A comparison of penetrating keratoplasty to epikeratoplasty in the surgical management of keratoconus.
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Corneal Transplantation↗
Biomedical subjects
R G Lembach
Publications and source records attributed to R G Lembach.
Management of keratoconus: comparative visual assessments.
We compared the visual performance of keratoconus patients whose vision had been corrected with one of the following: RGP lenses alone, penetrating keratoplasty, or epikeratoplasty. Despite similar Snellen visual acuities with optimal correction, significant differences in visual performance were found in the three groups. Visual performance was assessed by measuring contrast thresholds for electronically-generated sinusoidal gratings and by measuring contrast thresholds in the presence of a glare source. These measurements were carried out on six bilateral keratoconus patients such that three eyes were corrected with RGP lenses alone, five eyes were corrected by penetrating keratoplasty, and four eyes by epikeratoplasty. There were statistically significant differences in the visual responses for the three correction types (ANOVA, F2,45 = 5.755, P = 0.0059), with the epikeratoplasty procedure providing the poorest results. Visual performance was further affected in the presence of a glare source. Statistically significant group differences were again found (ANOVA, F2,45 = 7.593, P = 0.0014), with the penetrating keratoplasty eyes being the most affected. These differences were spatial frequency dependent (p = 0.0293), the effect being most marked at medium spatial frequencies. These findings provide a ranking of the quality of vision provided by each management strategy.
Adult↗
Clinical management of keratoconus. A multicenter analysis.
The clinical management of 746 eyes in 417 patients referred for keratoconus from January 1984 through January 1988 was retrospectively analyzed. In 357 patients, 554 eyes (74%) did not require surgery and were managed with contact lenses or spectacles, 156 eyes (21%) in 137 patients either underwent penetrating keratoplasty (PK) (140 eyes) or surgery was recommended (16 eyes), and 36 eyes (4%) in 34 patients underwent epikeratoplasty. Comparing baseline and final examination findings, the nonsurgical group showed a significant improvement in average best-corrected visual acuity from 20/30 to 20/25, the PK group from 20/70 to 20/25, and the epikeratoplasty group from 20/40 to 20/30. Average keratometry was unchanged in the nonsurgical group, but decreased by 10.7 diopters (D) for the PK group and 6.5 D for the epikeratoplasty group. Corneal cylinder was unchanged in the nonsurgical group, whereas there was a reduction of the percentage of eyes with indeterminant cylinder from 55 to 2% in the PK group and from 36 to 0% in the epikeratoplasty group. Previous contact lens history, best-corrected visual acuity of 20/50 or worse, and average keratometry of 55 D or greater at baseline were associated with a significant risk for PK. No baseline variables were associated with significant risk for epikeratoplasty, suggesting that this group was similar to the nonsurgical group, except for contact lens intolerance. The nonsurgical management of keratoconus continues to play a predominant role in the management of this disorder in a referral population.
Adolescent↗
Factitious bilateral crystalline keratopathy.
We report a case of bilateral factitious crystalline keratopathy in an 18-year-old man. Initial slit-lamp examination revealed corneal ulcers characterized by stromal infiltrates with intrastromal blue refractile crystals O.D. greater than O.S. Through careful history taking, the patient admitted to bilaterally injecting eyeshadow into the corneal stroma. The importance of maintaining a high index of suspicion in bilateral atypical corneal ulcers in patients without a history of trauma or contact lens exposure is essential. Discussion of the differential diagnoses and approach to therapy is included.
Adolescent↗
The use of contact lenses after keratoconic epikeratoplasty.
Thirty-three epikeratoplasties were performed on 31 keratoconic contact lens intolerant patients. Thirty-two of these procedures were anatomically successful with clear lenticules and flattening of the postoperative keratometric measurements in all but one eye. One patient's lenticule developed a persistent epithelial defect that eventually required its removal at 42 days. This patient subsequently underwent a successful penetrating keratoplasty. Of the 32 eyes that were anatomically successful, 20 eyes in 19 patients were able to achieve satisfactory visual improvement requiring either no correction or spectacle lenses. Twelve eyes in 11 patients were successfully refit with contact lenses for anisometropic refractive errors (11 eyes) and residual irregular astigmatism (one eye). Three patients (two in the non-contact lens group and one in the contact lens group) have subsequently undergone penetrating keratoplasty for further visual improvement. Our data suggest that the majority of keratoconic epikeratoplasties achieve a satisfactory visual result either unaided or with spectacles; however, those patients who wish to resume contact lens wear may do so successfully.
Adult↗
Acute onset of central retinal vein occlusion and retinal detachment.
The simultaneous occurrence of a central retinal vein occlusion and retinal detachment has not been previously reported. Although both are well recognized entities with characteristic appearances, their simultaneous acute onset led to a misdiagnosis in our case report. The need for a complete eye examination in the face of obvious pathology is stressed.
Humans↗
Rigid gas permeable contact lenses.
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Biocompatible Materials↗