William Thorburn

THE ACCURACY OF CLINICAL APPLANATION TONOMETRY

The differences between two careful applanation tonometries performed by one and by two observers, respectively, were compared. Two measurements by one observer differed by 2 mmHg or more in 8% of the pairs of measurements and by 3 mmHg or more in 2% of the pairs. One tonometry each by two observers differed by 2 mmHg or more in 40% of the pairs of measurement and by 3 mmHg or more in 17% of the pairs. There was no dependence on the intraocular pressure. Possible reasons for the increase in variance are discussed.

Catquest questionnaire for use in cataract surgery care: Assessment of surgical outcomes

Purpose: To demonstrate the outcome for patients after cataract extraction using the Catquest cataract questionnaire and discuss the model’s validity in assessing outcomes. Setting: Thirty‐five Swedish departments of ophthalmology. Methods: Patients having cataract extraction performed by surgeons from 35 Swedish departments of ophthalmology participated in the study. The questionnaire was given to 2970 consecutive patients having surgery during March 1995 at the participating surgical units. The questionnaire was sent by mail to patients and completed on a voluntary basis. It focuses on visual disabilities in daily life, activity level, cataract symptoms, and degree of independence. The results from the questionnaire are interpreted using a benefit matrix that credits not only a decrease in visual disabilities and cataract symptoms but also an improvement in or maintenance of a preoperative activity level. Results: Complete surgical outcome data and completed preoperative and postoperative questionnaires were available in 1933 cases (65.1%). Benefit from surgery according to the model was achieved by 90.9% of the patients. Patients having their second cataract extraction had the highest frequency of the greatest benefit from surgery. There was good agreement between the different levels of benefit from surgery according to the model and the patient’s global rating of his or her vision or achieved visual acuity after surgery, respectively. Patients with missing data (did not return postoperative questionnaire or had missing surgical result variables) were older and had a higher frequency of other diseases and handicaps. Conclusion: The Catquest cataract questionnaire allowed the outcome of cataract surgery to be graded by different levels of benefit. There seemed to be good agreement between this model of assessment and the patient’s global rating of his or her vision. Missing data may be a problem when a postal questionnaire is used.

Cataract surgery and quality of life in patients with age related macular degeneration

Background: The coexistence of cataract and age related macular degeneration (AMD) is not unusual, especially in the very elderly. The outcome of cataract surgery in these cases depends on the effect of AMD on vision. In this study the authors have compared the outcome of cataract patients with AMD to that of cataract patients with no vision threatening ocular comorbidity, and analysed possible predictors of good or poor outcome. Methods: An observational prospective study on consecutive cases operated for cataract during 1 month at six surgical departments affiliated to the Swedish National Cataract Register (NCR). Data were collected according to the protocol of NCR and subjects completed the Catquest questionnaire before and 6 months after surgery. 90 subjects with AMD were compared to 335 subjects with no sight threatening ocular comorbidity. Results: Difficulties in performing various daily life activities improved significantly for AMD subjects after surgery (p<0.001, Wilcoxon signed rank test). Satisfaction with vision also improved significantly after surgery (p<0.001, Wilcoxon signed rank test). Activity level and independence were unchanged. Subjects with no ocular comorbidity had a still better outcome. The most important variable related to a good self assessed functional outcome was postoperative visual acuity irrespective of the presence of AMD. AMD subjects scheduled for second eye surgery and AMD subjects dissatisfied with their vision before surgery had a poorer outcome. Conclusion: Subjects with various stages of dry AMD and cataract improved their self assessed visual function and satisfaction with vision significantly after cataract extraction.

Decreasing rate of capsule complications in cataract surgery: eight-year study of incidence, risk factors, and data validity by the Swedish National Cataract Register.

PURPOSE: To define the incidence of capsule complication and its risk factors in Sweden over an 8‐year period. SETTING: Fifty‐two ophthalmic surgery units in Sweden. DESIGN: Database study. METHODS: 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. RESULTS: 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. CONCLUSION: The incidence of capsule complications decreased over time. This may be partly the result of fewer risk factors and of better surgical quality. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Outcome of cataract surgery considering the preoperative situation: a study of possible predictors of the functional outcome

AIM To analyse possible predictors of the self assessed functional outcome of a cataract extraction. METHODS The patients’ self assessed visual function was studied by use of a questionnaire, the “Catquest”, before and 6 months after surgery. All patients (n=1933, mean age 75.5 years, 66.8% women) who were undergoing cataract surgery in March 1995, in 35 different departments of ophthalmology participating in the National Swedish Cataract Register, were included in the study. A routine ophthalmic examination was performed before and after surgery. The following preoperative variables were studied with regard to a possible relation to the outcome: age, sex, ocular comorbidity, best corrected preoperative vision (better eye), first or second eye surgery, other diseases with a need for long term medication, need for home help, need for subsidised travel by taxi. RESULTS Ocular comorbidity was strongly related to a “no benefit” outcome after surgery (p= 0.005). Second eye surgery and young age was related to a “very good benefit” outcome after surgery (p=0.0001 and p<0.0001 respectively). CONCLUSIONS Patients with an ocular comorbidity in the eye undergoing a cataract extraction were characterised by a significantly higher frequency of deteriorated self assessed visual function after surgery than patients with no ocular comorbidity. The highest degree of improvement was most frequently found in younger patients undergoing second eye surgery.

PREVALENCE OF VISUAL FIELD DEFECTS DUE TO CAPSULAR AND SIMPLE GLAUCOMA IN HÄLSINGLAND, SWEDEN

In a region where both simple and capsular glaucoma are common, the observed prevalence of glaucoma with glaucomatous visual field defects based on hospital records is presented. The prevalence increased with increasing age to a maximum of 4.5% of the age group 81–85. Capsular glaucomas accounted for two thirds of the glaucomatous visual field defects. A comparison with previous population surveys indicates that the frequency of simple glaucoma is of the same magnitude as elsewhere. The high frequency of glaucomatous visual field defects can be due to the occurrence of capsular glaucoma. This supports the hypothesis that capsular glaucoma has its own epidemiology.

Fibrinoid reaction after extracapsular cataract extraction and relationship to exfoliation syndrome

ABSTRACT A transitory deposit of a fibrin‐like material in the anterior chamber following extracapsular cataract extraction and intraocular lens (IOL) implantation is described. In two studies, one retrospective of 352 operations and one prospective of 189 operations, the fibrinoid reaction was observed in 17% and 11% of the eyes, respectively. The reaction appeared in the early postoperative period in an otherwise quiet eye and the signs varied from a few threads in the pupil area to a dense pupillary membrane in front of the IOL. The deposit disappeared one day to three weeks postoperatively, usually without any remnants. The majority of eyes with the fibrinoid reaction had received a posterior chamber IOL. A strong association with the exfoliation syndrome was found and an increased vascular permeability is suggested as a probable cause of the reaction.

Assessment of Waiting Time and Priority Setting by Means of a National Register

To increase access to care for cataract patients in Sweden, it was decided, starting in 1992, that all cataract patients listed for surgery and with priority should have their cataract extraction performed within three months. To evaluate the effect of this waiting time guarantee, a National Cataract Register (NCR) was initiated in late 1991. In 1992, 81% of all cataract extractions performed in Sweden were reported to the NCR; in 1993 this figure was 92%. Reasons for this high participation ratio are discussed. In 1993, 74.4% (range between different clinics, 40-99%) of the patients with priority had their operation performed within three months. Great variation in visual acuity and age was found in patients with priority among the different surgical units.

Capsule complication during cataract surgery: Background, study design, and required additional care Swedish Capsule Rupture Study Group report 1

PURPOSE: 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. SETTING: Ten ophthalmic surgery departments in Sweden. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

SURVIVAL TIME AMONG PATIENTS WITH GLAUCOMATOUS VISUAL FIELD DEFECTS

During our studies on glaucoma we have made an important and surprising observation. We think it is urgent to report that we have found the survival time of glaucoma patients seems to be substantially shortened. To the best of our knowledge this has not been previously reported.