Argon laser iridotomy-induced bullous keratopathy a growing problem in Japan

The Japan Glaucoma Society guidelines for glaucoma 5th edition

We are pleased to bring you the 5th edition of the Glaucoma Clinical Practice Guidelines. Clinical practice guidelines are based on evidence (scientific grounds). It is a document that presents the treatment that is the most appropriate for the patient. "Glaucoma Clinical Guidelines" was first published in 2003. This was the first guideline for glaucoma treatment in Japan. The principle of glaucoma treatment is to lower intraocular pressure. Means for lowering intraocular pressure includes drugs, lasers, and surgery; Glaucoma is a disease that should be considered as a complex syndrome rather than a single condition. Therefore, the actual medical treatment is not as simple as one word. This time we set the Clinical Questionnaire with a focus on glaucoma treatment. We hope that you will take advantage of the 5th edition.

Effect of Topical Pilocarpine Instilled Before Laser Peripheral Iridotomy on Regional Iris Thickness in Primary Angle Closure Disease: A Swept-Source Anterior Segment Optical Coherence Tomography Pilot Study

PURPOSE

To determine whether the temporal-superior or the nasal-superior iris area becomes thinner (more optimal) for laser peripheral iridotomy (LPI) after pilocarpine instillation in primary angle closure disease (PACD); and to identify an angle for optimal penetration of the laser beam.

PATIENTS AND METHODS

Iris thickness at 2 mm from the iris root in the preset scanning axes was measured using swept-source anterior segment optical coherence tomography before and 60 minutes after the instillation of pilocarpine 2% in one eye of 30 consecutive Japanese PACD patients with thick, dark brown iris. Iris thickness at 1:30 and 10:30 clock hour positions were evaluated in sagittal and oblique directions, resulting sagittal iris thickness (SIT) and minimum iris thickness (MIT) parameters, respectively.

RESULTS

Compared to the baseline values, iris thickness decreased significantly (P < .001) in both locations after pilocarpine instillation. Both before and after pilocarpine instillation the temporal-superior iris thickness was significantly smaller than the nasal-superior thickness (P ≤ .001). After pilocarpine instillation, the temporal-superior iris was significantly thinner in an approximately 13° angle direction temporal to the sagittal direction than in the sagittal direction (MIT: 0.322 mm; SIT: 0.346 mm, P < .001).

CONCLUSIONS

After pilocarpine instillation, the temporal-superior iris and an approximately 13° angle temporal to the sagittal direction may provide an optimal location and laser beam angle for LPI in PACD eyes.

Unraveling the mechanobiology of cornea: From bench side to the clinic

The cornea is a transparent, dome-shaped structure on the front part of the eye that serves as a major optic element and a protector from the external environment. Recent evidence shows aberrant alterations of the corneal mechano-environment in development and progression of various corneal diseases. It is, thus, critical to understand how corneal cells sense and respond to mechanical signals in physiological and pathological conditions. In this review, we summarize the corneal mechano-environment and discuss the impact of these mechanical cues on cellular functions from the bench side (in a laboratory research setting). From a clinical perspective, we comprehensively review the mechanical changes of corneal tissue in several cornea-related diseases, including keratoconus, myopia, and keratectasia, following refractive surgery. The findings from the bench side and clinic underscore the involvement of mechanical cues in corneal disorders, which may open a new avenue for development of novel therapeutic strategies by targeting corneal mechanics.

Role of Monocytes/Macrophages in the Etiology of Bullous Keratopathy After Argon Laser Iridotomy

Purpose

The etiologic mechanisms of bullous keratopathy (BK) after argon laser iridotomy (ALI) are still unknown. Therefore, we investigated potential mechanisms on BK after ALI.

Methods

Corneal endothelial surface obtained in penetrating keratoplasty for BK after ALI was observed and analyzed immunohistochemically. We investigated how various leukocytes react to cultured human corneal endothelial cells in an inflamed condition and monocytes/macrophages respond to the iris treated by an argon and YAG laser or pigmented and nonpigmented iris treated by an argon laser.

Results

We detected infiltration of CD68- and CD11b-positive monocytes/macrophages in the posterior surface of trephined corneas obtained during penetrating keratoplasty for BK after ALI in three of the seven eyes with ALI. In vitro, monocytes/macrophages, but not T cells, B cells, neutrophils, or pan-leukocytes, removed many cultured human corneal endothelial cells in the medium stimulated with proinflammatory cytokines. Human pigmented iris tissues treated by the argon laser, but not those treated by the YAG laser, attracted many monocytes/macrophages and formed large, round colonies. Human monocytes/macrophages formed large colonies on the argon laser–treated pigmented iris from C3H mice but not nonpigmented iris from albino BALB/c mice.

Conclusions

Our results suggest that monocytes/macrophages, argon laser, and pigmented iris are all involved in the pathogenesis of BK after LI.

Translational Relevance

Etiology in BK after ALI has not been clear, but our findings based on clinical and experimental findings give a critical clue to explain possible mechanisms on BK after ALI.

Investigation of the Sectorized Corneal Thickness of Eyes With Corneal Endothelial Dysfunction Using Anterior-Segment Optical Coherence Tomography

PURPOSE

The aim of this study was to investigate the sectorized corneal thickness of eyes with corneal endothelial dysfunction using anterior-segment optical coherence tomography.

METHODS

We retrospectively collected anterior-segment optical coherence tomography data conducted before endothelial keratoplasty on 53 eyes of 53 patients with corneal endothelial dysfunctions including Fuchs endothelial corneal dystrophy, bullous keratopathy (BK) after trabeculectomy, and BK after laser iridotomy and from 18 normal eyes of 18 subjects. The imaging points were divided into 17 sectors. The mean for each sector was calculated and compared with the corresponding superior/inferior and temporal/nasal sectors.

RESULTS

In the normal eyes, the superior sectors were thicker than the inferior and the temporal sectors thinner than the nasal. In the diseased eyes, the superior sectors were thicker than the inferior in all subgroups; however, this tendency was no longer observed after the values were divided by the mean for the normal eyes. No significant differences were found on horizontal comparisons; however, after the values were divided by the mean for the normal eyes, the temporal sectors were thicker than the nasal. When comparing the values between the with-hole and the without-hole sides in the BK after laser iridotomy eyes, the sectors on the with-hole side were thicker than the other side.

CONCLUSIONS

Corneal thickness of endothelial dysfunction was thicker in the superior sectors than the inferior but at a similar level to normal eyes. No significant differences were found for horizontal comparisons but, based on comparison with the normal eyes, the temporal sectors were thicker than the nasal.

Corneal Endothelial Changes Following Early Capsulotomy Using Neodymium:Yttrium-Aluminum-Garnet Laser

We aimed to survey whether the timing of neodymium:yttrium–aluminum–garnet (Nd:YAG) laser capsulotomy would alter the corneal endothelial morphology and density. A retrospective cohort study was conducted, and 48 patients with unilateral posterior capsular opacity (PCO) and Nd:YAG laser capsulotomy performance were enrolled. The participants were divided into the early Nd:YAG group (timing ≤ 12 months, n = 20) and late Nd:YAG group (timing > 12 months, n= 28) depending on elapsed months between phacoemulsification and Nd:YAG laser capsulotomy. Endothelial cell density (ECD), coefficient of variant (CV), hexagonality (HEX), and central corneal thickness (CCT) between the two groups were collected. A generalized estimate equation was conducted to evaluate the corneal endothelial parameters between the two groups with an adjusted odds ratio (aOR) and 95% confidence interval (CI). The CDVA was improved after treatment in both groups (both p < 0.001). Chronically, ECD in the early group was significantly decreased one week after treatment (2221.50 ± 327.73/mm² vs. 2441.55 ± 321.80/mm², p < 0.001), which recovered to 2369.95 ± 76.37/mm² four weeks after the treatment but was still lower than the preoperative status (p < 0.001). In addition, the HEX percentage showed a significant reduction at four weeks after treatment (p = 0.028). The ECD in the early group was significantly lower than that in the late group (aOR: 0.167, 95% CI: 0.079–0.356, p = 0.003) in both week 1 (p < 0.001) and week 4 (p = 0.004) after laser treatment. In conclusion, the early application of Nd:YAG laser capsulotomy within one year after cataract surgery may be the reason for postoperative ECD decrement without known etiology.

[Laser-induced damage to the cornea after YAG laser surgery of anterior segment structures]

Laser photodestruction (LPD) of tissues is the basis of modern laser reconstructive surgery in ophthalmology. The most common laser technologies based on LPD mechanisms include YAG laser capsulotomy (discission) (LD) of secondary cataract and YAG laser iridectomy (LIE) for glaucoma. Laser reconstructive interventions for secondary cataract, as well as LIE, have a number of advantages over traditional surgery, but at the same time are associated with the risk of complications, including in the cornea. Corneal endothelium is the most susceptible to laser damage, while Descemet's membrane and corneal stroma are injured less often. This review describes cases of iatrogenic perforation and purulent inflammation of the cornea. In the long-term, laser interventions can lead to bullous keratopathy and corneal graft rejection. At this time, the most popular and available among the methods for assessing the cornea after YAG laser interventions is the method of specular microscopy. Ultrasound biomicroscopy is used less commonly. The modern method of corneal confocal microscopy is practically not used for this purpose, and taking into account the risks of developing laser-induced injuries, it indicates its relevance and the need for further research.

Association between aqueous humor cytokines and postoperative corneal endothelial cell loss after Descemet stripping automated endothelial keratoplasty

This study measured the intraoperative anterior aqueous humor concentrations of various cytokines during corneal endothelial transplantation and searched for relationships between these concentrations and postoperative corneal endothelial cell (CEC) depletion. We recruited 30 consecutive patients who underwent corneal endothelial transplantation with Descemet’s stripping automated endothelial keratoplasty (DSAEK) at Tohoku University Hospital between February 2014 and July 2017. During surgery, we obtained aqueous humor samples and later measured the concentrations of 27 cytokines with a Multiplex Bead Assay (Bio-Plex Pro). We counted CECs 1, 6 and 12 months after surgery, and used Spearman’s rank correlation coefficient to identify relationships between CEC depletion and the concentrations of detected cytokines. The loss of CECs 1–6 months after surgery was significantly correlated with IL-7, IP-10, MIP-1a and MIP-1b concentrations (-0.67, -0.48, -0.39, and -0.45, respectively, all P <0.01). CEC loss 1–12 months after surgery was significantly correlated with IL-1b, IL-7, IP-10 and RANTES concentrations (-0.46, -0.52, -0.48, and -0.43, respectively). Multiple regression analysis showed that IL-7 concentration was significantly associated with CEC loss 1–6 months after surgery (b = -0.65, P < 0.01) and IP-10 concentration was associated with CEC loss 1–12 months after surgery (β = -0.38, P < 0.05). These results suggest that not only inflammatory cytokines but also IL-7, a cytokine related to lymphocytes, may be involved in the depletion of CECs after DSAEK, particularly depletion that occurs relatively early.

Changing Indications for Corneal Transplantations in Southern Taiwan From 2008 to 2018

OBJECTIVES

To investigate the changing indications for corneal transplantations in southern Taiwan from 2008 to 2018 and compare the results with those of other previous studies.

METHODS

We retrospectively reviewed the records of patients who underwent corneal transplantations from January 2008 to December 2018 at Kaohsiung Veterans General Hospital. The patients' age, sex, indication for corneal transplantation, and the surgical technique were recorded and analyzed.

RESULTS

In total, 336 patients (421 eyes) were included in our study from January 1, 2008, to December 31, 2018. The mean age was 63.6±15.3 years; 371 penetrating keratoplasty (88.1%), 35 deep anterior lamellar keratoplasty (8.3%), and 15 Descemet-stripping automated endothelial keratoplasty (3.6%) were performed. The leading indication for corneal transplantation was regraft (n=103, 24.5%), followed by bullous keratopathy (n=82, 19.5%), corneal scar and opacity (n=79, 18.8%), keratitis (n=59, 14.0%), corneal dystrophy (n=58, 13.8%), other indications (n=26, 6.2%), and keratoconus (n=14, 3.3%).

CONCLUSION

The indications for corneal transplantations changed with time in Taiwan. Regraft was the leading indication, but there was a decreasing trend over time. The proportion of bullous keratopathy increased significantly over the past decade and is the second most common indication, similar to the most developed countries. Both corneal scar and opacity, and keratitis showed a decreasing trend of occurrence compared with a previous study in Taiwan. The proportion of keratoconus remained low, making it the least common indication for corneal transplantation.

Trends in surgical procedures and indications for corneal transplantation over 27 years in a tertiary hospital in Japan

PURPOSE

To characterize trends in procedures, and indications for corneal transplantation over 27 years in a single referral center in Japan.

STUDY DESIGN

Retrospective study.

METHODS

Data from a consecutive series of corneal transplant surgery cases performed from 1991 to 2017at Ichikawa General Hospital were collected. The surgical procedures, indications, and causes of corneal endothelial dysfunction were evaluated.

RESULTS

Among 6,025 transplantations, a total of 3,991 cases underwent penetrating keratoplasty (PKP), 1009 underwent (deep) anterior lamellar keratoplasty, 746 underwent endothelial keratoplasty, and 309 underwent epithelial transplantation. Over that period the frequency of PKP decreased, whereas the frequency of lamellar keratoplasty increased. The four major surgical indications were bullous keratoplasty (BK 30.0%), regraft (24.2%), post-keratitis scars (17.1%), and keratoconus (11.4%). After dividing the study period into four time periods, we found that BK and regraft increased (from 20.3% to 34.5% and 18.2% to 31.1%, respectively), whereas post-keratitis scars and keratoconus decreased (from 26.0% to 9.5% and 14.1% to 7.2%, respectively) between the first and last period. Pseudophakic or aphakic BK were the major causes of corneal endothelial dysfunction until 2010. Cases of laser-iridotomy-induced BK peaked in 35 eyes (34.3% of BK) in 2000 and declined after 2013. Cases of Fuchs endothelial corneal dystrophy increased from 0 in 1991, to 15 eyes (18.5% of BK) in 2017.

CONCLUSION

Lamellar keratoplasty has replaced PKP in our hospital. BK and regraft have increased, whereas post-keratitis scars and keratoconus have decreased. Laser-iridotomy-induced BK has decreased during the past decade, whereas Fuchs endothelial corneal dystrophy has increased.

Iridotrabecular and Iridocorneal Contact Changes after Cataract Surgery and Endothelial Keratoplasty in Bilateral Iridoschisis

We report a case of bilateral iridoschisis with corneal oedema and a quantitative evaluation of the changes in iridotrabecular and iridocorneal contact before and after cataract surgery and after Descemet stripping automated endothelial keratoplasty (DSAEK). A 76-year-old woman with iridoschisis and cataracts, previously managed with laser iridotomy, experienced progressive vision loss. The preoperative iridotrabecular contact (ITC) index measured by anterior segment optical coherence tomography was 23.6% in the right eye and 24.4% in the left eye. Preoperative corneal oedema in the right eye was more severe than that in the left eye. Cataract surgery, followed by DSAEK, was performed in the right eye and subsequently in the left eye. Her visual acuity improved postoperatively, and the corneal oedema of both eyes was treated successfully. Moreover, the ITC index improved in both eyes, to 4.7 and 6.9% after cataract surgery and to 0 and 0% after DSAEK in the right and left eyes, respectively. Staged cataract surgery and DSAEK were effective for endothelial decompensation caused by iridoschisis. Additionally, we confirm that iridotrabecular and iridocorneal contacts improved after both surgical procedures not only after cataract surgery but also after DSAEK. This case report showed the clinical usefulness of the ITC index in the detection of changes after different surgical procedures.

Long-term outcomes of Descemet stripping automated endothelial keratoplasty for bullous keratopathy after argon laser iridotomy

PURPOSE

To report the long-term outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) for bullous keratopathy secondary to argon laser iridotomy (BK-ALI).

STUDY DESIGN

Retrospective chart review.

METHODS

Forty-five eyes from 41 consecutive patients with BK-ALI who underwent DSAEK from July 2007 to December 2013 were retrospectively analyzed. Best spectacle-corrected visual acuity (BCVA), endothelial cell density (ECD), and any complications were investigated over a 10-year postoperative period.

RESULTS

The mean BCVA improved from 0.80 logMAR before DSAEK to 0.28 logMAR at 6 months after DSAEK; the mean values showed an additional slight improvement between 6 months and 10 years after the surgery (P < .01). The mean ECD decreased from 2864 cells/mm² at baseline to 2269 cells/mm² (20.8% loss) at 6 months post-DSAEK, and this decreasing trend continued throughout the 10 years after DSAEK (P < .01). The mean ECD was 1148 cells/mm² (59.9% loss) after 5 years, and 568 cells/mm² (80.2% loss) after 10 years. No graft deaths were observed throughout the 10-year period (5-year follow-up rate 60.0%, 10-year follow-up rate 20.0%).

CONCLUSIONS

The 10-year outcomes of DSAEK for BK-ALI were excellent with a high graft survival rate.

Iridocorneal contact as a potential cause of corneal decompensation following laser peripheral iridotomy

PURPOSE

This study aimed to investigate the relationship between corneal decompensation following laser peripheral iridotomy (LPI) and iridocorneal endothelial contact.

STUDY DESIGN

Retrospective observational case series.

METHODS

Specular microscopy images of LPI recipients with narrow angles were taken at the central cornea and the 8 midperipheral corneal regions at approximately 3 mm from the center. Eleven eyes of 11 patients had a minimum of  ≤ 1600 cells/mm² among 8 midperipheral corneal endothelial cell densities (ECDs). Radial scans of the angles in the 8 directions were taken with ultrasound biomicroscopy (UBM) in the supine and face-down positions. The minimum and maximum angle opening distance at 750 μm from the scleral spur of the 8 directions were defined as the narrowest and widest angles, respectively. The ECD of the narrowest angle direction was compared with the ECD of the widest angle direction.

RESULTS

When UBM was performed with the subject in the supine position, the iris and cornea at the narrowest angle were in contact in only 4 of 11 eyes, while in the face-down position, the iris and the cornea at the narrowest angle were in contact in 10 of the 11 eyes. In the face-down UBM, the midperipheral ECD of the narrowest angle direction was significantly smaller than the midperipheral ECD of the widest angle direction (P = 0.006).

CONCLUSION

The ECD of the narrow angle direction can decrease after LPI. This suggests that corneal endothelial cell damage following LPI may be due to mechanical damage from iridocorneal endothelial contact.

Long-term effect of YAG laser iridotomy on corneal endothelium in primary angle closure suspects: a 72-month randomised controlled study

PURPOSES

To evaluate the effect of YAG laser peripheral iridotomy (LPI) on corneal endothelial cell density (ECD) and morphology in primary angle closure suspects (PACS) over 72 months.

METHODS

The Zhongshan Angle Closure Prevention Trial is a single-centre randomised controlled trial. Subjects with bilateral PACS received YAG LPI prophylactic treatment in one eye randomly, while the fellow eye served as control. Central corneal ECD and morphology were assessed using non-contact specular microscopy (SP-2000P, Topcon) at baseline, 6, 18, 36, 54 and 72 months postoperatively. Mixed model analysis was conducted to compare the difference between treated and fellow eyes.

RESULTS

A total of 875 participants were included, with a mean age of 59.3±5.0 years and 83.5% female. The ECD declined significantly (p<0.001) over time in both treated and fellow eyes, but the treated eyes showed more progressive cell loss with increasing time (p<0.001). The difference in ECD loss between LPI-treated and fellow eyes was not significant at each follow-up until 72 months (4.9% in LPI eyes vs 4.2% in non-LPI eyes, p=0.003). Mean cell areas increased significantly over time in both treated and fellow eyes (p<0.001), but no longitudinal change was observed for hexagonality. In LPI-treated eyes, no significant correlation was found between age, gender, ocular biometrics, intraocular pressure and laser settings with endothelium change, except for time effect (p<0.01).

CONCLUSION

ECD decreases over time primarily due to ageing effect. YAG LPI does not appear to cause clinically significant corneal endothelial damage over 72 months after treatment.

TRIAL REGISTRATION NUMBER

ISRCTN45213099.

Fuchs endothelial corneal dystrophy and corneal endothelial diseases: East meets West

Fuchs endothelial corneal dystrophy (FECD) is amongst one of the most common indications for endothelial keratoplasty worldwide. Despite being originally described among Caucasians, it is now known to be prevalent among a large number of populations, including Asians. While the FECD phenotype is classically described as that of central guttate and pigment deposits associated with corneal endothelial dysfunction, there are subtle yet important differences in how FECD and its phenocopies may present in Caucasians vs Asians. Such differences are paralled by genotypic variations and disease management preferences which appear to be geographically and ethnically delineated. This article provides a succinct review of such differences, with a focus on diagnostic and management issues which may be encountered by ophthalmologists practicing in the different geographic regions, when evaluating a patient with FECD.

Aqueous humour flow in the posterior chamber of the eye and its modifications due to pupillary block and iridotomy

The anterior chamber (AC) and posterior chamber (PC) of the eye are connected through the pupil and are filled with aqueous humour. The aqueous flows from the posterior to the AC at an approximately constant rate, and the intraocular pressure is governed by this rate and the resistance to aqueous outflow. In some patients the iris and lens come into contact, leading to pressure build-up in the PC, peripheral axial shallowing of the AC and, possibly, to angle-closure glaucoma. This can lead to blindness, which may be prevented by surgically creating an iridotomy, that is a hole through the iris to facilitate the flow from the posterior to the AC. The problem of optimal size and location of an iridotomy is still poorly understood. In this article, we study aqueous flow in the PC and investigate how it is modified in the presence of an iridotomy. Our approach is based on the lubrication theory, which allows us to solve the problem semi-analytically. We treat the iridotomy as a point sink and assume that the flux through it is proportional to the pressure. We find that the ideal size and location of an iridotomy are influenced by various geometrical and fluid mechanical factors, the most relevant of which are the size of the hole and the length and height of the iris-lens channel. For certain iridotomy diameters, we find that the jet velocity through the iridotomy might be large enough to cause possible corneal damage.

Clinical evaluation of a newly developed graft inserter (NS Endo-Inserter) for Descemet stripping automated endothelial keratoplasty

Purpose

The aim of this study was to describe the postoperative outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) performed using our newly developed graft inserter (NS Endo-Inserter) and compare the findings with those for DSAEK performed using the Busin glide.

Patients and methods

In this retrospective, case-control, institutional study, we studied the clinical outcomes of DSAEK performed using the NS Endo-Inserter (NS group, n=13) or the Busin glide (Busin group, n=10) for patients with corneal endothelial dysfunction. Clinical parameters, including the distance-corrected visual acuity (DCVA), endothelial cell (EC) loss, and intraoperative/postoperative complications, were assessed over a 6-month follow-up period.

Results

At 6 months after surgery, the mean DCVA showed no significant difference between the two groups. EC loss at 3 and 6 months after DSAEK was 9.1%±20.7% and 18.2%±22.6%, respectively, in the NS group and 44.0%±25.5% and 46.5%±23.3%, respectively, in the Busin group; differences between groups were statistically significant at both 3 and 6 months (P=0.024 and P=0.016, respectively). Anterior chamber hemorrhage was observed in one patient in the Busin group. Rebubbling after surgery was required for one eye in the Busin group. No complications were observed in the NS group.

Conclusion

Our newly developed graft inserter for DSAEK may cause significantly less EC damage than the conventional pull-through technique using the Busin glide. Our inserter permits safe endothelial graft delivery without anterior chamber collapse and can result in successful graft attachment without complications at 6 months after surgery.

Short Axial Length and Iris Damage Are Associated With Iris Posterior Synechiae After Descemet Membrane Endothelial Keratoplasty in Asian Eyes

PURPOSE

To evaluate the frequency and severity of iris posterior synechiae after Descemet membrane endothelial keratoplasty (DMEK) and to investigate possible causes of iris posterior synechiae.

METHODS

Twenty-three eyes were investigated in 20 Asian patients who underwent DMEK 1 month after phacoemulsification and intraocular lens implantation surgery. A preexisting iris damage score was defined by iris damage and classified into 5 grades. Six months after DMEK, the iris posterior synechiae severity score was evaluated based on the extent of posterior synechiae, according to every 45 degrees of the pupillary rim (posterior synechiae score, 0-8). Correlations were analyzed between the posterior synechiae score and preexisting factors (preexisting iris damage score, axial length [AXL], anterior chamber depth, and anterior chamber volume, both before and after cataract surgery).

RESULTS

Iris posterior synechiae appeared in 20 of 23 eyes (87.0%). Best spectacle-corrected visual acuity significantly improved at 6 months after DMEK (P < 0.001). Endothelial cell density was 1596 ± 530 cells/mm (P < 0.001); loss of cell density was 37.8 ± 19.9% at 6 months. Single regression analysis showed that the onset of iris posterior synechiae was correlated with the preexisting iris damage score (P = 0.006, r = 0.55), AXL (P < 0.001, r = -0.71), anterior chamber depth (P < 0.001, r = -0.70), and anterior chamber volume before cataract surgery (P < 0.001, r = -0.79).

CONCLUSIONS

Iris posterior synechiae after DMEK frequently appeared in Asian eyes with shorter AXLs or a damaged iris.

A 10-year review of underlying diseases for endothelial keratoplasty (DSAEK/DMEK) in a tertiary referral hospital in Japan

Purpose

To report a 10-year review of endothelial keratoplasty (EK) procedures, Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK), and underlying diseases at a tertiary referral hospital in Japan.

Study design

A single-center, retrospective case series.

Methods

We retrospectively reviewed all medical records of bullous keratopathy (BK) surgically treated by EK (DSAEK/DMEK) at Kanazawa University Hospital from January 2007 to December 2016. Changes or modifications to the annual number of EK procedures and underlying diseases were analyzed.

Results

During this period, 320 EK procedures (DSAEK: 288 cases, DMEK: 32 cases) were performed on 250 patients. Total annual EKs gradually increased from 19 to 45 cases between 2007 and 2016. The annual number of DSAEKs was stable, although the proportion of DSAEKs to other procedures decreased significantly as re-DSAEKs and DMEKs increased. BK after argon laser iridotomy (ALI) was the leading cause in 2007, followed by Fuchs' endothelial dystrophy (FED) and failed penetrating keratoplasty. In 2016, BK after trabeculectomy (TLE) was most prevalent, followed by failed DSAEK, failed penetrating keratoplasty, and pseudophakic BK. The decreased ALI and FED, and increased BK after TLE and failed DSAEK were statistically significant.

Conclusion

The distribution of EK procedures (DSAEK/DMEK) and underlying diseases changed over 10 years at a tertiary referral hospital in Japan. The proportion of re-DSAEK and DMEK increased among all EK procedures. Most significantly, among the underlying diseases, decreased ALI and FED and increased TLE and failed DSAEK were observed. Extended multicenter analysis may further elucidate the changes in EK procedures and the causes of BK in Japan.

Descemet membrane endothelial keratoplasty using ophthalmic viscoelastic devices for eyes with laser iridotomy-induced corneal endothelial decompensation: Analysis of 11 eyes

Graft insertion into the anterior chamber is one of the most important procedures for successful Descemet membrane endothelial keratoplasty (DMEK). Especially in eyes with fragile zonular fibers and a shallow anterior chamber, smooth graft insertion tends to become more difficult. Ophthalmic viscoelastic devices (OVDs) can usually help to retain the space in the anterior chamber and to improve the safety of manipulations during various ophthalmic surgeries. Therefore, we postulated that graft insertion into the anterior chamber could be improved by their use. The purpose of this study is to investigate the availability and efficacy of OVDs during graft insertion in DMEK surgery.A total of 11 eyes of 9 patients with bullous keratopathy who underwent DMEK were retrospectively analyzed. The cause of bullous keratopathy was corneal endothelial decompensation following laser iridotomy in all eyes. We used low viscous dispersive OVD (Opegan) to maintain the anterior chamber depth during graft insertion in all of the eyes.The graft insertion was uneventful in all of the eyes. The inserted graft was attached to the back surface of the cornea. However, 2 eyes needed rebubbling, and after rebubbling, all of the 2 grafts completely attached to the back surface of the cornea. The best spectacle-corrected visual acuity significantly improved 6 months after surgery (P < .001) and the central corneal thickness significantly decreased (P < .001).The use of OVD facilitates safer graft insertion during DMEK, and subsequently prevents endothelial cell loss, which leads to a successful procedure.

Endothelial cell loss and graft survival after penetrating keratoplasty for laser iridotomy-induced bullous keratopathy

PURPOSE

To assess corneal endothelial cell loss after penetrating keratoplasty (PK) treatment for laser iridotomy (LI)-induced bullous keratopathy (BK).

METHODS

A retrospective study conducted on consecutive patients who underwent PK between March 2000 and December 2011. Patients who had undergone more than 24 months of follow-up were included. Patients who underwent PK were subcategorized into two groups based on their diagnosis of BK prior to PK; PK was performed to treat either LI-BK or non LI-BK. The cell density of the central corneal endothelium and the graft survival were evaluated during follow-up.

RESULTS

Corneal endothelial cell density decreased in a similar fashion in both the LI-BK and non LI-BK patients, though the cell density decreased significantly faster in the LI-BK group than in the non LI-BK group throughout the 108 months of the study (p = 0.026). The mean cell loss at 36 months for the LI-BK group was 57.7% vs. 63.2% for the non LI-BK, 76.9% vs. 70.1% at 72 months, and 85.6% vs. 72.0% at 108 months. No eye among 21 eyes in the LI-BK group (0%) had failed grafts, whereas 4 of 25 eyes in the non LI-BK group (16.0%) had failed grafts at 60 months (p = 0.114).

CONCLUSIONS

The outcome of PK for BK secondary to LI was no worse than the outcome of PK for other types of BK. However, our long-term follow-up after PK showed that cell density decreased faster in the LI-BK group than in the non LI-BK, suggesting that cell loss might be involved in the existence of LI prior to PK.

Late-onset descemet membrane detachment and corneal decompensation after laser peripheral iridotomy: A case report

RATIONALE

The incidence of cornea disorders after laser peripheral iridotomy (LPI) is extremely low. However, cornea Descemet membrane detachment (DMD) combined with corneal decompensation after LPI could still occur.

PATIENT CONCERNS

A 69-year-old Chinese woman presented with persistent widespread corneal edema and inferior bullous lesions in her right eye for half a year. She had undergone LPI in both eyes 10 years ago for a prophylactic treatment. The patient received a detailed examination of vivo corneal confocal microscopy and sept-source optical coherence tomography (SS-OCT).

DIAGNOSES

It was a late-onset DMD that has a positional relationship with LPI, combined with corneal decompensation.

INTERVENTION

Treatment was only supportive with artificial tears and soft contact lenses.

OUTCOMES

This patient declined to accept keratoplasty because of financial difficulties.

LESSONS

Laser peripheral iridotomy may cause spontaneous, late-onset DMD and corneal decompensation. Ophthalmologists should be aware of this potential complication and proceed carefully. A careful examination of cornea especially around the LPI before keratoplasty seems to be necessary to circumvent other complication.

Techniques for Learning Descemet Membrane Endothelial Keratoplasty for Eyes of Asian Patients With Shallow Anterior Chamber

Supplemental Digital Content is Available in the Text.

Purpose:

To describe several essential surgical techniques that overcome difficulties in performing Descemet membrane endothelial keratoplasty (DMEK) for inexperienced surgeons, especially those who perform DMEK on eyes of Asian patients.

Methods:

Nine eyes of 9 Asian patients with bullous keratopathy who underwent DMEK were analyzed retrospectively. All patients were given a diuretic such as d-mannitol or acetazolamide shortly before surgery, with retrobulbar anesthesia and a Nadbath facial nerve block. Core vitrectomy before DMEK was performed in several cases in which a high vitreous pressure during surgery was predicted. The donor graft was stained with trypan blue, and a 25-G anterior chamber maintenance cannula was used to maintain the anterior chamber depth during graft insertion in all eyes.

Results:

The cornea became clear in all eyes. The best spectacle-corrected visual acuity had improved significantly 6 months after the surgery compared with preoperative values (P = 0.026). The corneal endothelial cell density was 1371 cells per square millimeter at postoperative 6 months.

Conclusions:

Although DMEK is technically difficult, especially for inexperienced surgeons who operate on eyes of Asian patients, controlling anterior chamber pressure using various manipulations may help to prevent iatrogenic primary graft failure and lead to successful DMEK.

Predictive clinical factors of cystoid macular edema in patients with Descemet's stripping automated endothelial keratoplasty

The purpose of this present study was to investigate predictive clinical factors associated with cystoid macular edema (CME) post Descemet’s stripping automated endothelial keratoplasty (DSAEK) in a large case series. Of 393 consecutive patients who underwent DSAEK at Baptist Eye Institute, Kyoto, Japan between July 2011 and November 2016, 241 patients without CME at the pre- or early-postoperative periods were enrolled. The occurrence of anatomic CME was prospectively examined via optical coherence tomography (OCT). Possible predictive clinical factors for CME were analyzed by multivariate logistic regression analysis. At 1-month post DSAEK, CME occurred in 27 (11.2%) of the 241 patients. Multivariate analysis revealed that primary angle closure glaucoma (PACG) was significantly associated with postoperative CME (odds ratio = 6.4, P = 0.04). The findings of this study revealed that DSAEK in patients with PACG showed a high incidence of CME, thus indicating that they should undergo a careful postoperative observation of the macula via OCT.

Occult lens subluxation related to laser peripheral iridotomy: A case report and literature review

RATIONALE

Laser peripheral iridotomy (LPI) is commonly performed as a primary treatment for acute primary angle closure glaucoma after administration of anti-glaucoma medications or for prevention of this condition. Minor complications may occur following LPI and most of them do not have deleterious consequences. We report a rare case of lens subluxation that has a possible relationship with LPI treatment.

PATIENT CONCERNS

A 54-year-old female patient was initially referred for surgical treatment of medication-uncontrollable angle closure glaucoma in her left eye. The patient had undergone Neodymium:YAG LPI at an outside hospital 2 months prior to the presentation due to an episode of elevated intraocular pressure (IOP). About 5 days after the LPI, she had spontaneous blurred vision, redness, and pain in the left eye. Her IOP was found to re-rise and was not controlled well even with maximum tolerated anti-glaucoma medications during the following 2 months. On slit-lamp examination, the significant shallowing of both peripheral and central anterior chamber was noted in the left eye. Ultrasound biomicroscopy examination revealed the lens tilting towards the iris and the inferior zonular dehiscence corresponding to the iridotomy site.

DIAGNOSES

Lens subluxation secondary to LPI treatment in the left eye.

INTERVENTIONS

Phacoemulsification combined with in-the-bag intraocular lens implantation was performed in the left eye. The zonular weakness corresponding to the iridotomy site was further confirmed during surgery.

OUTCOMES

The patient's IOP remained stable in the first postoperative 3 months without additional anti-glaucoma medications.

LESSONS

Laser peripheral iridotomy may cause structural zonular damage, and ophthalmologists should be aware of this potential complication and proceed with caution.

Effects of Laser Peripheral Iridotomy on Corneal Endothelial Cell Density and Cell Morphology in Primary Angle Closure Suspect Subjects

Purpose:

To evaluate the effects of prophylactic laser peripheral iridotomy on corneal endothelial cell density and cell morphology in subjects with primary angle closure suspect (PACS) within a one-year follow-up period.

Methods:

In this quasi-experimental prospective study, from June 2012 to November 2013, thirty-five PACS eyes underwent laser peripheral iridotomy at clinics affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. After obtaining informed consent, specular microscopy was performed at baseline and at 3-month, 6-month and 12-month follow-up visits. Central, nasal and temporal endothelial cell counts and cell morphology were evaluated via non-contact specular microscopy.

Results:

The mean subject age was 53.4 ± 7.9 years, and the majority of subjects were women (88.2%). The mean central corneal endothelial cell count prior to laser peripheral iridotomy was 2528 ± 119.2, and this value changed to 2470 ± 175.9, 2425 ± 150.6, and 2407 ± 69.02 at the 3-month, 6-month, and 12-month follow-up visits, respectively; these differences did not reach statistical significance. Additionally, the changes in the number of cells, the hexagonality of cells, and the coefficient of variation (CV) in the central, nasal, and temporal areas were not significant.

Conclusion:

In PACS eyes, we did not find a decline in corneal endothelial cell density or a change in cell morphological characteristics, including cell hexagonality and CV, in the central, nasal, and temporal regions of the cornea in any of our subjects over a one-year follow-up period.

The effects of proinflammatory cytokines on the apoptosis of corneal endothelial cells following argon laser iridotomy

The aim of this study was to evaluate the relationship between the expression of proinflammatory cytokines and the apoptosis of corneal endothelial cells after argon laser iridotomy (ALI). ALI was performed on each quadrant of the iris in the right eye of mice (ALI1 group). Left eyes were used as control group. The levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, and interferon (IFN)-γ in mice eyes were measured, and TUNEL staining was performed 12 h after ALI. Mice in the ALI-Dexa group were pretreated daily with an intraperitoneal injection of dexamethasone for 4 days before undergoing ALI and compared with mice without dexamethasone pretreatment (ALI2 group). Twelve corneas from six rabbits were incubated ex vivo with (n = 6) or without (n = 6) IL-1β. TUNEL staining was performed 24 h after ex vivo incubation. In the mice experiment, the levels of IL-1β, TNF-α, TGF-β, and IFN-γ were increased in the ALI1 group compared to the control group. Although many TUNEL-positive cells were observed in the ALI1 group, those were not detected in the control group. Dexamethasone pretreatment inhibited the increase in the levels of all four proinflammatory cytokines and reduced TUNEL-positive cells. In the rabbit experiment, TUNEL-positive cells were increased in the incubated corneas with IL-1β compared to those without IL-1β. Expression of proinflammatory cytokines following ALI seems to play a role in the apoptosis of corneal endothelial cells after ALI. Dexamethasone pretreatment inhibited increases in proinflammatory cytokines and reduced the apoptosis of corneal endothelial cells.

How Much Progress Has Been Made in Corneal Transplantation?

To assess the benefits of component lamellar corneal surgery, we investigated the surgical outcomes of deep anterior lamellar keratoplasty (DALK) for keratoconus and Descemet stripping automated endothelial keratoplasty (DSAEK) for laser iridotomy-induced bullous keratopathy (LI-BK). The results were compared with the surgical outcomes of penetrating keratoplasty (PKP). Seventy-nine eyes with keratoconus treated with DALK and 81 eyes with LI-BK treated with DSAEK were studied, and the graft clarity rate, best spectacle-corrected visual acuity, endothelial cell density (ECD), and surgical complications were compared with 273 eyes with keratoconus and 98 eyes with LI-BK all treated with PKP. Keratoconus eyes showed excellent visual outcomes with DALK and PKP, but graft survival was higher for PKP (100%, 98.9%, and 96.3% vs. 98.6%, 90.6%, and 86.1%, at 1, 3, and 5 years after surgery, respectively; P < 0.0001). There were no significant differences in the ECD up to 1 year after surgery. Greater ECD decline was observed for PKP at 3 and 5 years after surgery. Descemet membrane microperforation was observed in 49 eyes treated with DALK. Postoperative complications in eyes treated with PKP were increased incidence of immunological rejection and secondary glaucoma compared with eyes treated with DALK. LI-BK graft survival rates were excellent in both groups (DSAEK: 89.6% and 86.1%; PKP: 100% and 98.6%, 1- and 2-year rates, respectively; P = 0.17). Best spectacle-corrected visual acuity was better in the DSAEK group, and ECD showed a higher rate of decrease with DSAEK than with PKP. DALK and DSAEK considerably improved surgical outcomes in eyes with keratoconus and those with LI-BK, respectively. However, several key areas require further work, including development of safe surgical methods in DALK and prevention of early postoperative ECD loss in DSAEK.

Subsequent Receipt of Interventions for Glaucoma Among a Nationwide Sample of Patients Who Underwent Laser Peripheral Iridotomy

PURPOSE

To evaluate use of medical, laser, or incisional surgical interventions for glaucoma after laser peripheral iridotomy (LPI).

DESIGN

Retrospective longitudinal cohort study.

METHODS

All enrollees aged ≥21 years in a US managed-care network who underwent bilateral LPIs in 2001-2011 were identified. The mean numbers of pre- and post-LPI glaucoma medication classes prescribed and the proportion of enrollees requiring cataract or glaucoma surgery within 2 years after the LPIs were determined. Multivariable logistic regression assessed factors associated with enrollees' prescription of ≥1 glaucoma medication class after bilateral LPIs.

RESULTS

Of the 1660 patients undergoing bilateral LPIs, 1280 (77.1%) had no pre- or post-LPI prescriptions for any glaucoma medication class. Of the remaining patients, 251 (66.1%) required more glaucoma medication classes after than before the procedures, whereas 44 (11.6%) used fewer after the procedures; 85 (22.4%) were prescribed the same number before and after the LPIs. A total of 167 patients (10.1%) underwent cataract surgery and 79 (4.8%) received glaucoma surgery over the 2-year follow-up. Black patients had a 130% increased odds for glaucoma medication-class prescriptions after bilateral LPIs, compared with white patients (P = .02). The odds of post-LPI glaucoma medication use increased by 21% for every additional 5 years of age (P < .0001).

CONCLUSION

Most patients undergoing bilateral LPIs received no pre- or post-LPI glaucoma medication-class prescriptions and had no cataract or additional glaucoma surgery within 2 years after LPIs. Clinicians should alert black or older patients and those already taking glaucoma medications before the procedure of their higher odds of requiring medications afterward.

Comparison of laser iridotomy using short duration 532-nm Nd: YAG laser (PASCAL) vs conventional laser in dark irides

AIM

To evaluate the outcome of laser iridotomy using 532-nm Nd: YAG laser (PASCAL) with short pulse duration and Nd: YAG laser compared to conventional combined laser iridotomy.

METHODS

Retrospective, nonrandomized, comparative case series. Forty-five eyes of 34 patients underwent laser iridotomy. Twenty-two eyes underwent iridotomy using short duration PASCAL and Nd: YAG laser, and 23 eyes underwent iridotomy using conventional combined laser method. The average settings of PASCAL were 60 µm and 700-900 mW with a short duration of 0.01s to reduce the total applied energy. The conventional laser was 50 µm and 700-900 mW for 0.1s. After photocoagulation with these laser, the Nd: YAG laser was added in each group. Endothelial cell counts of pre-iridotomy and 2mo after iridotomy were measured and compared.

RESULTS

All eyes completed iridotomy successfully. The total energy used in the PASCAL group was 1.85±1.17 J. Compared to conventional laser 13.25±1.67 J, the energy used was very small due to the short exposure time of PASCAL. Endothelial cell counts were reduced by 0.88% in the PASCAL group and 6.72% in the conventional laser group (P=0.044). The change in corneal endothelial cell counts before and after iridotomy was significant in conventional combined laser iridotomy group (P=0.004).

CONCLUSION

Combined PASCAL and Nd:YAG laser iridotomy is an effective and safe technique in the dark brown irides of Asians. Furthermore, the short duration of exposure in PASCAL offers the advantages of reducing the total energy used and minimizing the corneal damage.

The use of endoillumination probe-assisted Descemet membrane endothelial keratoplasty for bullous keratopathy secondary to argon laser iridotomy

Purpose

To report the first case of Descemet membrane endothelial keratoplasty (DMEK) for bullous keratopathy (BK) secondary to argon laser iridotomy (ALI).

Patient

A 71-year-old woman presented with decreased visual acuity in her right eye due to BK secondary to ALI that was performed 10 years prior.

Results

Phacosurgery was performed first, followed by successful DMEK 4 months later. A DMEK shooter was used for donor insertion, which allowed for a stable anterior chamber during donor insertion, even when the anterior chamber was quite shallow. Also, removal of edematous epithelial cells and endoillumination probe-assisted DMEK was quite useful to visualize DMEK graft on the background of the dark brown iris seen in Asian eyes. The patient’s best corrected visual acuity rapidly increased from 20/200 to 25/20 after 1 month, with complete resolution of corneal edema.

Conclusion

We reported the first successful DMEK case for BK secondary to ALI. The use of a DMEK shooter for donor insertion and endoillumination assistance to visualize the DMEK graft was a useful technique for BK secondary to ALI.

Three-year outcome of Descemet stripping automated endothelial keratoplasty for bullous keratopathy after argon laser iridotomy

PURPOSE

The aim of this study was to evaluate the 3-year outcome of Descemet stripping automated endothelial keratoplasty (DSAEK) for the treatment of bullous keratopathy secondary to argon laser iridotomy (ALI).

METHODS

A total of 22 consecutive patients (22 eyes) with ALI who underwent DSAEK were retrospectively analyzed. Best spectacle-corrected visual acuity (BSCVA), endothelial cell density, and complications were investigated over 3 years postoperatively. The outcome of DSAEK was also compared between the ALI group and 21 other patients with Fuchs endothelial dystrophy (FED) or pseudophakic bullous keratopathy (PBK) (FED/PBK group).

RESULTS

The median BSCVA improved from logarithm of the minimum angle of resolution 1.40 before DSAEK to 0.30 at 6 months, 0.30 at 12 months, 0.22 at 24 months, and 0.15 at 36 months after surgery. The median endothelial cell loss was 20.3% at 6 months, 18.4% at 12 months, 32.5% at 24 months, and 46.5% at 36 months. Comparison of the ALI group with the FED/PBK group showed no significant difference in the BSCVA or endothelial cell density. Rejection affected 9.1% of the ALI group versus 0% of the FED/PBK group (P = 0.49), the graft dislocation rate was 0% versus 9.5% (P = 0.23), and posterior synechiae were found in 31.8% versus 4.8% (P = 0.046).

CONCLUSIONS

The 3-year outcome of DSAEK for bullous keratopathy after ALI was excellent. However, caution should be exercised in patients with a history of ALI to avoid posterior synechiae after DSAEK.

Laser iridotomy and the corneal endothelium: a systemic review

This study aims to systemically review the effect of laser iridotomy on the corneal endothelium. Searches were performed for studies that either compared corneal endothelial cell density/count, corneal thickness and morphology pre- and postiridotomy, or evaluated the postiridotomy development of corneal decompensation. There were 26 eligible studies. Our review shows that the effect of laser iridotomy on the corneal endothelium has been investigated with varying results. Although it has been demonstrated to be a relatively safe procedure, there is still the potential long-term risk of corneal decompensation, for which a corneal transplantation may be indicated eventually. The longest interval between laser iridotomy and corneal decompensation reported was 8 years. Mechanisms proposed for endothelial damage include direct focal injury, thermal damage, mechanical shock waves, iris pigment dispersion, transient rise in intraocular pressure, inflammation, turbulent aqueous flow, time-dependent shear stress on endothelium, chronic breakdown of blood-aqueous barrier and damage from bubbles that settled onto the endothelium. Inherent risk factors identified were iridotrabecular contact, current or prior acute angle closure, pigmented irides, small iris-to-endothelium distance, pre-existing endothelial disease and diabetes. Intervention-related risk factors include laser type, delivery and quantity. The significance of the risk factors and their direct association with the development of corneal decompensation remain to be determined. Understanding these risk factors may allow physicians to counsel their patients better. They may offer opportunities for preventive strategies, allowing us to ensure that a procedure performed to prevent disease progression and visual loss does not cause further morbidity.

Effects of argon laser iridotomy on the corneal endothelium of pigmented rabbit eyes

Purpose

In Asian countries, laser iridotomy for the treatment of angle-closure glaucoma is a common cause of bullous keratopathy, which may be associated with a shallow anterior chamber and dark iris pigmentation in Asians. Several cases of corneal decompensation after argon laser iridotomy have been reported. In the present study, we evaluated the harmful effects of argon laser iridotomy on the corneal endothelium.

Methods

Argon laser iridotomy was performed on the right eyes of pigmented rabbits. Changes in corneal thickness and endothelial cell density after laser iridotomy were evaluated. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was performed for assessment of corneal endothelial cell apoptosis. Combined staining with alizarin red and trypan blue, as well as a live/dead cell assay, were performed for evaluation of damage to the corneal endothelium induced by laser iridotomy.

Results

Corneal thickness did not change immediately after laser iridotomy; however, a significant increase was observed 24 hours after iridotomy (p = 0.001). The endothelial cell density of laser-treated eyes four days after laser iridotomy was significantly decreased compared with control eyes (p < 0.001). TUNEL staining showed many TUNEL-positive cells in the corneal endothelium and corneal stroma. No endothelial trypan blue-stained cell nuclei were observed after laser iridotomy; however, several large endothelial cells with damaged membrane integrity were observed. The live/dead cell assay clearly showed a large number of dead cells stained red in several areas throughout the entire corneal button 24 hours after iridotomy.

Conclusions

Argon laser iridotomy induces corneal endothelial cell apoptosis in pigmented rabbit eyes, resulting in decreased endothelial cell density.

Long-term changes in corneal endothelial cell density after repeat penetrating keratoplasty in eyes with endothelial decompensation

PURPOSE

To compare the longitudinal changes in corneal endothelial cell density (ECD) and the incidence of postoperative complications between eyes with endothelial decompensation after repeat penetrating keratoplasty (RPK) and those after primary penetrating keratoplasty (PPK).

METHODS

Fifty-seven eyes with endothelial decompensation scheduled for RPK (RPK group) and 57 eyes with endothelial decompensation scheduled for PPK (PPK group) were enrolled. Corneal ECD was evaluated using a specular microscope at 1, 3, 6, 9, and 12 months, and every 6 months until 60 months postoperatively. Visual acuity (VA) and incidence of graft failure, graft rejection, or marked increase in intraocular pressure were examined.

RESULTS

Corneal ECD decreased gradually and percentage of cell loss at 60 months was approximately 73% in both groups; these did not differ significantly between groups throughout the follow-up (P ≥ 0.2209). The incidence of graft failure (52.6% in the RPK group and 36.8% in the PPK group), immune rejection, and marked increase in intraocular pressure did not differ significantly between groups (P ≥ 0.0898), although corrected VA was worse in the RPK group. The most common cause of graft failure in both groups was late endothelial failure. The outcomes were not significantly different between eyes that underwent a first RPK and those that underwent a second or subsequent RPK.

CONCLUSIONS

Corneal endothelial cell loss and complications are comparable between eyes with endothelial decompensation after RPK and those after PPK, although VA is worse in eyes after RPK. The outcomes after a first RPK did not differ from those after multiple RPKs.

Comparison of the Surgical Outcomes of Various Methods of Endothelial Keratoplasty

PURPOSE

The objective of this study was to evaluate the outcomes of various techniques of endothelial keratoplasty (EK) including deep lamellar endothelial keratoplasty (DLEK), Descemet stripping endothelial keratoplasty (DSEK), and Descemet stripping automated endothelial keratoplasty (DSAEK).

DESIGN

This was a retrospective comparative case series.

METHODS

The medical records of 48 consecutive patients who have undergone EK in a tertiary eye center between January 2005 and June 2011 were reviewed. Information related to demographics, visual acuity, corneal endothelial cell count, and postoperative complications was recorded.

RESULTS

The series included 11 eyes with DLEK, 11 eyes with DSEK, and 26 eyes with DSAEK. There was no significant difference in visual outcomes, endothelial cell loss, and postoperative complications between the 3 groups 1 year after surgery. The mean logMAR visual acuity at 12 months was 0.54 (SD, 0.26) for DLEK, 0.55 (SD, 0.47) for DSEK, and 0.63 (SD, 0.48) for DSAEK, respectively. The 6-month endothelial cell density loss was 48.4%, 39.2%, and 47.5% for the DLEK, DSEK, and DSAEK groups, respectively. Early postoperative graft dislocation occurred in 1 (9%) of the DLEK cases, 2 (18%) of the DSEK cases, and 1 (4%) of the DSAEK cases. All of these cases were successfully repositioned.

CONCLUSIONS

Despite the various evolution and surgical modifications and development in EK in the past few years, the visual outcomes and postoperative complications between DLEK, DSEK, and DSAEK were comparable.

Descemet stripping automated endothelial keratoplasty for microcornea

PURPOSE

Our aim was to evaluate the surgical technique and postoperative results of Descemet stripping automated endothelial keratoplasty (DSAEK) for bullous keratopathy in eyes with microcornea.

METHODS

Two patients with microcornea (8.8 mm in case 1 and 9.3 mm in case 2) and bullous keratopathy after cataract surgery or after laser iridotomy were treated by DSAEK. A donor lamella with a smaller diameter (7.5 mm) was inserted into the anterior chamber using the double-glide donor insertion technique (Busin glide with intraocular lens sheet glide).

RESULTS

No intraoperative or postoperative complications occurred. Corrected visual acuity improved from counting fingers to 0.222 logMAR in case 1 and from 1.000 to 0.155 logMAR in case 2 over 6 months. Corneal endothelial cell loss was 6.5 % in case 1 and 1.9 % in case 2.

CONCLUSIONS

DSAEK was useful for bullous keratopathy in patients with microcornea. However, surgery should be done with meticulous care, and modification of the diameter of the donor lamella and of the donor insertion technique may be required.

Scheimpflug imaging criteria for identifying eyes at high risk of acute angle closure

PURPOSE

To compare anterior segment and ocular biometric parameters in unaffectedfellow eyes of patients with a previous attack of acute angle closure (AAC), primary angle closure suspect (PACS) eyes, and normal eyes; and to identify eyes at high risk of AAC among primary angle closure suspects.

METHODS

In this case-control study, 16 unaffected fellow eyes of patients with aprevious attack of AAC (group I), 20 PACS eyes (group II) and 18 normal eyes (group III) underwent Pentacam and A-scan echography.

RESULTS

Mean anterior chamber volume was 72±18, 77±18 and 176±44 µl in groupsI, II, and III, respectively (P<0.001). Corresponding values for anterior chamber angle in the same order were 24.8±4.6, 22.6±6.3 and 35.8±6.9 degrees (P<0.001), and that for anterior chamber depth measured from the corneal endothelium were 1.80±0.26, 1.93±0.23 and 3.13±0.59 mm, respectively (P<0.001). Using receiver operating characteristic (ROC) curves, anterior chamber volume ≤100 µl was associated with a high risk of AAC with sensitivity of 93.3% and specificity of 100%. Corresponding values for anterior chamber depth ≤2.1 mm were 86.7% and 100%, and that for anterior chamber angle ≤26° were 73.3% and 88.2%, respectively. Age, sex, central corneal thickness, and lens thickness were comparable among the study groups (all P values >0.05).

CONCLUSION

Eyes with anterior chamber volume ≤100 µl, depth ≤2.1 mm and angle≤26° may be considered at high risk for developing AAC. These criteria could be helpful for making decisions regarding prophylactic laser peripheral iridotomy.

Long-term changes in endothelial cell counts after early phacoemulsification versus laser peripheral iridotomy using sequential argon:YAG laser technique in acute primary angle closure

OBJECTIVE

To compare the change in endothelial cell counts (ECC) after early phacoemulsification and laser peripheral iridotomy (LPI) using sequential argon:yttrium-aluminum-garnet (YAG) laser technique for the treatment of acute primary angle closure (APAC).

METHODS

This was a retrospective chart review, case-control study; 86 APAC patients were enrolled. Sixteen patients who underwent early phacoemulsification with intraocular lens implantation and 32 patients who underwent LPI were matched by propensity score analysis. All subjects underwent a complete ophthalmic examination, including intraocular pressure (IOP) measurements, optic disc examinations, and gonioscopy. ECC were acquired at the center of the cornea with a noncontact specular microscope before treatment, and at 1, 6, 12, and 24 months following phacoemulsification or LPI.

RESULTS

The mean follow-up was 26.1 ± 4.7 months in the phacoemulsification group and 26.3 ± 4.5 months in the LPI group. After intervention, the changes in anterior chamber depth and Shaffer grading by gonioscopy were significantly different between groups. ECC were not different before treatment; however, after phacoemulsification or LPI at 12 months (2280 ± 320 vs 1993 ± 380 cells/mm(2)) and 24 months (2113 ± 333 vs 1880 ± 422 cells/mm(2)), there was a significant difference between the two groups (P = 0.040 and P = 0.032 respectively). Regression analysis showed that anterior chamber depth at baseline (P = 0.041) and intervention modality (phacoemulsification vs LPI; P < 0.001) were significantly related to the change in ECC.

CONCLUSIONS

Early phacoemulsification showed lower endothelial cell loss than did LPI in the treatment of APAC after a 2-year follow-up. In terms of ECC, early phacoemulsification could be a better intervention modality for APAC.

Characteristic higher-order aberrations of the anterior and posterior corneal surfaces in 3 corneal transplantation techniques

PURPOSE

To investigate the corneal higher-order aberrations (HOAs) of the anterior and posterior corneal surfaces in eyes that underwent penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), and Descemet stripping automated endothelial keratoplasty (DSAEK).

DESIGN

Retrospective, case-control study.

METHODS

study population: Twenty-four eyes underwent PK, 28 eyes underwent DALK, and 19 eyes underwent DSAEK; 29 normal eyes served as controls. observation procedures: The anterior and posterior corneal heights and pachymetric data were obtained with a Scheimpflug-based corneal topographer. Corneal HOAs for 4-mm pupils were calculated from the height data and were expanded with normalized Zernike polynomials. The HOAs resulting from the anterior and posterior corneal surfaces were compared among the procedures. main outcome measures: Anterior and posterior corneal HOAs (root mean square).

RESULTS

Control eyes had significantly lower total HOAs and Zernike vector terms of the anterior and posterior surfaces than the other groups, except for spherical aberration. The mean anterior corneal surface total HOAs in the PK, DALK, DSAEK, and control groups were 1.38 ± 0.67 μm, 1.19 ± 0.57 μm, 0.61 ± 0.33 μm, and 0.21 ± 0.07 μm, respectively. The anterior corneal HOAs in the DSAEK group were significantly less than those in the PK group (P < .001) and DALK group (P < .001). The mean posterior corneal surface total HOAs were, respectively, 0.20 ± 0.09 μm, 0.24 ± 0.11 μm, 0.27 ± 0.15 μm, and 0.07 ± 0.02 μm. There were no significant differences in the posterior corneal HOAs among the treatment groups.

CONCLUSIONS

Because the refractive indices between the anterior and the posterior surfaces differed greatly, eyes that undergo DSAEK have lower anterior corneal HOAs compared with PK or DALK eyes. However, the anterior and posterior corneal HOAs in DSAEK eyes still were greater than those in control eyes.

Surgical outcome of Descemet's stripping automated endothelial keratoplasty for bullous keratopathy secondary to argon laser iridotomy

BACKGROUND: To report the 6-month clinical outcome of Descemet's stripping automated endothelial keratoplasty (DSAEK) for bullous keratopathy (BK) secondary to argon laser iridotomy (ALI), and compare the results with those of DSAEK for pseudophakic bullous keratopathy (PBK) or Fuchs' endothelial dystrophy (FED). METHODS: A total of 103 patients (54 with ALI, 28 with PBK, 21 with FED) undergoing DSAEK were retrospectively analyzed. Simultaneous cataract surgery was performed in 37 patients with ALI and 13 with FED. Preoperative ocular conditions, best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction (SE), induced astigmatism, keratometric value, endothelial cell density (ECD), and complications were determined over 6 months postoperatively. RESULTS: Mean axial length in the ALI group (21.8 ± 0.8 mm) was significantly shorter than that in the FED (P = 0.02) or PBK groups (P = 0.003). Severe corneal stromal edema (n = 6), advanced cataract (n = 10), posterior synechia (n = 3), poor mydriasis (n = 5), and Zinn zonule weakness (n = 1) were found only in the ALI group. A significant improvement was observed in postoperative BSCVA in all groups. No significant difference was observed in BSCVA, SE, induced astigmatism, keratometric value, ECD, or complications among the three groups. CONCLUSIONS: Descemet's stripping automated endothelial keratoplasty for BK secondary to ALI showed rapid postoperative visual improvement, with similar efficacy and safety to that observed in DSAEK for PBK or FED.