A benchmark for Monte Carlo simulations in gamma-ray spectrometry Part II: True coincidence summing correction factors.

The goal of this study is to provide a benchmark for the use of Monte Carlo simulation when applied to coincidence summing corrections. The examples are based on simple geometries: two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The coincidence corrective factors are computed for four radionuclides. The exercise input files and calculation results with practical recommendations are made available for new users on a dedicated webpage.

Clinical signs in cornea and ocular surface.

A careful examination of cornea and ocular surface eliciting the basic signs will help a clinician toward an accurate diagnosis. Flipping the upper lid or pulling the lower lid to look at the inferior fornix may help to pick up any subtle clinical sign. Meticulous documentation by diffuse and slit view will help in following up the disease. Eyelids and ocular surface are evaluated externally and by slit lamp. Slit-lamp examination with the use of the stains such as fluorescein, rose bengal, or lissamine green provides extensive knowledge about the ocular surface. Tests of tear production are also detailed herein. This review is intended to help the eye practitioners in eliciting common clinical signs seen in cornea and ocular surface diseases.

The role of anterior segment optical coherence tomography in the management of an intra-corneal foreign body.

INTRODUCTION: Corneal foreign bodies are reported to be the second most common type of ocular injury. Anterior segment optical coherence tomography (AS-OCT) is a valuable tool for the early diagnosis and monitoring the progress of treatment in cases of ocular trauma. Herein we aimed to report on a patient with an intra-corneal foreign body and the role of AS-OCT in management. CASE PRESENTATION: A 34-year-old male presented with foreign body sensation in his left eye. Slit-lamp biomicroscopic examination revealed a peripherally located intrastromally embedded foreign body with a free anterior edge extending outwards from the cornea. It was not possible to visualize the foreign body's entire route through the cornea because of localized corneal edema. AS-OCT showed shadowing of the corneal layers corresponding to the location of the corneal foreign body. A hyper-reflective lesion was observed close to the inside edge of the foreign body in the cornea, indicating that the foreign body had not completely penetrated the cornea. The foreign body was removed via the external route, as it had not completely penetrated the cornea. During the postoperative period the patient was asymptomatic, although the left eye's cornea healed with scar tissue. DISCUSSION AND EVALUATION: AS-OCT facilitates non-invasive rapid imaging of ocular tissue at va rious depths, thereby providing accurate assessment of foreign body characteristics.The location of an intracorneal foreign body and the status of the surrounding ocular structure dictate the optimal surgical technique to be employed. CONCLUSIONS: AS-OCT in the present case facilitated localization and determination of the size of a corneal foreign body. In addition, AS-OCT findings assisted in selection of the appropriate surgical intervention.

Hyperbaric oxygen for the treatment of the rare combination of central retinal vein occlusion and cilioretinal artery occlusion.

A 43-year-old male presented with sudden onset of painless, blurred vision in his left eye. Dilated fundoscopic examination showed signs consistent with the diagnosis of a combination of central retinal vein occlusion (CRVO) and cilioretinal artery occlusion (CLRAO). He received daily 2-h sessions of hyperbaric oxygen treatment (HBOT), 253 kPa for 14 days. At the end of the HBOT course, the patient's left visual acuity had improved from 20/200 to 20/20. Dilated fundoscopic examination showed that the intra-retinal haemorrhages in the entire retina and the retinal whitening along the course of the CLRA seen at presentation had completely resolved. The combination of CLRAO and CRVO comprises a discrete clinical entity. Even though there are many hypotheses concerning this condition, it is most likely the result of elevated intraluminal pressure in the retinal capillaries due to CRVO that exceeds the pressure in the CLRA. HBOT may be an effective treatment for CRVO-associated CLRAO.

Iris metastasis of gastric adenocarcinoma.

BACKGROUND: Iris metastasis in patients with gastric cancer is extremely rare. Herein, it is aimed to report on a patient with gastric adenocarcinoma and iris metastasis. CASE PRESENTATION: A 65-year-old patient with the history of gastric cancer was admitted for eye pain and eye redness on his left eye. There was ciliary injection, severe +4 cells with hypopyon in the anterior chamber and a solitary, friable, yellow-white, fleshy-creamy vascularized 2 mm × 4 mm mass on the upper nasal part of the iris within the left eye. The presented patient's mass lesion in the iris fulfilled the criteria of the metastatic iris lesion's appearance. The ocular metastasis occurred during chemotherapy. CONCLUSIONS: Iris metastasis can masquerade as iridocyclitis with pseudohypopyon or glaucoma. In patients with a history of gastric cancer that present with an iris mass, uveitis, and high intraocular pressure, ocular metastasis of gastric cancer should be a consideration.

Microbiologic, Pharmacokinetic, and Clinical Effects of Corneal Collagen Cross-Linking on Experimentally Induced Pseudomonas Keratitis in Rabbits.

PURPOSE: To determine the effects of corneal collagen cross-linking (CXL) on the penetration of topical 0.5% moxifloxacin, on the number of colony-forming units (CFUs) in the cornea, and on the clinical course in a rabbit eye model of experimentally induced Pseudomonas aeruginosa keratitis. METHODS: In this prospective animal study, experimental Pseudomonas corneal ulcers were induced in 56 corneas of 28 albino New Zealand rabbits. The corneas were randomly divided into the following 4 groups: the control group (14 eyes), the MOX group (moxifloxacin) (14 eyes), the MOX + CXL group (14 eyes), and the CXL group (14 eyes). On day 4 of the experiment, the eyes in the control group were enucleated and CFU counting was performed. On day 10 of the experiment, all eyes were enucleated and CFU counting was performed. In the MOX and MOX + CXL groups, the moxifloxacin level in the cornea, aqueous humor, iris, plasma, and serum was measured by reverse-phase high-performance liquid chromatography. RESULTS: The difference in the corneal CFU count between the MOX group and the MOX + CXL group was not significant (P = 0.317). Clinical improvement was greatest in the MOX + CXL group (P < 0.001). The mean corneal moxifloxacin level was 0.391 ± 0.09 µg·mg in the MOX group versus 0.291 ± 0.09 µg·mg in the MOX + CXL group; as such, CXL did not have a significant effect on antibiotic penetrance (P = 0.386). CONCLUSIONS: Clinical improvement was greatest in the MOX + CXL group. The synergistic effect of CXL on corneal ulcer treatment is not through antibiotic penetrance.

Comparison of keratometric data obtained by automated keratometer, Dicon CT 200, Allegro Topolyzer, and Pentacam.

PURPOSE: To compare the keratometric values measured by the automated keratometer, two Placido-based computerized topography systems (Dicon CT 200 [Vismed Inc] and Allegro Topolyzer [WaveLight Inc]), and Scheimpflug analysis (Pentacam [Oculus Optikgeräte GmbH]). METHODS: The keratometric data of 200 eyes from 200 patients evaluated for refractive surgery were reviewed retrospectively. Mean simulated keratometry (Sim K) and mean corneal astigmatism measured by the four devices were compared using repeated measures analysis of variance with Bonferroni correction. The analysis of agreement between two measurements was assessed using the method of Bland and Altman. RESULTS: Mean Sim K as measured by the automated keratometer, Dicon CT 200, Allegro Topolyzer, and Pentacam was 43.39±1.50 diopters (D), 43.55±1.50 D, 43.45±1.50 D, and 43.43±1.45 D, respectively. The Dicon CT 200 measured the mean Sim K to be steeper and the automated keratometer measured the mean Sim K to be flatter than the other devices. Significant differences in corneal astigmatism were noted among the four devices except Dicon CT 200 versus Allegro Topolyzer and Allegro Topolyzer versus Pentacam comparisons (P<.013). For mean Sim K, the 95% limits of agreement between the Pentacam and other three devices were significantly wider than the other comparisons. In Bland-Altman plots comparing the Pentacam to the other devices, extreme outliers were present in 11 (5.5%) eyes. CONCLUSIONS: Because of the wide distribution range and presence of extreme outliers, Pentacam data should be used cautiously in IOL power calculation and astigmatic keratotomy procedures.

Topography-guided LASIK with the wavelight laser after penetrating keratoplasty.

PURPOSE: To report a case of topography-guided LASIK in a patient after previous penetrating keratoplasty. METHODS: A 20-year-old man who had previous penetrating keratoplasty in his right eye for keratoconus and was intolerant to spectacles and contact lenses underwent topography-guided LASIK. RESULTS: Three months postoperatively, the patient's uncorrected visual acuity in the right eye was 20/25(+2). Best spectacle-corrected visual acuity was 20/20, with a manifest refraction of +0.25 -0.75 x 40 degree. CONCLUSION: Topography-guided LASIK is a useful therapeutic modality to address corneal irregularity after penetrating keratoplasty.

LASIK with an inferior hinge.

PURPOSE: To investigate the refractive results and corneal pachymetric changes after laser in situ keratomileusis (LASIK) with an inferior hinge. METHODS: Forty-six eyes of 23 patients who underwent LASIK with an inferior hinge were involved in this prospective study. All patients had a complete ophthalmic examination including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, computerized corneal topography (Orbscan II Corneal Topography System; Orbscan Inc, Salt Lake City, Utah), air-puff tonometry, slit-lamp examination of the anterior segment, and fundus examination. RESULTS: Preoperatively, mean sphere was -4.09+/-0.27 diopters (D) (range: -8.00 to -0.25 D), mean cylinder was -0.60+/-0.11 D (range: -3.25 to 0.00 D), and mean spherical equivalent refraction was -4.39+/-0.27 D (range: -8.63 to -1.50 D). At 1 month postoperatively, mean sphere was -0.04+/-0.01 D (range: -0.25 to 0.00 D), mean cylinder was -0.01+/-0.01 D (range: -0.50 to 0.00 D), and mean spherical equivalent refraction was -0.04+/-0.02 D (range: -0.00 to -0.50 D). At 1 month postoperatively, no eyes lost any lines of BSCVA. CONCLUSIONS: Laser in situ keratomileusis with an inferior hinge is an alternative technique, which was safe and effective in our series. Further studies with long-term follow-up comparing the incidence of corneal ectasia in eyes with a superior hinge to that in eyes with an inferior hinge are recommended.

Corneal topographic changes after phacoemulsification through steep axis incision.

PURPOSE: To evaluate the effect of 5.5 mm sutured and 4.0 mm sutureless corneal incisions after phacoemulsification on corneal topograpy. MATERIAL AND METHODS: Twenty eyes of 20 patients that underwent phacoemulsification with IOL implantation were randomly divided into two. The first group received a PMMA IOL through a sutured 5.5 mm corneal incision. The second group received a foldable hydrophilic acrylic IOL through a sutureless 4.0 mm incision. Complete ocular examination and computerized corneal topography (Keratron Corneal Analyzer, Software version 3.2, Optikon 2000, Italy) were performed preoperatively, at 1 week, and 1 month postoperatively. The Maloney indices [best fit sphere (BFS), best fit cylinder (BFC) and topographic irregularity (TI)] were provided by the Keratron Corneal Analyzer. RESULTS: There was no statistically significant difference in the mean BFS between the groups preoperatively (p = 0.305), at postoperative week 1 (p = 0.362), and at postoperative month 1 (p = 0.160). The BFC was significantly higher in the 5.5 mm incision group than in the 4.0 mm incision group preoperatively (p = 0.025), however, there was no statistically significant difference between the groups at postoperative week 1 (p = 0.909), and at postoperative month 1 (p = 0.382). There was no statistically significant difference in the mean TI between the groups preoperatively (p = 0.494) and at postoperative week 1 (p = 0.271). However the mean TI at postoperative month 1 was significantly higher in the 5.5 mm incision group than the 4.0 mm incision group (p = 0.05). CONCLUSION: The 5.5 mm sutured incisions caused an increase in TI at 1 week and 1 month postoperatively. For a more rapid visual rehabilitation, 4.0 mm sutureless incisions are recommended.

The efficacy of hourly prophylactic steroids in diffuse lamellar keratitis epidemic.

PURPOSE: To investigate the inciting agent, clinical features, and the efficacy of hourly steroids in the prophylaxis in a diffuse lamellar keratitis (DLK) epidemic. METHODS: One hundred and five eyes of 58 patients that had DLK after LASIK were included in the study. To identify the cause of the epidemic, some interventions were made: irrigation solution was changed from BSS to Ringer lactate (week 5), wiping of the interface with a sponge was discontinued (week 6), the air conditioner in the LASIK room was checked (week 6), the routine postoperative topical regimen was changed from fluoromethalone and fluoroquinolones 4 times a day to hourly prednisolone acetate or dexamethasone sodium and fluoroquinolones (week 7), and the trademark of the drape used was changed (week 12). RESULTS: There was no statistical difference in any of the attack rates associated with variables including BSS versus Ringer lactate (9.9 vs. 14%, p = 0.4), and air conditioner check with wiping versus not wiping the interface with the microsurgical sponge (14.0 vs. 18.2%, p = 0.6). There was a significant decrease in the attack rate from 18.2 to 5.3% with use of the hourly prophylactic topical steroids (p = 0.012). After introduction of a new trademark of the drape, the incidence of DLK was further reduced from 5.3 to 0.7% (p = 0.016). CONCLUSION: The cause in a particular DLK epidemic should be identified and eliminated adopting a scientific approach. Hourly steroid use for prophylaxis is recommended until the etiologic agent responsible has been identified.

Wavefront-guided laser in situ keratomileusis with the Bausch & Lomb Zyoptix system.

PURPOSE: To evaluate the clinical results of wavefront-guided laser in situ keratomileusis (LASIK) with the Zyoptix system. METHODS: Twelve patients (24 eyes) underwent wavefront-guided LASIK with the Bausch & Lomb Zyoptix system. Uncorrected and best spectacle-corrected visual acuity and manifest refraction were measured at postoperative day 1, week 1, and months 1 and 3. A subjective vision quality questionnaire evaluated light sensitivity, dryness, tearing, glare, halos, ghost images, and difficulties in night driving, preoperatively and 3 months postoperatively. RESULTS: Preoperatively, mean sphere was -3.70 +/- 2.33 D (range -0.50 to -8.00 D), mean cylinder was -0.90 +/- 0.98 D (range 0 to -3.00 D), and mean spherical equivalent refraction was -4.15 +/- 2.16 D (range -1.38 to -8.25 D). Three-month postoperative spherical equivalent refraction was within +/- 0.50 D of emmetropia in 17 eyes (70.8%) and within +/- 1.00 D in 22 eyes (91.7%). At 3 months postoperatively, no eyes lost any lines of BSCVA and eight eyes (33.3%) gained 2 lines. The ratio of postoperative BSCVA to preoperative BSCVA (safety) was 1.05 +/- 0.09 (range 1.00 to 1.20) at 1 month and 1.07 +/- 0.10 (range 1.00 to 1.29) at 3 months. The ratio of postoperative UCVA to preoperative BSCVA (efficacy) was 0.96 +/- 0.12 (range 0.80 to 1.20) at 1 month and 0.95 +/- 0.12 (range 0.8 to 1.2) at 3 months. The subjective vision quality questionnaire revealed less tearing, fewer halos, and less difficulty in night driving after wavefront-guided LASIK. Comparison of higher order optical aberrations before and after surgery was not done. CONCLUSIONS: Wavefront-guided LASIK with the Bausch & Lomb Zyoptix system was safe and effective in correcting low to moderate myopic refractive error.

Topical cyclosporine in pediatric keratoplasty.

PURPOSE: To evaluate the efficacy and safety of combined treatment with 2% topical cyclosporine (CsA) and topical corticosteroid compared to treatment with topical corticosteroids only after pediatric keratoplasty. METHODS: Twenty-two grafts in 16 pediatric patients were evaluated retrospectively. The eyes were divided into a CsA group (9 eyes) and a control group (13 eyes) based on the postoperative treatment regimen. Information reviewed included patient age and sex, clinical diagnosis; preoperative and postoperative intraocular pressure and lens status; previous, concurrent, and subsequent surgical procedures; operative and postoperative complications; number of graft rejections, timing of suture removal, and length of follow-up. The clinical outcome of penetrating keratoplasty (PK) was evaluated by the rate of rejection-free graft survival and graft survival evaluation by the Kaplan-Meier log-rank test. RESULTS: The rejection-free graft survival rate was 88.9% in the CsA group and 38.5% in the control group. This difference in rejection-free graft survival rate between the groups was statistically significant (P =.0465). The graft survival rate was 88.9% in the CsA group and 46.2% in the control group. The difference in the graft survival rate was not statistically significant between the groups (P =.6). No clinical signs of systemic or local toxicity were seen with the topical CsA treatment. CONCLUSIONS: Two percent topical CsA is safe and effective in reducing the risk of allograft rejection in pediatric recipients.

Orbscan corneal topography system in evaluating the anterior structures of the human eye.

PURPOSE: To investigate the relationship among horizontal corneal diameter, corneal thickness, anterior chamber depth, pupil size, and spherical equivalent and to evaluate the variation in these parameters attributable to age, sex, iris color, and refractive state of the eye. METHODS: One thousand three hundred forty-one eyes of 688 consecutive patients who had a LASIK evaluation at World Eye Hospital were involved in the study. The information that was reviewed included age and sex of the patient, horizontal corneal diameter, corneal thickness, anterior chamber depth, iris color, pupil size (scotopic and photopic), and spherical equivalent. RESULTS: The mean corneal thickness was 537.6 +/- 37.5 microm (range, 334-702). The mean anterior chamber depth was 3.5 +/- 0.38 mm (range, 1.99-4.75). The iris color was dark in 829 (61.8%) eyes and light in 512 (38.2%). The mean scotopic pupil size was 6.1 +/- 0.9 mm (range, 3.5-9.0) and the mean photopic pupil size was 4.0 +/- 0.7 mm (range, 2.1-7.4). The mean spherical equivalent was -3.4 +/- 3.7 D (range, -16.00-+7.50 D). Age was correlated with corneal thickness (r = 0.069, p = 0.012), spherical equivalent (r = 0.080, p = 0.003), and inversely correlated with corneal diameter (r = -0.367, p< 0.001), anterior chamber depth (r = -0.335, p< 0.001), scotopic pupil size (r = -0.309, p< 0.001), and photopic pupil size (r = -0.367, p< 0.001). Males had larger corneas (p< 0.001) and deeper anterior chambers (p< 0.001) than females. The eyes with a dark iris color had thicker corneas (p< 0.001), deeper anterior chambers (p< 0.001), and more minus spherical equivalents (p = 0.017) than the eyes with a light iris color. CONCLUSIONS: There is a substantial range of dimensions of anterior structures of the human eye. These dimensions are related to each other and are influenced by age, sex, iris color, and refractive state of the eye.

Phototherapeutic keratectomy versus diamond burr polishing of Bowman's membrane in the treatment of recurrent corneal erosions associated with anterior basement membrane dystrophy.

PURPOSE: To compare the efficacy of phototherapeutic keratectomy (PTK) to epithelial debridement and polishing of Bowman's membrane using a diamond burr (DB) in the treatment of recurrent corneal erosions associated with anterior basement membrane (ABM) dystrophy. DESIGN: Retrospective nonrandomized comparative trial. METHODS: Medical records of 39 patients (42 eyes) who underwent a PTK or DB procedure for recurrent corneal erosions associated with ABM dystrophy between March 1992 and June 2000 were reviewed. History of injury, prior treatment received, and the corneal slit-lamp findings were noted in all patients. In both procedures, all loose epithelium was completely removed. In PTK patients, 5 microm of Bowman's membrane was ablated with the excimer laser. In patients who underwent DB treatment, a hand-held battery-driven diamond dusted burr was used to gently and uniformly polish Bowman's membrane in the area of the epithelial defect. MAIN OUTCOME MEASURES: Symptomatic improvement, recurrence of painful erosions, development of haze, and change in the visual acuity. Statistical analysis was performed for comparison of data between the two groups. RESULTS: Fifteen eyes of 14 patients underwent PTK, and 27 eyes of 25 patients underwent epithelial debridement and DB treatment. In the PTK group, mild haze was seen in five (35.7%) eyes. Recurrence of painful erosions was seen in four eyes (26.7%). The mean follow-up was 17.6 +/- 5.7 months (range, 0.7-81.9 months). Best-corrected visual acuity was better in five eyes (35.7%) after the procedure and the same in nine eyes (64.3%). In the DB group, mild haze was seen in seven eyes (25.9%). Recurrence of painful erosions was seen in three eyes (11.1%). The mean duration of follow-up was 6.7 months (range, 1-24.2 months). Best-corrected visual acuity was better in 3 eyes (14.3%), the same in 17 eyes (81%), and worse in 1 eye (4.8%) after the procedure. Final visual acuity was not available for one eye in the PTK group and 6 eyes in the DB group. There was no statistically significant difference in haze (Fisher's exact test, P = 0.38), recurrence of erosions (Kaplan-Meier analysis with log rank, P = 0.73), and vision being better or the same (Fisher's exact test, P = 0.6) between the PTK and DB groups. CONCLUSIONS: Both PTK and DB treatment are effective methods of treating recurrent corneal erosions associated with ABM dystrophy. Diamond burr treatment, being a simpler, less expensive office procedure with a tendency toward lesser incidence of haze and recurrence in this study, seems to have advantages over PTK in the treatment of recurrent corneal erosions. Further prospective studies are required to confirm the long-term efficacy of DB treatment in the management of recurrent corneal erosions associated with ABM dystrophy.

The clinical efficacy of silicone punctal plug therapy.

PURPOSE: To evaluate the clinical efficacy and safety of silicone punctal plugs in various ocular surface disorders. PATIENTS AND METHODS: Medical records of patients who underwent silicone punctal plug insertion from January 1996 to November 2000 were retrospectively reviewed. The clinical data collected included sex and age of the patients, indications for plug insertion, symptoms, corneal fluorescein staining and frequency of lubricant use at baseline and at 4 +/- 2 weeks after the insertion, location (upper versus lower punctum), initial versus replacement plug, spontaneous extrusion or removal of the plug, and percentage of complications and punctum cauterization. RESULTS: There were 203 eyes of 153 patients (126 women and 27 men) in the study group. The total number of silicone punctal plug procedures was 312. Dry eye syndrome was the most common indication for punctal plug treatment (127 eyes, 62.5%), followed by epitheliopathy after penetrating keratoplasty (32 eyes, 15.8%). The symptoms improved in 150 (73.9%) of 203 eyes at 4 +/- 2 weeks' follow-up. The mean score of the fluorescein staining of the cornea was reduced from 2.7 +/- 0.1 to 1.3 +/- 0.1 with silicone punctal plug treatment at 4 +/- 2 weeks' follow-up. This reduction was statistically significant (p< 0.01). The overall success rate at 4 +/- 2 weeks follow up was 76.8%. The frequency of the lubricant use was significantly decreased with punctal plug treatment (p< 0.001). Considering all plugs, the estimated probability of plug retention was 49.4% with 85.1 +/- 7.3 weeks as the mean survival time. There was no statistical difference in plug retention rates between lower (49.6%) and upper (48.7%) plugs (p= 0.15). Retention rate of first plugs (53.5%) was significantly higher than that of second plugs (32.0%) (p= 0.05). The spontaneous total extrusion of silicone punctal plug was the most common complication in our study (158 plugs, 50.7%). The plug was removed in 14 eyes (14 plugs, 6.9%) because of epiphora in 11 eyes and conjunctival erosion in three eyes. The percentage of punctum cauterization performed in our population was 10.8%. CONCLUSIONS: Punctal plug insertion is a simple, effective, safe, and reversible method to treat aqueous tear deficiency and other ocular surface diseases, such as epitheliopathy after penetrating keratoplasty, superior limbic keratoconjunctivitis, neurotrophic keratitis, recurrent corneal erosions, and toxic epitheliopathy not controlled by lubrication with preservative-free tears. However, spontaneous extrusion of silicone plug occurs commonly. Careful choosing of the optimal plug size and close follow-up are recommended to ensure the success of the treatment.

Indications for penetrating keratoplasty and associated procedures, 1996-2000.

PURPOSE: To identify current indications and trends in indications for penetrating keratoplasty and associated procedures. METHODS: Retrospective chart review of all patients who underwent penetrating keratoplasty at Wills Eye Hospital from January 1, 1996 to December 31, 2000. RESULTS: A total of 1,529 corneal transplants were performed during this 5-year period. The leading indications for penetrating keratoplasty were pseudophakic bullous keratopathy (PBK) in 416 (27.2%) cases, followed by regraft in 276 (18.1%), keratoconus in 236 (15.4%), and Fuchs endothelial dystrophy in 233 (15.2%) cases. Of the 416 PBK cases, 271 (65.1%) were associated with posterior chamber intraocular lenses (PC IOLs), 141 (33.9%) with anterior chamber intraocular lenses (AC IOLs), and four (1%) with iris-fixated lenses. Of these 141 AC IOLs, 107 (75.9%) were closed-loop and 34 (24.1%) were open-loop. Of the 416 PBK cases, in 281 (67.5%) cases, the IOL was not exchanged; in 127 (30.5%) cases, the IOL was exchanged; in six (1.5%) cases, the IOL was repositioned; and in two (0.5%) cases, the IOL was removed at the time of surgery. Of the 271 PC IOLs, 248 (91.5%) were not exchanged and 19 (7.1%) were exchanged. Of the 141 AC IOLs, 33 (23.4%) were not exchanged and 104 (73.7%) were exchanged (p = 0.001). CONCLUSIONS: Pseudophakic bullous keratopathy remains the leading indication for corneal transplantation at our institution followed by regraft. The percentage of PBK cases associated with PC IOLs has increased significantly, whereas the percentage associated with AC IOLs has decreased. The frequency of regraft has also increased significantly.