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Archive for June, 2012

Posted by Jami Kuehn, June 21, 2012 11:49 AM

Jennifer Y. Li, MD ; Mark A. Terry, MD; Jeffrey Goshe, MD; David Davis-Boozer, MPH; Neda Shamie, MD

Purpose

To evaluate the long-term improvement of visual acuity after Descemet’s stripping automated endothelial keratoplasty (DSAEK) surgery.

Design

Retrospective analysis of a noncomparative, interventional case series.

Participants

One hundred eight patients undergoing DSAEK surgery for Fuchs’ endothelial dystrophy and pseudophakic bullous keratopathy without other ocular comorbidities who completed a full 3-year follow-up period.

Methods

Postoperative best spectacle-corrected visual acuity (BSCVA) was recorded at 6, 12, 24, and 36 months. Improvement in BSCVA between each time point was evaluated using paired-samples t tests. Subanalysis evaluating the percentage of eyes achieving a BSCVA of 20/20, 20/25, 20/30, and 20/40 at each time point was performed.

Main Outcome Measures

Improvement in postoperative BSCVA.

Results

There was a statistically significant trend toward improvement in average BSCVA with time at postoperative month 6 and postoperative years 2 and 3. There were also increasing proportions of eyes reaching vision of 20/20, 20/25, and 20/30 from 6 months to 1 year, 1 year to 2 years, and 2 years to 3 years. The percentage of patients achieving 20/25 BSCVA improved from 36.1% at 6 months to 70.4% at 3 years after surgery. A similar increase in the percentage of patients reaching a BSCVA of 20/20 after DSAEK surgery also was observed from 11.1% at 6 months to approximately 47.2% at 3 years.

Conclusions

There is gradual improvement of visual acuity over time after DSAEK surgery for Fuchs’ endothelial dystrophy and pseudophakic bullous keratopathy in patients without other vision-limiting ocular comorbidities.

Posted by Jami Kuehn, 11:48 AM

Jeffrey M. Goshe, MD ; Mark A. Terry, MD; Jennifer Y. Li, MD; Michael D. Straiko, MD; David Davis-Boozer, MPH

Purpose

To determine if patients with prior glaucoma surgery experience higher rates of postoperative graft dislocation after Descemet’s stripping automated endothelial keratoplasty (DSAEK) and to determine if postoperative hypotony may be a risk factor in these patients.

Design

Retrospective, comparative analysis of an interventional case series.

Participants

Eight hundred fifty-four eyes (67 eyes with prior glaucoma surgery and 787 controls) from 582 patients who underwent DSAEK at 1 institution between January 2005 and April 2011.

Methods

Groups were compared with regard to preoperative, intraoperative, and postoperative parameters. Continuous variables were compared using the independent samples t test or Mann–Whitney U test. Categorical variables were compared using the chi-square test or Fisher exact test.

Main Outcome Measures

Frequencies of postoperative graft dislocation and postoperative hypotony.

Results

Study eyes before surgery differed from control eyes with regard to corneal thickness (768 vs. 655 μm; P<0.001) and intraocular pressure (13 vs. 16 mmHg; P<0.001). Postoperative graft dislocation occurred significantly more frequently in study eyes compared with control eyes (9% vs. 2%; P = 0.008). Among eyes in which dislocation occurred, postoperative hypotony was present in 5 study eyes (83%) and 0 control eyes.

Conclusions

Previous glaucoma surgery was associated with a significantly increased rate of graft dislocation compared with control eyes. Dislocation was related strongly to postoperative hypotony in eyes with prior glaucoma surgery.

Posted by Jami Kuehn, 11:47 AM

Banu Torun Acar, MD, Canan A. Utine, MD, MSc, Suphi Acar, MD, Ferda Ciftci, MD

Purpose

To analyze the visual and refractive outcomes of laser in situ keratomileusis (LASIK) after deep anterior lamellar keratoplasty (DALK) for keratoconus.

Setting

Haydarpasa Numune Education and Research Hospital, Ophthalmology Clinic, Istanbul, Turkey.

Design

Cohort study.

Methods

Patients with compound myopic astigmatism after DALK and a spherical equivalent (SE) between −2.50 diopters (D) and −8.00 D had LASIK as a single-step procedure, correcting the manifest refraction error. The visual and refractive results at 1 month, 3 months, and the last follow-up were compared with preoperative values.

Results

The mean follow-up was 11.17 months ± 3.61 (SD). The mean manifest refraction SE (MRSE) and autorefractometer measurements and the autokeratorefractometer and corneal topography keratometry readings decreased significantly from preoperatively to 1 month postoperatively (P<.01) but did not change significantly thereafter (P>.05). Preoperatively, the mean uncorrected (UDVA) and corrected (CDVA) distance visual acuities were 0.21 ± 0.08 and 0.73 ± 0.08, respectively; postoperatively, the means were 0.73 ± 0.10 and 0.98 ± 0.05, respectively. All eyes achieved a postoperative UDVA better than 0.5. No eye lost CDVA lines. The safety index was 1.34. The mean MRSE was −5.18 ± 1.74 D preoperatively and −1.05 ± 0.64 D postoperatively (P<.01). Postoperatively, 11 eyes (91.67%) were within ±2.00 D of the SE, 8 (6.67%) were within ±1.00 D, and 5 (41.67%) were within ±0.50 D. No complications were encountered.

Conclusion

Treatment of post-DALK keratoconus patients with LASIK to correct manifest refraction error seems to be a viable option.

Posted by Jami Kuehn, 11:46 AM

Prince, Jessica; Chuck, Roy S.

Purpose of review: Descemet’s stripping endothelial keratoplasty (DSEK) has become a preferred surgical correction for endothelial dysfunction. Patient dissatisfaction secondary to refractive error is emerging as a significant complaint after anatomically successful DSEK. This article reviews refractive surgeries after DSEK to address this problem.

Recent findings: There are various surgical options available to treat refractive compromise following DSEK. Cataract extraction with intraocular lens (IOL) implantation is a well tolerated option to restore visual acuity after DSEK in cases with significant lens opacities. Laser in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) can otherwise successfully correct simple refractive errors. Phototherapeutic keratectomy (PTK) may be employed in cases wherein visually significant subepithelial fibrosis and scarring become evident after DSEK.

Summary: To obtain maximum visual rehabilitation, patients undergoing DSEK may require further refractive surgeries. Cataract extraction, LASIK, PRK, PTK, and various combination procedures have been shown to optimize corneal clarity and visual acuity in patients who previously had successful DSEK with subsequent refractive errors. Technological advancements and continued research are necessary to perfect optimal timing and outcomes of these secondary refractive surgeries.

Posted by Jami Kuehn, 11:45 AM

Shah, Sanket U.; Gritz, David C.

Purpose of review: To review the literature for recent advancements in the femtosecond laser technology with regard to its applications in corneal transplantation and eye banking.

Recent findings: Advancements in corneal surgery have encouraged the use of disease-specific corneal subcomponents, utilized in procedures such as anterior-lamellar keratoplasty and endothelial keratoplasty, instead of traditional transplant procedures to minimize adverse effects of penetrating keratoplasty. Femtosecond laser microkeratomes can precisely create flaps for such transplant procedures, achieve better wound stability, and promote healing by shaped wound configurations. Laser microkeratomes have been compared to traditional mechanical microkeratomes for keratoplasty procedures from various aspects and are superior in some aspects and offer unique capabilities.

Summary: Femtosecond laser applications in eye banking include preparation of donor and recipient corneas for use in penetrating keratoplasty, anterior-lamellar keratoplasty, and endothelial keratoplasty. Advantages of femtosecond laser microkeratomes include higher precision of the cut, ability to achieve thinner flaps, and wound configurations that allow greater wound stability, shorter recovery time, and less postoperative pain. However, cost and availability at the eye-bank level may hinder widespread and immediate application.

Posted by Jami Kuehn, 11:45 AM

Jhanji, Vishal; Mehta, Jod S.; Sharma, Namrata; Sharma, Bhavana; Vajpayee, Rasik B.

Purpose of review: Corneal transplantation surgery has moved from an era of conventional penetrating keratoplasty to selective replacement of the diseased corneal layer with complementary healthy donor corneal tissue. Anterior lamellar transplantation surgeries do not involve replacement of corneal endothelium, consequently eliminating the occurrence of endothelial rejection. Similarly, in diseases affecting the corneal endothelium, selective replacement with a lamellar lenticule bearing healthy endothelium provides better outcomes in terms of ocular surface, lesser astigmatism and quick visual recovery. In addition to the advantages of enhanced surgical outcomes, targeted corneal transplantation allows the use of one donor cornea for more than one recipient, thereby offering a viable solution to the problem of paucity of donor corneas.

Recent findings: Evolving techniques of corneal transplantation have enabled better utilization of donor corneal tissue. Anterior lamellar as well as endothelial keratoplasty surgeries have become first-choice surgeries in appropriately selected cases. This review briefly discusses some of these novel surgical techniques.

Summary: A better understanding of targeted corneal transplantation would lead to adaptation of the concept of component corneal surgery. This would further enable the corneal surgeons to circumvent the problem of donor corneal shortage especially in the developing world.

Posted by Jami Kuehn, 11:43 AM

Fu, Yao MD, PhD; Liu, Jingbo MD, PhD; Tseng, Scheffer C. G. MD, PhD

Purpose: To determine the ocular surface deficits contributing to persistent epithelial defect (PED) after penetrating keratoplasty (PKP).

Methods: Four ocular surface deficits that contribute to PED and their corrective measures were reviewed in 11 eyes of 11 patients with PED after PKP.

Results: Among these 11 eyes, PED developed early in 8 eyes and late in 3 eyes after PKP. They all had more than 2 ocular surface deficits, with infrequent blinking (11 eyes) and lagophthalmos (9 eyes) being more common. Proper corrective measures resulted in rapid epithelialization in 1 week (1 eye), 2 weeks (9 eyes), and 3 weeks (1 eye) via insertion of a bandage contact lens to maintain tear film for treating infrequent blinking (4 eyes), tarsorrhaphy to correct nocturnal lagophthalmos (2 eyes), and fornix reconstruction to eliminate pathogenic symblepharon (4 eyes). During the follow-up of 22.1 ± 7.6 months after healing of PED, 8 eyes retained a stable and clear graft, whereas 3 eyes with more ocular surface deficits had recurrent PED and graft failure develop. Two of the latter were corrected by a repeat PKP combined with oral mucosal graft to correct the remaining cicatricial eyelids.

Conclusions: Besides the neurotrophic state and aqueous tear deficiency dry eye common in this cohort, infrequent blinking, lagophthalmos, and pathogenic symblepharon also contribute to PED after PKP. Proper corrective measures and vigilant follow-up are crucial for maintaining PKP graft survival in these severe cicatricial ocular surface diseases.

Posted by Jami Kuehn, 11:42 AM

Higaki, Shiro MD, PhD; Fukuda, Masahiko MD, PhD; Matsumoto, Chota MD, PhD; Shimomura, Yoshikazu MD, PhD

Purpose: To report and compare the outcomes of penetrating keratoplasty (PKP) triple procedures [combined PKP, cataract extraction, and intraocular lens (IOL) implantation] with a 25-gauge (G) system, 20-G system, and without core vitrectomy.

Subjects and Methods: Subjects comprised the following 3 groups: the 25-G group including 12 eyes of 12 patients (4 men and 8 women) that underwent PKP with 25-G core vitrectomy, the 20-G group including 9 eyes of 9 patients (3 men and 6 women) that underwent PKP with 20-G core vitrectomy, and the non-core vitrectomy group including 9 eyes of 9 patients (1 man and 8 women) that underwent PKP without core vitrectomy.

Results: In the 25-G, 20-G, and non-core vitrectomy groups, the success rates of IOL implantation were 91.7% (11 of 12 eyes), 88.9% (8 of 9 eyes), and 66.7% (6 of 9 eyes), respectively; the average operation times were 69 minutes, 82 minutes, and 90 minutes, respectively. The 25-G group showed significantly shorter operation time than the other 2 groups. Although not statistically significant, a higher rate of capsular rupture was seen in the non-core vitrectomy group.

Conclusions: A PKP triple procedure with the 25-G system can be a safe treatment that offers a better success rate of IOL implantation and a significantly shorter operation time.

Posted by Jami Kuehn, 11:42 AM

Awdeh, Richard M. MD; Abbey, Ashkan M. MD; Vroman, David T. MD; Ying, Michelle S. MD; Goldman, David MD; Kymionis, George MD, PhD; Yoo, Sonia H. MD

Purpose: To describe the use of phototherapeutic keratectomy (PTK) and transepithelial photorefractive keratectomy (PRK) for the treatment of subepithelial fibrosis and anterior corneal scarring after Descemet stripping automated endothelial keratoplasty (DSAEK).

Methods: The settings included the Department of Ophthalmology, Bascom Palmer Eye Institute, Miami, FL, and Carolina Cataract and Laser Center, Ladson, SC. Two patients with Fuchs endothelial dystrophy were noted to have anterior corneal opacities and corneal decompensation before DSAEK. Although both patients demonstrated improvement in corneal edema after DSAEK, they were left with residual anterior corneal opacities that were visually significant. The opacities were treated with excimer laser photoablation.

Results: Both patients demonstrated an improvement in best-corrected visual acuity after elimination of the anterior corneal opacity using PTK or transepithelial PRK.

Conclusions: Excimer laser ablation is an effective option for the treatment of residual subepithelial fibrosis and anterior corneal scarring after DSAEK. When appropriate, use of PTK or PRK can also eliminate residual refractive error.

Posted by Jami Kuehn, 11:41 AM

Cleary, Catherine MD; Song, Jonathan C. MD; Tang, Maolong PhD; Li, Yan PhD; Liu, Ying MD; Yiu, Samuel MD, PhD; Huang, David MD, PhD

Objectives: To develop a dual laser-assisted lamellar anterior keratoplasty (LALAK) technique, using excimer and femtosecond lasers to perform surgery on eye bank eyes.

Methods: First, we compared corneal stromal surfaces produced by (1) deep excimer ablation, (2) femtosecond lamellar cuts, and (3) manual dissection and evaluated the effect of excimer laser smoothing with fluid masking on each surface. Masked observers graded scanning electron microscopy images on a 5-point roughness scale. Then, we performed a 6-mm diameter excimer laser phototherapeutic keratectomy ablation to a residual bed thickness of 200 μm, followed by laser smoothing. We used the femtosecond laser to cut donors in a modified top hat design with a thin tapered brim, which fitted into a manually dissected circumferential pocket at the base of the recipient bed. Fourier domain optical coherence tomography was used to measure corneal pachymetry and evaluate graft fit.

Results: Deep excimer ablation with smoothing (n = 4) produced a significantly (P < 0.05) smoother surface (grade = 3.5) than deep excimer alone (n = 4, grade = 3.8) or manual dissection with (n = 1, grade = 3.8) and without smoothing (n = 1, grade = 4.8). Deep femtosecond cuts (n = 2) produced macroscopic concentric ridges on the stromal surface. Experimental LALAK was performed on 4 recipients prepared by deep excimer ablation and 4 donors cut with the femtosecond laser. After suturing, good peripheral graft-host match was observed on Fourier domain optical coherence tomography imaging.

Conclusion: These preliminary studies show that the LALAK technique permits improved interface smoothness and graft edge matching. Clinical trials are needed to determine whether these improvements can translate to better vision.

Precision
Corneal Graft

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MedEd
Continuing Education

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GSN
Global Sight Network

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