Colin Chan

Effect of inferior-segment Intacs with and without C3-R on keratoconus.

PURPOSE: To determine whether corneal collagen cross‐linking with riboflavin (C3‐R) augments the effect of inferior‐segment Intacs (Addition Technology) in the treatment of keratoconus. SETTING: Private practice, Beverly Hills, California, USA. METHODS: A retrospective nonrandomized comparative case series comprised 12 eyes of 9 patients who had inferior‐segment Intacs placement without C3‐R (Intacs‐only group) and 13 eyes of 12 patients who had inferior‐segment Intacs placement combined with C3‐R (Intacs with C3‐R group). The 2 groups were matched preoperatively. All patients had inferior‐segment Intacs placed with the incision in the steep axis of manifest refraction. Corneal collagen cross‐linking with riboflavin was performed after the Intacs segments were inserted. Outcome measures were topographic keratometry values and the lower–upper (L–U) ratio, which is a topographic measure of the degree of keratoconus. Preoperative data were compared to results 1 day postoperatively and measurements at the last postoperative visit. RESULTS: The Intacs with C3‐R group had a significantly greater reduction in cylinder than the Intacs‐only group (P<.05). Steep and average keratometry were reduced significantly more in the Intacs with C3‐R group (P<.05). There was a greater reduction in L–U ratio in the Intacs with C3‐R group (P<.05). CONCLUSION: The addition of C3‐R to the Intacs procedure resulted in greater keratoconus improvements than Intacs insertion alone.

Steroid management in giant cell arteritis

AIM Ocular involvement in giant cell arteritis (GCA) is an ophthalmic emergency which, if untreated, can progress to permanent blindness. There is little evidence in the literature to support current protocols for the acute treatment of GCA with steroids. The authors sought to review the effects of intravenous and oral steroids in GCA. METHODS This retrospective study reviewed the records of 100 consecutive patients with biopsy proved giant cell arteritis. 73 patients with visual loss who were treated at the Royal Victorian Eye and Ear Hospital (RVEEH) and St Vincents Hospital were included in the final series. The authors studied the management of the patients in the first week after presentation, analysing types of treatment, dose, effect on visual acuity, and complications. RESULTS All the patients except one had visual loss due to anterior ischaemic optic neuropathy (AION). 17 patients (23%) had bilateral eye involvement. Visual acuity improved in 21 of 73 patients (29%) by a mean of two Snellen chart lines after commencement of steroids. There was an increased likelihood of improved vision in the group who had intravenous steroids (40%) compared with those who received oral steroids (13%). In all except four patients (95%) vision remained stable at 1 month review. CONCLUSIONS Prompt treatment of GCA with steroids leads to improvement of visual acuity in a significant number of cases. Intravenous steroids may offer a greater prospect of improvement compared with oral steroids. A prospective trial comparing intravenous with oral steroids is needed to validate these findings and would not expose elderly patients to unacceptable risks.

Femtosecond laser cataract surgery: technology and clinical practice

The recent introduction of femtosecond lasers to cataract surgery has generated much interest among ophthalmologists around the world. Laser cataract surgery integrates high‐resolution anterior segment imaging systems with a femtosecond laser, allowing key steps of the procedure, including the primary and side‐port corneal incisions, the anterior capsulotomy and fragmentation of the lens nucleus, to be performed with computer‐guided laser precision. There is emerging evidence of reduced phacoemulsification time, better wound architecture and a more stable refractive result with femtosecond cataract surgery, as well as reports documenting an initial learning curve. This article will review the current state of technology and discuss our clinical experience.The recent introduction of femtosecond lasers to cataract surgery has generated much interest among ophthalmologists around the world. Laser cataract surgery integrates high-resolution anterior segment imaging systems with a femtosecond laser, allowing key steps of the procedure, including the primary and side-port corneal incisions, the anterior capsulotomy and fragmentation of the lens nucleus, to be performed with computer-guided laser precision. There is emerging evidence of reduced phacoemulsification time, better wound architecture and a more stable refractive result with femtosecond cataract surgery, as well as reports documenting an initial learning curve. This article will review the current state of technology and discuss our clinical experience.

Carotid dissection: a common cause of Horner's syndrome

Purpose: To highlight that internal carotid artery dissection is a common cause of Horners syndrome and that it is important to diagnose dissection as anticoagulation can prevent carotid thrombosis and embolism.

Infective keratitis in older patients: a 4 year review, 1998–2002

Background/aim: There are few clinical series in the literature of infective keratitis in the elderly, even though this age group constitutes a significant proportion of those affected by this condition. The authors aimed to determine the incidence and risk factors for infective keratitis in those over 60 years, the causative organisms, antibiotic susceptibilities, visual and tectonic outcome, and surgical intervention rate. Methods: A retrospective review of all patients aged 60 years and over admitted to the Sydney Eye Hospital with a diagnosis of infective keratitis, between September 1998 and December 2002. Results: 190 patients were identified with a mean age of 75.5 (SD 9.6) years (range 60–101). Local risk factors were found in 93.7%, and systemic risk factors in 27.9%. Organisms were cultured in 62.8%, and 7.9% had positive herpes simplex virus (HSV) polymerase chain reaction (PCR). Perforation or severe thinning occurred in 36% overall, but in 80% with positive HSV PCR. Acute surgical intervention was required in 43.7%, with acute penetrating keratoplasty performed in 17.9%, and 8.9% required evisceration. Mean presenting visual acuity was 1.82 (SD 1.24), equivalent to 6/300, excluding 26.3% with vision of light perception (LP) or worse. Mean final visual acuity was 1.24 (SD 1.16), equivalent to 6/100, excluding 19.5% with vision of LP or worse (p<0.0005). Conclusions: The elderly represent a distinct clinical group in the context of microbial keratitis. Predisposing factors are very common, they present with poor vision, have a high complication and surgical intervention rate, and a poor visual outcome compared to younger patients. The microbiological spectrum is similar to younger age groups, except that HSV is more common and may increase the risk of severe corneal thinning and perforation. Most bacterial isolates remain sensitive to currently available antibiotic preparations.

Higher Order Aberrations and Relative Risk of Symptoms After LASIK

PURPOSE To understand what level of higher order aberrations increases the relative risk of visual symptoms in patients after myopic LASIK. METHODS This study was a retrospective comparative analysis of 103 eyes of 62 patients divided in two groups, matched for age, gender, pupil size, and spherical equivalent refraction. The symptomatic group comprised 36 eyes of 24 patients after conventional LASIK with different laser systems evaluated in our referral clinic and the asymptomatic control group consisted of 67 eyes of 38 patients following LADARVision CustomCornea wavefront LASIK. Comparative analysis was performed for uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), contrast sensitivity, refractive cylinder, and higher order aberrations. Wavefront analysis was performed with the LADARWave aberrometer at 6.5-mm analysis for all eyes. RESULTS Blurring of vision was the most common symptom (41.6%) followed by double image (19.4%), halo (16.7%), and fluctuation in vision (13.9%) in symptomatic patients. A statistically significant difference was noted in UCVA (P = .001), BSCVA (P = .001), contrast sensitivity (P < .001), and manifest cylinder (P = .001) in the two groups. The percentage difference between the symptomatic and control group mean root-mean-square (RMS) values ranged from 157% to 206% or 1.57 to 2.06 times greater. CONCLUSIONS Patients with visual symptoms after LASIK have significantly lower visual acuity and contrast sensitivity and higher mean RMS values for higher order aberrations than patients without symptoms. Root-mean-square values of greater than two times the normal after-LASIK population for any given laser platform may increase the relative risk of symptoms.

Outcomes of Femtosecond Laser Cataract Surgery With a Diffractive Multifocal Intraocular Lens

PURPOSE To report the visual and refractive outcomes in an initial series of eyes undergoing femtosecond laser cataract surgery with implantation of a diffractive multi-focal intraocular lens (IOL). METHODS The first 61 consecutive eyes undergoing femtosecond laser cataract surgery and ReSTOR (Alcon Laboratories Inc) +3.00-diopter (D) add IOL implantation between May and July 2011 were enrolled in the study (LCS group). The control group consisted of a retrospective consecutive cohort of 29 eyes that underwent manual phacoemulsification cataract surgery and ReSTOR +3.00-D add IOL implantation (MCS group) between December 2010 and April 2011. Visual and refractive parameters were collected pre- and postoperatively at 1 and 3 months. RESULTS Mean postoperative spherical equivalent refraction was -0.01±0.35 D and -0.06±0.30 D in the LCS and MCS groups, respectively (P=.492). Mean absolute refractive prediction error (PE) was 0.26±0.25 D for the LCS group and 0.23±0.16 D for the MCS group (P=.489). Mean arithmetic refractive PE was 0.06±0.44 D and -0.02±0.30 D for the LCS and MCS groups, respectively (P=.388). No significant difference was noted in mean postoperative uncorrected distance visual acuity or uncorrected near visual acuity between groups. No eyes in either group had surgical complications or loss of corrected distance visual acuity in the follow-up period. CONCLUSIONS Mean spherical equivalent refraction and visual acuity of our initial group of patients undergoing laser cataract surgery are comparable to the manual phacoemulsification cohort for the AcrySof ReSTOR +3.00-D add IOL.

Melanoma‐associated retinopathy: does autoimmunity prolong survival?

Purpose: To discuss the autoimmune basis of melanoma‐associated retinopathy (MAR) and its implications for management and prognosis.

External analysis of the Randleman Ectasia Risk Factor Score System: a review of 36 cases of post LASIK ectasia

Background:  To validate Randlemans model of ectasia risk factor scores using a large unbiased sample of unpublished cases.

Centration analysis of ablation over the coaxial corneal light reflex for hyperopic LASIK.

PURPOSE To analyze postoperative topographic centration when the coaxially sighted corneal light reflex was used for laser centration in hyperopic LASIK. METHODS Centration photographs of 21 eyes (12 patients) that underwent hyperopic LASIK with centration over the coaxially sighted corneal light reflex were reviewed to determine the distance from the entrance pupil center to the coaxially sighted corneal light reflex. Postoperative ablation centration was determined topographically at day 1 and 3 months by four different methods. The difference between the actual decentration and the decentration that would have occurred had the ablation been centered over the entrance pupil center was calculated. RESULTS The mean deviation of the coaxially sighted corneal light reflex from the entrance pupil center preoperatively was 0.34 +/- 0.24 mm nasal or 4.5 +/- 3.0 degrees. At 1 day, the average decentration was 0.10 mm or 1.3 degrees temporal. The mean decentration that would have occurred if the ablation had been centered over the entrance pupil center was 0.44 mm or 5.5 degrees temporal. At 3 months, the average decentration was 0.07 mm or 0.25 degrees temporal. The mean decentration that would have occurred if the ablation had been centered over the entrance pupil center was 0.45 mm or 5.6 degrees temporal. Mean uncorrected visual acuity (logMAR) improved 3 lines from 0.54 +/- 0.14 (20/70) to 0.22 +/- 0.17 (20/32). No eye lost >2 lines of best spectacle-corrected visual acuity (BSCVA); 2 (10%) eyes lost 1 line of BSCVA at 3-month follow-up. CONCLUSIONS Excellent centration in hyperopic ablation is possible even in eyes with positive angle kappa when the ablation is centered over the corneal light reflex.