Purpose: To analyze the visual outcomes and method of final visual correction in eyes with corneal ectasia after laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK).
Setting: Emory University Department of Ophthalmology and Emory Vision, Atlanta Georgia, USA.
Methods: This retrospective review comprised 74 eyes of 45 patients with corneal ectasia after LASIK (72 eyes) or PRK (2 eyes). Outcomes included postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), best corrected visual acuity (BCVA), and refraction; method of final visual correction; and time to rigid gas-permeable (RGP) contact lens failure.
Results: Corneal ectasia developed a mean of 19.2 months after surgery. Postoperatively, the mean UCVA was 20/400, the mean BSCVA before ectasia management was 20/108, and the mean BCVA was 20/37. After ectasia management, the final BCVA was 20/40 or better in 78% of eyes. Final visual correction was achieved with RGP lenses in 77% of eyes, spectacles in 9%, collagen crosslinking in 3%, intracorneal ring segments in 1%, and penetrating keratoplasty (PKP) in 8%. Two eyes with intracorneal ring segments required segment explantation and subsequent PKP. One eye that had PKP had a graft-rejection episode; there were no graft failures. Two eyes (3%) did not require a visual device to improve visual acuity. The mean time to successful RGP lens wear was 24.8 months; 80% of cases initially managed with RGP lenses were successful with this form of treatment.
Conclusions: The majority of eyes developing postoperative corneal ectasia achieved functional visual acuity with RGP lens wear and did not require further intervention. Penetrating keratoplasty can usually be postponed or avoided by alternative methods of visual rehabilitation; however, PKP, when necessary, can provide good visual outcomes.
Purpose: To analyze the changes in higher-order aberrations (HOAs) that occur after wavefront-optimized photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).
Setting: Private practice, Atlanta, Georgia, USA.
Methods: This retrospective analysis comprised eyes that had PRK or LASIK from June 2004 through October 2005. Postoperative outcome measures included 3-month uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction spherical equivalent (MRSE), changes in the root mean square (RMS) and grouped coefficient HOAs (microns) measured with a corneal analyzer, and subjective assessment of visual aberrations.
Results: One hundred consecutive eyes of 54 patients had PRK, and 100 contemporaneous consecutive eyes of 71 patients had LASIK. The PRK and LASIK populations were similar in general demographics, preoperative HOAs, and postoperative UCVA and BSCVA. The mean MRSE was slightly hyperopic after PRK (mean +0.11 diopters [D]) and slightly myopic after LASIK (mean −0.19 D) (P<.0001). There were no statistically significant changes in RMS or grouped coefficient HOA values after PRK or LASIK, nor were there significant differences in postoperative RMS or grouped coefficient HOA values between PRK and LASIK. One percent of PRK and LASIK patients reported a subjective increase in postoperative visual aberrations; 5% reported a subjective improvement postoperatively.
Conclusions: Wavefront-optimized excimer laser surgery did not induce significant HOAs after PRK or LASIK. The 2 techniques were equally efficacious and had equivalent postoperative HOA profiles.
Purpose: To determine the effect of different blades on laser in situ keratomileusis (LASIK) flap thickness created with the Amadeus I microkeratome (Ziemer Ophthalmic Systems).
Setting: Emory University Department of Opthalmology and Emory Vision, Atlanta, Georgia, USA.
Methods: This retrospective nonrandomized comparative case study from January 2005 through June 2006 compared LASIK flap thickness created with blades from 2 manufacturers: the Surepass from Surgical Instrument Systems and distributed by AMO and the ML7090 CLB distributed by Med-Logics, Inc. Sex, preoperative corneal thickness, surgical-eye sequence, flap thickness and variance, and residual stromal bed were evaluated in each group.
Results: This study evaluated 424 eyes of 226 patients. Surepass blades were used in 238 eyes and ML7090 CLB blades in 186 eyes. There were no significant differences between the 2 blade groups in preoperative corneal thickness, sex, or cases with corneal thickness greater than 550 µm. Mean flap thickness and variance were significantly lower in the ML7090 CLB group than in the Surepass group (P<.0001). There were no significant differences in flap thickness in either group based on sex; however, in both groups, flap thickness was significantly lower in second eyes and in eyes with a preoperative thickness less than 550 µm (P<.001).
Conclusions: The Amadeus I microkeratome created thinner, more consistent LASIK flaps with the ML7090 CLB blade than with the Surepass blade. Preoperative corneal thickness and eye sequence affected flap thickness, while sex did not.
Purpose
To describe a rare case of primary conjunctival clear cell carcinoma.
Methods
The clinical history and pathologic findings were reviewed.
Results
An 82-year-old white man presented with a lesion on his right conjunctiva for 8 months. An excisional biopsy was performed with wide margins and mitomycin C. Pathologic examination showed a papillary clear cell carcinoma of the conjunctiva. The patient has been followed for 6 months without recurrence.
Conclusions
Primary clear cell carcinoma, a variant of squamous cell carcinoma, can occur in the conjunctiva.
Objective
To evaluate the clinical features of and histologic findings from failed Descemet stripping automated endothelial keratoplasty (DSAEK).
Methods
This retrospective observational case series evaluated 47 consecutive corneal specimens from 42 patients who underwent either penetrating keratoplasty or repeated DSAEK for failed DSAEK. Clinical information was obtained for the cases. Sections of the specimens were examined using light microscopy. Immunohistochemical staining was performed for cytokeratins AE1/AE3 and for the myogenic marker smooth-muscle actin when indicated. Transmission electron microscopic examination was performed in some cases.
Results
Graft survival ranged from 0.5 to 34 months. Histologic examination showed that 94% of the specimens (44 of 47) had endothelial cell loss. Residual host Descemet membrane (19%; 9 of 47), fibrocellular tissue (19%; 9 of 47), epithelial implantation (15%; 7 of 47), and fungal infection (4%; 2 of 47) were also identified. Immunohistochemical stains were positive for AE1/AE3 in the epithelial implantations and for smooth-muscle actin in cells in the fibrocellular proliferations.
Conclusions
The principal cause of failed DSAEK is endothelial cell loss. Residual host Descemet membrane, fibrocellular tissue at the edge of the lenticule, and epithelial implantation are common histologic findings. Fungal infection may occur in the setting of DSAEK.
Purpose
To validate the Ectasia Risk Score System for identifying patients at high risk for developing ectasia after laser in situ keratomileusis (LASIK)..
Design
Retrospective case-control study
Methods
Fifty eyes that developed ectasia and 50 control eyes with normal postoperative courses after LASIK were analyzed and compared using the previously described Ectasia Risk Score System, which assigns points in a weighted fashion to the following variables: topographic patter, predicted residual stromal bed thickness (RSB), age, preoperative corneal thickness (CT), and manifest refraction spherical equivalent (MRSE).
Results
In this series 92% of eyes with ectasia were correctly classified as being at high risk for the development of ectasia, while 6% of controls were incorrectly classified as being at high risk for ectasia. (p< 1 × 10−10). Significantly more eyes were classified as high risk by the ectasia risk score than by traditional screening parameters relying on abnormal topography or residual stromal bed thickness less than 250 μ (92% vs. 50%, p <0.00001). There was no difference in the sensitivity or specificity of the Ectasia Risk Score System in the population from which it was derived and this independent population of ectasia cases and controls.
Conclusion
The Ectasia Risk Score System is a valid and effective method for detecting eyes at risk for ectasia after LASIK and represents a significant improvement over previously utilized screening strategies.
Purpose: To study the effect of flap thickness on visual acuity and refractive outcomes after laser in situ keratomileusis (LASIK) using 2 blade types with a mechanical microkeratome.
Setting: Emory Vision, Atlanta, Georgia, USA.
Methods: This retrospective analysis was of LASIK cases performed between January 2005 and June 2006 using an Amadeus I microkeratome and an ML7090 CLB blade (blade A) or a Surepass blade (blade B). Outcomes analyzed included flap thickness, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), the enhancement rate, and surgical complications 3 months postoperatively.
Results: Two hundred sixty-three eyes of 153 patients were analyzed; blade A was used in 158 eyes and blade B, in 105 eyes. The mean flap thickness was significantly thinner with blade A than with blade B (107 μm ± 12 [SD] versus 130 ± 20 μm) (P<.0001). There was no overall correlation with either blade between flap thickness and UDVA, CDVA, or MRSE (all r<0.2). At 3 months, there was no statistically significant difference in UDVA, CDVA, or MRSE between the 2 blade groups at 3 months (all P > .10), and there was no difference in the complication rates.
Conclusion: Flap thickness did not affect visual or refractive outcomes with a mechanical micro-keratome with either blade type.
Financial Disclaimer: No author has a financial or proprietary interest in any material or method mentioned.
A 40 year-old Caucasian male, status post radial keratotomy OU in 1993, suffered pain, extreme photophobia, and mild loss of uncorrected visual acuity in the right eye after being struck by a nail. The patient presented with a small deep stromal lesion and was initially treated with a variety of antibiotic regimens without improvement in the lesion’s appearance. Upon referral the patient had confocal microscopy performed, which clearly demonstrated epithelial cells in the deep stroma and on the endothelial surface. Upon cessation of all medications the patient’s mild symptoms resolved, and his clinical appearance has remained stable without intervention for 9 months. Patients with radial keratotomy incisions are at risk for traumatic epithelial downgrowth even many years after surgery. Confocal microscopy can make the definitive diagnosis of epithelial downgrowth. Management of this condition remains controversial.
Purpose: To report spontaneous corneal clearing with improved visual acuity and central endothelial cell repopulation after Descemet’s stripping without endothelial replacement.
Design: Interventional case report.
Methods: A 34 year-old female with bilateral decreased vision secondary to corneal edema from endothelial dysfunction underwent Descemet’s stripping endothelial keratoplasty (DSEK) in the right eye and Descemet’s stripping (DS) only in her contralateral eye. Histopathologic evaluation confirmed a dual diagnosis of Fuchs endothelial dystrophy (Fuchs) and posterior polymorphous membrane dystrophy (PPMD) from Descemet’s membrane specimens removed from each eye. Following primary graft failure with regraft in the right eye, the second posterior corneal lenticule detached, was removed and was not replaced. The cornea cleared and central endothelial cell repopulation was documented by confocal microscopy. Therefore, Descemet’s stripping without endothelial replacement was performed in the left eye. The left cornea also cleared with central endothelial cell repopulation.
Main Outcome Measures: Postoperative visual acuity and central endothelial cell repopulation
Results: Endothelial migration after Descemet’s stripping alone in the second eye, with probably host endothelial cell repopulation in the right eye.
Conclusions: Endothelial cell migration after Descemet’s stripping procedure without insertion of endothelial graft can occur, resulting in host endothelial cell repopulation with corneal clearing and improved visual acuity.
Purpose
To describe a novel technique for toric intraocular lens (IOL) repositioning and fixation in the absence of adequate capsular support
Methods
Case report and literature review
Results
Two cases are presented with scleral fixation of a one-piece toric IOL (SN6AT series, Alcon Inc.) In both cases, toric IOLs initially placed within the capsular bag became decentered due to poor capsular support and/or posterior capsule rupture. To avoid the potential complications of lens explantation and maintain the astigmatic benefits of the toric IOL, scleral fixation of the lenses was performed. The Hoffman technique was used to create reverse scleral pockets without conjunctival dissection. A 10-0 suture was used to capture and then secure the lens haptics in a lasso-type fashion. Sutures were then buried within the previously created scleral pockets. Both patients had well centered lenses postoperatively and have remained stable at last follow-up, up to thirty months postoperatively.
Conclusion
In the absence of adequate capsular support, scleral fixation is a viable option for one-piece toric IOL fixation to avoid IOL explanation