Volumetric de-escalation and improved acute toxicity with proton craniospinal irradiation using a vertebral body-sparing technique.

PURPOSE: In growing children, craniospinal irradiation (CSI) has historically treated the entire vertebral body (VB) to avoid potential long-term spinal abnormalities. Vertebral body-sparing proton craniospinal irradiation (VBSpCSI) is a technique that spares the majority of the VB from significant irradiation, and long-term safety outcomes have been reported previously. This retrospective study reviews the acute toxicity profile of children treated with VBSpCSI in a cohort comparison with photon-based craniospinal radiotherapy (3DCRT). METHODS: Thirty-eight pediatric CSI patients treated between 2008 and 2018 were retrospectively evaluated for treatment-related toxicity. Acute toxicity outcomes and acute hematologic profiles were compared according to treatment modality, either VBSpCSI or 3DCRT. Statistical analysis was performed using Fisher's exact test for toxicity. RESULTS: Twenty-five patients received VBSpCSI and 13 patients received photon CSI. Mean patient age at treatment was 7.5 years (range 2-16). The cohorts were well matched with respect to gender, age, and CSI dose. Patients receiving VBSpCSI had lower rates of grade 2+ gastrointestinal (GI) toxicity (24% vs. 76.5%, p = .005), grade 2+ nausea (24% vs. 61.5%, p = .035), and any-grade esophagitis (0% vs. 38%, p = .0026). Patients treated with VBSpCSI had lower red blood cell transfusion rates (21.7% vs. 60%, p = .049) and grade 4+ lymphopenia (33.3% vs. 77.8%, p = .046). CONCLUSIONS: VBSpCSI in children is a volumetric de-escalation from traditional volumes, which irradiate the entire VB to full or intermediate doses. In our study, VBSpCSI was associated with lower rates of acute GI and hematologic toxicities. Long-term growth outcomes and disease control outcomes are needed for this technique.

Management of stage I and II cervical cancer: a review.

In the modern era, cervical cancer treatment has become more multidisciplinary in nature. Accurate and precise staging based on clinical and radiographic findings, as well as identification of pathologic and molecular risk factors, may alter treatment recommendations. Additionally, the body of evidence guiding optimal treatment recommendations continues to grow. Multiple specialists including gynecologic oncologists, radiation oncologists, medical oncologists, radiologists, pathologists, and other ancillary staff, often with subspecialty experience in gynecology or cancer care, now staff multidisciplinary gynecologic oncology teams. This review highlights the basis of multidisciplinary treatment of early-stage cervical cancer, with a focus on surgical interventions, the role of adjuvant therapy, and indications for definitive chemoradiation. We specifically focus on the treatment of cervical cancer from stage IA1 (microinvasive disease) to stage IIB (parametrial involvement without involvement of pelvic sidewall). The staging manuals referenced in this review include the International Federation of Gynecology and Obstetrics (FIGO) 2018 staging as well as the updated American Joint Committee on Cancer (AJCC) 9th edition (2021).

Spontaneous retrobulbar hemorrhage in the setting of warfarin therapy and latent scurvy diagnosis.

We present a case of spontaneous nontraumatic retrobulbar hemorrhage associated with anti-coagulation therapy and a new diagnosis of scurvy. A 68-year-old male on chronic anti-coagulation therapy presented with a retrobulbar hemorrhage requiring urgent canthotomy and cantholysis. Despite the absence of a supratherapeutic INR and normal clotting factors, the patient continued to have spontaneous hemorrhages within the orbit and elsewhere. Workup revealed a severe vitamin C deficiency consistent with scurvy. Further investigation of dietary history demonstrated an avoidance of all citrus fruit upon starting warfarin due to misunderstanding in medication counseling on avoidance of grapefruit. With repletion of vitamin C and further medication counseling, the patient had no further episodes of spontaneous hemorrhage.

Bombarding Oligoprogression: Oncologic Outcomes After Radiation to Patients With Oligoprogressive Non-Small Cell Lung Cancer on Maintenance Systemic Therapy.

OBJECTIVES: This study aims to evaluate the efficacy and toxicity of radiotherapy (RT) to oligoprogressive metastatic non-small cell lung cancer (NSCLC). METHODS: This is a retrospective analysis of 23 patients with metastatic NSCLC on maintenance systemic therapy, developed oligoprogression (1 to 5 sites), and all oligoprogressive sites amenable to and treated with RT. The primary endpoints included progression-free survival (PFS) and median time to start next-line therapy (MTT). Kaplan-Meier survival analysis and log-rank testing were performed using R-Studio software. RESULTS: Twenty-three patients met the inclusion criteria. The median overall survival for the entire cohort was 31.3 months (interquartile range [IQR]: 17.86 to 45.4). The median event-free survival for the entire cohort was 8.3 months (IQR: 2.7 to 12). Patients with no prior radiation had longer median event-free survival of 11.9 months (IQR: 8.4 to 18.2) compared with patients with a history of prior radiation at 4.1 months (IQR: 2.7 to 12; P = 0.041). The local control rate for the treated lesions was 97.5%. At 12 months follow-up, 6 (43%) of 14 living patients maintained systemic therapy without initiating next-line therapy. The median PFS for the entire cohort was 8.4 months (IQR: 4.1 to 17.5). Patients who did not receive prior radiation had longer median PFS of 11.9 months (IQR: 8.4 to 18.2) compared with patients who received prior radiation 6.2 months (IQR: 2.7 to 8.5; P = 0.018). Two patients (9%) had grade 3 chronic toxicity related to RT and were medically managed. CONCLUSION: We identified that in patients with oligoprogressive metastatic NSCLC, targeted RT to all progressive sites yielded high LC and favorable rates of PFS and MTT.

Investigation of Polyethylenimine/DNA Polyplex Transfection to Cultured Cells Using Radiolabeling and Subcellular Fractionation Methods.

Quantitative analysis of the intracellular trafficking of nonviral vectors provides critical information that can guide the rational design of improved cationic systems for gene delivery. Subcellular fractionation methods, combined with radiolabeling, produce quantitative measurements of the intracellular trafficking of nonviral vectors and the therapeutic payload. In this work, differential and density-gradient centrifugation techniques were used to determine the intracellular distribution of radiolabeled 25 kDa branched polyethylenimine (bPEI)/plasmid DNA complexes ("polyplexes") in HeLa cells over time. By differential centrifugation, [(14)C]bPEI was found mostly in the lighter fractions whereas [(3)H]DNA was found mostly in the heavier fractions. A majority of the intracellular polymer (∼60%) and DNA (∼90%) were found in the nuclear fraction. Polymer and DNA also differed in their distribution to heavier and denser organelles (lysosomes, mitochondria) in density-gradient centrifugation studies. An unexpected finding from this study was that between 18 and 50% of the DNA applied to the cells became cell-associated (either with the cell membrane and/or internalized), while only 1-6% of the polymer did so, resulting in an effective N/P ratio of less than 1. These results suggest that a significant amount of cationic polymer is dissociated from the DNA cargo early on in the transfection process.

Influence of histidine incorporation on buffer capacity and gene transfection efficiency of HPMA-co-oligolysine brush polymers.

One of the major intracellular barriers to nonviral gene delivery is efficient endosomal escape. The incorporation of histidine residues into polymeric constructs has been found to increase endosomal escape via the proton sponge effect. Statistical and diblock copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA), oligolysine, and oligohistidine were synthesized via reversible-addition fragmentation chain transfer (RAFT) polymerization and tested for in vitro transfection efficiency, buffering ability, and polyplex uptake mechanism via the use of chemical endocytic inhibitors. Interestingly, histidine-containing statistical and diblock polymers exhibited increased buffer capacity in different endosomal pH ranges. Statistical copolymers transfected better than block copolymers that contained similar amounts of histidine. In addition, only the polymer containing the highest incorporation of oligohistidine residues led to increases in transfection efficiency over the HPMA-oligolysine base polymer. Thus, for these polymer architectures, high histidine incorporation may be required for efficient endosomal escape. Furthermore, inhibitor studies indicate that nonacidified caveolae-mediated endocytosis may be the primary route of transfection for these copolymers, suggesting that alternative approaches for increasing endosomal escape may be beneficial for enhancing transfection efficiency with these HPMA-oligolysine copolymers.

Local Therapies for Hepatocellular Carcinoma and Role of MRI-Guided Adaptive Radiation Therapy.

Hepatocellular carcinoma (HCC) is the most common liver tumor, with a continually rising incidence. The curative treatment for HCC is surgical resection or liver transplantation; however, only a small portion of patients are eligible due to local tumor burden or underlying liver dysfunction. Most HCC patients receive nonsurgical liver-directed therapies (LDTs), including thermal ablation, transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and external beam radiation therapy (EBRT). Stereotactic ablative body radiation (SABR) is a specific type of EBRT that can precisely deliver a high dose of radiation to ablate tumor cells using a small number of treatments (or fractions, typically 5 or less). With onboard MRI imaging, MRI-guided SABR can improve therapeutic dose while minimizing normal tissue exposure. In the current review, we discuss different LDTs and compare them with EBRT, specifically SABR. The emerging MRI-guided adaptive radiation therapy has been reviewed, highlighting its advantages and potential role in HCC management.

Prostate segmentation accuracy using synthetic MRI for high-dose-rate prostate brachytherapy treatment planning.

Objective. Both computed tomography (CT) and magnetic resonance imaging (MRI) images are acquired for high-dose-rate (HDR) prostate brachytherapy patients at our institution. CT is used to identify catheters and MRI is used to segment the prostate. To address scenarios of limited MRI access, we developed a novel generative adversarial network (GAN) to generate synthetic MRI (sMRI) from CT with sufficient soft-tissue contrast to provide accurate prostate segmentation without MRI (rMRI).Approach. Our hybrid GAN, PxCGAN, was trained utilizing 58 paired CT-MRI datasets from our HDR prostate patients. Using 20 independent CT-MRI datasets, the image quality of sMRI was tested using mean absolute error (MAE), mean squared error (MSE), peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM). These metrics were compared with the metrics of sMRI generated using Pix2Pix and CycleGAN. The accuracy of prostate segmentation on sMRI was evaluated using the Dice similarity coefficient (DSC), Hausdorff distance (HD) and mean surface distance (MSD) on the prostate delineated by three radiation oncologists (ROs) on sMRI versus rMRI. To estimate inter-observer variability (IOV), these metrics between prostate contours delineated by each RO on rMRI and the prostate delineated by treating RO on rMRI (gold standard) were calculated.Main results. Qualitatively, sMRI images show enhanced soft-tissue contrast at the prostate boundary compared with CT scans. For MAE and MSE, PxCGAN and CycleGAN have similar results, while the MAE of PxCGAN is smaller than that of Pix2Pix. PSNR and SSIM of PxCGAN are significantly higher than Pix2Pix and CycleGAN (p < 0.01). The DSC for sMRI versus rMRI is within the range of the IOV, while the HD for sMRI versus rMRI is smaller than the HD for the IOV for all ROs (p ≤ 0.03).Significance. PxCGAN generates sMRI images from treatment-planning CT scans that depict enhanced soft-tissue contrast at the prostate boundary. The accuracy of prostate segmentation on sMRI compared to rMRI is within the segmentation variation on rMRI between different ROs.

Thermal therapy for Sporothrix endogenous endophthalmitis of the anterior segment.

PURPOSE: To report a case of Sporothrix shenkii endophthalmitis successfully treated with local thermal therapy after failure of conventional systemic and local antifungal therapy. OBSERVATIONS: A 44-year-old female on long-term immunosuppressive therapy for extrapulmonary sarcoidosis presented with bilateral Sporothrix shenkii endophthalmitis. Despite prolonged systemic antifungal therapy, numerous intraocular antifungal injections, and surgical intervention with vitrectomy and lensectomy, her condition worsened with progressively increased fungal burden in the anterior chamber. At the patients request, interventional ocular procedures including intraocular injections were withdrawn and enucleation was considered secondary to pain and severe scleral thinning. Local thermal therapy was initiated as a palliative measure, supported by evidence for Sporothrix growth inhibition above 38.5 °C and efficacy with cutaneous Sporothrix. Initiation of ocular thermal therapy with a commercially available electronic heat mask was followed by a dramatic and durable improvement in pain and fungal burden. CONCLUSIONS AND IMPORTANCE: Thermal therapy may be an effective alternative for Sporothrix endophthalmitis affecting the anterior segment with lower risk for toxicity than intraocular injection of antimicrobial therapy.

Anti-adalimumab Antibodies in Patients with Non-infectious Ocular Inflammatory Disease: A Case Series.

PURPOSE: To report the clinical course of patients with ocular inflammatory disease treated with adalimumab in whom anti-adalimumab antibodies (AAA) were detected. METHODS: Single center case series. RESULTS: Eight patients with initial response to adalimumab developed a disease flare associated with positive AAA testing after 5 to 76 months of therapy. Six patients were receiving no concurrent antimetabolite therapy at the time of AAA diagnosis and four had a temporary lapse in adalimumab therapy prior to AAA discovery. AAA resulted in undetectable drug levels in five of the seven patients for whom data were available, and adalimumab was discontinued in six of the eight patients. Of two patients continued on adalimumab, one maintained detectable serum adalimumab despite AAA and one had a low AAA titer. CONCLUSIONS: For patients receiving adalimumab for ocular inflammatory disease, a disease flare in the setting of previously well-controlled disease should prompt consideration of AAA testing.

Implementing Predictive Models Within an Electronic Health Record System: Lessons from an External Validation of a Suicide Risk Model.

Over the past 5 years, there has been an increase in the development of EHR-based models for predicting suicidal behaviour. Using the McGinn (2000) framework for creating clinical prediction rules, this study discusses the broad validation of one such predictive model in a context external to its derivation. Along with reporting performance metrics, our paper high-lights five practical challenges that arise when trying to undertake such a project including (i) validation sample sizes, (ii) availability and timeliness of data, (iii) limited or incomplete documentation for predictor variables, (iv) reliance on structured data and (v) differences in the source context of algorithms. We also discuss our study in the context of the current literature.

Lymphocyte sparing normal tissue effects in the clinic (LymphoTEC): A systematic review of dose constraint considerations to mitigate radiation-related lymphopenia in the era of immunotherapy.

BACKGROUND: Radiation-related lymphopenia has been associated with suboptimal tumor control rates leading to inferior survival outcomes. To date, no standardized dose constraints are available to limit radiation dose to resident and circulating lymphocyte populations. We undertook this systemic review of the literature to provide a synopsis of the dosimetric predictors of radiation-related lymphopenia in solid malignancies. METHODOLOGY: A systematic literature review of PubMed (National Institutes of Health), Cochrane Central (Cochrane collaboration), and Google Scholar was conducted with the following keywords: "radiation", "lymphopenia", "cancer", "dosimetric predictors" with an inclusion deadline of May 31, 2022. Studies that met prespecified inclusion criteria were designated either Good, Fair, or Poor Quality based on the Newcastle-Ottawa quality assessment. The dosimetric parameters derived from Good Quality studies were tabulated as LymphoTEC dose constraints. Dosimetric parameters derived from Fair and Poor-quality studies were grouped as optional. RESULTS: An initial systematic search of the literature yielded 1,632 articles. After screening, a total of 48 studies met inclusion criteria and were divided into the following categories: central nervous system (CNS, 6), thoracic (11), gastrointestinal (26), gynecologic (2), head and neck, breast, and genitourinary (one each) cancers. Lung mean dose, heart mean dose, brain V25, spleen mean dose, estimated dose to immune cells, and bone marrow V10 were among the strongest predictors for severe lymphopenia related to radiotherapy. CONCLUSION: Optimizing the delivery of radiation therapy to limit dose to lymphocyte-rich structures may curb the negative oncologic impact of lymphocyte depletion. The dose constraints described herein may be considered for prospective validation and future use in clinical trials to limit risk of radiation-related lymphopenia and possibly improve cancer-associated outcomes.

Surveillance of long-term complications after treatment of adult brain tumor survivors-review and evidence-based recommendations.

As a result of treatment and diagnosis, adults with primary or metastatic brain tumors experience comorbidities that impacts their health and well-being. The Children's Oncology Group has guideline recommendations for childhood survivors of brain tumors; however, guidelines for monitoring long-term sequela among adult brain tumor survivors are lacking. The purpose of this review is to present the screening recommendations for the long-term complications after brain tumor treatment from a multidisciplinary panel of healthcare professionals. Chronic complications identified include cognitive dysfunction, vasculopathy, endocrinopathy, ophthalmic, ototoxicity, physical disability, sleep disturbance, mood disorder, unemployment, financial toxicity, and secondary malignancy. We invited specialists across disciplines to perform a literature search and provide expert recommendations for surveillance for long-term complications for adult brain tumor survivors. The Brain Tumor Center Survivorship Committee recommends routine screening using laboratory testing, subjective assessment of symptoms, and objective evaluations to appropriately monitor the complications of brain tumor treatments. Effective monitoring and treatment should involve collaboration with primary care providers and may require referral to other specialties and support services to provide patient-centered care during neuro-oncology survivorship. Further research is necessary to document the incidence and prevalence of medical complications as well as evaluate the efficacy of screening and neuro-oncology survivorship programs.

Solitary retinal hemangioblastoma findings in OCTA pre- and post-laser therapy.

PURPOSE: To report optical coherence tomography angiography (OCTA) findings pre- and post-thermal laser therapy of a rare, asymptomatic, unilateral, isolated retinal hemangioblastoma. OBSERVATIONS: A 40-year-old asymptomatic Caucasian man was found to have an isolated, unilateral retinal hemangioblastoma after referral for possible retinal hole. Comparison of OCTAs pre- and post-thermal laser therapy demonstrated a significant reduction of blood flow toward and within the lesion, in addition to contraction of the lesion and constriction of the accompanying feeder vessels. A 4-month follow-up OCTA showed marked reduction of lesion size, and caliber of treated vessels. CONCLUSIONS AND IMPORTANCE: Non-invasive OCTA imaging of a retinal hemangioblastoma demonstrated decreased blood flow signal and vessel caliber after treatment. OCTA shows potential as a new tool to improve our understanding of the effectiveness of therapy in these lesions.

Effects of vertebral-body-sparing proton craniospinal irradiation on the spine of young pediatric patients with medulloblastoma.

PURPOSE: To investigate the long-term effects of vertebral-body-sparing proton craniospinal irradiation (CSI) on the spine of young patients with medulloblastoma. METHODS AND MATERIALS: Six children between the ages of 3 and 5 years with medulloblastoma were treated with vertebral-body-sparing proton CSI after maximal safe resection. Radiation therapy was delivered in the supine position with posterior beams targeting the craniospinal axis, and the proton beam was stopped anterior to the thecal sac. Patients were treated with a dose of either 23.4 Gy or 36 Gy to the craniospinal axis followed by a boost to the posterior fossa and any metastatic lesions. Chemotherapy varied by protocol. Radiographic effects on the spine were evaluated with serial imaging, either with magnetic resonance imaging scans or plain film using Cobb angle calculations, the presence of thoracic lordosis, lumbar vertebral body-to-disc height ratios, and anterior-posterior height ratios. Clinical outcomes were evaluated by patient/family interview and medical chart review. RESULTS: Overall survival and disease free survival were 83% (5/6) at follow-up. Median clinical and radiographic follow-up were 13.6 years and 12.3 years, respectively. Two patients were clinically diagnosed with scoliosis and treated conservatively. At the time of follow-up, no patients had experienced chronic back pain or required spine surgery. No patients were identified to have thoracic lordosis. Diminished growth of the posterior portions of vertebral bodies was identified in all patients, with an average posterior to anterior ratio of 0.88, which was accompanied by compensatory hypertrophy of the posterior intervertebral discs. CONCLUSION: Vertebral-body-sparing CSI with proton beam did not appear to cause increased severe spinal abnormalities in patients treated at our institution. This approach could be considered in future clinical trials in an effort to reduce toxicity and the risk of secondary malignancy and to improve adult height.

Reduction of pupil size and halos with minus lenses after laser in situ keratomileusis.

PURPOSE: To evaluate the amount of miosis induced by over-minused lenses and to assess subjective reduction of halos following laser in situ keratomileusis (LASIK) with such lenses. METHODS: Part I: Infrared pupil diameter was assessed in 14 patients who had not had ocular surgery. The accommodative/miotic reflex was stimulated with concave trial lenses in -1.00-D increments up to -4.00 D while viewing the 20/40 acuity line. Part II. Subjective halos around a distant light were assessed in 14 patients following LASIK for myopia, with and without a -1.00-D lens over manifest refraction. RESULTS: Part I: 100%, 79%, and 64% of patients clearly saw the 20/40 line with a -1.00-D lens, -2.00-D lens, and -3.00/-4.00-D lens, respectively. Mean pupil diameter decreased by 0.2 mm with the -1.00-D lens (P = .02), 0.5 mm with the -2.00-D lens (P = .003), 0.9 mm with the -3.00-D lens (P = .008,), and 1.1 mm with the -4.00-D lens (P = .008). Part II: 11 of 14 patients (79%) noticed a decrease in the size of the halo (30% average reduction) when over-minused by -1.00 D. CONCLUSIONS: Pupil diameters and halos decreased with a -1.00-D overcorrection in patients following LASIK. Patients with pupil-dependent night halos after LASIK may benefit from mildly over-minused lenses.

Effect of polyplex morphology on cellular uptake, intracellular trafficking, and transgene expression.

Nanoparticle morphology has been shown to affect cellular uptake, but there are few studies investigating the impact of particle shape on biologic drug delivery. Recently, our group synthesized a series of N-(2-hydroxypropyl) methacrylamide (HPMA)-oligolysine brush polymers for nucleic acid delivery that varied in oligolysine peptide length and polymer molecular weight. Interestingly, a 50% longer peptide (K15) transfected very poorly compared to the optimized polymer comprised of K10 peptide despite similar chemical composition and molecular weight. We hypothesized that differences in particle morphology contributed to the differences in plasmid DNA delivery. We found that particles formed with plasmid DNA and a polymer with the longer oligolysine peptide (pHK15) had larger aspect ratios than particles formed with optimized polymer (pHK10). Even though both formulations showed similar percentages of cellular association, particles of a higher aspect ratio were internalized to a lesser extent. Furthermore, the rod-like particles accumulated more in endosomal/lysosomal compartments, leading to delayed nuclear delivery. Other parameters, such as particle surface charge, unpackaging ability, uptake mechanism, intracellular trafficking, and the presence of heparan sulfate proteoglycans did not significantly differ between the two polymer formulations. These results indicate that, for this system, polyplex morphology primarily impacts nucleic acid delivery efficiency through differences in cellular internalization rates.

ZO-1 alters the plasma membrane localization and function of Cx43 in osteoblastic cells.

ZO-1 is the major connexin-interacting protein in ROS 17/2.8 (ROS) osteoblastic cells. We examined the role of ZO-1 in Cx43-mediated gap junction formation and function in ROS cells that expressed the connexin-interacting fragment of ZO-1 (ROS/ZO-1dn) cells. Expression of this ZO-1(7-444) fusion protein in ROS cells disrupted the Cx43/ZO-1 interaction and decreased dye transfer by 85%, although Cx43 was retained on the plasma membrane as assessed by surface biotinylation. Fractionation of lysates derived from ROS/ZO-1dn cells on a 5-30% sucrose flotation gradient showed that 40% of the Cx43 floated into these sucrose gradients, whereas none of the Cx43 in ROS cell lysates entered the gradients, suggesting that more Cx43 is associated with lipid rafts in the transfected ROS cells than in lysates derived from untransfected ROS cells. In contrast to the ROS/ZO-1dn cells, ROS cells that over-expressed ZO-1 protein (ROS/ZO-1myc cells) exhibited increased gap junctional permeability and appositional membrane staining for Cx43. These data demonstrate that ZO-1 regulates Cx43-mediated gap junctional communication in osteoblastic cells and alters the membrane localization of Cx43. They suggest that ZO-1-mediated delivery of Cx43 from a lipid raft domain to gap junctional plaques may be an important regulatory step in gap junction formation.

Intacs for keratoconus.

PURPOSE: To evaluate the efficacy and safety of placement of Intacs in subjects with keratoconus. DESIGN: Retrospective, nonrandomized comparative trial. INTERVENTION: Intrastromal corneal ring segment implantation. PARTICIPANTS: Seventy-four eyes of 50 subjects (41 male and 9 female) were evaluated. The mean age of subjects in the study was 35 years, ranging from 20 to 73 years. Twenty-six subjects underwent single-eye treatment, and 24 subjects had both eyes treated. METHODS: A modified Intacs procedure was performed on subjects with keratoconus. Pachymetry was measured at the incision site, and the incision was made at 66% of the corneal thickness. A thicker ring segment was typically placed inferiorly, and a thinner segment was placed superiorly on the basis of a refractive nomogram. MAIN OUTCOME MEASURES: Differences between preoperative and postoperative uncorrected visual acuity, best spectacle-corrected acuity, and spherical equivalent. Changes in irregular astigmatism were evaluated with the inferior-superior value from comeotopographic maps, and differences in refractive cylinder groups were studied. RESULTS: Preoperative mean best-corrected logarithm of the minimum angle of resolution (LogMAR) visual acuity was 0.41 (20/50 - 1) (standard deviation [SD], +/-0.48), which improved to a postoperative mean of 0.24 (20/32 - 2) (SD, +/-0.31) (two lines of improvement). Preoperative mean uncorrected LogMAR visual acuity was 1.05 (20/200 - 2 1) (SD, +/-0.48), which improved to a mean of 0.61 (20/80-) (SD, +/-0.52) (four lines of improvement) at postoperative follow-up. Preoperative mean best-corrected LogMAR acuity in the corneal scarring group was 0.96 (20/200 + 2) (SD, +/-0.72), which improved to a mean of 0.54 (SD, +/-0.43) (20/63 - 2) (five lines of improvement). Uncorrected mean LogMAR acuity in the eyes with corneal scarring was 1.42 (20/400 - 4) (SD, +/-0.27), which improved to a mean of 1.03 (20/200 - 1) (SD, +/-73) (three lines of improvement). The mean spherical equivalent before surgery was -3.89 diopters (D) (SD, +/-5.16), which was reduced to a mean of -1.46 D (+/-4.11) at the postoperative follow-up. CONCLUSIONS: Asymmetric Intacs implantation can improve both uncorrected and best spectacle-corrected visual acuity and can reduce irregular astigmatism in corneas with and without corneal scarring.