Per Montan

Sahlgrenska University Hospital, Goeteborg, Västra Götaland, Sweden

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Publications (39)121.03 Total impact

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    ABSTRACT: To evaluate the efficacy of adding nepafenac 0.1% ophthalmic suspension to dexamethasone 0.1% eyedrops in controlling macular swelling and other manifestations of inflammation after uneventful cataract surgery.
    Journal of Cataract and Refractive Surgery 09/2014; 40(9):1498-505. · 2.75 Impact Factor
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    ABSTRACT: To analyze changes over time in biometry prediction error (BPE) after cataract surgery with special reference to the impact of gender and the intra-ocular lens (IOL) calculation formula.
    Acta ophthalmologica 06/2014; · 2.44 Impact Factor
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    ABSTRACT: To study the epidemiology and risk factors of early- and late-onset postoperative endophthalmitis (PE) and severe blebitis following trabeculectomy. Retrospective, single-centre, observational study with a case-control design in part. Patients sustaining PE and severe blebitis following trabeculectomy or a combined trabeculectomy with a cataract extraction procedure performed from 1990 through 2008 and diagnosed from 1990 through 2012 were recorded at St Erik Eye Hospital. Incidence data were calculated with help from the hospital records. Notes data of cases and of six randomly selected but procedure matched control patients for each case were compared. The joint rate of infection was 0.46% or 34 incidents in 7402 procedures. The frequency of early (occurring <6 weeks after surgery) onset PE was 0.19%, late PE was 0.19% and severe blebitis was 0.08%. Dominating aetiologies were staphylococci and streptococci. Overall, the infection severely impaired the visual function. Combined cataract and fistulating operations were less prone to develop late infections, p = 0.04, but no other decisive factors were identified in the case-control study. Data collection for all trabeculectomy surgeries from 1998 and onward identified an increased rate for late infection with the use of mitomycin C (MMC), 8 in 1171 surgeries or 0.7%, versus no such use, 0 case of late PE in 2136 surgeries, p < 0.001. Postoperative endophthalmitis is a devastating complication after trabeculectomy. The use of MMC increases the risk for delayed infection. Early PE after trabeculectomy is clearly more common than PE after cataract surgery. Developing efficacious prophylactic antibiotic regimens to reduce early PE after penetrating filtering procedures should be a major priority in ophthalmic surgery.
    Acta ophthalmologica 09/2013; · 2.44 Impact Factor
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    ABSTRACT: To report the nationwide incidence and risk factors for endophthalmitis after cataract surgery in Sweden. Swedish National Cataract Register containing reports on cataract operations from all Swedish ophthalmic surgical units. Prospective epidemiologic study. Endophthalmitis case reports were collected from 2005 through 2010. Case and control parameters pertaining to patient characteristics and surgical technique were generated from the database. In addition, information from annual surveys regarding the topical prophylactic protocol was analyzed. The reports showed 135 endophthalmitis cases in 464 996 operations, equaling an incidence of 0.029%. Patient age over 85 years, perioperative communication with the vitreous and, above all, nonuse of intracameral cefuroxime showed a statistically significant association with endophthalmitis in the logistic regression. Short-term topical antibiotics given as add-on prophylaxis to the intracameral regimen before, after, or before and after the operation did not confer a clear-cut benefit. Groups with topical treatment were small, comprising 14% of the sample. The incidence of endophthalmitis after cataract surgery in Sweden is declining, which appears to be explained by a fall in the frequency of major risk factors. Operating earlier in the cataract course, avoiding capsule breakage, and giving intracameral antibiotics universally should further reduce the endophthalmitis rate. No author has a financial or proprietary interest in any material or method mentioned.
    Journal of Cataract and Refractive Surgery 01/2013; 39(1):15-21. · 2.75 Impact Factor
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    ABSTRACT: To assess and analyze refractive outcome after cataract surgery in Sweden from 2008 through 2010. Swedish cataract surgery units participating in outcome registration of National Cataract Register. Cohort study. Planned and actual postoperative refractions were analyzed for cataract procedures and preoperative and postoperative corneal astigmatism for procedures performed in 2008 though 2010. Induced astigmatism was calculated with Naeser and Behrens polar coordinates. Postoperative refraction was analyzed for 17,056 procedures and corneal astigmatism for 7448 procedures. Emmetropia was targeted in 78.1% of eyes and achieved in 52.7%; 43.0% had less than 1.00 diopter (D) of astigmatism. "Reading myopia" of -3.5 to -1.6 D was targeted in 7.0% of eyes and achieved in 7.8%. Planned hyperopia greater than 1.0 D or myopia greater than -3.5 D was rare. The mean absolute biometry prediction error was 0.402 D ± 0.338 (SD) in all eyes; however, astigmatic eyes and eyes planned for myopia or hyperopia had higher biometry prediction errors. Younger patients were more often astigmatic and planned for a more myopic outcome. Preoperatively, one third of eyes had more than 1.0 D of corneal astigmatism; postoperatively this figure was largely unaltered. The mean induced astigmatism was 0.525 ± 0.804 D in all eyes. Emmetropia (spherical equivalent -0.5 to +0.5 D and <1.0 D astigmatism) is the goal in most cataract cases but was reached in only 55% of eyes planned for emmetropia. Factors precluding emmetropia included remaining corneal astigmatism and biometry prediction errors in astigmatic and ametropic eyes. No author has a financial or proprietary interest in any material or method mentioned.
    Journal of Cataract and Refractive Surgery 07/2012; 38(7):1181-6. · 2.75 Impact Factor
  • Talal Ali, Karin Jung, Per G Montan
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    ABSTRACT: Purpose:  To evaluate the effect on conjunctival micro-organisms of chlorhexidine alcohol 0.5% eyelid wash in cataract patients. Methods:  In this single-centre experimental study, 120 patients scheduled to undergo cataract operation were cultured in the conjunctiva before the operation and after the insertion of the intraocular lens. Bacterial samples for aerobic and anaerobic cultures were taken with a polyvinyl alcohol pad and transported in peptone water to the microbiological laboratory where they were analysed in a blinded fashion. Half of the patients received a standardized eyelid scrub with chlorhexidine alcohol 0.5%, while the rest did not. The conjunctiva of all patients was rinsed preoperatively with chlorhexidine solution 0.05%. Results:  In all the between-group comparisons, the treated eyelid group had slightly lower bacterial counts than the control group on the postoperative samples, but differences were far from statistically significant. Within-group comparisons revealed statistically significant reduction in colonies and species between the preoperative and postoperative sampling. Conclusion:  In this experimental culture study, no evidence was found to suggest that preoperative eyelid chlorhexidine alcohol wash is effective in further reducing bacterial counts in the conjunctiva when the conjunctiva itself is rinsed preoperatively with chlorhexidine solution. The present results, however, do not contradict that the wash may be of some marginal help in reducing bacterial contamination of the operation field. Consequently, this part of the prophylactic protocol is still in practice in our institution.
    Acta ophthalmologica 04/2012; · 2.44 Impact Factor
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    ABSTRACT: The purpose of this study was to use the Catquest-9SF to measure cataract surgery outcomes, and to use Rasch analysis to test the psychometric properties of this questionnaire, including its validity and responsiveness. Patients were recruited as consecutive cataract surgery patients during 1 month at six surgical units in Sweden (via the National Cataract Register). The patients completed the questionnaire before surgery and 3 months after. The Catquest-9SF data were assessed for fit to the Rasch model using version 3.63.2 of the WINSTEPS software (Winsteps.com, Beaverton, OR, USA). Both preoperative and postoperative questionnaires were included in the analysis. The responsiveness to cataract surgery was calculated as the effect size. Completed questionnaires before and after surgery were received from 846 patients. The Rasch analysis showed that the category thresholds were ordered. All items fit a single overall construct (infit range 0.79-1.40; outfit range 0.74-1.40). The ability to discriminate different strata of person ability was good, with a real patient separation of 2.58 and patient separation reliability of 0.87. The questionnaire showed unidimensionality and was largely free from differential item functioning. The item difficulty was reasonably well targeted to both preoperative and postoperative patient ability. The Catquest-9SF Rasch score correlated significantly with visual acuity, and cataract surgery resulted in a significant improvement with an effect size of 1.8. The Catquest-9SF shows excellent psychometric properties, as demonstrated by Rasch analysis. It is highly responsive to cataract surgery, and its brevity (nine items) makes it well suited for use in daily clinical practice.
    Acta ophthalmologica 12/2011; 89(8):718-23. · 2.44 Impact Factor
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    ABSTRACT: Atopic keratoconjunctivitis (AKC) is a chronic eye disease with periods of exacerbations. Many patients experience no obvious seasonal variation, although a majority of patients are allergic to common airborne allergens. To investigate the allergic reaction, to conjunctival provocation with airborne allergens, in patients with AKC. Eleven patients with AKC and birch and/or grass pollen allergy participated in the study, which was performed outside the pollen season. Five patients with seasonal allergic conjunctivitis (SAC) and five healthy subjects were included for validation purposes. The challenge was performed in one eye with the allergen, to which the patient was reactive, and with dilution buffer in the other eye. Signs and symptoms from both eyes were graded at baseline and at 10 min, 8 and 48 h after provocation. Tear fluid was collected from both eyes for cytokine analyses at baseline and at 8 and 48 h. A significant change in clinical symptoms and signs, (redness and chemosis) was evident 10 min after provocation compared with baseline (P = 0.005) and compared with the unprovoked eye (P = 0.005) in AKC subjects. These parameters were normalized after 8 and 48 h. A significant increase for IFN-γ (P = 0.021) and IL-6 (P = 0.015), and a near significant increase for IL-10 (P = 0.066) were seen in the tear fluid of the challenged eye at 48 h after provocation vs. baseline and vs. the control eye for IFN-γ (P = 0.005), IL-6 (P = 0.028) and IL-10 (P = 0.008) in AKC subjects. In this single dose allergen provocation study, AKC patients responded with a typical IgE-mediated allergic reaction. An increase in cytokines at 48 h after the challenge was demonstrated and might, with further studies, give us a better understanding of the nature of inflammation in AKC.
    Clinical & Experimental Allergy 09/2011; 42(1):58-65. · 4.79 Impact Factor
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    ABSTRACT: To define the incidence of capsule complication and its risk factors in Sweden over an 8-year period. Fifty-two ophthalmic surgery units in Sweden. Database study. Data were collected prospectively in the Swedish National Cataract Register (NCR) from 2002 through 2009. The NCR contains 97.3% of the total number of cataract extractions in Sweden over the 8-year study period. One mandatory variable in the register is capsule complications during surgery. As a means to validate the accuracy of register data on capsule complications, a randomly selected sample of 2400 registrations was compared with corresponding medical records. The analyses were based on 602,553 cataract extractions reported to the NCR. A capsule complication was reported in 12,574 cataract extractions, corresponding to a frequency of 2.09%. The incidence of this complication consistently decreased each year from 2002 to 2006, after which it stabilized. Poor corrected distance visual acuity in the surgical eye (≤ 0.1), the occurrence of glaucoma, diabetic retinopathy, and age were among the parameters significantly related to a capsule complication. Some of these parameters also decreased over time. However, even after adjusting for this, there was an obvious decrease in capsule complications over time. The validity test showed a certain underreporting of capsule complications to the registry, but it was not significant and did not change over time. The incidence of capsule complications decreased over time. This may be partly the result of fewer risk factors and of better surgical quality. No author has a financial or proprietary interest in any material or method mentioned.
    Journal of Cataract and Refractive Surgery 08/2011; 37(10):1762-7. · 2.75 Impact Factor
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    ABSTRACT: This review summarizes data collected by the Swedish National Cataract Register, which now contains data pertaining to more than a million cataract surgery procedures, representing 95.6% of the surgeries performed in Sweden during 1992-2009. During this period, the rate of cataract surgery rose from 4.47 to 9.00 per 1000 inhabitants. The mean patient age increased until 1999 but has slowly decreased since then. Preoperative visual acuity has risen steadily. The distribution between the sexes was stable until 2000, after which the proportion of women slowly decreased. Registration of subjective benefit has brought new knowledge regarding indications and expectations. An improved questionnaire, Catquest-9SF has been used since 2008. The outcome register generally shows good results from the surgery. Endophthalmitis has decreased from 0.10% to below 0.040%.
    Journal of Cataract and Refractive Surgery 08/2011; 37(8):1539-45. · 2.75 Impact Factor
  • Per Montan, Gisela Wejde
    Ophthalmology 04/2010; 117(4):854-5. · 5.56 Impact Factor
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    ABSTRACT: To report the selection procedure of complicated and uneventful cataract extractions included in the Swedish Capsule Rupture Study and to describe the additional care required after a capsule complication during cataract surgery. Ten ophthalmic surgery departments in Sweden. Consecutive cataract extractions with a reported capsule complication were selected from the national database. Surgical data and data from the matching ophthalmic records at the participating clinics were analyzed. Controls were selected as the first uneventful procedure in the database after each procedure with a complication. Data on 655 cataract extractions were studied for evaluation of risks and additional care; a capsule complication occurred in 324 procedures and no complication in 331 procedures. Using these records, 369 patients were recruited for a follow-up examination of the outcomes 3 years after the original cataract extraction. The records showed a substantial increase in additional care after a capsule complication, including more visits after surgery, increased need for in-patient care, and a significantly greater percentage of reoperations than after the uneventful surgery. With additional care, the average cost of a procedure with a capsule complication was approximately double the cost of an uneventful cataract extraction. The combined study of the database and matching medical records showed a substantial increase in additional care after a capsule complication. Using the database allowed identification of a large number of capsule complication cases and uneventful cases, indicating that national databases are excellent sources of data for studying unusual complications.
    Journal of Cataract and Refractive Surgery 10/2009; 35(10):1679-87.e1. · 2.75 Impact Factor
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    ABSTRACT: To describe the long-term outcomes after cataract extractions with a capsule rupture included in the Swedish Capsule Rupture Study. Ten ophthalmic surgery departments in Sweden. From the cohort of patients originally selected for inclusion in the Swedish Capsule Rupture Study, cases with a capsule complication (study group) and cases without a complication (control group) were examined approximately 3.5 years postoperatively. Visual acuity and objective and subjective parameters were registered. The study group comprised 171 patients and the control group, 198 patients. Patients with a capsule complication had a significantly worse visual outcome and a doubled risk for no improvement in preoperative visual acuity. Pupil distortion, iris damage, synechias, and subjective complaints related to the eye were significantly more common in patients with a capsule complication. Capsule complications decreased the probability of good postoperative visual acuity and in general yielded a worse long-term outcome after phacoemulsification surgery.
    Journal of Cataract and Refractive Surgery 10/2009; 35(10):1694-8. · 2.75 Impact Factor
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    ABSTRACT: To study the incidence, characteristics, and results of retinal detachment (RD) after cataract surgery with a capsule complication. Ten ophthalmic surgery departments in Sweden. In this case-control study, data on cataract surgery cases with a capsule complication (study group) or with no complication (control group) in 2003 were extracted from the Swedish National Cataract Register. Patients with RD during a 3-year follow-up were identified. The study group comprised 324 patients and the control group, 331 patients. Retinal detachment occurred in 13 study group patients, for a 3-year incidence of 4.0%. In the control group, 1 patient (0.3%) had RD. Multivariate analysis showed an adjusted odds ratio (OR) of 14.8 for RD after capsule complication (95% confidence interval [CI], 1.9-114; P = .01). Subgroup analysis of the study group using a binary logistic regression model showed that male sex (OR, 8.5; 95% CI, 1.7-43.8; P = .001) and lens remnants in the vitreous (OR, 14.4; 95% CI 2.6-78.8; P = .002) were additional risk factors. Axial myopia was significantly associated with an increased risk as a single factor but not as a multiple factor. In general, the final visual outcome for RD after a capsule complication was poor; 3 eyes had a visual acuity of 0.50 or better. Eight eyes (62%) had a final visual acuity worse than 0.10 and 6 eyes, 0.02 or worse. The risk for RD after cataract surgery increased significantly when a capsule complication occurred, leading to poor final visual acuity in most cases.
    Journal of Cataract and Refractive Surgery 10/2009; 35(10):1699-705. · 2.75 Impact Factor
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    ABSTRACT: To identify preoperative and intraoperative factors associated with a capsule complication; that is, a capsule tear or a zonular dehiscence during cataract surgery. Ten ophthalmic surgery departments in Sweden. A retrospective review of files of patients with a capsule complication and control patients with no complication operated on in 2003 was performed. The review comprised 324 patients with a capsule complication and 331 control patients. In the logistic regression analyses, preoperative conditions associated with a capsule complication were previous trauma, white and brunescent/hard cataract, and phacodonesis. The intraoperative factors of loose zonules, the use of trypan blue, and miosis were all statistically significantly overrepresented in the capsule complication group. The same was true for eyes operated on by surgeons with the least experience. By preoperatively identifying cataract cases with the identified risk factors and allocating them to surgeons with the longest experience, the number of capsule complications could be kept low. Operating early in the course of the disease to prevent the cataract from becoming a poor surgical risk and improving training of junior surgeons should further reduce the frequency of capsule complications.
    Journal of Cataract and Refractive Surgery 10/2009; 35(10):1688-93. · 2.75 Impact Factor
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    ABSTRACT: The main objective of this explorative study was to evaluate if tacrolimus ointment could be safer than corticosteroid ointment, with special reference to the intraocular pressure in the treatment of eyelid eczema in patients with atopic keratoconjunctivitis (AKC). Secondary aims were to compare the effects of the treatments on eyelid eczema and their potential impact on ocular surface inflammation. Tacrolimus 0.1% ointment and clobetasone butyrate 0.05% ointment were compared in a double-masked explorative crossover study. In total, 25 AKC patients were included. Each ointment was applied twice daily for 3 weeks, with 2 weeks of washout before, between, and after treatments. Efficacy was determined by eye examination and the patients' own symptom scoring. Cytology and cytokine measurements were performed on tear samples. Safety parameters were intraocular pressure, presence of bacteria and fungi, and the patients' reports of adverse events. The validity of the crossover design was explored with analysis of variance, and the effect of each medication was calculated with paired t-test and Wilcoxon paired test. A total of 20 patients completed the study. Both treatments were effective in reducing signs and symptoms of eyelid eczema, with a near superior benefit for tacrolimus in terms of eczema (total skin score) signs (P=0.05). No serious adverse events occurred and interestingly, intraocular pressure was not evidently affected by either treatment. Tacrolimus 0.1% ointment is a promising alternative therapy for eyelid eczema in AKC patients. Long-term studies are needed to further determine the value of tacrolimus in this patient group.
    Eye 08/2007; 21(7):968-75. · 1.82 Impact Factor
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    ABSTRACT: It is widely accepted that nonspecific tissue reactivity is a distinct pathophysiological hallmark of allergic diseases, influenced by genetic and environmental factors different from those involved in causing sensitization and allergen response of target organs. This consensus document aims at reviewing procedures currently used for nonspecific provocation of the bronchi, nose and eye and for measuring their responsiveness to nonspecific stimuli.
    Allergy 07/2007; 62(6):683-94. · 5.88 Impact Factor
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    ABSTRACT: To establish the nationwide rate of postoperative endophthalmitis (PE) after cataract extraction (CE) and to study the relationship between PE and type of incision and other possible risk factors. Prospective, multicenter, comparative, nonrandomized, observational study. All cataract surgeries in Sweden performed from January 2002 through December 2004 and all endophthalmitis cases in the same period that were reported to the Swedish National Cataract Register (NCR). Through a standard reporting form sent to the NCR, patient and operation technique data were recorded. In addition, PE cases with a traceable number to the main register were collected. Various parameters with a possible impact on endophthalmitis development were evaluated. Univariate analyses and logistic regression were statistical methods. The rate and etiology of PE; possible risk factors pertaining to patient history and operation technique, with a special emphasis on incision type and location; use of injector for the intraocular lens implantation; kind of prophylaxis; and presence of peroperative communication between the anterior chamber and vitreous. The overall rate of PE was 0.048% (109 cases in 225 471 CEs). Incidences of PE were 0.053% with clear corneal incisions and 0.036% with sclerocorneal incisions (P = 0.14, logistic regression analysis). The corresponding results were 0.040% for superior incisions and 0.055% for temporal incisions (P = 0.14). Communication between the anterior segment and vitreous was found to be a highly significant independent risk factor for PE (P<0.001), as were patient age > or = 85 years (P<0.001) and the nonuse of intracameral cefuroxime (P<0.001). The overall rate of PE after cataract surgery is low in Sweden, which may be a consequence of the widespread use of prophylactic intracameral cefuroxime. Only a trend for an increased risk of PE was detected for clear corneal and temporal wounds. The present data indicate that the use of clear corneal and/or temporal approaches will result in 1 additional PE case in approximately 5500 procedures on top of the PE rate after sclerocorneal or superior incisions, which was approximately 1 case in 2400 operations.
    Ophthalmology 05/2007; 114(5):866-70. · 5.56 Impact Factor
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    Per G. Montan
    Acta Ophthalmologica Scandinavica 10/2005; 83(5). · 1.85 Impact Factor
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    ABSTRACT: To investigate the epidemiology of postoperative endophthalmitis (POE) following cataract surgery in Sweden during a 3-year period, using the framework of the Swedish National Cataract Register. Clinically presumed cases of POE were reported in a prospective survey involving all Swedish ophthalmic surgical units except one. Data on results of the intraocular culture and visual outcome after infection, as well as patient age and gender and various elements of the surgical procedure, were collected. The nationwide incidence of POE was 0.0595%, representing 112 cases in 188 151 cataract operations. Gram-positive bacteria were the predominant aetiology, with an 84.6% share of culture-positive cases. A significantly decreased risk for POE was found for patients who had received prophylactic intracameral antibiotics (mainly cefuroxime) in comparison with those who had been treated with topical antibiotics only. The prevalence of POE after cataract surgery in Sweden is at the lower end of the spectrum of incidence currently reported in the developed world. The administration of intracameral antibiotics may have contributed to these results.
    Acta Ophthalmologica Scandinavica 03/2005; 83(1):7-10. · 1.85 Impact Factor

Publication Stats

752 Citations
121.03 Total Impact Points

Institutions

  • 2009–2014
    • Sahlgrenska University Hospital
      Goeteborg, Västra Götaland, Sweden
  • 2007–2014
    • Karolinska Institutet
      • Department of Clinical Neuroscience
      Solna, Stockholm, Sweden
  • 2013
    • Lund University
      Lund, Skåne, Sweden
  • 2011–2012
    • Umeå University
      Umeå, Västerbotten, Sweden
  • 1999
    • Stockholm County Council
      Tukholma, Stockholm, Sweden