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Biomedical subjects

K D Teichmann

Publications and source records attributed to K D Teichmann.

At least 37 records · Page 2Linked to original sources
PubMed1997

The torque and tilt gamble.

PURPOSE: To analyze possible suture configurations at the haptics of posterior chamber intraocular lenses (IOLs) and estimate the resulting tilt. SETTING: King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia. METHODS: Using a plastic cylinder with two pairs of holes drilled on opposite sides and an IOL with eyelets in the haptics, we determined possible suture configurations and analyzed them for net torque on the IOL haptics that would result in tilting of the optic. RESULTS: We identified 64 combinations of regular and countless combinations of irregular suture configurations. Among the 16 most likely combinations, only 4 were torque-free (or torque neutral), 2 caused maximum tilt, and 10 induced some tilting. Theoretically, torque could be eliminated by radial suture placement, but this is anatomically undesirable, and by positioning the eyelet perpendicular to the haptic, but this is technically difficult. Longer suture bites tended to lessen the torsion on the haptic but increased the risk of the suture looping around the free end of the haptic. CONCLUSION: Surgeons using scleral fixation of a posterior chamber IOL should be aware of the possibility of inducing tilt and should aim for symmetrical suture configurations at the two haptics.

Foreign-Body Migration↗
PubMed1997

Phacoemulsification at King Khaled Eye Specialist Hospital--the experience of the past.

OBJECTIVE: To study the outcome of phacoemulsification (PE) compared to standard extracapsular surgery before the introduction of state-of-the-art techniques (capsulorhexis, hydrodissection, nuclear cracking, nuclear chopping, sutureless incisions) and sophisticated equipment. STUDY DESIGN: Charts from 375 patients (453 eyes) undergoing PE between 1984 and 1989 were randomly selected and studied retrospectively. A minimum age of 35 years, and a minimum follow-up of three months were required. SETTING: A large eye hospital in the Kingdom of Saudi Arabia staffed with an international faculty of ophthalmic surgeons. PATIENTS: Patients over 35 years of age undergoing PE for immature, mature and traumatic cataract. MAIN OUTCOME MEASURES: Postoperative visual acuity, and rate or frequency of intraoperative complications. RESULTS: 66.5% achieved visual acuity of 20/40 or better, which compares favourably with the 36.5% of eyes reaching this level of visual acuity after mainly standard extracapsular cataract surgery in another study at our hospital. Posterior capsule ruptures occurred in 7.5% and vitreous loss in 5.5%. Other ocular disease (odds ratio 7.51 confidence interval 4.43-12.7) and intraoperative complications (odds ratio 2.97 confidence interval 1.38-6.42) were statistically significant predictors for final visual acuity of under 20/40 (p = < 0.001 and 0.005 respectively). CONCLUSION: The outcome of PE was better than that of standard extracapsular cataract extraction in the same setting. However, since PE appeared to be used selectively, no clear advantage compared to extracapsular cataract extraction is evident in the period before the introduction of modern state-of-the-art PE-techniques.

Adult↗
PubMed1996

Management of perforations during epikeratoplasty for keratoconus.

Epikeratoplasty (EKP) in keratoconus generally has few intraoperative complications. Perforations during EKP are rare but may force the surgeon to abandon the procedure. We developed a special suture technique to manage this problem. Several deep mattress sutures are placed by taking shallow bites of the central corneal rim and deep bites of the peripheral corneal rim. This leaves the peripheral corneal rim projecting forward by approximately one third the corneal thickness. Slight stretching of this peripheral corneal rim allows adaptation of the epilenticule to form a smooth tissue plane. This method was used in two patients with significant corneal scarring and led to satisfactory visual results.

Astigmatism↗
PubMed1994

Retrobulbar (intraconal) anesthesia with a curved needle: technique and results.

We report the results of two prospective studies of retrobulbar anesthesia using curved 25 mm and 28 mm needles. These studies were prompted by our experience with the 25 mm needle in more than 13,000 cases of intraconal anesthesia in which one case of postoperative ischemic neuropathy was the only complication. The technique involves the transcutaneous introduction of the curved needle at the middle of the lower lid, following a curved track close to the inferior orbital wall, around the globe, parallel to the plane of the medial orbital wall (i.e., in a strictly sagittal plane lateral to the optical axis in primary gaze). No complications were noted in the prospective studies. Side effects were chemosis in 30% of cases, subconjunctival hemorrhage in 5%, and lid hemorrhage in 2%. Since these comparative studies, we have used the 28 mm needle without significant complications in more than 8,000 cases. This method of retrobulbar anesthesia is superior to peribulbar anesthesia, and because of its safety and reliability, is preferable.

Aged↗
PubMed1994

Pars plana fixation of posterior chamber intraocular lenses.

Given the problems associated with iris-sutured and scleral-fixated intraocular lenses (IOLs), pars plana fixation might be a safer and more effective approach. Significant improvements in lens design and materials, and changes in surgical approach and technique may now make pars plana fixation an attractive alternative. As contrasted with Girard's technique (1981), the implant loops would not be incorporated (buried) into the scleral wall, nor would the IOL be inserted through the pars plana. Advantages of a pars plana fixation include the low risk of intraoperative and postoperative hemorrhage, and the chance of avoiding contact between the IOL, iris, and pars plicata, depending on the lens design. Only the nonpigmented inner layer of the pars plana would be in direct contact with the haptic of the IOL. Thus, pigment dispersion should not occur unless there is contact with the iris.

Anterior Eye Segment↗