Priyanka Chhadva

Comparison of IOL power calculation methods and intraoperative wavefront aberrometer in eyes after refractive surgery.

PURPOSE To compare preoperative methods for calculating intraocular lens (IOL) power versus the intraoperative wavefront aberrometer in eyes with a history of refractive surgery. METHODS A retrospective study of 46 eyes (33 patients) with previous refractive surgery that underwent subsequent cataract surgery was conducted. Suggested IOL power predicted by ORange intraoperative wavefront aberrometer (WaveTec Vision Systems, Inc., Aliso Viejo, CA) was compared to power predicted by the (1) SRK-T formula using keratometry and axial length measurements from the IOLMaster (Carl Zeiss Meditec, Dublin, CA), (2) average central keratometry (Avg K) from corneal topography, and (3) average IOL power predicted by the American Society of Cataract and Refractive Surgery (ASCRS) web site. No historical information was used for the calculations. IOL power required for emmetropia was back-calculated using manifest refraction and implanted IOL power after cataract surgery. RESULTS Mean age was 60 ± 7.9 years. Fifteen percent had a history of myopic photorefractive keratectomy (n = 7), 57% myopic LASIK (n = 26), 13% hyperopic LASIK (n = 6), and 22% radial keratectomy (RK) (n = 10). In 37% of cases, ORange predicted IOL power to within ±0.50 diopters (D) of emmetropia, compared to 30% for IOLMaster keratometry, 26% for Avg K, and 17% for ASCRS web site. In eyes after myopic treatment, ORange, IOLMaster, Avg K, and ASCRS web site predicted within ±0.50 D of emmetropia in 39%, 27%, 24%, and 18%, respectively, and within ±1.0 D in 60%, 39%, 39%, and 51%, respectively. In eyes after RK, ORange, Avg K, and ASCRS web site predicted to within ±0.50 D of emmetropia in 14% and the IOLMaster in 43% cases. CONCLUSIONS Although the ORange most often predicted to within ±0.5 D of emmetropia, no method was able to achieve this accuracy more than 50% of the time. Predictions for eyes after RK were worse than for other types of refractive procedures.

The impact of conjunctivochalasis on dry eye symptoms and signs.

PURPOSE The purpose of this project was to study the relationship between conjunctivochalasis (Cch) and ocular signs and symptoms of dry eye. METHODS Ninety-six patients with normal eyelid and corneal anatomy were prospectively recruited from a Veterans Administration hospital over 12 months. Symptoms (via the dry eye questionnaire 5 [DEQ5]) and signs of dry eye were assessed along with quality of life implications. Statistical analyses comparing the above metrics among the three groups included χ(2), analysis of variance, and linear regression tests. RESULTS Participants were classified into three groups: nasal conjunctivochalasis (NCch; n = 31); nonnasal conjunctivochalasis (non-NCch; n = 41); and no conjunctivochalasis (no-Cch; n = 24). Patients with NCch had more dry eye symptoms than those with non-NCch (DEQ5: NCch = 13.8 ± 5.0, non-NCch = 10.2 ± 5.0, no-Cch = 11.6 ± 5.8; P = 0.014), and more ocular pain than those with Non-NCch and no-Cch (numerical rating scale [NRS]: NCch = 4.5 ± 3.0, non-NCch = 2.3 ± 2.8, no-Cch = 3.3 ± 2.6; P = 0.008). They also had worse dry eye signs compared to those with no-Cch measured by Schirmer score with anesthesia (NCch = 14.5 ± 6.9, non-NCch = 16.8 ± 8.2, no-Cch = 19.9 ± 6.4; P = 0.039); meibomian gland dropout (NCch 1.8 ± 0.9, non-NCch = 1.4 ± 1.0, no-Cch = 1.0 ± 1.0; P = 0.020); and eyelid vascularity (NCch = 0.84 ± 0.8, non-NCch = 0.74 ± 0.7, no-Cch = 0.33 ± 0.6; P = 0.019). Moreover, those with NCch more frequently reported that dry eye symptoms moderately to severely impacted their quality of life (NCch = 87%, non-NCch = 51%, no-Cch = 58%; P = 0.005). CONCLUSIONS The presence of NCch associates with dry eye symptoms, abnormal tear parameters, and impacts quality of life compared with non-NCch and no-Cch. Based on these data, it is important for clinicians to look for Cch in patients with symptoms of dry eye.

Impact of Eyelid Laxity on Symptoms and Signs of Dry Eye Disease.

Purpose: To study the relationship between eyelid laxity and ocular symptoms and signs of dry eye (DE). Methods: A total of 138 patients with normal external anatomy were prospectively recruited from a Veterans Administration hospital. Symptoms (via the Dry Eye Questionnaire 5 and Ocular Surface Disease Index) and signs of DE were assessed along with presence or absence of eyelid laxity. Results: It was observed that 71% of participants (n = 98) had clinical evidence of eyelid laxity (upper and/or lower) compared with 29% (n = 40) with no eyelid laxity. Individuals with eyelid laxity were older (67 ± 10 vs. 55 ± 8 years without laxity, P < 0.005) and more frequently male (76% of males had laxity vs. 18% females, P < 0.005). Patients with eyelid laxity had increased symptoms and signs of DE compared with their counterparts without laxity including ocular pain described as grittiness (63% vs. 45%, P = 0.049), decreased tear break-up time (8.6 ± 3 vs. 10.3 ± 4 seconds, P = 0.02), increased corneal staining (2.5 ± 3 vs. 1 ± 2, P = 0.002), decreased Schirmer score (14±6 vs. 17±7 mm, P = 0.01), increased meibomian gland drop out (2 ± 1 vs. 0.8 ± 0.8, P < 0.005), increased eyelid vascularity (0.8 ± 0.8 vs. 0.2 ± 0.5, P < 0.005), and more abnormal meibum quality (2 ± 1.3 vs. 1.4 ± 1.2, P = 0.02). In a multivariable analysis considering both signs of DE and laxity, lower eyelid laxity remained significantly associated with ocular surface disease index scores, suggesting a direct effect of laxity on symptoms of DE. Conclusions: The presence of eyelid laxity associates with abnormal tear parameters compared with the absence of eyelid laxity. Based on these data, it is important for clinicians to test for eyelid laxity in patients with symptoms and/or signs of DE.

Human Tear Serotonin Levels Correlate with Symptoms and Signs of Dry Eye

PURPOSE Serotonin, a neurotransmitter known to be involved in nociceptor sensitization, is present in human tears. The purpose of this study was to correlate tear serotonin levels, as a marker of nociceptor sensitization, to facets of dry eye (DE), including symptoms and signs. DESIGN Cross-sectional study. PARTICIPANTS A total of 62 patients with normal eyelid and corneal anatomy were prospectively recruited from a Veterans Administration Ophthalmology Clinic over 11 months. METHODS Dry eye symptoms (Ocular Surface Disease Index [OSDI]), signs (tear break-up time [TBUT], corneal staining, and Schirmers score), and clinical descriptors of neuropathic ocular pain (NOP) (sensitivity to light or sensitivity to wind) were assessed. For tear analysis, each patients tears were collected after instilling 50 μl of sterile saline to the lower cul-de-sac of each eye and using capillary action microcaps to collect the ocular wash. Tear serotonin levels were measured using enzyme-linked immunosorbent assay. MAIN OUTCOME MEASURES Correlations between tear serotonin concentrations and DE symptoms and signs. RESULTS The mean age of the population was 61±14 years, and 84% (n = 52) of the patients were male. Serotonin concentrations negatively correlated with Schirmers scores (r = -0.28; P = 0.02) but did not correlate with other DE parameters, such as OSDI scores, sensitivity to light or wind, TBUT, and staining. According to our hypothesis, we divided patients into groups based on both DE symptoms and aqueous tear production; serotonin concentrations were significantly higher in DE group 1 (OSDI ≥6 and Schirmers <8) compared with both DE group 2 (OSDI ≥6 and Schirmers ≥8) and controls (OSDI <6 and Schirmers ≥8). Patients in DE group 2 more frequently reported sensitivity to light (64%) and wind (67%) compared with DE group 1 (40% and 60%, respectively) and controls (8% and 17%, respectively). CONCLUSIONS Patients with DE symptoms and aqueous tear deficiency had higher tear serotonin levels compared with those with DE symptoms but normal tear production and those without DE symptoms.

Persistent corneal opacity after descemet stripping automated endothelial keratoplasty suggesting inert material deposits into the interface

Purpose: To report a case of interface deposits after Descemet stripping automated endothelial keratoplasty (DSAEK) imaged by means of an electron microscope. Methods: An 88-year-old man was referred with a history of corneal edema resulting from pseudophakic bullous keratopathy. A DSAEK was performed on his left eye without complications; however, the follow-up examination revealed a well-attached graft with persistent interface opacities at the donor–recipient interface. The DSAEK was repeated in this eye 1 year after the first surgery because of these corneal opacities that interfered with his vision. Results: In the immediate postoperative period, the patient had adequate visual acuity with intact graft placement and a clear interface. Pathology and electron microscope analysis were performed on the removed endothelial graft, which revealed diffuse particles on the stromal surface of the endothelial graft. Conclusions: A repeated DSAEK procedure sufficiently removed this patients corneal opacities and improved the visual acuity. The opacity is believed to have occurred because of residual viscoelastic material, which was used to maintain anterior chamber volume during surgery. This solution must be thoroughly removed to avoid similar complications.

Intrastromal Corneal Ring Segment Explantation in Patients With Keratoconus: Causes, Technique, and Outcomes.

PURPOSE To assess the causes for intrastromal corneal ring segment (Intacs; Addition Technology Inc., Lombard, IL) explantation in patients with keratoconus, and technique for explantation, long-term outcomes, and secondary procedures to correct visual acuity. METHODS Ten eyes of 8 patients with a history of Intacs explantation between 2004 and 2012 were included in a retrospective study performed at the Bascom Palmer Eye Institute, Miami, Florida. Causes of Intacs removal, surgical technique, preoperative and postoperative corneal examination, and uncorrected and corrected distance visual acuity were documented. Additionally, corneal topography (Tomey, Nagoya, Japan) parameters such as average keratometry and corneal cylinder were assessed. RESULTS Although the segments were well positioned, the most common cause of Intacs removal was worsening visual acuity (80%). There was no statistically significant difference between pre-Intacs placement, post-Intacs placement, and post-Intacs removal in uncorrected and corrected distance visual acuity, average keratometry, or corneal cylinder, except between 1-year post-Intacs placement corrected distance visual acuity (0.57 logMAR [20/75 Snellen]) and 1-month post-Intacs removal corrected distance visual acuity (0.25 logMAR [20/36 Snellen], P =.03). Four patients underwent penetrating keratoplasty after Intacs removal with good visual outcomes. CONCLUSION This study demonstrates the visual and structural outcomes that returned to near baseline after Intacs explantation in keratoconic eyes.

Long-term Outcomes of Flap Amputation After LASIK.

To the Editor: Several complications can occur after LASIK due to the creation of a non-physiological potential space, including epithelial ingrowth, diffuse lamellar keratitis, and infectious keratitis. Although some of these complications can be mild and not visually significant, others can be vision-threatening and require medical or surgical intervention. Treatment of complications after LASIK depends on the etiology and severity but, in general, flap amputation is considered a last option when alternative treatment options fail.1 There are few reports in the literature that examine the long-term outcomes of this treatment modality. We present all cases of flap amputation after LASIK at our institution during the past 15 years to evaluate long-term visual and structural outcomes of this procedure. Eight eyes of 7 patients with a history of LASIK, performed at outside institutions, were identified. Flap amputation was performed at Bascom Palmer Eye Institute by three surgeons (AG, CLK, and SHY) to treat epithelial ingrowth after LASIK in 2 patients and infectious keratitis after LASIK in 5 patients. Two eyes of 2 patients with a history of bilateral LASIK underwent unilateral flap amputation due to recurrent and uncontrollable epithelial ingrowth (Figure A, available in the online version of this article). Mean uncorrected visual acuity (UCVA) was 20/80 preoperatively and improved to 20/302 years after amputation. Additionally, 6 eyes of 5 patients with a history of bilateral LASIK underwent flap amputation (4 unilateral, 1 bilateral) due to infectious keratitis. Five eyes had Mycobacterium infections soon after LASIK (8.4 ± 3 weeks), whereas 1 eye had an Acanthamoeba infection 10 years after LASIK. The patient with Acanthamoeba keratitis had a UCVA of 20/200 and persistent infection despite medical management. Thus, LASIK flap amputation was performed 3.5 weeks after diagnosis, and UCVA was 20/40 6 months after the procedure (Figure B, available in the online version of this article). The 5 eyes with Mycobacterium infection (including Mycobacterium chelonae, M. mucogenicum, M. atypical, and M. abscessus) also had persistent infection despite medical management. Mean preoperative UCVA was 20/200 and UCVA improved to 20/50 at 6 years after flap amputation. In all patients, corneal topography remained stable through follow-up with no signs of ectasia. Our study demonstrates that flap removal after LASIK-induced complications is a viable option in patients unresponsive to medical treatment. Similar to our results after epithelial ingrowth, Kymionis et al. reported good visual outcomes with corrected visual acuity of 20/32 at 6 months after amputation.2 After infectious keratitis due to Mycobacterium infection, Giaconi et al. also reported good visual outcomes with corrected visual acuity of 20/30.3 On the contrary, flap amputation related to other etiologies such as central flap necrosis syndrome and trauma have been reported to result in less optimal visual outcomes (from 20/90 to 20/40 at 4 months after flap amputation).4,5 This study demonstrates that flap amputation after epithelial ingrowth and infectious keratitis can lead to good long-term visual (corrected visual acuity of 20/30 or better) and structural (no ectasia) outcomes.

The Effect of LASIK on Timing of Cataract Surgery.

PURPOSE To compare the age at the time of cataract surgery in patients who have undergone microkeratome-assisted LASIK versus individuals matched for axial length, cataract grade, and visual acuity with no history of refractive surgery. METHODS Retrospective chart review of patients who underwent cataract extraction between September 2013 and March 2015 at the Bascom Palmer Eye Institute. Patients had a history of either microkeratome-assisted LASIK or no prior ocular surgery. Corrected distance visual acuity (CDVA) before and after cataract extraction, uncorrected distance visual acuity (UDVA) before cataract extraction, gender, axial length, and cataract grade were assessed, along with age at the time of LASIK, age at the time of cataract extraction, and the time lapse between LASIK and cataract extraction. RESULTS Fifty eyes of 38 patients were included in the LASIK group and 155 eyes of 136 patients were included in the control group. There was no significant difference between these groups with respect to gender (P = .87), CDVA before cataract extraction (P = .11), UDVA before cataract extraction (P = .09), axial length (P = .67), and cataract grade (P = .46). Mean age at the time of cataract extraction for patients in the LASIK group and control group were 64 ± 7 and 73 ± 8 years, respectively (P < .005). Negative correlations were found between age at time of cataract extraction and axial length in the LASIK and control groups (r = -0.18, P = .20 vs r = -0.36, P =. 01, respectively). CONCLUSIONS Microkeratome-assisted LASIK seems to be correlated with earlier cataract extraction. Patients with a history of microkeratome-assisted LASIK under-went cataract surgery a decade sooner than patients with similar demographic and ocular characteristics. [J Refract Surg. 2016;32(5):306-310.].

Long-Term Outcomes of Radial Keratotomy, Laser In Situ Keratomileusis, and Astigmatic Keratotomy Performed Consecutively over a Period of 21 Years

Purpose. To describe a case of 3 refractive procedures performed in one eye over 2 decades. Methods. Case report. Results. A 41-year-old patient presented for refractive surgery evaluation. His ocular history includes bilateral radial keratotomy performed 21 years ago for moderate myopia: spherical equivalence of −4.25 D bilaterally. Postoperative uncorrected visual acuity (UCVA) was 20/30; however, over time he developed a hyperopic shift and UCVA decreased to 20/40 in the right eye. Thus, laser-assisted in situ keratomileusis (LASIK) was performed at an outside institution 6.5 years later, and the patient had initial improvement of UCVA to 20/25. Due to a change in refractive error, the patient underwent uneventful astigmatic keratotomy 13 years after LASIK in the right eye, and 1.5 years after surgery best-corrected visual acuity was 20/25 with manifest refraction of −1.00 + 5.50 × 134°.  Conclusion. We report the outcomes and natural refractive progression in a patient who underwent three corneal refractive procedures over two decades. This case underlines the difficulties of long-term management of post-RK hyperopia and astigmatism.

Original articleMeibomian Gland Disease: The Role of Gland Dysfunction in Dry Eye Disease

TOPIC To discuss the pathology, causes, and ocular surface impact of meibomian gland disease (MGD), as well as its relationship to dry eye. CLINICAL RELEVANCE MGD is a common disorder with various contributing mechanisms and clinical manifestations. Understanding MGD pathophysiology and its relationship to dry eye is important in order to optimize diagnosis and treatment algorithms. METHODS A review of current literature was performed to discern MGD in terms of pathophysiology, risk factors, and ocular surface impact, and the relationship to dry eye. RESULTS Meibomian gland obstruction and meibocyte depletion are important components of MGD. Many pathologies can disrupt function of meibomian glands, ranging from congenital to acquired causes. Once gland disruption occurs, the quality and quantity of meibum is altered, with a negative impact on the ocular surface. Increased tear evaporation, tear hyperosmolarity, increased ocular surface staining, increased inflammation, symptomatic irritation of the eyelid and globes, as well as decreased visual acuity have all been observed. CONCLUSION MGD leads to changes in meibum quality and quantity that can cause evaporative dry eye and ocular surface disruption, leading to dry eye symptoms in some individuals.