

The mean log contrast sensitivities under photopic (P=0.017) and scotopic conditions (P=0.009) were improved after surgery, and these differences were significant. The degree of lash ptosis was also decreased after blepharoplasty (P<0.001).

CONCLUSION

In our study, a significant increase in contrast sensitivity was found after surgery. These results suggest that upper lid blepharoplasty can be helpful for improving visual quality.

Reduction in Rectus Muscle Recession Depending on the Distance Between Rectus Muscle Suture Placement and Scleral Insertion in Rabbit Eyes

PURPOSE

To quantitatively determine how a large tendon remnant reduces the effect of the rectus muscle recession procedure with respect to the distance between the placement of the muscle suture and the scleral insertion.

METHODS

Thirty-six eyes from 18 rabbits were randomly divided into four groups according to the distance between the superior rectus muscle suture placement and the scleral insertion (1, 2, 3, and 4 mm). The superior rectus muscle was sutured at the previously listed distances from the insertion. Each superior rectus muscle was reattached using a scleral pass at a site 4 mm posterior to its original insertion. The amount of recession was measured as the distance between the most anterior aspect of the reattached muscle and the original insertion site.

RESULTS

The mean amount of recession was 4.07 ± 0.25 mm in the 1-mm group and 2.76 ± 0.55 mm in the 4-mm group at postoperative week 4. There were significant differences in the amount of recession between the four groups. Linear regression analyses revealed a significant relationship between the distance of the muscle suture placement from the scleral insertion and the amount of recession (r(2) = 0.521). The superior rectus muscle was estimated to be reattached 0.437 mm anterior to the desired location for every 1 mm that the muscle suture was placed posterior to the scleral insertion.

CONCLUSIONS

The potential error that depends on the distance between the muscle suture placement and the scleral insertion should be considered to reduce undercorrection and ensure a good surgical outcome.

Changes in refractive error in patients with accommodative esotropia after being weaned from hyperopic correction

BACKGROUND

To determine the long-term changes in refractive error and ocular alignment in patients with accommodative esotropia (AET) who were able to discontinue wearing hyperopic glasses because of emmetropisation.

METHODS

Forty-seven patients with refractive AET who achieved emmetropisation and orthotropia without hyperopic glasses and were followed up for at least 3 years were enrolled. All of the patients had been prescribed the weakest possible glasses for best corrected vision. Refractive error and ocular alignment were analysed after the cessation of hyperopic glasses use.

RESULTS

The mean length of follow-up was 5.7±3.21 years after successful weaning from hyperoptic glasses. The mean spherical equivalent (SE) of the refractive error was -1.01±1.53 dioptres (D), and the mean esotropia (ET) was 1.0±8.70 Δ at the final visit. Myopia developed in 55.3% of all patients. The mean myopic progression rate per year was -0.19±0.23 D/year. Forty-one patients (87.2%) showed orthotropia; in addition, three of the patients (6.4%) developed ET, and three (6.4%) developed exotropia (XT). The six patients who had ET or XT all showed myopia. Two of the three patients who developed ET underwent surgery. Both patients initially had a low degree of hyperopia and a high ratio of accommodative convergence to accommodation (AC/A). The initial hyperopia correlated with the SE refractive error at the final follow-up (p<0.001).

CONCLUSIONS

When emmetropisation occurs early in patients with AET, it is necessary to note the development of myopia and the deterioration of ocular alignment.

Acute angle-closure glaucoma in a patient with miller fisher syndrome without pupillary dysfunction

PURPOSE

To report a case of an angle-closure glaucoma in a patient with Miller Fisher syndrome (MFS) without pupillary dysfunction.

METHODS

We present a case report of a 75-year-old male presenting with total ophthalmoplegia, complete bilateral ptosis, and gait disturbance. He was diagnosed with MFS without pupillary dysfunction, which precipitated unilateral acute angle-closure glaucoma (AACG) due to complete lid ptosis.

RESULTS

The initial ocular examination revealed hand motion in the right eye. Intraocular pressure, as assessed by Goldmann applanation tonometry, was 50 mm Hg, and gonioscopic findings revealed a closed angle on the right eye. After maximal tolerated medical therapy, laser peripheral iridotomy was performed. The unilateral AACG with MFS resolved without further incident.

CONCLUSIONS

This is the first reported case of a patient with MFS without autonomic dysfunction and AACG. We believe that pupillary dysfunction or lid ptosis due to neurological disorders may increase the possibility of AACG.

Herpes zoster ophthalmicus with isolated trochlear nerve palsy in an otherwise healthy 13-year-old girl

Herpes zoster ophthalmicus is rare in healthy children. It is occasionally associated with extraocular muscle palsies and rarely with isolated trochlear nerve palsy. We report a case of unilateral isolated trochlear nerve palsy associated with herpes zoster ophthalmicus in an immunocompetent 13-year-old girl who presented with diplopia and blurred vision in her right eye. The right cornea had multiple subepithelial opacities. Ocular motility returned to normal and diplopia and corneal opacification resolved with steroid therapy. To our knowledge, this is the first such case involving the troclear nerve in a child.

The effect of a temperature-sensitive poloxamer-alginate-CaCl2 mixture after strabismus surgery in a rabbit model

PURPOSE

To determine the efficacy of a temperature-sensitive poloxamer-alginate mixture in reducing adhesions after strabismus surgery in a rabbit model.

METHODS

The superior rectus muscle was recessed in each of 36 eyes from 18 rabbits. One randomly assigned eye in each rabbit was treated with a poloxamer-alginate mixture (PA group); the other eye was treated with a subconjunctival injection of saline (control group). The adhesions between the superior rectus muscle, sclera, and conjunctiva were clinically evaluated by a masked observer at 1 day, 1 week, and 4 weeks after surgery. Inflammation was analyzed by hematoxylin and eosin staining and anti-CD11b staining. Late fibrosis was assessed by the Masson trichrome and α-smooth muscle actin staining. Adhesion, inflammation, and fibrosis were graded on a scale of 0-4.

RESULTS

There was no significant between-group difference in the degree of adhesion at 1 day and 4 weeks after surgery. However, the degree of adhesion in the PA group was lower than that in the control group at postoperative week 1 (P < 0.05). Acute inflammation was similar between the groups (P > 0.05). At postoperative week 4, inflammatory cell infiltration was reduced in the PA group (P = 0.046). A significant between-group difference in late fibrosis at postoperative week 4 was observed through the Masson trichrome (P = 0.024) and α-smooth muscle actin staining (P = 0.025).

CONCLUSIONS

The poloxamer-alginate mixture significantly decreased adhesion after strabismus surgery in a rabbit model. Additional studies are warranted to evaluate the use of this mixture in preventing postoperative adhesions.

Microscopic characteristics of the inferior tarsal muscle and its surroundings in Korean

AIM

To investigate the detailed microscopic anatomic structures of the lower eyelid in Korean cadavers.

METHODS

Eight lower eyelids of 4 formalin-fixed Asian cadavers (4 males; age range, 48-69 years; mean age, 60.2 years) were examined. Three perpendicular dissected sections with a 2mm thickness were obtained from each eyelid to investigate anatomic shapes, size and relationship with surrounding structures. One section was obtained from the midline and 2 the other sections were obtained from a 3mm apart from the lateral and medial tarsus margins.

RESULTS

The inferior tarsal muscle fibers were not directly attached to the tarsus but were only linked to the tarsus with enclosed fibrous fascia. The inferior tarsal muscles connected loosely with the capsulopalpebral fascia anteriorly and the conjunctiva posteriorly. The inferior tarsal muscle runs horizontally to the tarsus according to the shape of muscle fibers. The capsulopalpebral fascia consisted of an anterior and posterior layer. The anterior layer reached the orbital septum and subcutaneous fat but the posterior layer forwarded into the tarsus. Lockwood's ligament was separated from the inferior tarsal muscle and capsulopalpebral fascia or fused into the capsulopalpebral fascia.

CONCLUSION

This study suggests that the inferior tarsal muscle which runs horizontally and doesn't insert directly into the tarsus, plays an important role in the movement and localization of the lower eyelid.

Changes in sagging extraocular muscle following surgical recession of the superior rectus muscle in rabbit eyes

PURPOSE

To verify whether central muscle sag actually induces excessive recession after recession of the rectus muscle in rabbit models.

METHODS

Twenty-four eyes of 12 rabbits were divided into two groups. In the right eyes (the muscle sagging group), half of the width of the original insertion was used to create a scleral suture during a 4-mm superior rectus muscle (SRM) recession and a central muscle sag of 2 mm was generated. Conventional 4-mm SRM recessions were performed in the left eyes (control group). At postoperative weeks 1, 2, and 4, the distances between the locations of the new insertion and the original insertion were measured at the center and nasal and temporal poles.

RESULTS

At postoperative week 4, the difference between the two groups at center was 1.38 ± 1.17 mm (P = .008). The mean extent of the recession at the nasal edge of the insertion was 5.21 ± 0.94 mm in the muscle sagging group, which showed posterior migration and slippage relative to the mean extent of the recession in the control group (4.29 ± 0.50 mm; P = .014). The mean extent of the recession at the temporal edge of the insertion was 5.50 ± 0.74 mm in the muscle sagging group and 4.50 ± 0.77 mm in the control group (P = .005).

CONCLUSIONS

Overcorrection that occurred in cases of central muscle sag in the rabbit models resulted from posterior migration of recessed muscle that occurred in conjunction with slippage of its nasal and temporal edges.

Efficacy of Seprafilm(®) graft with adhesiolysis in experimentally induced lid adhesion in rabbits

AIM

To evaluate the efficacy of Seprafilm(®) transplantation following adhesiolysis for preventing postoperative readhesion and improving surgical outcomes.

METHODS

Primary blepharoplasty was carried out on both eyelids of 18 albino rabbits. After 2 weeks, a new skin incision was made, and adhesiolysis was performed on both eyelids. The rabbits were categorized into two groups, one with adhesiolysis alone in the left eyelid (control group), and the other with adhesiolysis with a Seprafilm(®) graft in the right eyelid (Seprafilm(®) group). The degrees of inflammation and fibrosis were examined with hematoxylin-eosin (HE) and Masson's trichrome stains. Expression of α-smooth muscle actin (α-SMA) was also immunohistochemically examined.

RESULTS

Eyelid examination immediately after the operation revealed mild swelling and hemorrhage in both groups, but these symptoms resolved after 1 week-2 weeks, and eyelid shape had recovered completely in both groups. Microscopic assessments demonstrated that the Seprafilm(®) group showed less inflammation and fibrosis than the control group. The Seprafilm(®) group also exhibited fewer α-SMA-positive cells than the control group.

CONCLUSION

Based on these findings, we conclude that Seprafilm(®) graft with adhesiolysis is an effective method for preventing postoperative readhesions after eyelid surgery.

Cytoplasmic and nuclear anti-apoptotic roles of αB-crystallin in retinal pigment epithelial cells

In addition to its well-characterized role in the lens, αB-crystallin performs other functions. Methylglyoxal (MGO) can alter the function of the basement membrane of retinal pigment epithelial (RPE) cells. Thus, if MGO is not efficiently detoxified, it can induce adverse reactions in RPE cells. In this study, we examined the mechanisms underlying the anti-apoptotic activity of αB-crystallin in the human retinal pigment epithelial cell line ARPE-19 following MGO treatment using various assays, including nuclear staining, flow cytometry, DNA electrophoresis, pulse field gel electrophoresis, western blot analysis, confocal microscopy and co-immunoprecipitation assays. To directly assess the role of phosphorylation of αB-crystallin, we used site-directed mutagenesis to convert relevant serine residues to alanine residues. Using these techniques, we demonstrated that MGO induces apoptosis in ARPE-19 cells. Silencing αB-crystallin sensitized ARPE-19 cells to MGO-induced apoptosis, indicating that αB-crystallin protects ARPE-19 cells from MGO-induced apoptosis. Furthermore, we found that αB-crystallin interacts with the caspase subtypes, caspase-2L, -2S, -3, -4, -7, -8, -9 and -12 in untreated control ARPE-19 cells and that MGO treatment caused the dissociation of these caspase subtypes from αB-crystallin; transfection of S19A, S45A or S59A mutants caused the depletion of αB-crystallin from the nuclei of untreated control RPE cells leading to the release of caspase subtypes. Additionally, transfection of these mutants enhanced MGO-induced apoptosis in ARPE-19 cells, indicating that phosphorylation of nuclear αB-crystallin on serine residues 19, 45 and 59 plays a pivotal role in preventing apoptosis in ARPE-19 cells. Taken together, these results suggest that αB-crystallin prevents caspase activation by physically interacting with caspase subtypes in the cytoplasm and nucleus, thereby protecting RPE cells from MGO-induced apoptosis.