Outcome monitoring in cataract surgery.

The short-term surgical results are reported in a consecutive series of 1473 patients undergoing cataract surgery (60% planned extracapsular cataract extraction and 40% phacoemulsification) on an out-patient basis in a major university eye clinic. Preoperatively, 80% of all cases had a visual acuity of 0.3 (6/18) or lower. On the first day after surgery, 51% of all patients had a corrected visual acuity of 0.5 (6/18) or better and 9% had a visual acuity of 1.0 (20/20) or better. The unaided visual acuity was 0.5 (6/12) or better in 20% of all patients (78% of these after phaco-emulsification). The average postoperative refraction was -0.43 D (+/- 1.03 D SD, range -6.00 D to +5.00 D). A significant improvement in refractive error was achieved in many patients. The mean intraocular lens power prediction error was found to be +0.04D (+/- 0.84D). The surgically induced astigmatism (vector analysis) was found to be +4.91D (+/- 2.08) in the extracapsular cataract extraction cases and +1.37D (+/- 1.38) in the phacoemulsification cases (p < 0.001). Capsular or zonular rupture and/or vitreous loss occurred in 43 (2.9%) of which 26 (1.8%) received an anterior chamber lens rather than the intended posterior chamber lens. The results of this study document the favorable results of modern cataract surgery.

[Results after cataract surgery]. / Resultater efter operation for katarakt.

This study reports the short term surgical results in a consecutive series of 1473 patients undergoing cataract surgery (60% planned extracapsular cataract extraction (ECCE) and 40% phacoemulsification (KPE) on an outpatient basis in a major university eye clinic. Preoperatively, 80% of all cases had a corrected visual acuity of 0.3 (6/18) or lower. On the first day after surgery, 51% of all patients had a corrected visual acuity of 0.5 (6/12) or better and 9% had a visual acuity of 1.0 (20/20) or better. The unaided visual acuity was 0.5 (6/12) or better in 20% of all patients (78% of these after KPE). The average postoperative refraction was -0.43 D (+/- 1.03 D SD, range -6.00 D to +5.00 D). A significant improvement in refractive error was achieved in many patients. The mean intraocular lens (IOL) power prediction error was found to be +0.04 D (+/- 0.84 D). The surgically induced astigmatism (vector analysis) was found to be +4.91 D (+/- 2.08) in the ECCE cases and +1.37 D (+/- 1.38) in the KPE cases (p < 0.001). Capsular or zonular rupture and/or vitreous loss occurred in 43 (2.9%) of which 26 (1.8%) received an anterior chamber lens rather than the intended posterior chamber lens. The results of this study document the favourable results of modern cataract surgery.

Ohmmeter-guided nasolacrimal intubation.

Retrieval of steel probes via the inferior meatus of the nose in monocanalicular and bicanalicular nasolacrimal intubation can be a tricky maneuver, possibly complicated by bleeding from lacerated soft tissue around the inferior turbinate. Using a low-voltage device (essentially, an ohmmeter) to assure contact between the retrieval hook and the distal end of the steel probe greatly facilitates the procedure.

Vaulted posterior chamber lenses and the posterior capsule.

Sixty-eight patients who had extracapsular cataract surgery with intraocular lens implantation in the bag received one of two types of lenses that had been designed to create a gap between the posterior surface of the optic and the posterior capsule. Two to four months after surgery, we found that the central spacing between the posterior lens surface and the posterior capsule measured by optical pachymetry averaged 0.25 mm. The mean of the spacing for the Pharmacia LSP laser ridge was 0.25 mm (range 0.1 to 0.6) and that of the 3M LE meniscus lens was 0.24 mm (range 0 to 0.8). The amount of adherence of the posterior capsule to the posterior lens surface was less with the laser ridge design than with the meniscus lens.

Biometry of the posterior lens capsule: a new method to predict pseudophakic anterior chamber depth.

The distance between the anterior corneal vertex and the posterior lens capsule was measured in 60 eyes before and three months after extracapsular cataract extraction with implantation of a posterior chamber lens. The preoperative capsule position ranged from 6.15 mm to 8.60 mm and averaged 7.64 +/- 0.47 mm (+/- SD). All posterior lens capsules had moved anteriorly following surgery. The postoperative capsule position ranged from 4.31 mm to 5.53 mm and averaged 4.93 +/- 0.29 mm. The postoperative capsule position could be predicted by the following optimized multiple linear regression equation: 2.4 + 0.011 x patient age + 0.171 x anterior chamber depth + 0.051 x axial length. The multiple correlation coefficient was 0.48. The postoperative anterior depth could be predicted with a correlation coefficient of 0.61 by subtracting both the averaged value of the clinical "laser space" and the exact central implant thickness from the estimated position of the posterior lens capsule. We suggest that this principle for predicting the postoperative anterior chamber depth may be useful for a number of lenses with different designs.

Axial length following implantation of posterior chamber lenses.

We used ultrasound to measure axial length in 66 eyes before and three months after extracapsular cataract extraction with implantation of a posterior chamber lens. An ultrasound velocity of 2,718 m/s for poly(methyl methacrylate) was assumed. The intraindividually measured difference (postoperative--preoperative axial length) ranged from -0.4 mm to 0.6 mm and averaged 0.11 mm. The lengthening of the eye was statistically significant (P less than .001; two-tailed, paired t-test). Statistical analysis of the regression equation between the preoperative and the postoperative axial lengths disclosed that this correlation was not more accurate than simply substituting the two measurements. Assuming no real change in axial lengths, our data suggest an ultrasound velocity of 1,679 m/s for the natural lens or an average velocity of 1,560 m/s for the phakic eye. We conclude that the preoperatively measured axial length may be used as a fairly accurate estimate of the postoperative distance in intraocular lens power calculation formulas.

Prediction of pseudo-phakic anterior chamber depth from pre-operative data.

Multiple linear regression analysis of pre-operative data were used to construct formulas to predict the anterior chamber depth 3 months after implantation of two different posterior chamber lenses. The resulting formulas differed widely. For lens I (27 eyes) the formula had a correlation coefficient of 0.78 and a standard deviation of +/- 0.2 mm. The corresponding figures for lens II (41 eyes) were 0.52 and +/- 27 mm. For lens I the predictors of significance were axial length (P less than 0.0001) and anterior corneal curvature (P = 0.07). For lens II significant predictors were patient age (P = 0.0008) and pre-operative anterior chamber depth (P = 0.04). We suggest that post-operative anterior chamber depth may not solely depend on the dimensions of the eye, but also on the lens architecture and the 'memory' of the lens haptics. We conclude that formulas to predict post-operative anterior chamber depth should be derived empirically for each lens type separately.

Differential diagnosis of normoornithinaemic gyrate atrophy of the choroid and retina.

A case of localized chorioretinal atrophy resembling gyrate atrophy of the choroid and retina is presented. Plasma ornithine concentration was normal and the clinical course characterized by late onset of relatively mild symptoms. The differential diagnoses are discussed and the term normoornithinaemic gyrate atrophy of the choroid and retina is suggested for similar variant cases.

Scintigraphic localization of intermittent gastrointestinal haemorrhage with indium-111-labelled platelets.

Because of the central role of blood platelets in haemostasis, 111In-labelled platelets might be supposed to participate in the haemostatic process and give rise to scintigraphic hot spots at the bleeding sites in cases of intermittent gastrointestinal haemorrhage. Three patients with intermittent gastrointestinal haemorrhage are described in whom focal tracer accumulations after injection of autologous 111In-labelled platelets indicated the presence of transient gastrointestinal haemorrhage. Repeatedly performed scintigraphy after injection of 111In-labelled platelets may prove to be a useful tool for the localization of intermittent gastrointestinal haemorrhage.