What Happens 20 to 30 years After Radial Keratotomy? Case Series.

ABSTRACT: Radial keratotomy (RK) was commonly performed in the 1980s and 1990s. We aimed to clarify the current status of post-RK refractive correction and treatment. We retrospectively reviewed the charts of 70 patients with a history of RK. Of the 70 patients, 44 were identified for clinical outcomes. Refractive or therapeutic intervention (rigid gas-permeable contact lens fit, spectacle prescription, corneal surgery, and use of pilocarpine hydrochloride for photophobia) was possible in 59% of patients with postoperative visual deterioration after RK; in the remaining 41%, therapeutic intervention was not possible. Rigid gas-permeable contact lens fit for corneal irregular astigmatism was the most common refractive intervention and was effective in 36% of cases in the university hospital.

Advances in Corneal Surgical and Pharmacological Approaches to the Treatment of Presbyopia.

The purpose of this article is to review the current status of presbyopia amelioration with surgical and pharmacologic procedures that partially compensate for loss of accommodation in advance of cataract surgery and lens replacement. Over the last few years, several corneal surgical and topical pharmacological approaches for the treatment of presbyopia have been introduced to the marketplace or are in the developmental pipeline. The approaches vary in invasiveness, duration of effect, reversibility, risk/benefit ratio, and clinical results. The advantages and disadvantages for each are discussed. Corneal surgical interventions aim to provide improved near and intermediate vision in patients with presbyopia through refractive means that extend ocular depth of focus through shape modification. The use of miotic drops or corneal lamellar implants extend depth of focus with the "pinhole" aperture size reduction effect. Unlike in adults younger than 40 years, the refractive status of the patient with presbyopia is not stable. Hence, procedures that provide a permanent refractive change may not provide long-term full correction; eye drops or other treatments that are self-reversing in time or are easily reversible may be used as needed. On the horizon, procedures are being explored that may add years of functional lens accommodation by preserving the deformable gel properties of the lens. [J Refract Surg. 2021;37(6 Suppl):S20-S27.].

The Prospective Health Assessment of Cataract Patients' Ocular Surface (PHACO) study: the effect of dry eye.

PURPOSE: To determine the incidence and severity of dry eye as determined by the International Task Force (ITF) scale in patients being screened for cataract surgery. PATIENTS AND METHODS: This was a prospective, multi-center, observational study of 136 patients, at least 55 years of age, who were scheduled to undergo cataract surgery. The primary outcome measure was the incidence of dry eye as evaluated by grade on the ITF scale and secondary outcome measures include tear break-up time (TBUT), ocular surface disease index score, corneal staining with fluorescein, conjunctival staining with lissamine green, and a patient questionnaire to evaluate symptoms of dry eye. RESULTS: Mean patient age was 70.7 years. A total of 73.5% of patients were Caucasian and 50% were female. Almost 60% had never complained of a foreign body sensation; only 13% complained of a foreign body sensation half or most of the time. The majority of patients (62.9%) had a TBUT ≤5 seconds, 77% of eyes had positive corneal staining and 50% of the eyes had positive central corneal staining. Eighteen percent had Schirmer's score with anesthesia ≤5 mm. CONCLUSION: The incidence of dry eye in patients scheduled to undergo cataract surgery in a real-world setting is higher than anticipated.

Screening Patients With Cataract for Premium IOL Candidacy Using Microperimetry.

PURPOSE: To explore the use of microperimetry in the evaluation of macular dysfunction in patients with cataract, to aid in proper intraocular lens selection (multifocal vs monofocal), and to set expectations for postoperative visual function. METHODS: One randomly chosen eye of 10 patients diagnosed as having mild (1+) to moderate (3+) cataract was evaluated before and 1 week after cataract surgery with the MAIA microperimeter (Centervue S.p.A, Padova, Italy). Corrected distance visual acuity, dilated and undilated biomicroscopy and indirect fundus examinations, intraocular pressure measurement, and a MAIA microperimeter test to measure macular sensitivity and fixation pattern were also performed. RESULTS: Two patients showed macular abnormalities before and after surgery that were noted on MAIA testing: one patient showed reduced average threshold sensitivity and abnormal percent reduced threshold, whereas the other patient showed fixation drift demonstrating eccentric fixation. Both eyes had reduced postoperative visual performance after uneventful cataract surgeries. CONCLUSIONS: Because not every macular lesion noted on fundus examination or optical coherence tomography may be clinically significant, microperimetry can be useful to detect clinically significant retinal dysfunction prior to cataract surgery. The outcome may aid in the selection of intraocular lens type and may yield a better documented surgical prognosis. Further studies are necessary to confirm these findings.

Antibiotic resistance in acute postoperative endophthalmitis.

Acute postoperative endophthalmitis (APE) is a serious, although infrequent, complication of eye surgery that can result in significant morbidity and costs. This review addresses APE risk factors, associated bacterial pathogens, antibiotic resistance, and prevention.

Functional significance of macrophage-derived exosomes in inflammation and pain.

Exosomes, secreted microvesicles transporting microRNAs (miRNAs), mRNAs, and proteins through bodily fluids, facilitate intercellular communication and elicit immune responses. Exosomal contents vary, depending on the source and the physiological conditions of cells, and can provide insights into how cells and systems cope with physiological perturbations. Previous analysis of circulating miRNAs in patients with complex regional pain syndrome (CRPS), a debilitating chronic pain disorder, revealed a subset of miRNAs in whole blood that are altered in the disease. To determine functional consequences of alterations in exosomal biomolecules in inflammation and pain, we investigated exosome-mediated information transfer in vitro, in a rodent model of inflammatory pain, and in exosomes from patients with CRPS. Mouse macrophage cells stimulated with lipopolysaccharides secrete exosomes containing elevated levels of cytokines and miRNAs that mediate inflammation. Transcriptome sequencing of exosomal RNA revealed global alterations in both innate and adaptive immune pathways. Exosomes from lipopolysaccharide-stimulated cells were sufficient to cause nuclear factor-κB activation in naive cells, indicating functionality in recipient cells. A single injection of exosomes attenuated thermal hyperalgesia in a murine model of inflammatory pain, suggesting an immunoprotective role for macrophage-derived exosomes. Macrophage-derived exosomes carry a protective signature that is altered when secreting cells are exposed to an inflammatory stimulus. We also show that circulating miRNAs altered in patients with complex regional pain syndrome are trafficked by exosomes. With their systemic signaling capabilities, exosomes can induce pleiotropic effects potentially mediating the multifactorial pathology underlying chronic pain, and should be explored for their therapeutic utility.

Safety of besifloxacin ophthalmic suspension 0.6% in refractive surgery: a retrospective chart review of post-LASIK patients.

BACKGROUND: To evaluate the safety of besifloxacin ophthalmic suspension 0.6% when used in laser-assisted in situ keratomileusis (LASIK) prophylactic antibiotic regimens. METHODS: Retrospective surveillance of LASIK surgery cases where besifloxacin ophthalmic suspension 0.6% or moxifloxacin ophthalmic solution 0.5% were prescribed as prophylactic medications. Surgeons from nine US surgical centers provided retrospective case information on surgical outcomes from consecutive cases and reported any adverse events related to the antibacterial used. The primary endpoint was the incidence of adverse drug reactions. RESULTS: A total of 801 case reports (801 eyes; 534 besifloxacin, 267 moxifloxacin) were obtained. The mean (standard deviation [SD]) age at time of surgery was 36.1 (10.6) years. The mean (SD) duration of antibiotic treatment was 8.6 (2.2) days in the besifloxacin group and 8.0 (2.3) in the moxifloxacin group; daily dosing frequency was higher in the moxifloxacin group preoperatively, on the day of surgery, and postoperatively. There were no reports of adverse drug reactions for the 801 eyes in this surveillance. There were no differences between the besifloxacin and moxifloxacin treatment groups in rates of unexpected corneal findings (2.1% vs 1.5%, P = 0.949). The distribution of final visual acuity for the besifloxacin and moxifloxacin groups were similar (P = 0.793). Most cases had a final visual acuity of 20/20 or better. CONCLUSION: In this retrospective surveillance study, the prophylactic use of besifloxacin ophthalmic suspension 0.6% and moxifloxacin ophthalmic solution 0.5% in patients undergoing LASIK surgery was not associated with any adverse drug reactions.

Sensitivity and specificity of the AdenoPlus test for diagnosing adenoviral conjunctivitis.

OBJECTIVE: To compare the clinical sensitivity and specificity of the AdenoPlus test with those of both viral cell culture (CC) with confirmatory immunofluorescence assay (IFA) and polymerase chain reaction (PCR) at detecting the presence of adenovirus in tear fluid. METHODS: A prospective, sequential, masked, multicenter clinical trial enrolled 128 patients presenting with a clinical diagnosis of acute viral conjunctivitis from a combination of 8 private ophthalmology practices and academic centers. Patients were tested with AdenoPlus, CC-IFA, and PCR to detect the presence of adenovirus. MAIN OUTCOME MEASURES: The sensitivity and specificity of AdenoPlus were assessed for identifying cases of adenoviral conjunctivitis. RESULTS: Of the 128 patients enrolled, 36 patients' results were found to be positive by either CC-IFA or PCR and 29 patients' results were found to be positive by both CC-IFA and PCR. When compared only with CC-IFA, AdenoPlus showed a sensitivity of 90% (28/31) and specificity of 96% (93/97). When compared only with PCR, AdenoPlus showed a sensitivity of 85% (29/34) and specificity of 98% (89/91). When compared with both CC-IFA and PCR, AdenoPlus showed a sensitivity of 93% (27/29) and specificity of 98% (88/90). When compared with PCR, CC-IFA showed a sensitivity of 85% (29/34) and specificity of 99% (90/91). CONCLUSION: AdenoPlus is sensitive and specific at detecting adenoviral conjunctivitis. APPLICATION TO CLINICAL PRACTICE: An accurate and rapid in-office test can prevent the misdiagnosis of adenoviral conjunctivitis that leads to the spread of disease, unnecessary antibiotic use, and increased health care costs. Additionally, AdenoPlus may help a clinician make a more informed treatment decision regarding the use of novel therapeutics. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00921895.

Sensitivity and specificity of a point-of-care matrix metalloproteinase 9 immunoassay for diagnosing inflammation related to dry eye.

OBJECTIVES: To determine the clinical sensitivity, specificity, negative predictive value, and positive predictive value of a rapid point-of-care diagnostic test to detect elevated matrix metalloproteinase 9 levels (InflammaDry). METHODS: In a prospective, sequential, masked, multicenter clinical trial, InflammaDry was performed on 206 patients: 143 patients with clinical signs and symptoms of dysfunctional tear syndrome (dry eyes) and 63 healthy individuals serving as controls. Participants were assessed as healthy controls or for a clinical diagnosis of dry eye using the Ocular Surface Disease Index, Schirmer tear test, tear breakup time, and keratoconjunctival staining. MAIN OUTCOME MEASURES: The sensitivity and specificity of InflammaDry were compared with clinical assessment. RESULTS: InflammaDry showed sensitivity of 85% (in 121 of 143 patients), specificity of 94% (59 of 63), negative predictive value of 73% (59 of 81), and positive predictive value of 97% (121 of 125). CONCLUSION: Compared with clinical assessment, InflammaDry is sensitive and specific in diagnosing dry eye. APPLICATION TO CLINICAL PRACTICE: Dry eye is often underdiagnosed resulting from poor communication between the clinical assessment of dry eye severity between clinicians and patients. This often leads to a lack of effective treatment. Matrix metalloproteinase 9 is an inflammatory biomarker that has been shown to be elevated in the tears of patients with dry eyes. The ability to accurately detect elevated matrix metalloproteinase 9 levels may lead to earlier diagnosis, more appropriate treatment, and better management of ocular surface disease. Preoperative and perioperative management of inflammation related to dry eyes may reduce dry eyes that develop after laser in situ keratomileusis, improve wound healing, and reduce flap complications. Recognition of inflammation may allow for targeted perioperative therapeutic management of care for patients who undergo cataract and refractive surgery and improve outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01313351.

Improving awareness, identification, and management of meibomian gland dysfunction.

Ocular surface disorder--and dry eye, in particular--is a leading reason for visits to eye care professionals. It has been generally accepted that meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye, as well as being associated with aqueous-deficient dry eye. Yet, researchers and clinicians have lacked a global consensus on the definition of MGD, its epidemiology, pathophysiology, and management. Various systemic diseases and medications have been associated with the progression of both dry eye and MGD, as have several ocular disorders beyond those directly affecting the surface. It is in the best interest of patients for clinicians to be able to better identify and diagnose MGD, differentiating it from other ocular surface disorders, and to recognize the effects of MGD on the ocular surface, and thus initiate appropriate therapy. This CME activity provides expert insight into the Tear Film and Ocular Surface Society's International Workshop on MGD consensus report, offering practical application of its findings to better manage MGD patient care, particularly for those patients facing or undergoing ocular surgery.

Emerging antibiotic resistance in ocular infections and the role of fluoroquinolones.

Resistance to antibiotic agents is becoming increasingly prevalent among ocular infections. Between 19% and 60% of Streptococcus pneumoniae and Staphylococcus aureus isolates have been shown to be resistant to macrolide antibiotic agents, penicillin, and older fluoroquinolones. Although topical fluoroquinolones are considered first-line treatment of ocular infections, as much as 85% of methicillin-resistant S aureus isolates are resistant to ophthalmic fluoroquinolones, including the newer 8-methoxy fluoroquinolones, gatifloxacin and moxifloxacin. Besifloxacin, an 8-chlorofluoroquinolone, has a lower minimum inhibitory concentration against multidrug-resistant staphylococcal strains than other fluoroquinolones and less selective pressure for resistance development because of the lack of a systemic counterpart. In addition to the development of new antibacterial agents, antibiotic resistance in ocular infections may be reduced by following the same strategies used to minimize antimicrobial resistance in systemic infections.

Cyclosporine 0.05% to improve visual outcomes after multifocal intraocular lens implantation.

PURPOSE: To evaluate the efficacy of cyclosporine 0.05% in alleviating dry-eye signs and improving visual quality after multifocal intraocular lens (IOL) implantation. SETTING: Private practice and university medical center, New York, New York, USA. METHODS: This randomized prospective contralaterally controlled double-masked trial comprised patients scheduled to have bilateral phacoemulsification with implantation of a refractive multifocal IOL (ReZoom). Patients received twice-daily cyclosporine 0.05% in 1 eye and an artificial tear in the other eye from 1 month before to 2 months after second-eye surgery. Outcomes were evaluated at baseline and 2 months after second-eye surgery. RESULTS: The study enrolled 28 eyes of 14 patients. At baseline, there were no statistically significant between-group differences in outcome measures. Two months postoperatively, the cyclosporine group had significantly lower mean uncorrected distance visual acuity than the artificial tear group (0.11 logMAR +/- 0.03 [SD] [20/25 Snellen equivalent] versus 0.19 +/- 0.05 logMAR [20/30]; P = .045) as well as significantly lower mean corrected distance visual acuity (0.0 +/- 0.02 logMAR [20/20] versus 0.1 +/- 0.02 logMAR [20/25]; P = .005) and corneal staining scores (0.210 +/- 0.07 versus 0.645 +/- 0.18; P = .034). Treatment with cyclosporine 0.05% also improved contrast sensitivity, conjunctival staining, and tear breakup time. Significantly more patients preferred the eye treated with cyclosporine 0.05% to the eye treated with artificial tears (57.1% versus 14.3%; P = .007). CONCLUSION: Cyclosporine 0.05% therapy reduced dry-eye signs and improved visual quality after multifocal IOL implantation. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Acute conjunctivitis: truth and misconceptions.

OBJECTIVE: Acute conjunctivitis is an extremely common condition and can be associated with significant morbidity and economic burden. Despite this, considerable controversy exists pertaining to the prevalence, diagnosis, management, and treatment of the condition. A panel of ophthalmology experts was assembled to review and discuss the current evidence based literature as it pertains to each of these persistent controversies. METHODS AND SCOPE: An acute conjunctivitis round table symposium was convened at the American Academy of Ophthalmology meeting in Atlanta, November 2008. The expert panelists consisted of four academic ophthalmologists in the field of cornea and external disease, whose discussion was informed by an English language literature survey carried out on the PubMed database for the period of January 1972 to October 2008. A narrative summary was generated from the literature review and direct transcription of this event, from which this Review article was developed. FINDINGS AND CONCLUSIONS: Considerable light has been shed on acute microbial conjunctivitis and especially those cases caused by adenovirus. Many of the myths that have perpetuated for years have been debunked by emerging evidence. The advent and the implementation of better diagnostic tools and anti-viral medications will help clinicians to improve their diagnostic accuracy, improve management and treatment decisions, and ultimately benefit patients while saving overall healthcare costs.

Intracorneal inlay for the surgical correction of presbyopia.

PURPOSE: To evaluate the clinical safety and efficacy of the ACI-7000 intracorneal inlay in increasing the depth of field in emmetropic presbyopic patients. SETTING: Beyoglu Eye Research and Education Hospital, Istanbul, Turkey. METHODS: This prospective unmasked study comprised 39 presbyopic patients; 12 were naturally emmetropic and 27 had emmetropia resulting from previous hyperopic laser in situ keratomileusis. The intracorneal inlay was placed over the pupil in the patient's nondominant eye after flap lift or creation of a conventional flap using a microkeratome. The inlay was centered on the visual axis. Postoperative follow-up was 1 year. RESULTS: Of the 39 inlays implanted, 3 were explanted during the study. At 1 year, the mean uncorrected near visual acuity improved from J6 (preoperatively) to J1+. All eyes with an inlay had an uncorrected near acuity of J3 or better and 85.3%, of J1 or better. Binocularly, the mean uncorrected near acuity remained J1 or better throughout the study. The mean uncorrected distance visual acuity in eyes with an inlay did not change significantly from preoperatively and remained 20/20 throughout the study period. All 3 eyes with inlay explantation returned to within +/-1.00 diopter of the preoperative refractive state for near and distance vision, with no loss of best corrected distance visual acuity. CONCLUSION: The ACI-7000 intracorneal inlay showed the potential to provide safe, effective, and reversible treatment of presbyopia.

Safety and efficacy of cyclosporine 0.05% drops versus unpreserved artificial tears in dry-eye patients having laser in situ keratomileusis.

PURPOSE: To evaluate dry-eye signs, symptoms, and refractive outcomes in patients with dry-eye disease having laser in situ keratomileusis (LASIK). METHODS: In this randomized parallel double-masked prospective clinical trial, 42 eyes of 21 myopic patients (mean spherical equivalent -4.3 diopters [D], range -1.00 to -10.63 D) with dry-eye disease were treated with unpreserved artificial tears or cyclosporine 0.05% ophthalmic emulsion twice a day beginning 1 month before LASIK. Treatment with the study drug was discontinued for 48 hours post surgery and then resumed for 3 additional months. Both groups used additional artificial tears as needed. Study visits occurred pretreatment (baseline), before surgery, and at 1 week and 1, 3, 6, and 12 months after surgery. RESULTS: Statistically significant increases from baseline were found in Schirmer scores for artificial tears at 1 month (P = .036) and for cyclosporine 0.05% before surgery and 1 week, 1 month, and 6 months after surgery (P<.018). There were no significant differences from baseline or between groups in responses to the Ocular Surface Disease Index questionnaire or best corrected visual acuity (BCVA), nor were there significant between-group differences in superficial punctate keratitis or uncorrected visual acuity. Mean refractive spherical equivalent in cyclosporine-treated eyes was significantly closer to the intended target at 3 and 6 months after surgery than in artificial-tears-treated eyes (P = .007). A greater percentage of cyclosporine eyes was within +/-0.5 D of the refractive target 3 months after surgery than artificial tears eyes (P = .015). CONCLUSION: Successful outcomes after LASIK were achieved for dry-eye disease patients. Treatment with cyclosporine 0.05% provided greater refractive predictability 3 and 6 months after surgery than unpreserved artificial tears.

Safety and efficacy of levofloxacin 1.5% eyedrops in nonhuman primates having penetrating keratoplasty: clinical and laboratory findings.

PURPOSE: To determine the safety and efficacy of levofloxacin 1.5% eyedrops. SETTING: Tulane University Delta Research Primate Center, New Orleans, Louisiana, USA. METHODS: Ten monkeys had preoperative slitlamp examinations, photographs, and confocal microscopy. Levofloxacin 1.5% or control eyedrops were given 4 times a day in both eyes for 2 days and every 5 minutes for the hour before surgery and 4 times a day in both eyes for 1 week. Confocal microscopy, slitlamp examination, and slitlamp photography were repeated preoperatively. Intraoperative aqueous humor and corneal biopsies were taken. RESULTS: There were no differences between groups in slitlamp examinations, slitlamp photography, confocal microscopy, or histology; the mean levofloxacin level in the aqueous humor was 4.49 mug/mL +/-1.59 SD and in the corneal biopsies, 103.85 +/- 51.48 mug/g. CONCLUSION: Levofloxacin 1.5% drops given on a typical perioperative schedule to monkeys having penetrating keratoplasty showed no clinical or histological signs of toxicity and reached corneal issue levels well over the minimum inhibitory concentrations for all known ocular pathogens.

Treatment of presbyopia with conductive keratoplasty: six-month results of the 1-year United States FDA clinical trial.

PURPOSE: To provide 6-month results of a 1-year clinical trial evaluating conductive keratoplasty (CK) for the treatment of presbyopic symptoms in emmetropic and hyperopic eyes. METHODS: A total of 143 patients with presbyopic symptoms were enrolled in this 1-year United States FDA clinical trial and treated to improve near vision in 1 eye (unilateral treatment). In addition, 33 fellow eyes were treated to improve distance vision (bilateral treatment). For near vision correction, the target refraction was up to -2.0 D in the nondominant eye, and for distance vision correction, 0.0 D. Enrolled patients had a preoperative spherical equivalent of plano to +2.00 D, no more than 0.75 D of refractive astigmatism, and were 40 years of age or older. No retreatments were performed. RESULTS: Of the eyes treated for near, 77% had uncorrected near vision of J3 or better at 6 months postoperatively. A total of 85% of all patients had binocular distance UCVA of 20/25 or better along with J3 or better near, a combination that represents functional acuity for a presbyope. Sixty-six percent of eyes treated for near had a manifest refractive spherical equivalent (MRSE) within +/- 0.50 D of intended at 6 months. In 89% of eyes, the MRSE changed 0.05 D or less between 3 and 6 months postoperatively. After month 1, the incidence of variables associated with safety was 1% or lower. Seventy-six percent were very satisfied or satisfied with their procedure. CONCLUSIONS: CK appears to be very safe and effective in producing functional visual acuity in presbyopic eyes up to 6 months following the procedure. Patient satisfaction with the procedure is similar to that of monovision LASIK.

Conductive keratoplasty for the correction of low to moderate hyperopia: U.S. clinical trial 1-year results on 355 eyes.

OBJECTIVE: To document the 1-year safety, efficacy, and stability results of 355 eyes treated in the multicenter study of conductive keratoplasty (CK) used to correct low to moderate hyperopia. DESIGN: Nonrandomized comparative (self-controlled) trial. PARTICIPANTS: Twenty surgeons at 13 centers performed CK on the eyes of all patients enrolled in a multicenter, 2-year, U.S. phase III clinical trial. Treated eyes had +0.75 to +3.00 diopters (D) of hyperopia and < or =0.75 D of cylinder. Patients were 40 years of age or older. INTERVENTION: Low-energy, high-frequency current was applied directly into the peripheral corneal stroma through a delivery tip inserted at 8 to 32 treatment spots. The number of treatment spots was increased for increasing levels of hyperopia, but the amount of radiofrequency energy remained constant. Emmetropia was intended. All eyes were treated once (there were no retreatments). MAIN OUTCOME MEASURES: Data from 355 eyes with 1 year of follow-up were analyzed for safety and stability, and data from 318 eyes were analyzed for efficacy and predictability, as well as stability and safety. All patients reported on satisfaction and quality of vision after surgery. RESULTS: At 1 year, uncorrected visual acuity was < or =20/20 in 56%, < or =20/25 in 75%, and < or =20/40 in 92% of eyes. The manifest refractive spherical equivalent refraction was within 0.50 D in 63%, within +/-1.00 D in 89%, and within +/-2.00 D in 99%. Seven of 355 eyes lost 2 lines of best spectacle-corrected visual acuity at 1 year, but no eye lost >2 lines. One eye of 355 had induced cylinder of >2.00 D. The cycloplegic refractive spherical equivalent changed a mean of 0.25 +/- 0.50 D between months 3 and 6, 0.11 +/- 0.41 D between months 6 and 9, and 0.11 +/- 0.35 D between months 9 and 12. Refractive stability seemed to be attained by 6 months and remained stable through 12 months. Histology and confocal microscopy showed deep penetration of the treatment into the stroma. Endothelial cell counts were not changed by the treatment. CONCLUSIONS: CK seems to be safe, effective, and stable for correcting low to moderate spherical hyperopia in patients 40 years old or older. Treatment penetration is deep and cylindrical in shape, and it does not damage the corneal endothelium. Uncorrected visual acuity, predictability, and stability are as good as or better than those obtained with other techniques used to correct hyperopia.

Conductive keratoplasty for the correction of low to moderate hyperopia: 1-year results on the first 54 eyes.

OBJECTIVE: To document the 1-year postoperative clinical results of the safety, efficacy, and stability of conductive keratoplasty (CK) to correct low to moderate hyperopia. DESIGN: Prospective, nonrandomized, self-controlled trial. PARTICIPANTS: Five surgeons at four centers performed CK on the first 54 eyes of a multicenter, 2-year clinical trial. Treated eyes had +0.875 to +4.00 diopters (D) of hyperopia and < or =0.75 D of cylinder. The nature of this procedure was explained to all participating patients who signed informed consent forms prior to undergoing the procedure. INTERVENTION: Low energy, high-frequency current was applied directly into the peripheral corneal stroma through a delivery tip inserted at 16 or more treatment spots. An early nomogram was used for the first 54 eyes with an intended refraction of plano. MAIN OUTCOME MEASURES: Data from all 54 eyes were analyzed for safety and stability. A subset of 30 of the 54 eyes was found that had been treated with the appropriate number of spots with the early nomogram. These eyes were categorized as current nomogram eyes; the data for these eyes were analyzed for efficacy and predictability, as well as stability and safety. All patients reported on satisfaction and quality of vision after surgery. RESULTS: Preoperatively, the manifest refractive spherical equivalent refraction (MRSE) of the 30 current nomogram eyes was +1.57 D. At 1 year postoperatively, uncorrected visual acuity was 20/20 or better in 57% of the eyes and 20/40 or better in 93%. The MRSE was within 0.50 D in 46%, within +/-1.00 D in 93%, and within +/-2.00 D in 100%. No eye lost > or =2 lines of best spectacle-corrected visual acuity at 1 year postoperatively nor had an induced cylinder of > or =2.00 D. The MRSE changed a mean of 0.25 D +/- 0.43 between 3 and 6 postoperative months, 0.16 D +/- 0.38 between 6 and 9 postoperative months, and 0.07 D +/- 0.38 between 9 and 12 postoperative months. Refractive stability appeared to be attained by 6 months postoperatively. CONCLUSIONS: Conductive keratoplasty appears to be safe, effective, and stable for correcting low to moderate spherical hyperopia. Stability appeared by the 6-month follow-up visit. For the eyes treated with the current CK nomogram, uncorrected visual acuity, predictability, and stability are as good as or better than those obtained with hyperopic laser in situ keratomileusis or noncontact laser thermal keratoplasty.

Photorefractive keratectomy for moderate myopia with the VISX and Summit excrimer lasers: a retrospective study

Objetivo: Apresentar os resultados obtidos com ceratectomia fotorrefrativa (PRK) para a correção de miopia variando de -4,0 a -6,0 dioptrias realizadas com os excimer lasers VISX e Summit. Métodos: Para o estudo foram avaliados os resultados de PRK realizados em pacientes com idade entre 20 e 45 anos, miopia entre -4,0 e -6,0 diotropias e astigmatismo até 1,0 diotropia .O grupo operado com o laser da marca Summit era composto de 51 olhos. O equivalente esférico médio pré-operatório era de -5,22ñ0,17 diatropias e as cirurgias foram realizadas com o Excimed UV 200 LA Excimer Laser. O grupo operado com o laser VISX, era composto de 53 olhos e o erro refrativo preoperatório era de -4,85ñ0,16 diatropias e as cirurgias foram realizadas com o Twenty/Twenty Excimer Laser.