[Correction of myopia and astigmatism using topography-assisted laser in situ keratomileusis (TopoLink LASIK)]

PATIENTS AND METHODS

We treated 114 patients (eyes) with myopia of -1 to 6 D and astigmatism of 0 to -4 D (group 1), and 89 patients (eyes) with myopia of -6.1 to -12 D and astigmatism of 0 to -4 D (group 2). All treatments were calculated on the basis of corneal topography measured with the Orbscan II system. The Keracor 217 excimer laser and the Hansatome microkeratome were used.

RESULTS

At 3 months, 51 patients in the low myopia group and 40 patients in the high myopia group were available for examination. In the low (high) myopia group, 96.1% (75.0%) were within +/- 0.50 D of emmetropia, and uncorrected visual acuity was 20/20 or better in 82.4% (62.5%), 20/25 or better in 98.0% (70.0%), and 20/40 or better in 100% (95.0%). A loss of two or more lines of spectacle-corrected visual acuity occurred in 3.9% of the low and 5.0% of the high myopia group. In low myopia, spectacle-corrected visual acuity was 20/12.5 or better in 5.9% preoperatively and in 13.7% at three months and 20/15 or better in 37.3% and 47.1%, respectively (P = 0.0002 and P = 0.01).

CONCLUSIONS

LASIK based on corneal topography showed very high efficacy in low and moderate myopia with astigmatism, and maximal visual acuity could even be improved in some cases. There was somewhat less precision in high myopia with astigmatism.

Treatment of myopia and myopic astigmatism by customized laser in situ keratomileusis based on corneal topography

OBJECTIVE

To evaluate the predictability, efficacy, and safety of customized laser in situ keratomileusis (LASIK) based on corneal topography in myopia and myopic astigmatism.

DESIGN

Prospective, noncomparative interventional case series.

PARTICIPANTS

One hundred fourteen patients (eyes) with myopia of -1 to -6 diopters (D) and astigmatism of 0 to -4 D (low myopia group), and 89 patients (eyes) with myopia of -6.10 to -12.00 D and astigmatism of 0 to -4.00 D (high myopia group).

INTERVENTION

LASIK was performed with the Hansatome Microkeratome and the Keracor 217 spot-scanning excimer laser (Bausch & Lomb Surgical Technolas, Munich, Germany). Individual ablation patterns were calculated on the basis of elevation data obtained with the Orbscan II corneal topography system (Bausch & Lomb Surgical, Irvine, CA).

MAIN OUTCOME MEASURES

Manifest spectacle refraction, visual acuity, and change in visual acuity at 3 months after surgery.

RESULTS

At 3 months, 51 patients in the low myopia group and 40 patients in the high myopia group were available. In the low (high) myopia group, 96.1% (75.0%) were within +/-0.50 D of emmetropia, and uncorrected visual acuity was 20/20 or better in 82.4% (62.5%), 20/25 or better in 98.0% (70.0%), and 20/40 or better in 100% (95.0%). A loss of two or more lines of spectacle-corrected visual acuity occurred in 3.9% of the low and 5. 0% of the high myopia group. In low myopia, spectacle-corrected visual acuity was 20/12.5 or better in 5.9% preoperatively and in 13.7% at 3 months and 20/15 or better in 37.3% and 47.1%, respectively. Differences were statistically significant.

CONCLUSIONS

The customized LASIK based on corneal topography used in this study showed high predictability and efficacy in myopia and myopic astigmatism of -1.00 to -6.00 D, and could possibly improve spectacle-corrected visual acuity in myopia of -1.00 to -6.00 D. Predictability and efficacy were somewhat lower in myopia and myopic astigmatism of -6.10 to -12.00 D. In both groups, a small number of patients lost two or more lines of spectacle-corrected visual acuity.

Posterior limbal incision

BACKGROUND

Sutureless cataract incisions should ideally remain sealed with increased intraocular pressure and be able to withstand increased external pressure to the posterior aspect. Cadaver eye studies have shown that meeting these criteria requires an internal corneal lip of at least 1.5 mm and a square wound. Scleral incisions can meet these criteria but sacrifice aesthetics and surgical efficiency. Clear corneal incisions provide aesthetics and surgical efficiency but not wound stability. An ideal incision would combined stability with aesthetics and efficiency.

METHODS

We tested a posterior limbal incision to assess its stability, aesthetics, and efficiency. The incision originated at the posterior limbus within the conjunctiva, gaining about 1.0 mm in tunnel length over a clear corneal incision. This was enough to obtain a square profile for 3.0 x 3.0 mm wide incisions, while providing the aesthetics and surgical efficiency of a clear corneal incision. We compared a 3.0 x 2.0 mm posterior limbal with a 3.0 x 2.0 mm clear corneal incision. Each was tested in stepped, paracentesis, and hinged profiles.

CONCLUSIONS

When compared with the clear corneal incision, the posterior limbal incision is equal in aesthetics and surgical efficiency, slightly superior in patient comfort, and far more stable.

Development, advantages, and methods of the continuous circular capsulorhexis technique

The development of the continuous circular capsulorhexis (CCC) technique has contributed significantly to the safety and effectiveness of cataract extraction and intraocular lens implantation. This technique facilitates every size of smooth, circular, capsular opening, and it produces a strong capsular rim that resists tearing even when stretched during lens material removal or lens implantation. Maintaining the general integrity of the eye and facilitating such procedures as hydrodissection, endolenticular phacoemulsification, capsule polishing, and safe lens implantation in both adults and children are some of the advantages of CCC. This procedure can be performed in several ways, and it has been proven to be consistently reproducible by experienced surgeons.

[Neuhann capsulorhexis: a technic for reliable implantation of the capsule sack]

The Neuhann Capsulorhexis allows for a continuous, circular opening in the anterior lens capsule. After excavation of the lens matter the circular round edge in the anterior capsule provides maximum stability in the zonulolenticular diaphragm and facilitates controlled in-the-bag implantation of the lens haptic. Histologic studies of cadaver eyes have revealed that the correlation between the position of the lens loops as intended by the surgeon intraoperatively and their actual positioning is poor. It has therefore not been possible to prove the advantages of all-in-the-bag implantation as compared to sulcus fixation. The Neuhann Capsulorhexis reduces the morphological variability of the anterior capsule; furthermore, the position of the lens haptic can easily be determined both intraoperatively as well as postoperatively. This is a prerequisite for evaluating the best position for the lens haptic as well as for clinical evaluation of new types of intraocular lens.

[Theory and surgical technic of capsulorhexis]

Kapsulorhexis is a surgical technique for opening the anterior lens capsule with a circular, smooth-edged and continuous margin. Basically, the technique consists of a precisely controlled continuous capsular tear (rhexis), using only a sharp disposable needle with a bent tip. The method is reproducible, requires minimal instrumentation, is compatible with all current techniques of extracapsular surgery, and can be learned at no risk.

[Papillomatous hyperplastic conjunctivitis caused by contact lenses]

The characteristic features of contact lens-induced giant papillary conjunctivitis, as observed in 64 cases between 1978 and 1980, are described. The main symptoms are increasing lens intolerance with foreign body sensation, mucus discharge and reduced vision. The typical subtarsal sign is cobblestone formation resembling vernal conjunctivitis. Therapy must achieve complete disappearance of the conjunctival lesions, to avoid recurrences. Discontinuing lens wear is sufficient only in the less pronounced cases (stage I and II). In the fully developed cases, additional cryocoagulation of the lesions proved to be effective. The differences in the clinical pattern between our group of patients and that of Allansmith et al. (1977) support the opinion that surface deposits on the contact lenses are pathogenetically of prime importance.

[Headache and the eye]

The contribution of ophthalmology in the diagnostic evaluation of a patient with headache is outlined. When asthenopia or an organic eye disease is cause of the headache, the ophthalmologist cannot only diagnose the etiology but can also cure the patient by adequate therapy. When the headache is sign of CNS-disease, the ophthalmologist can provide the neurologist with valuable information regarding nature and localization of the process.

[Variations of intraocular pressure during valsalva's maneuver in relation to body position and length of the bulbus in myopia (author's transl)]

Intraocular pressure was measured in 49 persons of either sex while carrying out Valsalva's maneuver in erect and recumbent position. 16 of the tested persons had myopia up to -8.0 D. The average intraocular pressure in recumbent position was 2 mm Hg higher when compared to the erect position. During Valsalva's maneuver the intraocular pressure was elevated in erect as well as in recumbent position. Three characteristic patterns of variation of intraocular pressure were seen after cessation of Valsalva's maneuver. The intraocular pressure in myopic persons was slightly higher than in those with emmetropia.

[Binocular functions in unilateral aphakia with intraocular lens, contact lens, and spectacle correction (author's transl)]

The quality of binocular vision in unilateral aphakia was tested in presbyopic patients. 10 of them were corrected by a contact lens, 10 by an intraocular implant. Unilateral aphakic young patients were submitted to the same tests. In the young patients the unilateral accommodation proves to be the main obstacle to binocularity. In the presbyopics there is no difference between intraocular and contact lens correction as to the quality of binocular functions. Which one of these two alternatives for the correction of unilateral aphakia should be preferred in the individual case must, therefore, be decided upon by other criteria than binocular vision. The results with unilateral spectacle correction demonstrate that binocular vision cannot be achieved by compensation of aniseikonia alone.

[A modified cataract incision: limbal step incision with partial conjunctival covering of the suture (author's transl)]

The authors describe a cataract incision technique, which combines the advantages of the corneoscleral site (conjunctival covering, mechanical strength of the resulting scar) with those of a corneal incision (sparing of the angle structures, good visibility, simple and nontraumatic suture removal) and those of a continuous nylon suture (unimpaired wound healing, even adaptation).

[Collagenase inhibition: an experiment in the treatment of scleromalacia perforans (author's transl)]

Report on local application of Cystin eye drops in a case of scleromalacia perforans. This medication brought the necrotizing disease process to a standstill. There was even discrete neoformation of scleral tissue, which we attribute to the collagenase inhibiting action of this drug.

[Contact lenses: indications and limits]

Contact lens wear may be indicated for cosmetic, professional, optical or therapeutic reasons. For each of these indications the arguments are given, why and when contact lenses are better than spectacle correction and which possibilities there are. Contact lens wear is contraindicated in certain eye diseases and in the case of problems of handling and hygiene. The author's preferences concerning the different contact lens materials are summarized briefly.

[B scan sonography in drusen of the optic disc]

The B scan sonographic characteristics of drusen of the optic disc are strong reflexion at low energy levels, shadowing in oblique and pseudobroadening of the optic nerve in orthograde beam direction. These signs provide additional security in differentiating deep drusen from a choked disc.

Differential diagnosis of typical and atypical congenital achromatopsia. Analysis of a progressive foveal dystrophy and a nonprogressive oligo-cone trichromasy (general cone dysfunction without achromatopsia), both of which at first had been diagnosed as achromatopsia

Report on two patients whose symptoms suggested the presence of congenital achromatopsia. In one case there was indeed total colour blindness, but a normal photopic ERG. Here, achromatopsia is the present stage in a process of slow functional decay of the central retina. Most probably the underlying disorder is progressive foveal dystrophy, a central form of cone dystrophy. In the other case there was a nonrecordable photopic ERG, but trichromatic colour vision. This appears to be another patient with oligo-cone trichromasy (general cone dysfunction without achromatopsia), as described by Van Lith.

[Fungal growth on soft contact lenses (author's transl)]

The relevance of fungal contamination of soft contact lenses is demonstrated by own clinical observations in 25 cases. It can be shown by surface-microscopical, histological and mycological analysis, that various fungi can not only grow on the surface of HEMA-lenses, but can also invade the material. The efficacy of chemical disinfectants, as tested against two of the isolated fungi seems to be inferior to that of heat sterilisation. The resulting fundamentally and clinically important consequences, especially concerning permanent wear of hydrophilic contact lenses, are discussed.

[Complications due to soft hydrophilic contact lenses]

Soft hydrophilic contact lenses are widely favored thanks to their minimal ocular irritation. They may, however, also cause severe eye disease. In this report, allergies, hypoxia, tear film alterations, toxic effects and infections, as caused by soft lenses, are described, and their diagnosis, differential diagnosis and prophylaxis discussed. Moreover, it is pointed out that a misdiagnosis of "contact lens intolerance" may have serious consequences.

[Treatment of amblyopia with soft occlusion lenses (author's transl)]

Inverse and regular occlusion therapy is carried out by means of a block coloured soft contact lens in cases, in which previous conventional patching had not been successful for external reasons. The technical data of the lens used and the indications for its application are given. Preliminary results show the usefulness of this method.