Clinical results of 123 femtosecond laser-assisted penetrating keratoplasties

Background

Postoperative astigmatism following penetrating keratoplasty is a major problem after corneal transplantation. The main goal of new trephination techniques such as femtosecond laser or excimer-laser trephination is to improve refractive and visual outcomes. The femtosecond laser technique makes profiled corneal trephinations such as the top hat or mushroom profile possible. We present the postoperative outcome of femtosecond laser-assisted penetrating keratoplasties.

Methods

We performed 123 femtosecond laser-assisted penetrating keratoplasties in 119 patients. The main outcome measures were intraoperative specifics, astigmatism, and irregularity in Orbscan corneal topography, as well as the occurrence of immune reactions and side-effects.

Results

All sutures have been removed in 49 of these 123 eyes. Their mean follow-up was 13.9?±?4.5 months. Time to complete suture removal (n?=?49) was 12.0?±?3.7 months in the mushroom group and 9.8?±?2.1 months in the top hat group. Mean astigmatism in Orbscan topography was 6.4?±?3.0 diopters in the mushroom and 5.8?±?4.6 diopters in the top hat group (all sutures out).

Conclusions

Femtosecond laser-assisted penetrating keratoplasty is a safe surgical technique. Due to the steps in profiled trephinations, the wound area is larger and theoretically the wound healing is, thus, faster and more stable. Complete suture removal is possible at an earlier time point compared to conventional penetrating keratoplasty. However, refractive results are not superior to those following conventional trephination.     

Comparison of corneal sensitivity between FS-LASIK and femtosecond lenticule extraction (ReLEx flex) or small-incision lenticule extraction (ReLEx smile) for myopic eyes

Background

To compare the effect on corneal sensitivity between femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and femtosecond lenticule extraction (ReLEx flex) or FS-LASIK and small-incision lenticule extraction (ReLEx smile) surgery.

Methods

Twenty-seven subjects (54 eyes) underwent FS-LASIK, 22 subjects (40 eyes) underwent ReLEx flex, and 32 subjects (61 eyes) underwent ReLEx smile surgery. Cochet-Bonnet esthesiometry (Luneau Ophthalmologie Chartres, Cedex, France) was used to evaluate corneal sensitivity preoperatively as well as at 1 week and 1 and 3 months after surgery.

Results

At 1 week, central, superior, nasal, and temporal corneal sensitivity in the ReLEx flex group was significantly higher than in the FS-LASIK group (P?=?0.007, 0.004, 0.020, 0.004 respectively) and in the central and inferior areas at 3 months (P?=?0.002, 0.009 respectively). A higher corneal sensitivity after ReLEx smile surgery was observed in every quadrant at 1 week and 1 and 3 months compared with FS-LASIK surgery (P?<?0.01). Furthermore, in the ReLEx smile group, there were no statistical differences in the superior and temporal quadrants at 1 month postoperatively compared with preoperatively (5.19?±?0.61 cm, P?=?0.198 and 5.64?±?0.48 cm, P?=?0.330 respectively) and no significant differences in any quadrant at 3 months.

Conclusions

Postoperative corneal sensitivity was not remarkably changed after ReLEx smile surgery compared with FS-LASIK. This might be because ReLEx is a flapless procedure.     

Einfluss der kornealen Biomechanik auf die Myopieregression nach Laser-in-situ-Keratomileusis

Background

Laser in situ keratomileusis is a safe and accepted method for correcting myopia. The operational results in terms of accuracy as well as the subjective acceptance of patients for corrections to – 8 D are now considered to be promising (Seiler, Refraktive Chirurgie der Hornhaut, 2000); however, postoperative results show individual patient problems in long-term stability. It is believed that the preoperative condition of the cornea (e.g. thickness, biomechanical properties) could have an influence on postoperative problems such as myopic regression.

Method

This study included a total of 46 eyes from 25 patients. At 3 months postoperatively, 15 patients (19 eyes) showed a SEQ of ??0.50 D or more. Within this group, 11 patients (15 eyes) developed a regression (regression group) within the first 3 postoperative months. The remainder of the total group did not show any regression (stability group). The subjects of this study were on average 33?±?8 years (stability group) and 31?±?7 years old (regression group). The corneal thickness was tested and refractive error, visual acuity (BCVA/UCVA) and intraocular pressure was measured. In addition, the corneal hysteresis (CH) and corneal resistance factor (CRF) were determined.

Results

The mean preoperative spherical equivalent refraction was ??3.14 D?±?1.41 D (SE) in the stability group and ? 6.47 D?±?1.40 D (p?=?0.001)in the regression group. Also, the postoperative spherical equivalents were statistically significant different (p?<?0.05). In contrast, the mean preoperative corneal thickness showed no differences in both groups (p?=?0.96) (stability group 563?±?36 µm and regression group 563?±?28 µm).

Conclusions

The aim of the study to detect a possible causal relationship between myopia regression after LASIK and the biomechanical properties of the cornea and corneal thickness could not be clearly identified.     

Secondary piggyback implantation versus IOL exchange for symptomatic pseudophakic residual ametropia

Background

To evaluate the safety and efficacy of implanting a secondary IOL in comparison with IOL exchange to correct residual spherical refractive error after cataract surgery.

Method

This prospective case series included 23 pseudophakic eyes of 23 patients. They were divided into two groups: group I included 12 eyes for whom secondary piggyback IOL implantation in the ciliary sulcus was done, and group II included 11 eyes for whom IOL exchange was done. The mean follow up was 18?±?4.2 months and 20?±?3.6 months in groups I and II respectively. The visual and refractive outcomes were evaluated, and any intraoperative or postoperative complications was recorded.

Results

The mean spherical equivalent in group I (secondary piggyback implantation), was reduced from ?6.2?±?2.2 diopters preoperatively to ?0.28?±?0.59D postoperatively in myopic eyes and from 4.79?±?1.02D to 0.03?±?0.74D in hyperopic eyes. Ninety-two percent of eyes were within ±0.5D of intended correction. In group II (IOL exchange), the mean SE was reduced from ?5.88?±?3.1D preoperatively to 0.16?±?1.09 D postoperatively in myopic eyes and from 5.05?±?0.93D preoperatively to 0.11?±?0.69D postoperatively in hyperopic eyes. Eighty-two percent of eyes had postoperative SE within?±?0.5D of the intended correction. UCVA improved significantly in both groups. Rupture of the posterior capsule occurred in one eye in group II. Only one eye in group II lost one line of BCVA.

Conclusion

Secondary piggyback implantation in the ciliary sulcus is an effective, safe, and easy treatment for a pseudophakic ametropia.     

Narbenbildung nach Hornhautvernetzung beim Keratokonus

Background

Corneal scar development after riboflavin-UVA-induced corneal collagen cross-linking (CXL) was retrospectively evaluated.

Patients and methods

A total of 163 CXL-treated eyes in 127 patients with stage 1–3 keratoconus according to Krumeich’s classification were included in this retrospective analysis. The follow-up period was 1 year. At the first and at all follow-up examinations uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), biomicroscopic findings, corneal topography and corneal thickness were recorded.

Results

At 1 year following CXL, 149 eyes (91.4%) of 114 patients had a clear cornea without corneal scar (control group), while 14 eyes (8.6%) of 13 patients developed clinically significant corneal scar (scar group). Preoperatively, the mean K value of the apex was 62.1 ± 13.8 D in the control group and 71.1 ± 13.2 D in the scar group (P=.02). The mean value of corneal thickness before the procedure was 478.1 ± 52.4 μm in the control group and 420.0 ± 33.9 μm in the scar group (P=.001). The UCVA and BCVA, which were preoperatively similar between groups (P=.59, P=.75 respectively), were postoperatively improved in the control group (P=.023, P=.001 respectively), but reduced in the scar group (P=.012, P=.004 respectively).

Conclusion

K-values and corneal thickness could be considered as predictive factors for the possible development of corneal scarring after riboflavin-UVA-induced CXL. Advanced keratoconus appears to be associated with a higher risk of corneal scar development due to lower corneal thickness, greater curvature and intrinsic tissue characteristics.     

Three different aspheric treatment algorithms of laser-assisted sub-epithelial keratectomy in patients with high myopia

Purpose

To compare visual outcomes and quality in high myopia patients treated using one of three aspheric treatment algorithms based on the NIDEK Advanced Vision Excimer Laser System.

Methods

Sixty eyes of 60 high myopia patients (>?6 diopter) underwent topography-guided (CATz) (20 eyes), wavefront-guided (OPDCAT) (20 eyes), or topography and wavefront-guided (OPA) (20 eyes) laser-assisted sub-epithelial keratectomy. Visual acuity, manifest refraction spherical equivalent (MRSE), ocular and corneal higher order aberrations, corneal asphericity, point spread function (Strehl ratio) and modulation transfer function (MTF) were compared preoperatively and 1, 3 and 6 months postoperatively.

Results

Six months after surgery, logMAR uncorrected visual acuity was 0.02 ± 0.09 in the CATz group, 0.02 ± 0.07 in the OPDCAT group and 0.02 ± 0.08 in the OPA group, and there were no statistically significant differences (P = 0.5355). No statistical differences were found among the three groups in MRSE (P = 0.3541). Induced spherical aberrations and the change of corneal asphericity were less in the OPA group than in the others (P < 0.0001). The MTF was slightly better in the OPA group than in the others. The Strehl ratio showed no statistically significant differences among the three groups.

Conclusions

All three aspheric treatment algorithms were safe and effective in correcting high myopia. Among them, the OPA algorithm maintained optical quality and physiologic cornea longer than the others.     

Subbasal nerve morphology, corneal sensation, and tear film evaluation after refractive femtosecond laser lenticule extraction

Background

The purpose of this study was to compare corneal subbasal nerve morphology, corneal sensation, and tear film parameters after femtosecond lenticule extraction (FLEX) and small-incision lenticule extraction (SMILE).

Methods

A prospective, randomized, single-masked, paired-eye design clinical trial of 35 patients treated for moderate to high myopia with FLEX in one eye and SMILE in the other. In both techniques, an intrastromal lenticule was cut by a femtosecond laser and manually extracted. In FLEX, a LASIK-like flap allowed removal of the lenticule, whereas in SMILE, it was removed through a small incision. In-vivo confocal microscopy was used to acquire images of the central corneal subbasal nerve plexus, from which nerve density, total nerve number, and nerve tortuosity were analyzed. Corneal sensation was measured using Cochet–Bonnet esthesiometry. A visual analog scale, tear osmolarity, non-invasive tear film break-up time (keratograph) tear meniscus height (anterior segment OCT), Schirmer's test, and fluorescein tear film break-up time were used to evaluate tear film and ocular surface symptoms. Patients were examined before and 6 months after surgery.

Results

There were no statistically significant differences in baseline parameters between FLEX and SMILE (p?>?0.050). With regard to changes from before to 6 months after surgery, mean reduction in subbasal nerve density was 14.22?±?6.24 mm/mm² in FLEX eyes, and 9.21?±?7.80 mm/mm² in SMILE eyes (p?<?0.05). The total number of nerves decreased more in FLEX eyes than in SMILE eyes (p?<?0.05). No change was found when comparing tortuosity (p?>?0.05). Corneal sensation was reduced with 0.38?±?0.49 cm in FLEX eyes, and 0.10?±?0.34 cm in SMILE eyes (p?<?0.01). No differences were found between FLEX and SMILE in tear film evaluation tests (p?>?0.05). Significantly more patients felt postoperative foreign body sensation in the FLEX eye within the first days after surgery, as compared to the SMILE eye.

Conclusions

Six months after surgery, the less invasive SMILE technique seemed better at sparing the central corneal nerves as compared to FLEX. Corneal sensation was only significantly reduced in FLEX eyes. There were no differences between FLEX and SMILE when comparing tear film evaluation tests 6 months after surgery.     

Rezidivbehandlung der neovaskulären altersbedingten Makuladegeneration mit Ranibizumab nach dem PrONTO-Schema

Background

The goal of this retrospective study was to evaluate the development of visual acuity before and after recurrence treatment of neovascular age-related macular degeneration (AMD) in a university eye clinic with referring ophthalmologists.

Methods

Data from patients with recurrent neovascular AMD who initially had been treated for neovascular AMD and followed by referring ophthalmologists were analyzed. An intravitreal recurrence treatment with ranibizumab using the same PrONTO scheme as used in the “upload” phase followed.

Results

Mean best corrected visual acuity (BCVA) of all 100 patients included in the study was ??0.61?±?0.33 LogMAR before treatment and improved to ??0.36?±?0.24 LogMAR (p?<?0.001) after “upload” therapy. Mean central retinal thickness (CRT) was 291.5?±?85.3 μm before treatment and decreased to 200.1?±?63.7 μm after “upload” therapy (p?<?0.001). At the time of recurrence the mean BCVA was ??0.63?±?0.33 LogMAR and improved significantly to ??0.52?±?0.28 LogMAR (p?<?0.001) after recurrence treatment. At the time of recurrence the mean CRT was 281.2?±?94.4 μm and decreased significantly to 202.7?±?59.9 μm after recurrence treatment (p?<?0.001).

Conclusions

Retreatment criteria according to the PrONTO scheme showed good morphological and functional results in the patients with recurrent neovascular AMD treated but seemed to be defined too broadly for everyday clinical use with an irreversible loss under those conditions in cases of a recurrent episode. Accordingly, the latest recurrence criteria of the DOG/BVA/DOC recommendations should be applied.     

Comparison of clear corneal incision injuries between torsional and conventional phacoemulsification

Purpose

To compare thermal and mechanical clear corneal incision (CCI) injuries after conventional and torsional phacoemulsification.

Design

A prospective, randomized clinical study.

Methods

A total of 80 eyes were evaluated for the profile of the incision at 1 day and 3 months postoperatively. The wound architecture was recorded with anterior segment optical coherence tomography (AS-OCT). The incisional thickness increased by thermal injury, Descemet’s membrane detachment (DMD) caused by mechanical injury, the presence of endothelial gaping, loss of coaptation, and wound retraction of the conventional phaco group and the torsional phaco group were compared.

Results

The corneal thickness at the incision site of the torsional ultrasound group was significantly lower than the conventional group compared to at the first postoperative visit (1187.55?±?75.66, 1233.62?±?85.87, P?=?.013). However, this thickness was similar between the two groups at 3 months postoperatively. The central endothelial cell loss was significantly lower in the torsional ultrasound group after 3 months (417?±?143, 322?±?130, P?=?.003). There was a positive correlation between cumulated dissipated energy (CDE) and the incisional corneal thickness change that was observed by AS-OCT. Other OCT outcome parameters (such as endothelial gap, DMD, epithelial gap, and uncoaptation) that may be caused by mechanical injury did not differ significantly between the groups on postoperative day one or after 3 months.

Conclusions

The torsional ultrasound mode may provide a lower level of phacoemulsification time and energy and induce less incisional corneal thickness caused by thermal injury in the early postoperative period. The long-term wound healing appeared the same in both ultrasound mode groups.     

Langzeitergebnisse nach Trabekulektomie mit 5-Fluorouracil

Purpose

Trabeculectomy is among the first choice surgical treatments for glaucoma. Antimetabolites, especially mitomycin C, have improved the success rate. The aim of this study is to present the results of trabeculectomy with 5-fluorouracil (5-FU).

Methods

A total of 71 consecutive trabeculectomies with 5-FU for decompensated glaucoma with at least 1 year follow-up data were retrospectively evaluated. The absolute (without therapy) and relative (with therapy) success rates for glaucoma medication were determined for intraocular pressure (IOP) levels of ≤?21 mmHg, ≤?18 mmHg, ≤?15 mmHg and ≤?12 mmHg respectively. Postoperative 5-FU administration rates, needling procedures and complications were recorded.

Results

Sufficient follow-up data were available for a total of 55 patients. The average IOP was preoperatively 29.6?±?7.3 mmHg (3?±?1.4 active ingredients, partly acetazolamide), after 6 months 13.2?±?4.1 mmHg and after 1 year 13.7?±?4.3 mmHg. Complete success at 6 months postoperatively for the given pressure levels: were 92 %, 87 %, 79 % and 52?% and at 1 year 87 %, 84 %, 51 % and 56?%, respectively. Postoperative relative success for these pressure levels at 6 months were 96 %, 90 %, 81 % and 54?% and at 1 year 96 %, 93 %, 58 % and 58?%, respectively. Administrations of 5-FU postoperatively were no intervention (n?=?30 patients), subconjunctival 5-FU administration (n?=?25) and needling procedures (n?=?6). A temporary hypotension with a shallow anterior chamber was seen in ?6 patients, cataract development in 5 patients and 1 patient developed corneal decompensation (multiple previous operations before trabeculectomy).

Conclusion

Trabeculectomy with intraoperative 5-FU administration showed very high success rates after 1 year. Serious complications were rarely seen. Intraoperative 5-FU administration can be considered as an alternative treatment to trabeculectomy with intraoperative use of mitomycin C.     

A comparison between Goldmann applanation tonometry and dynamic contour tonometry after photorefractive keratectomy

Background

The intraocular pressure (IOP) could be measured by both Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT). Although these two methods have been discussed widely after laser-assisted sub-epithelial keratectomy (LASIK), there is little data in the cases undergoing photorefractive keratectomy (PRK). We aimed to compare the changes of IOP measurements obtained by GAT and DCT after PRK for myopia/myopic astigmatism.

Methods

This prospective study enrolled 77 candidates (154 eyes) for PRK to correct myopia or myopic astigmatism and 30 matched patients (30 eyes) with myopia or myopic astigmatism who served as controls. Changes of the IOP measurements (ΔIOP) obtained by GAT and DCT before and at 6 months after PRK in the operated eyes, and at baseline and 6 months later in the controls, were documented. Changes of the central corneal thickness (ΔCCT) were determined in the same fashion.

Results

The mean IOP readings obtained by DCT were comparable before and at 6 months after procedure (18.34 ± 3.03 mmHg and 17.87 ± 2.61 mmHg respectively, p?=?0.41); whereas the mean IOP reading obtained by GAT decreased significantly 6 months postoperatively (17.92 ± 3.63 mmHg and 16.25 ± 2.66 mmHg, p?<?0.001). A significant correlation was present between the ΔIOP obtained by GAT and ΔCCT (r?=?0.61, p?<?0.001). Similar correlation was not significant between the DCT-obtained ΔIOP and the ΔCCT (r?=?0.07, p?=?0.44). The mean ΔIOP obtained by GAT was significantly higher in the operated eyes than in the controls (?1.54?±?1.45 vs 0.07?±?0.44 mmHg, p?=?0.02). The mean DCT-obtained ΔIOP was just marginally insignificant between the operated and nonoperated eyes (?0.63?±?0.59 vs 0.02?±?0.38 mmHg respectively; p?=?0.09).

Conclusions

The authors recommend DCT after PRK in the cases with myopia or myopic astigmatism     

Visus und Astigmatismus nach Keratoplastik

Background

The purpose of this study was to assess the differences in postoperative visual acuity, astigmatism, and selected postoperative complications between a guided trephine system (GTS) and motor trephine after penetrating keratoplasty.

Patients and methods

In this retrospective analysis 74 patients who had undergone penetrating keratoplasty either by GTS (n?=?53) or by motor trephine (Motortrepan) (n?=?21) were included. Both patient groups included in this analysis were selected to ensure a homogeneous distribution of preoperative parameters to the greatest possible extent. However, some significant differences in patient selection between the two groups could not be avoided. Patients in the motor trephine group were older (mean age 68.4 years vs 56.4 years; p?<?0.01) and had Fuchs’ endothelial dystrophy more often (47.6 % vs 26.4 %) and significantly less keratoconus (14.3 % vs 32.1 %).

Results

No significant differences regarding visual acuity outcomes could be found between GTS and Motortrepan. In both patient groups there were no differences in the amount of preoperative astigmatism (1.36 vs. 2.0 dpt., p?=?0.39). However, at the time of final corneal suture removal (2.23 vs. 3.5 dpt., p?=?0.03) and at a postoperative control 1 year after final suture removal (2.29 vs. 3.85 dpt., p?=?0.005) the amount of astigmatism in the motor trephine group was found to be significantly higher.

Conclusion

In summary penetrating kerastoplasty using the motor trephine was found to result in significantly higher postoperative astigmatism than those performed with the GTS.     

Evaluierung der dynamischen Konturtonometrie bei Keratokonus

Purpose

The gold standard for measuring intraocular pressure (IOP) until now has been Goldmann applanation tonometry (GAT), which depends on the central corneal thickness (CCT) and curvature. In patients with keratoconus who have an abnormal corneal geometry and thickness, measurement of pressure with GAT is often difficult and not very reproducible. We compared the impact of the central corneal thickness (CCT) on the IOP measured with dynamic contour tonometry (DCT), a digital method which is adapted to the corneal geometry, and GAT in patients with keratoconus.

Methods

IOP was measured in 54 patients (38 men and 16 women, mean age of 36±9.9 years) with GAT and DCT in randomized order. All patients had a keratoconus which was assured by topography. In addition central corneal thickness (CCT) was measured with the Pentacam. For statistical analysis the Pearson correlation was calculated and a Bland-Altman diagram plotted.

Results

Mean corneal thickness was 486.2±45.5 μm. DCT measured the IOP at a mean value of 14.9±2.6 mmHg and GAT at 13.3±2.9 mmHg. With a mean difference of 1.6±2.4 mmHg DCT measured significantly higher than GAT (p≤0.05) Neither IOP measurements with GAT (r=?0.03; p>0.05) nor those with DCT (r=0.08; p>0.05) showed a significant correlation to central corneal thickness.

Conclusion

The example of keratoconus confirms that IOP measured by GAT is lower than if measured by DCT. Because both methods are independent of the CCT they are equally acceptable for IOP follow-up in eyes with keratoconus, which may result in progressive corneal thinning in the long term.     

Comparative analysis of the relationship between anterior and posterior corneal shape analyzed by Scheimpflug photography in normal and keratoconus eyes

Background

To analyze and compare the relationship between anterior and posterior corneal shape evaluated by a tomographic system combining the Scheimpflug photography and Placido-disc in keratoconus and normal healthy eyes, as well as to evaluate its potential diagnostic value.

Methods

Comparative case series including a sample of 161 eyes of 161 subjects with ages ranging from 7 to 66 years and divided into two groups: normal group including 100 healthy eyes of 100 subjects, and keratoconus group including 61 keratoconus eyes of 61 patients. All eyes received a comprehensive ophthalmologic examination including an anterior segment analysis with the Sirius system (CSO). Antero-posterior ratios for corneal curvature (k ratio) and shape factor (p ratio) were calculated. Logistic regression analysis was used to evaluate if some antero–posterior ratios combined with other clinical parameters were predictors of the presence of keratoconus.

Results

No statistically significant differences between groups were found in the antero–posterior k ratios for 3-, 5- and 7-mm diameter corneal areas (p?≥?0.09). The antero–posterior p ratio for 4.5- and 8-mm diameter corneal areas was significantly higher in the normal group than in the keratoconus group (p?<?0.01). The k ratio for 3, 5, and 7 mm was significantly higher in the keratoconus grade IV subgroup than in the normal group (p?<?0.01). Furthermore, significant differences were found in the p ratio between the normal group and the keratoconus grade II subgroup (p?≤?0.01). Finally, the logistic regression analysis identified as significant independent predictors of the presence of keratoconus (p?<?0.01) the 8-mm anterior shape factor, the anterior chamber depth, and the minimal corneal thickness.

Conclusions

The antero-posterior k and p ratios are parameters with poor prediction ability for keratoconus, in spite of the trend to the presence of more prolate posterior corneal surfaces compared to the anterior in keratoconus eyes.     

Corneal biochemical features of patients with vernal keratoconjunctivitis

Background

Vernal keratoconjunctivitis (VKC) is a chronic, bilateral, seasonally exacerbated, allergic inflammation of the ocular surface, involving bulbar and ? or tarsal conjunctiva and cornea. The ocular response analyzer (ORA) measures corneal biomechanical properties in vivo by monitoring and analyzing the corneal behavior when its structure is submitted to a force induced by an air jet. This study was designed to examine corneal biomechanical properties and intraocular pressure in patients with VKC, and to compare with control eyes.

Methods

ORA measurements were performed on the both eyes of 26 patients with VKC (group I) and 14 healthy children who served as the control group (group II). Corneal hysteresis (CH), corneal resistance factor (CRF) and intraocular pressure [Goldmann correlated (IOPg) and corneal compensated (IOPcc)] were recorded with ORA.

Results

Mean age of patients with VKC and control groups were 11.3?±?5.8 and 10.6?±?1.9 years for groups I and II respectively. Mean (± SD) of the CH and CRF readings were 10.1?±?1.6 versus 10.5 ±1.6 (p?>?0.05) and 9.5?±?1.7 versus 10.8?±?1.7 mmHg (p?<?0.05), in groups I and II respectively. Mean (± SD) of the IOPg and IOPcc recordings were 13.3 ±3.4 versus 16.6 ±3.6 mmHg (p?<?0.05) and 14.3?±?3.4 versus 16.9?±?3.7 mmHg (p?>?0.05) in groups I and II respectively. Statistical analysis revealed significant differences for CRF and IOPg between the study groups.

Conclusion

The mean CRF and IOPg values of patients with VKC were lower than those of controls. According to the results of our study, one can conclude that corneal biomechanical property, CRF, could be different in VKC patients compared to normals.     

Comparison of cornea endothelial cell counts after combined phacovitrectomy versus pars plana vitrectomy with fragmentation

Background

To compare postoperative cornea endothelial cell loss between combined phacovitrectomy and pars plana vitrectomy (PPV) with fragmentation.

Methods

Eighty-eight consecutive patients (92 eyes) who underwent combined phacovitrectomy (53 eyes from 50 patients) or PPV with fragmentation (39 eyes from 38 patients) were enrolled in this retrospective study. Endothelial cell density (ECD) was calculated with specular microscopy at 1 and 3 months after surgery.

Results

At 3 months after surgery, the mean ECD decreased significantly from 2,646?±?296 cells/mm² to 2,422?±?347 cells/mm² in the combined phacovitrectomy group (P?<?0.001). However, the PPV with fragmentation group did not show any significant changes in ECD during the same period (from 2,123?±?628 cells/mm² to 2,073?±?574 cells/mm²). The mean endothelial cell loss in the combined phacovitrectomy group (7.9 and 9.5 %) was significantly higher than that in the PPV with fragmentation group (0.7 and 2.4 %) both at 1 and 3 months postoperatively (P?=?0.001 and P?=?0.001 respectively).

Conclusion

In this study, corneal endothelial cell loss during the early postoperative period was significantly higher after combined phacovitrectomy than after PPV with fragmentation.     

The impact of tear functions on visual outcome following keratoplasty in eyes with keratoconus

Background

To investigate the impact of preoperative and postoperative tear functions on visual outcome and the recovery of visual function following keratoplasty in eyes with keratoconus.

Methods

Twenty-five eyes of 25 consecutive patients (5 females, 20 males, mean age: 34.3?±?15.8 years (range: 19–70 years) with keratoconus who underwent either penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK) were included in this prospective study. One patient who had a rejection episode during the follow-up period was excluded. All subjects underwent best corrected visual acuity (BCVA), corneal topography (refractive cylinder, surface regularity index: SRI and surface asymmetry index: SAI), Schirmer I test, tear film break-up time (BUT), corneal sensitivity, and fluorescein staining score measurements before as well as 1, 3, 6 and 12 months after keratoplasty. The relation between the tear functions and the duration until the achievement of maximum BCVA was also evaluated. Linear regression analysis was performed to study the statistical significance of the correlations and the time wise change of each examined parameter.

Results

SRI, SAI, and BCVA significantly improved after keratoplasty. The postoperative corneal sensitivity was still significantly low even at 12 months postoperatively. Postoperative BCVA at 3, 6 months and maximum BCVA showed a significant linear negative correlation with the preoperative BUT (3 months; r?=??0.461, p?=?0.036, 6 months; r?=??0.494, p?=?0.023, maximum BCVA; r?=??0.473, p?=?0.030). The duration until the achievement of maximum BCVA showed a significant negative correlation with the preoperative Schirmer test (r?=??0.429, p?=?0.036). BCVA at 1 and 3 months postoperatively showed significant linear negative correlations with BUT value at the respective periods (1 month; r?=??0.665, p?=?0.0036, 3 months; r?=??0.580, p?=?0.0059).

Conclusion

Preoperative tear functions appeared to have an influence on postoperative BCVA and the duration of visual recovery in keratoconus patients undergoing keratoplasty. Postoperative tear film stability appears to play an important role for obtaining a better BCVA in the early postoperative period after keratoplasty.     

Konfokale In-vivo-Hornhautmikroskopie nach Keratoplastik

Background

Seven eyes with clear grafts after penetrating keratoplasty were examined with in vivo confocal corneal microscopy in 1999. Our aim was the confocal microscopic investigation of the subclinical changes in clear grafts after long-term follow-up.

Methods

The preoperative diagnoses were keratoconus (two), granular corneal dystrophy (two), pseudophakic bullous keratopathy due to ACL (two), and corneal ulcer (one). The epithelium, corneal nerves, keratocytes of the anterior and posterior stroma, and endothelium were evaluated with confocal microscopy.

Results

Mean density of basal epithelial cells was 3928±378 cells/mm² at 15 months and 3284±565 cells/mm² at 66 months postoperatively. At 15 months the keratocyte density was 750±113 cells/mm² in the anterior stroma and 601±98 cells/mm² in the posterior stroma, at 66 months 383±53 cells/mm² in the anterior stroma and 411±98 cells/mm² in the posterior stroma. Endothelial cell density decreased from 1719±576 cells/mm² (15 months) to 965±272 cells/mm² (66 months).

Conclusions

In the follow-up period a significant decrease of keratocyte and endothelial cell density was detectable with confocal microscopy. The clinical importance of our findings must be clarified with further examinations on more patients.     

Clinical utility of femtosecond laser-assisted astigmatic keratotomy after cataract surgery

Purpose

To examine the clinical utility of femtosecond laser-assisted astigmatic keratotomy (FSL-AK) for eyes after cataract surgery.

Methods

Eight eyes of 6 patients with an intraocular lens and corneal astigmatism of 2.0 diopters (D) or more underwent FSL-AK. The mean preoperative manifest cylindrical refraction was 2.88 ± 0.64 D and the mean corneal astigmatism was 2.84 ± 0.83 D. Paired symmetrical arcuate incisions were created with the same settings, except for the incision depth. Uncorrected distance visual acuity (UDVA), manifest cylindrical power, and surgically induced astigmatism (SIA) were measured at 1 day, 1 week, and 1 month postoperatively. Fourier analysis of corneal topography and incision depths measured with anterior-segment optical coherence tomography were evaluated 1 month postoperatively.

Results

In all eyes, the UDVA improved at 1 week and 1 month postoperatively, and the manifest cylinder also decreased postoperatively, while the SIA showed overcorrections in 6 eyes. Fourier analysis showed decreases in spherical and regular astigmatic components and increases in higher-order irregularity. The mean incision depth was measured as 60 µm deeper than the intended depth.

Conclusion

The FSL-AK effectively reduced corneal astigmatism and improved the UDVA, although it was demonstrated that the deeper incisions led to overcorrection.

     

Femtosecond laser-assisted deep anterior lamellar keratoplasty for keratoconus and keratectasia

AIM: To describe the initial outcomes and safety of femtosecond laser-assisted deep anterior lamellar keratoplasty (DALK) for keratoconus and post-LASIKkeratectasia.METHODS:In this non-comparative case series, 10 eyes of 9 patients underwent DALK procedures with a femtosecond laser (Carl Zeiss Meditec AG, Jena, Germany). Of the 9 patients, 7 had keratoconus and 2 had post-LASIK keratectasia. A 500 kHz VisuMax femtosecond laser was used to perform corneal cuts on both donor and recipient corneas.The outcome measures were the uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal thickness, astigmatism, endothelial density count (EDC), and corneal power.RESULTS: All eyes were successfully treated. Early postoperative evaluation showed a clear graft in all cases. Intraoperative complications included one case of a small Descemet’s membrane perforation. Postoperatively, there was one case of stromal rejection, one of loosened sutures, and one of wound dehiscence. A normal corneal pattern topography and transparency were restored, UCVA and BCVA improved significantly, and astigmatism improved slightly. There was no statistically significant decrease in EDC.CONCLUSION: Our early results indicate that femtosecond laser-assisted deep anterior lamellar keratoplasty could improve UCVA and BCVA in patients with anterior corneal pathology. This approach shows promise as a safe and effective surgical choice in the treatment of keratoconus and post-LASIK keratectasia.